Speed reduction mechanism, cover, drive wheel, and conveying carriage
阅读说明：本技术 减速机构、罩、驱动轮、输送台车 (Speed reduction mechanism, cover, drive wheel, and conveying carriage ) 是由 原田亮平 中村江児 于 2021-04-26 设计创作，主要内容包括：本发明提供一种减速机构、罩、驱动轮、输送台车。本发明的罩是减少向外方传递的声音的罩。罩具有吸音层和隔音层。(The invention provides a speed reduction mechanism, a cover, a driving wheel and a conveying trolley. The cover of the present invention is a cover for reducing sound transmitted to the outside. The cover has a sound absorbing layer and a sound insulating layer.)
1. A cover which is a cover for reducing sound transmitted to the outside, wherein,
the cover has a sound absorbing layer and a sound insulating layer.
2. The cover of claim 1,
the sound absorbing layer is located on the inner side of the cover, and the sound insulating layer is located on the outer side of the cover.
3. The cover of claim 1,
the sound insulation layer has a plurality of sound reduction spaces in a bottomed cylindrical shape extending in a thickness direction and opening inward,
the sound absorbing layer is made of a foamed resin material.
4. The cover of claim 3,
the ratio of the diameter dimension of the opening to the length dimension of the sound insulating layer in the thickness direction is set within the range of 0.5/50 to 1/25 in the sound reduction space.
5. The cover of claim 3,
the sound insulation layer includes a wall portion having a honeycomb structure and an outer plate located outside the sound reduction space.
6. The cover of claim 3,
the sound insulation layer reduces the peak value in the frequency band of 500 Hz-5000 Hz by 0-99%.
7. The cover of claim 3,
the sound absorption layer reduces the dB value of a frequency band of 500 Hz-5000 Hz by 0-10%.
8. The cover according to any one of claims 1 to 7,
the thickness of the sound absorbing layer is set in the range of 25/50-26/18 relative to the thickness of the sound insulating layer.
9. A speed reducing mechanism includes:
a speed reducer having a gear meshing portion for generating sound; and
the cover of any one of claims 1 to 8, which reduces sound transmitted to the outside,
the cover covers an area corresponding to the engagement portion when viewed from the outside.
10. A speed reducing mechanism includes:
a speed reducer having a gear meshing portion for generating sound; and
a cover having a sound absorbing layer and a sound insulating layer for reducing sound transmitted to the outside,
the cover covers an area corresponding to the engagement portion when viewed from the outside.
11. The reduction mechanism according to claim 10,
the sound insulation layer is located on the outer side, and the sound absorption layer is located at a position close to the speed reducer.
12. The reduction mechanism according to claim 10,
the sound insulation layer has a plurality of sound reduction spaces in a bottomed cylindrical shape extending in a thickness direction and opening toward the reduction gear,
the sound absorbing layer is made of a foamed resin material.
13. The reduction mechanism according to claim 12,
the ratio of the diameter dimension of the opening to the length dimension of the sound insulating layer in the thickness direction is set within the range of 0.5/50 to 1/25 in the sound reduction space.
14. The reduction mechanism according to claim 12,
the sound insulation layer includes a wall portion having a honeycomb structure and an outer plate located outside the sound reduction space.
15. The reduction mechanism according to claim 12,
the sound absorption layer reduces the dB value of a frequency band of 500 Hz-5000 Hz by 0-10%.
16. The reduction mechanism according to any one of claims 10 to 15,
the thickness of the sound absorbing layer is set in the range of 25/50-26/18 relative to the thickness of the sound insulating layer.
17. The reduction mechanism according to any one of claims 10 to 15,
the speed reducer is provided with a speed reduction axis as a rotation center,
the cover covers more than half of the reduction gear as viewed in a direction along the reduction axis.
18. The reduction mechanism according to claim 17,
the cover has:
a peripheral surface portion along a circumferential direction of the reduction gear;
an input surface portion that is opposed to an input surface of the reduction gear at one end in a direction along the reduction axis; and
an output surface portion that is opposed to an output surface of the speed reducer at the other end in the direction along the speed reduction axis.
19. The reduction mechanism according to claim 18,
the speed reducer is provided with:
a sun gear having the deceleration axis as a rotation center; and
a spur gear meshed with the sun gear,
the meshing portion between the spur gear and the sun gear is located on the input face.
20. The reduction mechanism according to claim 19,
the speed reducer is provided with:
an outer cylinder having inner teeth formed on an inner circumferential surface thereof and arranged along a circumferential direction;
an eccentric oscillating gear having external teeth meshing with the internal teeth of the outer cylinder;
a crankshaft connected to the spur gear and oscillating the eccentric oscillating gear; and
and a carrier that supports the crankshaft and rotates relative to the outer cylinder.
21. A drive wheel is provided with:
a wheel; and
the retarding mechanism of claim 18 or 19 which retards drive rotation and outputs it to the wheel, which is connected to the output face.
22. The drive wheel of claim 21, wherein,
the reduction gear reduces the drive rotation input from the input surface and outputs the drive rotation from the output surface to the wheel.
23. A conveyance carriage is provided with:
a drive wheel as set forth in claim 21 or 22; and
and a drive source that inputs drive rotation to the reduction gear.
Technical Field
The present invention relates to a reduction mechanism, a cover, a drive wheel, and a conveyance carriage, and particularly to a technique suitable for improving quietness of a reduction gear.
Background
A conveyance carriage using a motor as a driving source is used in various fields. As the transport Vehicle, not only a human-operated transport Vehicle but also a transport Vehicle such as an unmanned Guided Vehicle (AGV) or a Rail Guided Vehicle (RGV) is known.
The power output from the motor is transmitted to the wheels via the speed reducer, and the transport vehicle travels. The speed reducer reduces the speed of the power output from the motor and outputs the power with increased torque.
An unmanned transport vehicle is exemplified in patent document 1.
Documents of the prior art
Patent document
Patent document 1: japanese patent laid-open publication No. 2019-008359
Disclosure of Invention
Problems to be solved by the invention
However, if a speed reducer is used, there are the following problems: noise is generated due to rotation caused by driving of the motor. In particular, there is a demand for reducing such noise when people are located in the same space such as a distribution site regardless of whether people are present in a transport vehicle or not. It is also desirable not to change the reduction ratio of the reduction gear so as not to cause an increase in size of the drive source.
The invention aims to reduce noise generated by a speed reducer.
Means for solving the problems
The cover according to the first aspect of the present invention is a cover for reducing sound transmitted to the outside, and has a sound absorbing layer and a sound insulating layer. Thereby, the above-described problems are solved.
According to the cover of the first aspect of the present invention, sound in a predetermined frequency band can be absorbed by the sound absorbing layer. Further, the sound insulation layer can shield sound of a predetermined frequency band from the outside so as to have a predetermined reduction rate. Therefore, the sound transmitted from the inside of the cover to the outside can be reduced, and the silencing effect can be achieved.
In the cover according to the first aspect of the present invention, the sound absorbing layer may be located inside the cover, and the sound insulating layer may be located outside the cover.
In the cover according to the first aspect of the present invention, the sound insulating layer may have a plurality of bottomed tubular sound-deadening spaces extending in the thickness direction and opening inward, and the sound absorbing layer may be made of a foamed resin material.
In the cover according to the first aspect of the present invention, the ratio of the diameter dimension of the opening to the length dimension of the sound insulating layer in the thickness direction may be set in the sound-deadening space within a range of 0.5/50 to 1/25.
Specifically, the ratio of the diameter dimension of the opening to the length dimension of the sound-insulating layer in the thickness direction of the sound-deadening space may be set within a range of 0.5/50 to 1/50 or a range of 1/50 to 1/25.
In the cover according to the first aspect of the present invention, the sound insulation layer may include a wall portion having a honeycomb structure and an outer plate located outside the sound reduction space.
In the cover according to the first aspect of the present invention, the sound insulation layer may reduce a peak value in a frequency band of 500Hz to 5000Hz by 0 to 99%.
In the cover according to the first aspect of the present invention, the sound absorbing layer may reduce a dB value in a frequency band of 500Hz to 5000Hz by 0 to 10%.
In the cover according to the first aspect of the present invention, the thickness of the sound absorbing layer may be set within a range of 25/50 to 26/18 with respect to the thickness of the sound insulating layer.
Specifically, the thickness of the sound absorbing layer may be set to a range of 25/50 to 50/50 or a range of 50/50 to 26/18 with respect to the thickness of the sound insulating layer.
A speed reducing mechanism according to a second aspect of the present invention includes: a speed reducer having a gear meshing portion for generating sound; and the above-mentioned cover, it reduces the sound transmitted to the outside; the cover covers an area corresponding to the engagement portion when viewed from the outside. Thereby, the above-described problems are solved.
A speed reducing mechanism according to a second aspect of the present invention includes: a speed reducer having a gear meshing portion for generating sound; and a cover having a sound absorbing layer and a sound insulating layer that reduce sound transmitted to the outside, the cover covering a region corresponding to the engagement portion when viewed from the outside. Thereby, the above-described problems are solved.
According to the speed reducing mechanism of the second aspect of the present invention, sound in a predetermined frequency band can be absorbed by the sound absorbing layer. The sound insulation layer can shield sound of a predetermined frequency band from the outside so as to have a predetermined reduction rate. Therefore, it is possible to reduce the sound transmitted from the inside of the cover to the outside, which covers the meshing portion that is the portion where the sound is most generated, to have a silencing effect in the speed reducing mechanism.
In the reduction gear mechanism according to the second aspect of the present invention, the sound insulating layer may be located outward, and the sound absorbing layer may be located close to the reduction gear.
In the reduction gear mechanism according to the second aspect of the present invention, the sound insulating layer may have a plurality of bottomed cylindrical sound-absorbing spaces extending in the thickness direction and opening toward the reduction gear, and the sound absorbing layer may be made of a foamed resin material.
In the reduction mechanism according to the second aspect of the present invention, the ratio of the diameter dimension of the opening to the length dimension of the sound insulating layer in the thickness direction may be set in the range of 0.5/50 to 1/25 in the sound reduction space.
In the reduction gear mechanism according to the second aspect of the present invention, the sound insulation layer may include a wall portion having a honeycomb structure and an outer plate located outside the sound reduction space.
In the reduction mechanism according to the second aspect of the present invention, the sound absorption layer may reduce a dB value in a frequency band of 500Hz to 5000Hz by 0 to 10%.
In the reduction mechanism according to the second aspect of the present invention, the thickness of the sound absorbing layer may be set within a range of 25/50 to 26/18 with respect to the thickness of the sound insulating layer.
Specifically, the thickness of the sound absorbing layer may be set to a range of 25/50 to 50/50 or a range of 50/50 to 26/18 with respect to the thickness of the sound insulating layer.
In the reduction mechanism according to the second aspect of the present invention, the reduction gear may include a reduction axis as a rotation center, and the cover may cover at least half of the reduction gear as viewed in a direction along the reduction axis.
In the reduction mechanism of the second aspect of the present invention, the cover may include: a peripheral surface portion along a circumferential direction of the reduction gear; an input surface portion that is opposed to an input surface of the reduction gear at one end in a direction along the reduction axis; and an output surface portion that is opposed to an output surface of the speed reducer at the other end in the direction along the speed reduction axis.
In the reduction mechanism according to the second aspect of the present invention, the reduction gear may include: a sun gear having the deceleration axis as a rotation center; and a spur gear that meshes with the sun gear, a meshing portion between the spur gear and the sun gear being located on the input surface.
In the reduction mechanism according to the second aspect of the present invention, the reduction gear may include: an outer cylinder having inner teeth formed on an inner circumferential surface thereof and arranged along a circumferential direction; an eccentric oscillating gear having external teeth meshing with the internal teeth of the outer cylinder; a crankshaft connected to the spur gear and oscillating the eccentric oscillating gear; and a carrier that supports the crankshaft and rotates relative to the outer cylinder.
A driving wheel according to a third aspect of the present invention includes: a wheel; and the above-mentioned deceleration mechanism, it makes the drive rotate and reduce the speed and export to the said wheel, the said wheel is connected with the said output surface.
In the drive wheel according to the third aspect of the present invention, the reduction gear may reduce the speed of the drive rotation input from the input surface and output the drive rotation from the output surface to the wheel.
A fourth aspect of the present invention is a conveyance carriage comprising: the above-mentioned drive wheel; and a drive source that inputs drive rotation to the reduction gear.
ADVANTAGEOUS EFFECTS OF INVENTION
According to the present invention, the following effects can be obtained: a reduction gear capable of reducing noise generated can be provided.
Drawings
Fig. 1 is a sectional view showing a first embodiment of a cover according to the present invention.
Fig. 2 is a schematic cross-sectional view showing a sound-insulating state in embodiment 1 of the cover of the present invention.
Fig. 3 is a schematic plan view showing a conveyance carriage according to embodiment 2 of the present invention.
Fig. 4 is a schematic plan view, partially in section, showing a2 nd embodiment of a reduction mechanism and a drive wheel according to the present invention.
Fig. 5 is a schematic side sectional view showing a2 nd embodiment of a speed reducing mechanism and a drive wheel according to the present invention.
Fig. 6 is a schematic side sectional view, partially in section, showing a reduction mechanism and a drive wheel according to embodiment 2 of the present invention, as viewed in a direction along a reduction axis.
Fig. 7 is a sectional view along the deceleration axis showing embodiment 3 of the speed reducer in the speed reducing mechanism of the present invention.
Fig. 8 is a schematic side sectional view, partially in section, showing a 4 th embodiment of a speed reducing mechanism and a drive wheel according to the present invention, as viewed in a direction along a speed reducing axis.
Fig. 9 is a schematic side sectional view, partially in section, showing a 5 th embodiment of a speed reducing mechanism and a drive wheel according to the present invention, as viewed in a direction along a speed reducing axis.
Description of the reference numerals
V, conveying the trolley; v10, vehicle body; v16, a driving device; v15, drive wheel; v20, motor (drive source); v30, a speed reducer; v40, wheel; v35, input section; v32, output unit; v33, shell; v200, a driving surface; VAx, deceleration axis (rotation axis); v34, base; V35A, sun gear; V35B, spur gear; VV, an engaging portion; v25, output part (output shaft); C. a cover; cp, motor end face portion (input face portion); cq, wheel end face portion (output face portion); cr, peripheral surface portion; c1, sound absorption layer; c2, sound insulation layer; c2a, sound attenuation space; c2a1, open; c2a2, wall portion; c2b, outer plates; c3, lower end; c3a, C3b, lower convex portion.
Detailed Description
Hereinafter, embodiment 1 of the cover of the present invention will be described with reference to the drawings.
Fig. 1 is a sectional view showing a cover in the present embodiment, and in the drawing, reference symbol C denotes a cover.
As shown in fig. 1, the cover C of the present embodiment has a structure in which a sound absorbing layer C1 and a sound insulating layer C2 are laminated.
In the cover C, the sound absorbing layer C1 and the sound insulating layer C2 are laminated over the entire surface thereof, and the sound absorbing layer C1 is disposed on the sound generation side in on the inner side in, and the sound insulating layer C2 is disposed on the mute side on the outer side out.
The sound absorbing layer C1 defines a sound absorbing material and a thickness which reduce the dB value in the frequency band of 500 Hz-5000 Hz by 0-10%. That is, the sound absorbing layer C1 is configured to reduce the sound pressure by 0 to 6 dB.
Therefore, the sound absorbing layer C1 can be made of a foamed resin material. Specifically, it is composed of a foamed polyurethane, particularly, a sponge-like polyurethane resin, and has an areal density of 5kg/m2～50kg/m2The thickness is defined to be 10mm to 40 mm.
Wherein the thickness of the sound absorbing layer C1 is set in the range of 25/50 to 50/50 relative to the thickness of the sound insulating layer C2. Alternatively, the thickness of the sound absorbing layer C1 is set to be in the range of 50/50 to 26/18 with respect to the thickness of the sound insulating layer C2.
The plate-like sponge material that can be used as the sound absorbing layer C1 is not particularly limited as long as the sound absorbing performance is within the above range, and examples thereof include rubber sponge/foam (e.g., neoprene sponge, natural rubber sponge, polyethylene sponge, ethylene-propylene rubber sponge, nitrile rubber sponge, fluorine sponge, silicon sponge, opselaler, rusela, etc.), polyurethane sponge (e.g., soft polyurethane foam (ether type), soft polyurethane foam (urethane type), rigid polyurethane foam, low-resilience polyurethane foam, enethane (for imparting antibacterial property to low-resilience polyurethane foam), etc.), and surface density 10kg/m2～30～100kg/m2Examples of the recycled polyester include, as ethylene foams, SUNPELCA, OPCELL, SUPEROPCELL (trade name of Sanko Co., Ltd.), SOFTEN BOARD, SOFTLONS Toypef (trade name of hydrophylic chemical Co., Ltd.), Light-RonS, Light-Ronboard (trade name of hydrophylic chemical Co., Ltd.), and Suntecfoam (Asahi Kasei ライフ)&リビング Co., Ltd.), Moltfilter (registered trademark of Inoac Corporation), EVA foam, Degradable kenaf foam (manufactured by Kagaku Corporation), nonwoven fabric felt, foamed styrene, etc.
In addition, as the polyurethane foam, the density of the foaming resin material can be set as follows: 5kg/m3～50kg/m3。
The sound insulating layer C2 has a plurality of sound absorbing spaces C2a in a bottomed cylindrical shape extending in the thickness direction.
The surface of the soundproof layer C2 on the outer side out is covered with an outer panel C2 b. The outer panel C2b serves as a bottom of the sound-deadening space C2a and closes the outer end of each sound-deadening space C2 a. Each sound reduction space C2a has an opening C2a1 that opens toward the inner side in.
The openings C2a1 of the sound-deadening space C2a are adjacent at the inner in surface of the soundproof layer C2. The sound reduction space C2a is disposed so that the plurality of openings C2a1 are densely provided inside the sound insulating layer C2.
The openings C2a1 are disposed at equal distances from each other on the inner in surface of the soundproof layer C2.
The contour shape of each opening C2a1 is the same.
In the sound reduction space C2a, the ratio (C2a Φ/C2aL) of the diameter size C2a Φ of the opening C2a1 to the length size C2aL in the thickness direction of the sound insulation layer C2 is set in the range of 0.5/50 to 1/25.
The outline shape of the opening C2a1 of the sound attenuation space C2a in the present embodiment is a hexagon. The outline shape of the opening C2a1 may be circular, polygonal, or other shapes.
The sectional profile shape of the sound-deadening space C2a orthogonal to the thickness direction of the sound-insulating layer C2 has a substantially equal shape over the entire length in the thickness direction of the sound-insulating layer C2.
The sound reduction space C2a has a cross-sectional contour shape orthogonal to the thickness direction of the sound insulating layer C2 formed in the same manner as the contour shape of the opening C2a 1.
The sound insulating layer C2 includes a wall portion C2a2 of the sound-deadening space C2a and an outer panel C2b located outside the sound-deadening space C2 a. The wall portion C2a2 has a honeycomb structure. The wall portion C2a2 of the honeycomb structure and the outer panel C2b are both formed of PVC (polyvinyl chloride resin).
The sound insulation layer C2 reduces the peak value in the frequency band of 500 Hz-5000 Hz by 0-99%.
As shown in fig. 2, the sound insulation layer C2 has a function of blocking noise generated on the inner side in with respect to the outer side out in the frequency band. Specifically, in the sound attenuation space C2a, the sound snd entering from the opening C2a1 is reflected at the wall portion C2a2 of the sound attenuation space C2a and reaches the outer panel C2b as the bottom of the outside out. After the sound snd is reflected at the outer panel C2b, it is also reflected at the wall portion C2a2 of the sound attenuation space C2 a. Among them, in the soundproof layer C2, the sound snd attenuates while being reflected at the wall portion C2a2 and the outer panel C2b a plurality of times. Thereby, the sound snd incident to the sound reduction space C2a is attenuated and is isolated.
This sound insulation can be achieved by the attenuation of reflection by the material of the sound insulation layer C2 and the shape and size of the sound reduction space C2 a.
The sound absorbing layer C1 is made of the resin material and has the thickness set as described above, so that noise generated on the inner side in is absorbed by the outer side out in an audible range of 500Hz to 5000Hz, which is a frequency band, and the dB value is reduced by 0 to 10%.
The sound absorbing capability in the audible range can be achieved by setting the material and thickness of the sound absorbing layer C1.
In the cover C of the present embodiment, noise generated in the inner side in is first absorbed and muted in the sound absorbing layer C1 in the frequency band of 500Hz to 5000Hz, and is further attenuated and muted in the sound insulating layer C2 in the sound attenuating space C2 a.
Thus, the cover C can reduce the noise generated at the inner side in with respect to the outer side out, and has a silencing effect.
In the present embodiment, by providing the cover C, for example, 70dB of noise can be reduced to 65dB in the case where the cover C is not provided in the frequency band of 500Hz to 5000Hz, that is, the sound pressure can be reduced by about 0 to-6 dB. Moreover, the sound pressure in a frequency band range larger than 2000Hz can be effectively reduced. In particular, the sound pressure in the frequency band around 3500Hz to 4500Hz can be effectively reduced. Further, the noise reduction in the frequency band of 500Hz to 4000Hz can be examined.
Further, the cover C of the present embodiment includes the sound insulating layer C2 having a honeycomb structure, and can maintain a required strength while suppressing the weight thereof, thereby achieving a reduction in weight.
Hereinafter, embodiment 2 of the speed reducing mechanism, the drive wheel, and the conveyance carriage according to the present invention will be described with reference to the drawings.
Fig. 3 is a schematic plan view showing the conveyance carriage in the present embodiment. In the figure, reference sign V is a conveying carriage.
The transport vehicle V in the present embodiment will be described by taking an unmanned transport vehicle for transporting baggage as an example. In the figure, the direction in which the carriage V advances and retreats is defined as the X direction, the direction in which the carriage V moves transversely orthogonal to the X direction is defined as the Y direction, and the height direction of the carriage V orthogonal to the X direction and the Y direction is defined as the Z direction.
Fig. 4 is a schematic plan view, partially in section, showing the reduction mechanism and the drive wheels in the present embodiment.
Fig. 5 is a schematic side sectional view showing the speed reducing mechanism and the drive wheels in the present embodiment.
Fig. 6 is a schematic side sectional view showing a partial section of the speed reducing mechanism and the drive wheel in the present embodiment as viewed in the direction along the speed reducing axis.
As shown in fig. 3, the conveyance carriage V in the present embodiment includes a vehicle body V10 and a drive device V16 attached to the vehicle body V10. The conveyance carriage V is a carriage that travels on the travel surface V200 (fig. 5 and 6). The drive devices V16 are disposed at the four corners of the vehicle body V10. The drive device V16 includes a drive wheel V15 and a motor (drive source) V20.
As shown in fig. 4 to 6, a motor (drive source) V20 is connected to the drive wheel V15. The drive wheel V15 and the motor (drive source) V20 constitute a drive device V16. The drive wheel V15 includes a wheel V40 and a speed reducer V30 connected to the wheel V40. The speed reducer V30 decelerates the power input from the motor V20, i.e., the driving rotation, and outputs the decelerated power to the wheel V40, thereby rotating the wheel V40 attached to the speed reducer V30. The speed reducer V30 and the wheel V40 are housed in the cover C.
The speed reducer V30 and the cover C constitute a speed reduction mechanism.
The speed reducer V30 includes a speed reduction axis VAx as a rotation center.
The speed reducer V30 includes: a case V33 to which the cover C is fixed; an input section V35 to which power (rotation) from a motor V20 is input; an output unit V32 that outputs rotation to the wheel V40; and a structure that is at least partially housed in the case V33, and that decelerates the rotation of the input unit V35 and transmits the rotation to the output unit V32. In the example shown in fig. 4 to 6, the speed reducer V30 further includes a base V34 that supports the motor V20.
The case V33 is attached at its upper portion to the bottom surface of the vehicle body V10 by a fastening member not shown. Further, case V33 fixed to vehicle body V10 may be directly attached to vehicle body V10, may be indirectly attached via a connecting member attached to vehicle body V10, or case V33 may be attached to vehicle body V10 via motor (drive source) V20.
The terms related to the vertical direction and the longitudinal direction with respect to the speed reducer V30 or the drive wheel V15 mean, unless otherwise specified, "vertical", "front", "rear", "vertical direction" and "longitudinal direction", which are determined in a situation where the conveyance carriage V to which the drive wheel V15 is attached is disposed on the traveling surface V200 and advanced. Specifically, the "vertical direction" corresponds to a direction perpendicular to the paper surface in fig. 3 and a vertical direction, i.e., a Z direction, in the paper surface in fig. 6. The "front-rear direction" corresponds to the X direction, which is the vertical direction on the paper surface in fig. 3, and the left-right direction on the paper surface in fig. 6. The term "width direction" with respect to the driving wheel or the reduction gear is a direction orthogonal to both the "up-down direction" and the "front-rear direction". Specifically, the "width direction" corresponds to the Y direction which is the left-right direction of the paper surface in fig. 3 and the left-right direction of the paper surface in fig. 5.
The housing V33 and the base V34 are substantially cylindrical members and extend in the direction of the rotation axis VAx of the motor V20. At one end of the base V34, a motor V20 is attached to the base V34 by a fastening member not shown. On the other hand, one end of the case V33 is fixed to the other end of the base V34 by a fastening member, not shown.
The rotation axis VAx of the motor V20 coincides with a deceleration axis (rotation axis) VAx that is the rotation center of the speed reducer V30.
The input portion V35 extends in a direction parallel to the rotation axis VAx on the radially inner side of the housing V33 and the base portion V34 centered on the rotation axis VAx. Further, the structure of the speed reducer V30 and a part of the output portion V32 are housed and connected to the inside of the casing V33 in the radial direction about the rotation axis VAx.
The output portion V32 is relatively movable with respect to the housing V33. In the illustrated example, the rotation axis VAx is parallel to the width direction (Y direction). In addition, the radial direction is orthogonal to the rotation axis VAx.
The input portion V35 functions as an input gear for inputting the power of the motor 20 to the speed reducer V30. Further, the input portion V35 has a sun gear V35A and a spur gear V35B. The sun gear V35A and the spur gear V35B are meshed with each other. The sun gear V35A and the spur gear V35B constitute a speed reducer V30.
The sun gear V35A has a deceleration axis (rotation axis) VAx as a rotation center of the speed reducer V30 as a center axis. The spur gear V35B rotates about the deceleration axis (rotation axis) VAx while meshing with the sun gear V35A. The meshing portion VV between the sun gear V35A and the spur gear V35B can generate sound (fig. 5, 6). The meshing portion VV rotationally moves about the deceleration axis (rotation axis) VAx at a position on a circumference at substantially the same diameter size as that of the sun gear V35A.
An output portion (output shaft) V25 of the motor V20 is connected to the input gear of the input portion V35. Thereby, the input portion V35 is rotatable around the rotation axis VAx integrally with the output portion (output shaft) V25 of the motor V20. In this way, the power (rotation) output from the motor V20 is transmitted to the input unit V35. The input unit V35 inputs the power of the motor V20 to the speed reducer V30 via the sun gear V35A and the spur gear V35B.
The motor V20 and the output unit (output shaft) V25 may be attached to the base V34 and the input unit V35 so as to be detachable from the base V34 and the input unit V35, respectively. This allows the motor V20 to be replaced as needed.
The speed reducer V30 is an eccentric oscillating speed reducer. The speed reducer V30 may have another configuration such as a speed reducer having a planetary gear mechanism. The speed reducer V30 decelerates the power (rotation) input from the input portion V35 and transmits the power with increased torque to the carrier supporting the speed reducer V30 or the outer cylinder housing the carrier. For example, when the outer tube is fixed to the casing V33, the carrier functions as the output section V32, and the speed reducer V30 transmits power to the output section V32 to rotate the output section V32.
The speed reducer V30 in the present embodiment is configured as an eccentric oscillating type speed reducer. Inner teeth arranged in the circumferential direction are formed on the inner circumferential surface of the outer cylinder. The speed reducer V30 is an eccentric oscillating gear having external teeth meshing with the internal teeth of the outer cylinder. The eccentric oscillating gear constituting the speed reducer V30 is supported by a carrier constituting the output portion V32 so as to be eccentrically oscillatable. The eccentric oscillating gear constituting the speed reducer V30 oscillates eccentrically with respect to the carrier in accordance with the rotation of the input portion V35. At this time, the external teeth of the eccentric oscillating gear mesh with the internal teeth of the outer cylinder, and the carrier supporting the speed reducer V30 rotates relative to the outer cylinder. The eccentric oscillating type reduction gear is generally small in backlash, and can reduce malfunction of the entire drive wheel V15.
The speed reducer V30 is not limited to the eccentric oscillating type speed reducer, and other speed reducers may be used. For example, the speed reducer V30 may be a planetary gear type speed reducer, or may be a speed reduction structure in which a planetary gear type and an eccentric oscillating type are combined. The speed reducer V30 may be configured by any other speed reduction structure. In the case where the speed reducer V30 is a planetary gear type speed reducer, as an example, a sun gear is used as an input portion, a planetary gear having external teeth meshing with internal teeth of an outer cylinder is provided, and a carrier that rotatably supports the planetary gear and is rotatable relative to the outer cylinder can be used as the output portion V32.
The output portion V32 is connected to the outer tube so as to be rotatable relative to the outer tube by a pair of bearings disposed between the output portion V32 and the outer tube. In the present embodiment, the speed reducer V30 is meshed with an outer cylinder fixed to the casing V33, so that the output portion V32 rotates together with the speed reducer V30 around the rotation axis VAx at a reduced rotation speed. The output portion V32 is also restrained from movement relative to the housing V33 in a direction parallel to the axis of rotation VAx by a pair of bearings.
The pair of bearings also support the load applied to the output portion V32, the outer cylinder, and the like. For example, when the transport carriage V is traveling straight, a radial load can be applied from the wheel V40 to the output section V32, the outer cylinder, and the like. When the conveyance carriage V turns, the output portion V32, the outer cylinder, and the like receive the axial load as well as the radial load from the wheel V40. The radial direction here is a radial direction centered on the rotation axis VAx. In addition, the axial direction is a direction in which the rotation axis VAx extends. The pair of bearings can receive both the axial load and the radial load between the output portion V32 and the outer cylinder.
In the reduction mechanism, as shown in fig. 5 and 6, the reduction gear V30 is covered with a cover C.
The cover C has a motor end surface portion (input surface portion) Cp, a wheel end surface portion (output surface portion) Cq, and a peripheral surface portion Cr.
The motor end surface portion (input surface portion) Cp is orthogonal to the deceleration axis (rotation axis) VAx. The motor end surface portion (input surface portion) Cp is substantially flat and is disposed closer to the motor V20 than the speed reducer V30. The motor end surface portion (input surface portion) Cp is located away from the input surface at one end of the speed reducer V30 and approaches the motor V20. A part of the output section (output shaft) V25 and the casing V33 penetrates through the motor end surface section (input surface section) Cp.
The wheel end surface portion (output surface portion) Cq is orthogonal to the deceleration axis (rotation axis) VAx. The wheel end surface portion (output surface portion) Cq is substantially flat and is disposed at a position outside the wheel V40 with respect to the reduction gear V30. The wheel end surface portion (output surface portion) Cq is separated from the output surface at the other end of the speed reducer V30, and is disposed at a position away from the wheel V40 to the outside. The wheel end surface portion (output surface portion) Cq covers an end surface of the wheel V40 other than the area close to the running surface V200. The wheel end surface portion (output surface portion) Cq covers the end surface of the wheel V40 when viewed from the outside in the direction along the deceleration axis (rotation axis) VAx.
The peripheral surface portion Cr is arranged in the circumferential direction around the deceleration axis (rotation axis) VAx. The peripheral surface portion Cr is a curved surface formed by a cylindrical surface around the deceleration axis (rotation axis) VAx. The peripheral surface portion Cr is located radially outward of the deceleration axis (rotation axis) VAx of the speed reducer V30 and the wheel V40. The peripheral surface portion Cr is separated from the speed reducer V30 and the wheel V40.
In the cover C, the motor end surface portion (input surface portion) Cp, the wheel end surface portion (output surface portion) Cq, and the circumferential surface portion Cr are connected at their respective edges, and the speed reducer V30 and the wheel V40 are housed therein.
In the cover C, a motor end surface portion (input surface portion) Cp, a wheel end surface portion (output surface portion) Cq, and a peripheral surface portion C are sealed except for a lower surface facing the traveling surface V200.
The lower surface of the cover C facing the travel surface V200 in the present embodiment is open. The lower end C3 of the cover C has substantially the same height over the entire circumference thereof. That is, the lower end C3 of the cover C has a substantially equal predetermined separation distance HC3 from the running surface V200 over the entire circumference thereof. The lower end C3 of the cover C has a generally rectangular open profile shape. In the following description, the "separation distance HC 3" may be referred to as a height HC3 from the running surface V200 to the lower end C3.
The lower end C3 of the cover C has a predetermined separation distance HC3 from the running surface V200.
The separation distance HC3 of the cover C is set so that the area of the region covering the wheel V40 when viewed in the deceleration axis (rotation axis) VAx direction is at least half, that is, at least 50%, more preferably 70% to 90%, and still more preferably 75% to 85%. That is, the lower end C3 of the cover C is located below the deceleration axis (rotation axis) VAx and is closer to the running surface V200 than the deceleration axis (rotation axis) VAx.
In the speed reducer V30, as shown in fig. 5 and 6, the meshing portion VV formed by the sun gear V35A and the spur gear V35B in the input portion V35 is covered by the cover C. The lower end C3 of the cover C is located lower than the engagement portion VV at any position, that is, located close to the running surface V200.
The lower end C3 of the cover C is located below the meshing portion VV that is substantially circumferential about the deceleration axis (rotation axis) VAx, i.e., the lower end C3 of the cover C is closer to the running surface V200 than the outer periphery of the sun gear V35A.
The cover C in the present embodiment is set such that the cover height HV40 from the lower end C3 to the upper end of the wheel V40 is greater than 1 with respect to the height HC3 from the running surface V200 to the lower end C3. Specifically, as shown in FIG. 6, the ratio of the cladding height dimension HV40 to the height dimension HC3 is set in the range of 1. ltoreq. HV40/HC 3. ltoreq.1000, more preferably in the range of 2. ltoreq. HV40/HC 3. ltoreq.100, 2. ltoreq. HV40/HC 3. ltoreq.50.
Further, as the upper limit of the above ratio, the following states can be included: HC3 is 0, that is, running surface V200 is substantially in contact with the lower end and is close to the point where running is not hindered.
The cover C has a sound absorbing layer C1 over the entire inner surface facing the speed reducer V30 and the wheel V40. The cover C has a sound insulating layer C2 over the entire outer surface thereof apart from the speed reducer V30 and the wheel V40. In the cover C, the sound absorbing layer C1 and the sound insulating layer C2 are laminated over the entire surface thereof.
That is, the motor end surface portion (input surface portion) Cp has the sound absorbing layer C1 over the entire inner surface facing the speed reducer V30. The motor end surface portion (input surface portion) Cp has a sound insulating layer C2 over the entire outer surface facing the motor V20.
The wheel end surface portion (output surface portion) Cq has a sound absorbing layer C1 over the entire inner surface facing the wheel V40. The wheel end surface portion (output surface portion) Cq has a sound insulating layer C2 on the entire surface thereof on the outer side of the wheel V40.
The peripheral surface Cr has a sound absorbing layer C1 over the entire inner peripheral side facing the speed reducer V30 and the wheel V40. The peripheral surface portion Cr has a sound insulating layer C2 over the entire surface on the opposite side of the speed reducer V30 and the wheel V40 in the radial direction of the reduction axis (rotation axis) VAx.
The sound absorbing layer C1 is formed of a sound absorbing material, and has a thickness, etc. so as to reduce the dB value by 0-10% in a frequency band of 500 Hz-5000 Hz, which is a frequency band that is generated at the meshing portion VV and causes discomfort to a person who hears the sound absorbing layer when the sound absorbing layer is transmitted to the outside.
Therefore, the sound absorbing layer C1 can be made of a foamed resin material. Specifically, it is composed of a foamed polyurethane, particularly, a sponge-like polyurethane resin, and has an areal density of 5kg/m2～50kg/m2The thickness is defined to be 10mm to 40 mm.
The ratio of the thickness of the sound absorbing layer C1 to the thickness of the sound insulating layer C2 (the thickness of the sound absorbing layer C1/the thickness of the sound insulating layer C2) is set within the range of 25/50 to 50/50. Alternatively, the thickness of the sound absorbing layer C1 is set to be in the range of 50/50 to 26/18 with respect to the thickness of the sound insulating layer C2.
The plate-like sponge material that can be used as the sound absorbing layer C1 is not particularly limited as long as the sound absorbing performance is within the above range, and examples thereof include rubber sponge/foam (e.g., neoprene sponge, natural rubber sponge, polyethylene sponge, ethylene-propylene rubber sponge, nitrile rubber sponge, fluorine sponge, silicon sponge, opselaler, rusela, etc.), polyurethane sponge (e.g., soft polyurethane foam (ether type), soft polyurethane foam (urethane type), rigid polyurethane foam, low-resilience polyurethane foam, and Enethan (antibacterial property is imparted to low-resilience polyurethane foam)), and an areal density of 10kg/m2～30～100kg/m2Examples of the recycled polyester include, as ethylene foams, SUNPELCA, OPCELL, SUPEROPCELL (trade name of Sanko Co., Ltd.), SOFTEN BOARD, SOFTLONS Toypef (trade name of hydrophylic chemical Co., Ltd.), Light-RonS, Light-Ronboard (trade name of hydrophylic chemical Co., Ltd.), and Suntecfoam (Asahi Kasei ライフ)&リビング, trade name), Moltfilter (registered trademark of Inoac Corporation), EVA foam, Degradable kenaf foam (Degradable kenaf foam) (first chemical Co., Ltd.), nonwoven fabric/felt, foamed styrene plastic, and the like.
In addition, as the polyurethane foam, the density of the foaming resin material can be set as follows: 5kg/m3～50kg/m3。
The sound insulating layer C2 has a plurality of sound absorbing spaces C2a in a bottomed cylindrical shape extending in the thickness direction.
The surface of the soundproof layer C2 on the outer side is covered with an outer panel C2 b. The outer panel C2b serves as a bottom of the sound-deadening space C2a and closes the outer end of each sound-deadening space C2 a.
Each sound reduction space C2a has an opening C2a1 that is open opposite to the inner sound absorbing layer C1. The openings C2a1 of the sound-deadening space C2a are adjacent to each other on the surface facing the sound absorbing layer C1 inside the sound insulating layer C2. The sound reduction space C2a is disposed so that the plurality of openings C2a1 are dense on the inner surface side of the sound insulating layer C2.
The openings C2a1 are disposed at equal distances from each other on the inner surface of the soundproof layer C2.
The contour shape of each opening C2a1 is the same.
In the sound reduction space C2a, the ratio of the diameter dimension C2a Φ of the opening C2a1 to the length dimension C2aL in the thickness direction of the sound insulation layer C2 is set in the range of 0.5/50 to 1/25 (see fig. 2). The outline shape of the opening C2a1 of the sound attenuation space C2a in the present embodiment is a hexagon. The outline shape of the opening C2a1 may be circular, polygonal, or other shapes.
The sectional profile shape of the sound-deadening space C2a orthogonal to the thickness direction of the sound-insulating layer C2 has a substantially equal shape over the entire length in the thickness direction of the sound-insulating layer C2.
The sound reduction space C2a has a cross-sectional contour shape orthogonal to the thickness direction of the sound insulating layer C2 formed in the same manner as the contour shape of the opening C2a 1.
The sound insulating layer C2 includes a wall portion C2a2 of the sound-deadening space C2a and an outer panel C2b located outside the sound-deadening space C2 a. The wall portion C2a2 has a honeycomb structure. The wall portion C2a2 of the honeycomb structure and the outer panel C2b are both formed of PVC (polyvinyl chloride resin).
The sound insulation layer C2 reduces the peak value in the frequency band of 500 Hz-5000 Hz, which is a frequency band that is generated at the meshing part VV and is uncomfortable to a person when the sound insulation layer is transmitted to the outside, by 0-99%.
The sound insulation layer C2 has a function of blocking the sound of the frequency band of the noise generated at the meshing portion VV from the outside. Specifically, in the sound attenuation space C2a, the sound snd entering from the opening C2s1 is reflected at the wall portion C2a2 of the sound attenuation space C2a and reaches the outer panel C2b (refer to fig. 2) which is the bottom of the outside out. After the sound snd is reflected at the outer panel C2b, it is also reflected at the wall portion C2a2 of the sound attenuation space C2 a. Among them, in the soundproof layer C2, the sound snd attenuates while being reflected at the wall portion C2a2 and the outer panel C2b a plurality of times. Thereby, the sound snd incident to the sound reduction space C2a is attenuated and is isolated.
This sound insulation can be achieved by the attenuation of reflection by the material of the sound insulation layer C2 and the shape and size of the sound reduction space C2 a.
The sound absorbing layer C1 is made of the resin material and has the thickness set as described above, so that noise generated at the meshing portion VV is absorbed to the outside in an audible range of 500Hz to 5000Hz, which is a frequency band, and the dB value is reduced by 0 to 10%.
The sound absorbing capability in the audible range can be achieved by setting the material and thickness of the sound absorbing layer C1.
In the driving wheel V15 of the present embodiment, the sound in the frequency band of 500Hz to 5000Hz of the noise generated at the meshing portion VV is first absorbed and muted in the sound absorbing layer C1 of the cover C covering the meshing portion VV, and is further muted in the sound insulating layer C2 of the cover C by being attenuated and muted in the sound attenuating space C2 a.
Thus, the noise generated at the inner engagement portion VV can be reduced on the outer side of the cover C at the drive wheel V15, thereby providing a silencing effect.
In the driving wheel V15 according to the present embodiment, the cover C includes the sound insulating layer C2 having a honeycomb structure, and can maintain a required strength while suppressing the weight thereof, thereby achieving a reduction in weight.
In the present embodiment, by providing the cover C, for example, 70dB of noise can be reduced to 65dB in the case where the cover C is not provided in the frequency band of 500Hz to 5000Hz, that is, the sound pressure can be reduced by about 0 to-6 dB. Moreover, the sound pressure in a frequency band range larger than 2000Hz can be effectively reduced. In particular, the sound pressure in the frequency band around 3500Hz to 4500Hz can be effectively reduced. Further, the noise reduction in the frequency band of 500Hz to 4000Hz can be examined.
In the drive wheel V15 of the present embodiment, noise generated at the meshing portion VV of the speed reducer V30 can be reduced with respect to the outside of the cover C during driving, and the drive wheel V15 can be muted.
Thus, in the transport vehicle V of the present embodiment, noise during driving can be reduced, and noise can be reduced in the drive space of the transport vehicle V.
In the present embodiment, the same effects as those of the above-described embodiments can be obtained.
Hereinafter, embodiment 3 of the speed reducing mechanism according to the present invention will be described with reference to the drawings.
Fig. 7 is a sectional view along the deceleration axis showing the reduction gear in the deceleration mechanism of the present embodiment.
The reduction gear V30 in the reduction mechanism of the present embodiment is an eccentric oscillating reduction gear. As shown in fig. 7, the speed reducer V30 includes a case tube 200, a gear portion (external gear member) 300, 3 crankshaft assemblies 400, and a sun gear V35A. The casing barrel 200 houses the gear portion 300 and 3 crankshaft assemblies 400. In fig. 7, there is a configuration which is not shown or is shown as a modification.
The casing tube 200 includes an outer tube portion (tube portion) 210, a gear frame portion (carrier) 220, and two main bearings 230. The gear frame portion 220 is disposed inside the outer cylinder portion (cylinder portion) 210. The two main bearings 230 are disposed between the outer cylinder portion (cylinder portion) 210 and the gear frame portion 220. The two main bearings 230 enable relative rotational movement between the outer cylinder portion (cylinder portion) 210 and the gear frame portion 220. The gear frame unit 220 is exemplified as the output unit of the speed reducer V30 in the present embodiment.
As shown in fig. 7, the speed reducer V30 shows a speed reduction center axis (center axis) VAx defined as the rotation center axes of the two main bearings 230. When the gear mount portion 220 is fixed, the outer cylinder portion (cylindrical portion) 210 rotates around the main shaft VAx. That is, one of outer cylindrical portion (cylindrical portion) 210 and gear frame portion 220 is rotatable relative to the other of outer cylindrical portion (cylindrical portion) 210 and gear frame portion 220 about main shaft VAx.
In the present embodiment, a direction along a central axis (main shaft, deceleration axis) VAx of the reducer V30, which is a rotation central axis of the two main bearings 230, is referred to as an axial direction.
The outer cylinder portion (cylinder portion) 210 includes an outer cylinder 211 and a plurality of inner pins (inner teeth) 212. The outer cylinder 211 defines a cylindrical inner space for accommodating the gear frame portion 220, the gear portion 300, and the crankshaft assembly 400. The outer cylinder 211 is attached to the vehicle body V10. Each inner pin 212 is a columnar member extending substantially parallel to the main shaft VAx. Each internal gear pin 212 is fitted into a groove formed in the inner wall of the outer cylinder 211. Thus, each inner pin 212 is properly held by the outer cylinder 211.
The plurality of inner pins 212 are arranged at substantially regular intervals around the main axis VAx. The half circumferential surface of each inner pin 212 protrudes from the inner wall of the outer tube 211 toward the main axis VAx. Therefore, the plurality of inner gear pins 212 function as inner teeth that mesh with the gear portion 300.
Gear rack portion 220 includes a base portion (1 st member) 221, an end plate portion (2 nd member) 222, a positioning pin 223, and a stay bolt (fixing bolt) 224. The gear frame portion 220 has a cylindrical shape as a whole. Gear frame portion 220 has through hole 229 concentric with main shaft VAx. The inner tube 510 penetrates the through hole 229. The inner cylinder 510 is disposed concentrically with the main axis VAx.
The base portion (1 st member) 221 includes a base plate portion 225 and 3 shaft portions 226. The 3 shaft portions 226 extend from the base plate portion 225 toward the end plate portion (2 nd member) 222, respectively. A screw hole 227 and a bore 228 are formed in the tip end surface of each of the 3 shaft portions 226. The positioning pin 223 is inserted into the bore 228. As a result, the end plate portion (the 2 nd member) 222 is accurately positioned with respect to the base portion (the 1 st member) 221.
The stay bolt 224 is fastened to the threaded hole 227. As a result, the end plate portion (the 2 nd member) 222 is appropriately fixed to the base portion (the 1 st member) 221.
The fixing between the base portion (1 st member) 221 and the end plate portion (2 nd member) 222 by the stay bolt 224 is set so as to be a predetermined preload. The end plate portion (2 nd member) 222 is referred to as a holder.
The gear portion 300 is disposed between the substrate portion 225 and the end plate portion (2 nd member) 222. The 3 shaft portions 226 penetrate the gear portion 300 and are connected to the end plate portion (2 nd member) 222.
The gear portion 300 includes two gears 310, 320. The gear 310 is disposed between the substrate portion 225 and the gear 320. The gear 320 is disposed between the end plate portion (2 nd member) 222 and the gear 310.
Gear 310 is substantially identical in shape and size to gear 320. The gears 310 and 320 move in the outer cylinder 211 while rotating relative to the outer cylinder 211 while meshing with the internal gear pin 212. Thus, the centers of the gears 310, 320 and the outer cylinder 211 revolve around the main axis VAx.
The phase of the revolution of the gear 310 is deviated by substantially 180 ° from the phase of the revolution of the gear 320. While the gear 310 is engaged with half of the plurality of inner teeth pins 212 of the outer cylinder (cylinder) 210, the gear 320 is engaged with the remaining half of the plurality of inner teeth pins 212. Therefore, the gear portion 300 can rotate the outer cylinder portion (cylinder portion) 210 or the gear frame portion 220.
In the present embodiment, the gear portion 300 includes two gears 310, 320. Alternatively, a number of gears exceeding 2 may be used as the gear portion. Also, 1 gear may be used alternatively as the gear portion.
Each of the 3 crankshaft assemblies 400 includes a crankshaft 410, 4 bearings 421, 422, 423, 424, and a transmission gear (external teeth) V35B. The transmission gear (spur gear) V35B may be a general spur gear. In the speed reducer V30 of the present embodiment, the transmission gear (spur gear) V35B is not limited to a specific type.
The transmission gear (spur gear) V35B directly receives the driving force generated by the driving source (e.g., motor) from the center gear V35A. The transmission gear (spur gear) V35B has a rotation axis F3 parallel to the deceleration center axis (center axis) VAx.
As shown in fig. 7, the crankshaft 410 rotates about a crankshaft axis (transmission axis) F3. The transfer axis F3 is substantially parallel to the main axis VAx.
The crankshaft 410 includes two journals (crankshaft journals) 411, 412 and two eccentrics (eccentrics) 413, 414. The journals 411, 412 extend along a transfer axis F3. The central axes of the journals 411, 412 coincide with the transfer axis F3. Eccentric portions 413, 414 are formed between the journals 411, 412. The eccentric portions 413, 414 are eccentric with respect to the transmission axis F3, respectively.
The journal 411 is inserted into the bearing 421. The bearing 421 is disposed between the journal 411 and the end plate portion (2 nd member) 222. Thus, the journal 411 is supported by the end plate portion (2 nd member) 222 and the bearing 421. Journal 412 is inserted into bearing 422. The bearing 422 is disposed between the journal 412 and the base (1 st member) 221. Thus, journal 412 is supported by base (1 st member) 221 and bearing 422.
In the present embodiment, the bearing 421 is a needle bearing, and the plurality of rollers 431 are disposed around the journal 411. The bearing 422 is a needle bearing, and the plurality of rollers 432 are disposed around the journal 412.
The eccentric portion 413 is inserted into the bearing 423. The bearing 423 is disposed between the eccentric portion 413 and the gear 310. The eccentric portion 414 is inserted into the bearing 424. The bearing 424 is disposed between the eccentric portion 414 and the gear 320.
In the present embodiment, the bearing 423 is a needle bearing, and the plurality of rollers 433 are disposed around the eccentric portion (eccentric body) 413. The bearing 424 is a needle bearing, and the plurality of rollers 434 are disposed around the eccentric portion (eccentric body) 414.
When the driving force is input to the transmission gear V35B, the crankshaft 410 rotates about the transmission axis F3. As a result, the eccentric portions 413 and 414 eccentrically rotate about the transmission axis F3. The gears 310 and 320 connected to the eccentric portions 413 and 414 via the bearings 423 and 424 oscillate in a circular space defined by the outer cylindrical portion (cylindrical portion) 210. The gears 310 and 320 mesh with the internal gear pins 212, and therefore, relative rotational movement is caused between the outer cylindrical portion (cylindrical portion) 210 and the gear frame portion 220.
The sun gear V35A is rotatably supported on the outer periphery of the inner tube 510. The sun gear V35A is concentric with the main shaft VAx. The sun gear V35A meshes with the transfer gear V35B. The sun gear V35A is connected to a drive source via a drive gear. The sun gear V35A directly or indirectly receives a driving force generated by a motor V20 (fig. 4 to 6) as a driving source via an output portion (output shaft) V25. The sun gear V35A transmits a rotational driving force (input rotation) to the transmission gear (spur gear) V35B.
In speed reducer V30, a rotational driving force (input rotation) transmitted from motor V20 (fig. 4 to 6) as a driving source to sun gear V35A via output unit (output shaft) V25 is reduced in speed from gear carrier unit 220 and output. A wheel V40 is mounted on gear carrier portion 220. The output rotation decelerated and outputted from gear carrier part 220 drives wheel V40 to rotate via output part V32 (fig. 5).
In the reduction mechanism of the present embodiment, the sound in the frequency band of 500Hz to 5000Hz out of the noise generated at the meshing portion VV of the reduction gear V30 is first absorbed and muted in the sound absorbing layer C1 of the cover C covering the meshing portion VV, and is further muted by being attenuated and muted in the sound attenuating space C2a in the sound insulating layer C2 of the cover C.
In this way, sound in a predetermined frequency band can be absorbed and shielded from the outside by the cover C so as to have a predetermined reduction rate. Therefore, the noise transmitted from the engaging portion VV inside the cover C to the outside can be reduced, and the noise can be reduced.
In the present embodiment, the same effects as those of the above-described embodiments can be obtained.
Hereinafter, a 4 th embodiment of the speed reducing mechanism according to the present invention will be described with reference to the drawings.
Fig. 8 is a schematic side sectional view showing the speed reducing mechanism and the drive wheels in the present embodiment. In the present embodiment, the point different from the above-described embodiment 2 lies in the point relating to the shape of the lower end of the cover, and the same reference numerals are given to the corresponding other components, and the description thereof is omitted.
As shown in fig. 8, the cover C in the present embodiment is the same as that in embodiment 2 in that it opens on the lower surface facing the running surface V200.
The lower end C3 of the cover C is set to different heights in the circumferential direction of the opening. That is, the lower end C3 of the cover C has a convex shape protruding downward. Thereby, the lower end C3 sufficiently covers the engagement portion VV. Therefore, of the motor end surface portion (input surface portion) Cp and the wheel end surface portion (output surface portion) Cq, the lower convex portion C3a closer to the deceleration axis (rotation axis) VAx is closer to the running surface V200 than the lower end C3 of the circumferential surface portion Cr. The lower convex portion C3a forms an arc shape centered on the deceleration axis (rotation axis) VAx when viewed in the deceleration axis (rotation axis) VAx direction.
Thereby, the engagement portion VV that moves around the deceleration axis (rotation axis) VAx can be sufficiently covered. Therefore, the meshing portion VV that generates noise can be sufficiently covered and hidden, and sufficient noise reduction can be achieved. Further, since the lower end C3 of the peripheral surface portion Cr is located farther from the running surface V200 than the lower convex portion C3a, the running of the vehicle by the drive wheels V15 is not hindered even when the vehicle body V10 is inclined or when there is a concavity and convexity in the running surface V200.
In the present embodiment, the same effects as those of the above-described embodiments can be obtained.
Hereinafter, a 5 th embodiment of the speed reducing mechanism according to the present invention will be described with reference to the drawings.
Fig. 9 is a schematic side sectional view showing the speed reducing mechanism and the drive wheels in the present embodiment. In the present embodiment, the points different from the above-described embodiments 2 and 3 are related to the shape of the lower end of the cover, and the same reference numerals are given to the corresponding other components, and the description thereof is omitted.
As shown in fig. 9, the cover C in the present embodiment is similar to those in embodiments 2 and 3 in that it opens on the lower surface facing the running surface V200.
The lower end C3 of the cover C is set to different heights in the circumferential direction of the opening. That is, the lower end C3 of the cover C has a convex shape protruding downward. Thereby, the lower end C3 sufficiently covers the engagement portion VV. Therefore, of the motor end surface portion (input surface portion) Cp and the wheel end surface portion (output surface portion) Cq, the lower convex portion C3b closer to the deceleration axis (rotation axis) VAx is closer to the running surface V200 than the lower end C3 of the circumferential surface portion Cr. The lower convex portion C3a is formed in a straight line shape that rises obliquely toward the peripheral surface portion Cr with a position on the vertically downward side of the deceleration axis (rotation axis) VAx as the lowermost end portion when viewed in the deceleration axis (rotation axis) VAx direction.
Thereby, the engagement portion VV that moves around the deceleration axis (rotation axis) VAx can be sufficiently covered. Therefore, the meshing portion VV that generates noise can be sufficiently covered and hidden, and sufficient noise reduction can be achieved. Further, since the lower end C3 of the peripheral surface portion Cr is located farther from the running surface V200 than the lower convex portion C3b, the running of the vehicle by the drive wheels V15 is not hindered even when the vehicle body V10 is inclined or when there is a concavity and convexity in the running surface V200.
Also, the area of the wheel V40 covered by the lower convex portion C3b can be larger than the area of the wheel V40 covered by the lower convex portion C3a as viewed in the deceleration axis (rotation axis) VAx direction. This enables further sound insulation and absorption, and further quietness.
In the present embodiment, the same effects as those of the above-described embodiments can be obtained.
Industrial applicability
Examples of flexible applications of the present invention include a traveling shaft unit of an unmanned conveyor and a drive unit of an industrial robot (particularly, a cooperative robot).