阅读说明：本技术 扭矩限制器以及驱动装置 (Torque limiter and drive device ) 是由 舟杉征真 岩濑滋 小池信二 赤间有祐 于 2018-05-15 设计创作，主要内容包括：本发明提供一种更小型的扭矩限制器。本发明的代表性的实施方式所涉及的扭矩限制器(30)的特征在于,具有：通过驱动源而旋转的第一旋转体(32)；卡止于第一旋转体的第一摩擦体(33)；与第一摩擦体重叠配置,且通过与第一摩擦体之间的摩擦力从而随第一摩擦体的旋转而旋转的第二摩擦体(34)；卡止于第二摩擦体的第二旋转体(35)；将第一摩擦体以及第二摩擦体向第一摩擦体与第二摩擦体的层叠方向施力的至少1个碟形弹簧(37)；以及对碟形弹簧施加压缩力的固定构件(39)。(The invention provides a smaller torque limiter. A torque limiter (30) according to a representative embodiment of the present invention is characterized by comprising: a first rotating body (32) that is rotated by a drive source; a first friction body (33) locked to the first rotating body; a second friction body (34) which is arranged to overlap the first friction body and rotates with the rotation of the first friction body by a frictional force with the first friction body; a second rotating body (35) locked to the second friction body; at least 1 disc spring (37) for urging the first friction body and the second friction body in the direction of stacking the first friction body and the second friction body; and a fixing member (39) for applying a compressive force to the disc spring.)

1. A torque limiter, comprising:

a first rotating body that is rotated by a drive source;

a first friction body locked to the first rotating body;

a second friction body which is disposed to overlap the first friction body and rotates with the rotation of the first friction body by a frictional force with the first friction body;

a second rotating body locked to the second friction body;

at least 1 disc spring that urges the first friction body and the second friction body in a direction in which the first friction body and the second friction body are stacked; and

a fixing member compressing the disc spring.

2. The torque limiter of claim 1,

the fixing member does not contact the second rotating body and fixes the disc spring to the first rotating body.

3. The torque limiter of claim 2,

the first rotating body and the second rotating body have the same rotation axis,

the first friction body and the second friction body are stacked between the first rotating body and the second rotating body of the rotating shaft,

the disc spring is disposed coaxially with the first rotating body and in contact with the first rotating body,

the fixing member urges and fixes the disc spring to the first rotating body.

4. The torque limiter of claim 2,

the first rotating body includes: a hole with a bottom formed in the direction of the rotation axis thereof, and a first screw portion formed on the opening side of the inner peripheral surface of the first rotating body on which the hole is formed,

the first friction body and the second friction body are annular and arranged coaxially with a rotation axis of the first rotating body in the hole of the first rotating body,

the disc spring is disposed in the hole of the first rotating body coaxially with a rotation shaft of the first rotating body and in contact with at least one of the first friction body and the second friction body,

the fixing member has: a second screw portion corresponding to the first screw portion of the first rotating body, and a through hole formed through the rotating shaft of the fixed member,

the fixing member is fixed to the first rotating body by screwing the second screw portion to the first screw portion of the first rotating body in a state where the disc spring, the first friction body, and the second friction body are pressed against the bottom surface of the hole of the first rotating body,

the second rotating body is inserted into and penetrates the through hole of the fixed member and the hollow portions of the annular first friction body and the annular second friction body, and does not contact the fixed member.

5. A drive device, comprising:

the torque limiter of any one of claims 1 to 4;

a drive unit that rotationally drives the first rotating body; and

and a transmission unit that transmits the rotation of the second rotating body to a driving target.

Technical Field

The present invention relates to a torque limiter and a drive device using the same.

Background

Conventionally, when a predetermined or more torque is applied, a technique called a torque limiter is known in which transmission of torque is suppressed by disconnection or the like. For example, patent document 1 discloses a technique for realizing the function of a torque limiter by a ratchet mechanism.

(prior art documents)

(patent document)

Patent document 1: JP 2014-one 149013

Disclosure of Invention

(problems to be solved by the invention)

In recent years, with the demand for downsizing of the entire device on which the torque limiter is mounted, downsizing of the torque limiter as a component applied to the device is also required.

The present invention has been made in view of the above problems, and an object thereof is to provide a smaller torque limiter.

(means for solving the problems)

A torque limiter according to a representative embodiment of the present invention includes: a first rotating body that is rotated by a drive source; a first friction body locked to the first rotating body; a second friction body which is disposed to overlap the first friction body and rotates with the rotation of the first friction body by a frictional force with the first friction body; a second rotating body locked to the second friction body; at least 1 disc spring that urges the first friction body and the second friction body in a direction in which the first friction body and the second friction body are stacked; and a fixing member compressing the disc spring.

(effect of the invention)

According to an aspect of the present invention, a smaller torque limiter can be provided.

Drawings

Fig. 1 is a perspective view of a device provided with a drive device including a torque limiter according to an embodiment of the present invention.

Fig. 2 is a perspective view of a drive device having a torque limiter according to embodiment 1.

Fig. 3 is a perspective view of a torque limiter according to embodiment 1.

Fig. 4 is a sectional view of a torque limiter according to embodiment 1.

Fig. 5 is an exploded sectional view of a torque limiter according to embodiment 1.

Fig. 6 is a diagram showing a planar positional relationship among the second gear unit, the first friction body, the second friction body, and the third gear unit in the torque limiter according to embodiment 1.

Fig. 7 is a perspective view of a drive device having a torque limiter according to embodiment 2.

Fig. 8 is a sectional view of a torque limiter according to embodiment 2.

Fig. 9 is an exploded sectional view of a torque limiter according to embodiment 2.

Fig. 10 is a diagram showing a planar positional relationship among the housing, the first friction body, the second friction body, and the shaft in the torque limiter according to embodiment 2.

Detailed Description

1. Brief description of the embodiments

First, a typical embodiment of the invention disclosed in the present application will be briefly described. In the following description, reference numerals in the drawings corresponding to components of the invention are described with parentheses as an example.

[1] A torque limiter (30, 40) according to a representative embodiment of the present invention is characterized by comprising: a first rotating body (32, 41) that is rotated by a drive source (10); a first friction body (33, 43) locked to the first rotating body; a second friction body (34, 44) which is arranged to overlap the first friction body and rotates with the rotation of the first friction body by a frictional force with the first friction body; a second rotating body (35, 42) locked to the second friction body; at least 1 disc spring (37, 45) for urging the first friction body and the second friction body in the direction in which the first friction body and the second friction body are stacked; and a fixing member (39, 46) for applying a compressive force to the disc spring.

[2] In the torque limiter, the following configuration may be adopted: the fixing member does not contact the second rotating body and fixes the disc spring to the first rotating body.

[3] The torque limiter (30) may be configured as follows: the first rotating body (32) and the second rotating body (35) have the same rotating shaft (31), the first friction body (33) and the second friction body (34) are stacked between the first rotating body and the second rotating body of the rotating shaft, the disc spring is arranged coaxially with the first rotating body and is in contact with the first rotating body, and the fixing member presses and fixes the disc spring to the first rotating body.

[4] The torque limiter (40) may be configured as follows: the first rotating body (41) has: a bottomed hole (410) formed in a direction of a rotation axis thereof, and a first screw portion (412) formed on an opening side of an inner peripheral surface (410a) of the first rotating body on which the hole is formed, the first friction body (43) and the second friction body (44) being annular, and being arranged coaxially with the rotation axis of the first rotating body in the hole of the first rotating body, the disc spring (45) being arranged coaxially with the rotation axis of the first rotating body in the hole of the first rotating body and being in contact with at least one of the first friction body and the second friction body, the fixing member (46) having: and a second screw part (460) corresponding to the first screw part of the first rotating body, and a through hole (461) formed through the rotating shaft of the fixing member, wherein the fixing member is fixed to the first rotating body by being screwed to the first screw part of the first rotating body in a state in which the disc spring, the first friction body, and the second friction body are pressed against a bottom surface (410b) of the hole of the first rotating body, and the second rotating body is inserted into and penetrates the through hole of the fixing member and hollow parts of the annular first friction body and the annular second friction body without contacting the fixing member.

[5] A drive device (1, 1A) according to a representative embodiment of the present invention is characterized by comprising: the torque limiter (30, 40); a drive unit (10, 11, 13) for rotationally driving the first rotating body; and a transmission unit (20, 12) that transmits the rotation of the second rotating body to a drive target (5).

2. Specific examples of the embodiments

Specific examples of embodiments of the present invention will be described below with reference to the drawings. In the following description, the same reference numerals are given to the common components in the respective embodiments, and redundant description is omitted. In addition, it is noted that: the drawings are schematic, and the dimensional relationship of the respective portions, the ratio of the respective portions, and the like may be different from those in reality. There are also cases where portions having different dimensional relationships or ratios from each other are included between the drawings.

EXAMPLE 1

Fig. 1 is a perspective view of a device provided with a drive device including a torque limiter according to embodiment 1 of the present invention.

The drive device 1 according to the present embodiment is disposed in a hinge portion 3 of an apparatus main body 4 in an apparatus 2 having a movable portion 5, and drives the movable portion 5 to open and close. Examples of the device 2 include a toilet having an electric toilet seat and a toilet lid opening/closing function using a toilet seat or a lid of the toilet seat as a movable portion 5, a notebook computer having a display panel as a movable portion 5, and a garbage can having a lid as a movable portion 5.

Fig. 2 is a perspective view of a drive device having a torque limiter according to embodiment 1.

Specifically, the drive device 1 has a motor 10, a first gear portion 20, and a torque limiter 30.

The motor 10 functions as a driving source/power source for opening and closing the movable portion 5 in the device 2. In the motor 10, a drive signal is supplied via a lead wire not shown, and an output rotary shaft 10a of the motor 10 is rotated based on the drive signal. A gear 11 is attached to a distal end portion of an output rotary shaft 10a of the motor 10. Here, as the motor 10, for example, a stepping motor, a dc brushless motor, or the like can be used.

The motor 10 and the gear 11 function as a driving unit that drives a second gear unit 32, which will be described later, of the torque limiter 30.

The first gear portion 20 is a functional portion that transmits the rotational force generated by the motor 10 to a rotational shaft (opening/closing drive shaft) of the movable portion 5 via a gear train (not shown) or the like. The first gear portion 20 transmits torque transmitted from the motor 10 via the torque limiter 30 to the movable portion 5 to be driven. The first gear portion 20 includes a large-diameter gear 21 and a small-diameter gear 22 fixed coaxially with the large-diameter gear 21. The small-diameter gear 22 is connected directly or via a gear train to a gear connected to a rotating shaft (opening/closing drive shaft) of the movable portion 5. The large-diameter gear 21 meshes with a third gear 351 of the torque limiter 30, which will be described later. The large diameter gear 21 and the small diameter gear 22 are made of, for example, resin.

The first gear 20 functions as a transmission unit that transmits rotation of a third gear 35 of a torque limiter 30 described later to the movable unit 5 to be driven.

The torque limiter 30 is a safety device that limits the transmitted torque, and when a torque equal to or greater than a predetermined threshold value (hereinafter also referred to as a "slip torque value") is applied in a direction in a predetermined direction by an external force while transmitting a rotational force generated by the motor 10 to the first gear portion 20, limits the torque transmitted between the first gear portion 20 and the motor 10.

The structure of the torque limiter 30 will be described below with reference to fig. 3 to 6.

As shown in fig. 3 to 6, the torque limiter 30 includes: the shaft 31, the second gear unit 32 as the first rotating body, the first friction body 33, the second friction body 34, the third gear unit 35 as the second rotating body, the sliding washer 36, the disc spring 37, the washer 38, and the nut 39.

The shaft 31 is formed of metal or the like, and is a rotation center of the torque limiter 30. As shown in fig. 4, the shaft 31 is composed of: a head portion 311; a cylindrical portion 312 having an outer diameter smaller than that of the head portion 311; a screw portion 313 having an outer diameter smaller than the outer diameter of the cylindrical portion 312 and formed with a screw to be screwed with a nut 39 described later; and a small diameter portion 314 having an outer diameter smaller than that of the threaded portion 313.

The second gear unit 32 is a rotary body fixed to the shaft 31 and driven by the motor 10 via the gear 11. The second gear unit 32 is formed of resin or the like, and has an outer cylindrical portion 322 and a partition portion 321 as shown in fig. 4. The outer cylinder portion 322 is formed integrally with the partition portion 321, for example. Further, the second gear portion 32 is fixed with respect to the rotational direction of the shaft 31, and is movable in the axial direction of the shaft 31.

A second gear 324 is formed on the outer circumferential surface of the outer cylindrical portion 322. The second gear 324 is engaged with the gear 11 mounted to the output rotation shaft 10a of the motor 10. The second gear 324 may be coupled to the gear 11 via a gear train, not shown.

As shown in fig. 6, a notch portion (engaged portion) 325 that engages with a boss portion 33a formed on an outer peripheral portion of a first friction body 33, which will be described later, is formed on an inner peripheral surface of the outer cylindrical portion 322 so as to be rotationally symmetrical at 120 °, for example. Each notch 325 is formed in the inner peripheral surface 322a of the partition 321 on the side of the one main surface 321 a. Notch 325 and boss 33a are formed in a rectangular shape, for example.

The partition portion 321 is disposed substantially at the center of the outer cylindrical portion 322. A cylindrical inner cylindrical portion 323 stands integrally with the partition portion 321 at the center of the partition portion 321. Further, a circular through hole 326, which communicates with the hole of the inner cylindrical portion 323 and through which the cylindrical portion 312 of the shaft 31 is inserted, is formed in the circular center portion of the partition portion 321.

As shown in fig. 4, the space inside the second gear part 32 is divided into 2 spaces by the partition 321. That is, the space inside the second gear unit 32 is divided into: a space formed by the inner peripheral surface 322a of the outer cylindrical portion 322 and the one main surface 321a of the partition portion 321 (hereinafter, referred to as "accommodating portion SP 1"), and a space formed by the inner peripheral surface 322b of the outer cylindrical portion 322 and the other main surface 321b of the partition portion 321 (hereinafter, referred to as "accommodating portion SP 2").

The first friction body 33 is formed of a metal plate (e.g., SUS304), a resin plate, or the like, and has a circular ring shape as shown in fig. 6. The outer diameter of the first friction body 33 is slightly smaller than the inner diameter of the outer cylindrical portion 322 of the second gear portion 32. The inner diameter of the first friction body 33 is formed to be slightly larger than the outer diameter of an upright portion 353 formed in a third gear portion 35 described later. Further, a boss portion (engaging portion) 33a is formed on the outer peripheral edge of the first friction member 33, and the boss portion (engaging portion) 33a is engaged with 3 notch portions 325 formed in the outer cylindrical portion 322 of the second gear portion 32.

The second friction body 34 is formed of a metal plate (e.g., beryllium copper), a resin plate, or the like, and has a circular ring shape as shown in fig. 6. In order to avoid an insufficient contact area between the friction bodies due to burrs or the like at the edge portions of the friction bodies, the inner and outer diameters of the first friction body 33 and the second friction body 34 may be designed to have: the first friction member 33 and the second friction member 34 are stacked without overlapping each other at their edge portions.

On the inner peripheral edge of the second friction body 34, a convex portion (engagement portion) 34a that engages with a gap 354 formed between upright portions 353 of a third gear portion 35, which will be described later, is formed so as to be rotationally symmetrical at 120 °, for example.

As shown in fig. 4 and 5, the first friction bodies 33 and the second friction bodies 34 are alternately stacked and accommodated in the accommodating portion SP1 of the second gear unit 32. At this time, the projection 33a of the first friction member 33 is inserted into the notch 325 formed in the outer cylindrical portion 322 of the second gear portion 32.

In the present embodiment, as shown in fig. 4 and the like, the case where 10 pieces of the first friction body 33 and the second friction body 34 are stacked respectively is exemplified, but the number of the stacked first friction body 33 and second friction body 34 is not particularly limited.

The third gear portion 35 is a rotary body rotatably supported by the shaft 31. A part of the third gear unit 35 is disposed on the housing SP1 side of the second gear unit 32. The third gear portion 35 includes a third gear 351, a disk portion 352, and an upright portion 353. For example, the third gear 351, the disk portion 352, and the standing portion 353 are integrally formed of resin or the like.

The third gear 351 is formed to have a diameter smaller than that of the second gear part 32, and is disposed upright at the center of the disk part 352. A gear is formed on the outer peripheral surface of the third gear 351, and the gear meshes with the large diameter gear 21 of the first gear portion 20.

The disk portion 352 is formed to have an outer periphery smaller than the inner diameter of the outer cylindrical portion 322 of the second gear unit 32, and functions as a cover for pressing the first friction body 33 and the second friction body 34 accommodated in the accommodating portion SP1 of the second gear unit 32.

Further, a through hole 355 having a diameter larger than the outer diameter of the cylindrical portion 312 of the shaft 31 is formed in the rotation center of the third gear 351 and the disk portion 352. That is, a gap (Clearance) is formed between the inner circumferential surfaces of the third gear 351 and the disk portion 352 and the cylindrical portion 312 of the shaft 31.

The standing portion 353 extends in the rotation axis direction on the surface of the disk portion 352 opposite to the surface on which the third gear 351 is formed. As shown in fig. 4 to 6, the upright portion 353 is formed rotationally symmetric at 120 °, for example, and has a substantially cylindrical shape as a whole.

As shown in fig. 6, the outer diameter of the cylindrical portion 353a formed by the plurality of upright portions 353 and having a substantially circular shape in plan view is smaller than the inner diameters of the first frictional body 33 and the second frictional body 34. The inner diameter of the cylindrical portion 353a is larger than the outer diameter of the cylindrical portion 312 of the shaft 31. That is, a gap (clearance) is formed between the inner peripheral surface of the standing portion 353 of the third gear portion 35 and the columnar portion 312 of the shaft 31.

Further, 3 projections 34a of the second friction body 34 are engaged with 3 gaps (engaged portions) 354 between the upright portions 353. Thereby, the third gear 351 rotates integrally with the second friction body 34.

The slide spacer 36 is formed of, for example, resin. As shown in fig. 3 and 4, the slide washer 36 is inserted into the hollow portion thereof, passes through the cylindrical portion 312 of the shaft 31, and is disposed so as to contact an axial end surface of the third gear 351. Specifically, the sliding washer 36 is disposed at a stepped portion between the head portion 311 of the shaft 31 and the columnar portion 312, and is sandwiched between an axial end surface of the third gear 351 and the head portion 311 of the shaft 31.

The disc spring 37 is a member that biases the first friction member 33 and the second friction member 34 toward the head 311 in the stacking direction of the first friction member 33 and the second friction member 34. As shown in fig. 4 and 5, the disc spring 37 is disposed in the housing portion SP2 of the second gear unit 32. For example, the disc spring 37 is configured to: in the housing portion SP2 of the second gear portion 32, the shaft 31 is inserted into the hollow portion of the disc spring 37, and the disc spring 37 is in contact with the main surface 321b of the partition portion 321. In the present embodiment, the case where 3 disc springs 37 are stacked in the housing portion SP2 is exemplified, but the number of disc springs 37 is not particularly limited as long as there are at least 1 disc spring 37.

The spacer 38 is formed of, for example, metal. As shown in fig. 3 and 4, the washer 38 has the screw portion 313 of the shaft 31 inserted into the hollow portion thereof, and is disposed to face the main surface 321b of the partition portion 321 of the second gear unit 32 with the disc spring 37 interposed therebetween.

The nut 39 is a fixing member that applies a compressive force to the disc spring 37. As shown in fig. 3 and 4, the nut 39 is screwed to the threaded portion 313 of the shaft 31 in a state where the small diameter portion 314 of the shaft 31 protrudes from the through hole 326 of the partition portion 321 of the second gear unit 32 and the hollow portion of the washer 38, and presses and fixes the disc spring 37 to the second gear unit 32 via the washer 38. This applies a compressive force to the disc spring 37. At this time, the third gear portion 35 pressed against the head portion 311 side of the shaft 31 via the disc spring 37, the second gear portion 32, the first friction body 33, and the second friction body 34 is stopped at the step portion between the head portion 311 and the columnar portion 312 via the sliding washer 36.

By adjusting the tightening degree of the nut 39, the force with which the disc spring 37 presses the first friction body 33 and the second friction body 34 against the third gear portion 35 via the second gear portion 32 can be adjusted.

Next, an assembling method of the torque limiter 30 having the above-described configuration will be described with reference to fig. 5.

First, 10 alternating first friction members 33 and 10 second friction members 34 are stacked in alignment on the main surface 321a of the partition 321 of the second gear unit 32, and accommodated in the accommodating portion SP1 of the second gear unit 32. At this time, the projection 33a of the first friction member 33 is engaged with the notch 325 formed in the outer cylindrical portion 322 of the second gear unit 32. Further, a lubricating oil is filled as necessary. In addition, in order to obtain a stable frictional force, a resin sheet or the like may be interposed between the first friction member 33 and the second friction member 34 in addition to the lubricating oil.

Next, the third gear unit 35 is disposed in the housing SP1 of the second gear unit 32. At this time, the 3 convex portions 34a of the second friction body 34 are engaged with the gaps 354 of the 3 upright portions 353 of the third gear portion 35, respectively.

Next, in a state where shaft 31 is inserted through hole 355 of third gear part 35, columnar part 312 of shaft 31 is inserted through hole 326 of partition 321 of second gear part 32.

Next, the 3 disc springs 37 and the spacers 38 are inserted through the shaft 31 from the side of the small diameter portion 314 in this order, and the nut 39 is screwed to the threaded portion 313 of the shaft 31, whereby the disc springs 37 and the spacers 38 are accommodated in the accommodating portion SP2 of the second gear unit 32. At this time, the pressing force of the disc spring 37 applied to the first friction body 33 and the second friction body 34 via the second gear unit 32 can be adjusted by adjusting the tightening degree of the nut 39.

The torque limiter 30 according to embodiment 1 can be realized by the above-described assembly method.

Next, the operation of the drive device 1 mounted with the torque limiter 30 according to embodiment 1 will be described.

The driving device 1 having the torque limiter 30 mounted thereon is assembled to the equipment 2 shown in fig. 1 in a state shown below. That is, in the hinge portion 3 of the device 2, the second gear 324 of the torque limiter 30 is engaged with the gear 11 fitted to the output rotary shaft 10a of the motor 10. The small-diameter gear 22 of the first gear portion 20 connected to the third gear 351 of the torque limiter 30 is directly or indirectly connected to a gear not shown connected to the rotating shaft of the movable portion 5 to be driven. In this state, the drive device 1 is assembled to the equipment 2.

Here, a case where the movable unit 5 to be driven is opened, that is, a case where the movable unit 5 is driven in a direction indicated by reference numeral a in fig. 1 will be described.

In this case, a controller, not shown, supplies a drive signal to the motor 10 and rotates the motor 10 in one direction. The gear 11 fitted to the output rotary shaft 10a of the motor 10 rotates based on the rotation of the motor 10, and the second gear 324 engaged with the gear 11 rotates.

As the second gear 324 rotates, the first friction body 33 having the projection 33a engaged with the notch 325 of the second gear part 32 rotates. The rotational force of the first frictional body 33 is transmitted to the second frictional body 34 by the static frictional force of the first frictional body 33 and the second frictional body 34, and the second frictional body 34 is rotated. The upright portion 353 of the third gear portion 35 engaged with the second friction body 34 rotates based on the rotation of the second friction body 34, and the third gear 351 integrally formed with the upright portion 353 also rotates based on the rotation of the upright portion 353. The large diameter gear 21 of the first gear part 20 meshing with the third gear 351 is rotated by the rotation of the third gear 351, and the small diameter gear 22 formed integrally with the large diameter gear 21 is rotated along with the rotation of the large diameter gear 21. The rotation of the small diameter gear 22 is transmitted to the rotation shaft of the movable portion 5, and the movable portion 5 opens.

On the other hand, when the movable unit 5 to be driven is closed, that is, when the movable unit 5 is driven in the direction indicated by reference numeral B in fig. 1, the controller rotates the motor 10 in the reverse direction. Thereby, the rotational force in the opposite direction to the above is transmitted to the rotational shaft of the movable portion 5, and the movable portion 5 is closed.

Next, a case will be described in which a user of the apparatus 2 manually closes and opens the movable portion 5 to apply an overload to the movable portion 5.

In this case, the first gear 20 rotates with the rotation of the rotation shaft of the movable portion 5, and the third gear 351 meshing with the first gear 20 rotates. Further, the standing portion 353 integrally formed with the third gear 351 rotates, and the second friction body 34 engaged with the standing portion 353 rotates.

At this time, when the overload applied to the movable part 5 exceeds the limit torque, that is, when the overload applied to the movable part 5 is larger than the maximum stationary frictional force between the first frictional body 33 and the second frictional body 34, the second frictional body 34 slides with respect to the first frictional body 33, and the rotation of the third gear part 35 is not transmitted to the second gear part 32 after the first frictional body 33 and the motor 10.

In this way, in the case where the overload applied to the movable part 5 is greater than the maximum static frictional force between the first frictional body 33 and the second frictional body 34, the rotation of the third gear part 35 is not transmitted to the second gear part 32, and therefore the motor 10, the gear 11, and the second gear part 32 can be protected.

In addition, even when an overload exceeding a limit torque is transmitted from the motor 10 side to the second gear part 32 for some reason, since the first friction body 33 slides with respect to the second friction body 34, the overload is not transmitted to the third gear part 35, and the third gear part 35 and the first gear part 20 and the like can be protected.

As described above, according to the torque limiter 30 of embodiment 1, the torque generated by the motor 10 can be transmitted to the first gear portion 20 based on the frictional force between the first friction body 33 and the second friction body 34, and when an excessive overload is applied from the outside, the first friction body 33 and the second friction body 34 slide, and the transmission of the torque from the outside to the motor 10 can be suppressed.

Further, according to the torque limiter 30, since the disc spring 37 is used as a means for biasing the first friction body 33 and the second friction body 34, it is possible to achieve a reduction in thickness and a reduction in size of the torque limiter, as compared with a case where another biasing means such as a coil spring is used.

Further, according to the torque limiter 30, the nut 39 as the fixing member does not contact the third gear portion 35 as the second rotating body, and the plate spring 37 is fixed to the second gear portion 32 as the first rotating body, so that the fluctuation of the slip torque value of the torque limiter can be suppressed. This point will be described in detail below.

As described above, the slip torque value of the torque limiter 30, that is, the maximum static friction force between the first frictional body 33 and the second frictional body 34 is adjusted according to the fastening degree of the nut 39. Therefore, it is also considered that, when the tightening degree of the nut 39 changes for some reason, the slip torque value of the torque limiter 30 also changes.

For example, consider the following: if an external force is applied to the third gear portion 35 side in a state where the fastening position of the nut 39 is set to the third gear portion 35 side and the nut 39 is fixed by bringing the nut 39 into contact with the third gear portion 35, the second friction body 34 slides with respect to the first friction body 33. In this case, although torque is not transmitted to the second gear 324 coupled to the first friction body 33 and the gear 11 coupled to the output rotary shaft 10a of the motor 10, torque from an external force is transmitted to the third gear part 35, and the third gear part 35 rotates. At this time, the nut 39 in contact with the third gear 35 is positionally displaced according to the rotation of the third gear 35, and the tightening degree of the nut 39 is changed.

In contrast, according to the torque limiter 30 of embodiment 1, when the second friction body 34 slides with respect to the first friction body 33, the nut 39 is fixed at a position that does not rotate with respect to the rotating third gear portion 35, that is, at a position that does not contact the third gear portion 35, and a compression force is applied to the coned disc spring 37.

Accordingly, since the rotational force of the third gear portion 35 when the second friction body 34 slides with respect to the first friction body 33 is hardly transmitted to the nut 39, it is possible to suppress the variation in the slip torque value due to the positional deviation of the nut 39 and improve the stability of the slip torque value.

In particular, in the torque limiter 30 according to embodiment 1, the second gear unit 32 and the third gear unit 35 are arranged to have the same rotation axis, and the first friction body 33 and the second friction body 34 are stacked between the second gear unit 32 and the third gear unit 35 on the rotation axis. Further, in the torque limiter 30, the disc spring 37 disposed coaxially with the second gear portion 32 is pressed and fixed to the second gear portion 32 by the nut 39. Accordingly, the nut 39 can be fastened at a position physically separated from the third gear portion 35. This can more efficiently suppress the fluctuation of the slip torque value, and therefore, the stability of the slip torque value can be further improved.

EXAMPLE 2

Fig. 7 is a perspective view of a drive device having a torque limiter according to embodiment 2.

A driving device 1A shown in fig. 7 drives the movable section 5 to open and close by a hinge section 3 housed in a device 2 having the movable section 5 shown in fig. 1, similarly to the driving device 1 according to embodiment 1.

As shown in fig. 7, the drive device 1A includes a motor 10, a reduction gear 13, a torque limiter 40, and a coupling (coupling) 12.

The speed reducer 13 is a member that reduces the rotational force generated by the motor 10 and transmits the reduced rotational force to the rotational shaft (opening/closing drive shaft) of the movable portion 5. The speed reducer 13 transmits the torque transmitted from the motor 10 to the movable portion 5 to be driven via the torque limiter 40 and the coupling 12. The speed reducer 13 is constituted by a gear mechanism including a planetary gear, for example.

The motor 10 and the reduction gear 13 function as a drive unit that drives a housing 41, which will be described later, of the torque limiter 40.

The torque limiter 40 transmits the rotational force of the motor 10 input from the speed reducer 13 to the movable portion 5 via the coupling 12, and limits the torque transmitted between the movable portion 5 and the motor 10 when a torque equal to or greater than a slip torque value is applied.

The coupling 12 is a functional part that couples a shaft 42 of the torque limiter 40, which will be described later, and a rotating shaft (opening/closing drive shaft) of the movable part 5, and transmits the rotational force of the shaft 42 to the rotating shaft of the movable part 5. The coupling 12 functions as a transmission unit that transmits rotation of a shaft 42 of a torque limiter 40 described later to the movable unit 5 to be driven.

The structure of the torque limiter 40 will be described below with reference to fig. 8 to 10.

As shown in fig. 8 to 10, the torque limiter 40 includes: a housing 41 as a first rotating body, a first friction body 43, a second friction body 44, a disc spring 45, a fixed member 46, a shaft 42 as a second rotating body, and a bearing 47.

The housing 41 is formed of resin, metal, or the like, and is not only a container that houses the first friction body 43, the second friction body 44, and the disc spring 45, but also a rotating body that is coupled to the output shaft 13a of the reduction gear 13 and rotates upon receiving the rotational force of the motor 10 input via the output shaft 13 a.

The case 41 has a cylindrical shape in which a bottomed hole 410 formed in a direction of a rotation axis thereof is formed. On the opening side of the inner peripheral surface 410a of the housing 41 where the hole 410 is formed, a first screw portion 412 having a cut screw is formed.

As shown in fig. 10, a notch portion (engaged portion) 413 that engages with a boss portion 43a formed on an outer peripheral portion of a first friction body 43 described later is formed on an inner peripheral surface 410a of the housing 41 so as to be rotationally symmetrical at 90 °, for example. The notch 413 and the projection 43a are formed in an arc shape, for example.

Further, a hole 414 is formed in an end surface of the case 41 on the opposite side to the end surface on which the hole 410 is formed. As shown in fig. 8, the output shaft 13a of the reduction gear 13 is inserted into the hole 414 and fixed to the housing 41 by a fixing member 48 such as a screw.

The first friction body 43, the second friction body 44, and the disc spring 45 are accommodated in a space (hereinafter referred to as "accommodation portion SP 3") formed by the hole 410 of the housing 41.

The first friction body 43 is formed of a metal plate (e.g., SUS304), a resin plate, or the like, and has a circular ring shape as shown in fig. 10. The outer diameter of the first friction body 43 is slightly smaller than the inner diameter of the hole 410 of the housing 41. The inner diameter of the first friction member 43 is formed larger than the outer diameter of a fixing portion 422 of the shaft 42, which will be described later. Further, a projection (engaging portion) 43a is formed on the outer peripheral edge of the first friction body 43, and the projection 43a is engaged with the 4 notches 413 formed in the inner peripheral surface 410a of the housing 41.

The second friction body 44 is formed of a metal plate (e.g., beryllium copper), a resin plate, or the like, is formed in a disc shape as shown in fig. 10, and has a polygonal (e.g., hexagonal) opening 44a at the center thereof into which the fixing portion 422 of the shaft 42 having a polygonal (e.g., hexagonal) cross section is inserted.

As shown in fig. 8 and 9, the first friction bodies 43 and the second friction bodies 44 are alternately stacked and accommodated in the bottom surface 410b of the hole 410 in the accommodation portion SP3 of the housing 41. At this time, the projection 43a of the first friction body 43 is inserted into the notch 413 formed in the inner peripheral surface 410a of the housing 41.

In the present embodiment, as shown in fig. 9 and the like, a case where 7 first friction bodies 43 and 6 second friction bodies 44 are stacked is exemplified, but the number of the first friction bodies 43 and the second friction bodies 44 is not particularly limited.

The disc spring 45 is configured to: the housing portion SP3 of the housing 41 is coaxial with the rotation axis of the housing 41 and is in contact with at least one of the first friction body 43 and the second friction body 44. Specifically, as shown in fig. 8 and 9, at least 1 disc spring 45 is laminated on the side of the laminated body of the first frictional body 43 and the second frictional body 44 which does not contact the bottom surface 410 b.

In the present embodiment, as shown in fig. 9 and the like, a case where 5 disc springs 45 are stacked is exemplified, but the number of disc springs 45 is not particularly limited.

The shaft 42 has: a D-shaped portion 424 having a D-shaped cross section and connected to the rotating shaft (hole 120) of the coupling 12; a cylindrical portion 423; a fixing portion 422 having a polygonal (e.g., hexagonal) cross section to which the opening 44a of the second friction body 44 is fixed; and a front end 421.

The shaft 42 is inserted through the hole 410 of the housing 41 while passing through the disc spring 45, the first friction body 43, and the second friction body 44, and is supported by a bearing (e.g., a ball bearing) 47 disposed on the bottom surface 410b side of the hole 410 of the housing 41. The D-shaped portion 424 of the shaft 42 is inserted into a hole 120 formed at one end of the coupling 12, and is fixed to the coupling 12 by a fixing member 48 such as a screw.

The fixing member 46 is a functional portion that applies a compressive force to the disc spring 45. The fixing member 46 is made of, for example, the same material as the housing 41, and includes a second screw portion 460 corresponding to the first screw portion 412 of the housing 41, and a through hole 461 formed through the rotation shaft of the fixing member 46.

In the fixing member 46, the second screw portion 460 is screwed to the first screw portion 412 of the housing 41 and fixed to the housing 41 in a state where the disc spring 45, the first friction body 43, and the second friction body 44 are pressed against the bottom surface 410b of the hole 410 of the housing 41.

The shaft 42 is inserted into the through hole 461 of the fixing member 46, and the cylindrical portion 423 of the shaft 42 is supported by the bearing 47 disposed in the through hole 461.

At this time, a gap (clearance) is formed between the through hole 461 of the fixing member 46 and the shaft 42 (for example, the cylindrical portion 423), that is, the fixing member 46 and the shaft 42 are not in contact with each other.

Next, an assembling method of the torque limiter 40 having the above-described configuration will be described with reference to fig. 9.

First, the tip 421 of the shaft 42 is inserted into the bearing 47 disposed on the bottom surface 410b side of the hole 410 of the housing 41.

Next, 7 pieces of the first friction bodies 43 and 6 pieces of the second friction bodies 44 are alternately aligned and stacked on the bottom surface 410b of the hole 410 of the case 41, and are accommodated to the accommodating portion SP3 of the case 41. At this time, the boss portion 43a of the first friction body 43 is engaged with the notch portion 413 formed in the inner peripheral surface 410a of the housing 41, and the opening 44a of the second friction body 44 is fitted with the fixing portion 422 of the shaft 42. Further, a lubricating oil is filled as necessary. In addition to the lubricating oil, a resin sheet or the like may be interposed between the first friction member 43 and the second friction member 44 in order to obtain a stable frictional force.

Next, 5 disc springs 45 are inserted from the D-shaped portion 424 side through the shaft 42, and stacked on a stacked body composed of the first friction body 43 and the second friction body 44.

Next, the second screw portion 460 of the fixing member 46 is screwed to the first screw portion 412 formed on the inner peripheral surface 410a of the housing 41 in a state where the shaft 42 is inserted through the through hole 461 of the fixing member 46 and the cylindrical portion 423 of the shaft 42 is inserted in the bearing 47 disposed in the through hole 461 of the fixing member 46. Thereby, a compressive force is applied from the fixing member 46 to the disc spring 45. At this time, the pressing force of the disc spring 45 applied to the first friction body 43 and the second friction body 44 is adjusted by adjusting the fastening degree of the fixing member 46.

The torque limiter 40 according to embodiment 2 can be realized by the above-described assembly method.

Next, the operation of the drive device 1A mounted with the torque limiter 40 according to embodiment 2 will be described.

The drive device 1A having the torque limiter 40 mounted thereon is assembled to the apparatus 2 shown in fig. 1 in a state shown below. That is, in the hinge portion 3 of the device 2, the output shaft 13a of the reduction gear 13 is inserted into and fixed to the hole 414 of the housing 41 of the torque limiter 40, and the reduction gear 13 rotates upon receiving the rotational force from the output shaft of the motor 10. Further, the D-shaped portion 424 of the shaft 42 protruding from the fixing member 46 of the torque limiter 40 is inserted and fixed into the hole 120 formed at one end of the coupling 12, and the rotating shaft of the movable portion 5 is inserted and fixed into a hole, not shown, formed at the other end of the coupling 12. In this state, the drive device 1A is assembled to the equipment 2.

Here, a case where the movable unit 5 to be driven is opened, that is, a case where the movable unit 5 is driven in a direction indicated by reference numeral a in fig. 1 will be described.

In this case, a controller, not shown, supplies a drive signal to the motor 10 to rotate the motor 10 in one direction. Based on the rotation of the motor 10, the output shaft 13a of the reduction gear 13 fitted to the output rotation shaft of the motor 10 rotates, and the housing 41 into which the output shaft 13a is inserted rotates.

As the housing 41 rotates, the first friction body 43 rotates, and the first friction body 43 has a projection 43a that engages with the notch 413 formed in the inner circumferential surface 410a of the housing 41. The rotational force of the first frictional body 43 is transmitted to the second frictional body 44 by the static frictional force of the first frictional body 43 and the second frictional body 44, and the second frictional body 44 is rotated. The shaft 42, which is fitted to the second friction body 44 and the fixing portion 422, rotates based on the rotation of the second friction body 44. The coupling 12 fitted to the D-shaped portion 424 of the shaft 42 rotates by the rotation of the shaft 42. Then, the rotation of the coupling 12 is transmitted to the rotation shaft of the movable portion 5, and the movable portion 5 is opened.

On the other hand, when the movable unit 5 to be driven is closed, that is, when the movable unit 5 is driven in the direction indicated by reference numeral B in fig. 1, the controller rotates the motor 10 in the reverse direction. Thereby, the rotational force in the opposite direction to the above is transmitted to the rotational shaft of the movable portion 5, and the movable portion 5 is closed.

Next, a case will be described in which a user of the apparatus 2 manually closes and opens the movable portion 5 to apply an overload to the movable portion 5.

In this case, as the rotating shaft of the movable portion 5 rotates, the coupling 12 rotates, and the shaft 42 fitted in the hole 120 of the coupling 12 rotates. Thereby, the second friction body 44 fitted to the fixing portion 422 of the shaft 42 rotates.

At this time, when the overload applied to the movable portion 5 exceeds the limit torque, that is, when the overload applied to the movable portion 5 is larger than the maximum stationary frictional force between the first frictional body 43 and the second frictional body 44, the second frictional body 44 slides with respect to the first frictional body 43, and the rotation of the shaft 42 is not transmitted to the housing 41 and the motor 10 after the first frictional body 43.

In this way, in the case where the overload applied to the movable portion 5 is larger than the maximum stationary frictional force between the first frictional body 43 and the second frictional body 44, the motor 10 and the housing 41 can be protected.

Even if an overload exceeding the limit torque is transmitted from the motor 10 side to the housing 41 for some reason, the first friction body 43 slides with respect to the second friction body 44, and thus the overload is not transmitted to the shaft 42, and the shaft 42, the coupling 12, and the like can be protected.

As described above, according to the torque limiter 40 of embodiment 2, similarly to the torque limiter 30 of embodiment 1, the torque generated by the motor 10 can be transmitted to the coupling 12 by the friction between the first friction body 43 and the second friction body 44, while the torque applied to the motor 10 can be suppressed when an excessive overload is applied from the outside.

Further, according to the torque limiter 40, as in the torque limiter 30 according to embodiment 1, the disc spring 45 is used as the biasing means for biasing the first friction body 43 and the second friction body 44, and therefore, a more compact torque limiter can be realized.

In particular, in the torque limiter 40 according to embodiment 2, the second screw portion 460 of the fixing member 46 is screwed to the first screw portion 412 formed on the inner peripheral surface 410a of the case 41 in a state where the disc spring 45, the first friction body 43, and the second friction body 44 are pressed against the bottom surface 410b of the hole 410 of the case 41, and the fixing member 46 is fixed to the case 41. Accordingly, it is not necessary to prepare a cover for pressing the first friction body 43 and the second friction body 44 against the bottom surface 410b of the hole 410 of the housing 41 and a fixing member such as a nut for fixing the cover, respectively, and thus the number of components can be reduced and a more compact torque limiter can be realized.

Further, according to the torque limiter 40, since a space is formed between the fixed member 46 as a means for adjusting the slip torque value of the torque limiter and the shaft 42 as the second rotating body, the disc spring 45 can be fixed to the housing 41 as the first rotating body without the fixed member 46 contacting the shaft 42. As a result, similarly to the torque limiter 30 according to embodiment 1, it is possible to suppress fluctuations in the slip torque value of the torque limiter and improve the stability of the slip torque value.

Extension of the embodiment

It is needless to say that the invention carried out by the present inventors has been specifically described above based on the embodiments, but the present invention is not limited thereto, and various modifications can be made without departing from the scope of the invention.

For example, although embodiment 1 illustrates a case where the disc spring 37 is disposed in the housing portion SP2, the present invention is not limited to this. For example, the disc spring 37 may be disposed in the housing portion SP1 and stacked together with the first friction body 33 and the second friction body 34. Accordingly, as in the torque limiter 30 according to embodiment 1, the pressing force can be applied to the first friction member 33 and the second friction member 34.

In embodiment 2, the case where the disc spring 45 is disposed on the fixing member 46 side is exemplified, but the present invention is not limited thereto. For example, the disc spring 45 may be disposed between the bottom surface 410b of the hole 410 of the housing 41 and the first friction body 43 and the second friction body 44, or the disc springs 45 may be disposed on both sides of a stacked body formed by the first friction body 43 and the second friction body 44. Accordingly, as in the torque limiter 40 according to embodiment 2, the pressing force can be applied to the first friction body 43 and the second friction body 44.

Although the case where the notch 325 of the second gear unit 32 and the boss 33a of the first friction body 33 are formed in rectangular shapes in embodiment 1 has been illustrated, the case where the notch 413 formed in the inner peripheral surface 410a of the housing 41 and the boss 43a of the first friction body 43 are formed in arc shapes in embodiment 2 is not limited to this. The first friction member 43 may have various shapes as long as the first friction member 33 can be engaged with the second gear unit 32 and the first friction member 43 can be engaged with the housing 41.

In this regard, the shapes of the gap 354 between the upright portions 353 of the third gear portion 35 and the convex portion 34a of the second friction body 34 in embodiment 1, and the shapes of the fixing portion 422 of the shaft 42 and the opening 44a of the second friction body 44 in embodiment 2 are also the same.

(description of reference numerals)

1. 1a … driving device, 2 … device, 3 … hinge portion, 4 … device body, 5 … movable portion, 10 … motor, output rotation shaft of 10a … motor, 11 … gear, 12 … coupling, 13 … reducer, output shaft of 13a … reducer, 20 … first gear portion, 21 … large diameter gear, 22 … small diameter gear, 30, 40 … torque limiter, 31 … shaft, 32 … second gear portion, 33 … first friction body, 34 … second friction body, 33a … convex portion, 34a … convex portion, 35 … third gear portion, 36 … sliding pad, 37, 45 … spring, 38 … pad, 39 … nut, 41 … housing, 42 … shaft, 43 … first friction body, 44 … second friction body, 44a … opening, 46 … fixing member, … bearing, … screw portion, 36314 small diameter portion 36314, … screw portion, 321 … partition part, 321a and 321b … partition part 321 main surface, 322 … outer cylindrical part, 322a and 322b … outer cylindrical part inner surface, 323 … inner cylindrical part, 325 … notch part, 326 … through hole, 351 … third gear, 352 … disc part, 353 … upright part, 354 … gap, 355 … through hole, 410 and 414 … holes, 410a … casing 41 inner surface, 410b … bottom surface, 412 … first thread part, 413 … notch part, 421 … tip part, 422 … fixing part, 423 … cylindrical part, 424 … D character part, 421 460 … second thread part, 461 … through hole, SP1, SP2, SP3 … accommodating part.