阅读说明：本技术 线性致动器 (Linear actuator ) 是由 B·舍韦 M·K·克努森 H·斯科比 R·索伦森 于 2018-06-28 设计创作，主要内容包括：本发明涉及一种线性致动器,其包括支撑架(2),连接至所述支撑架的外管,电动机,传动装置,以及与所述传动装置连接的主轴。所述线性致动器包括所述主轴上的主轴螺母以及连接至所述主轴螺母的内管。所述主轴螺母和所述内管被引导于所述外管内部。为了安装所述线性致动器,后端配备有后安装件(5)并且所述内管的前端配备有前安装件。在这样的线性致动器中,所述后安装件应当以简单的方式安装至所述壳体。为此,所述支撑架(2)包括第一固定几何结构(18),其具有围绕所述轴线沿圆周方向分布的多个第一指状物(19),并且所述后安装件(5)包括作为所述第一固定几何结构的负形式的第二固定几何结构(20),其中所述第一固定几何结构和所述第二固定几何结构形成重叠区域。(The invention relates to a linear actuator comprising a support frame (2), an outer tube connected to the support frame, an electric motor, a transmission, and a spindle connected to the transmission. The linear actuator includes a spindle nut on the spindle and an inner tube connected to the spindle nut. The spindle nut and the inner tube are guided inside the outer tube. For mounting the linear actuator, the rear end is equipped with a rear mounting (5) and the front end of the inner tube is equipped with a front mounting. In such a linear actuator, the rear mounting should be mounted to the housing in a simple manner. To this end, the support frame (2) comprises a first fixing geometry (18) having a plurality of first fingers (19) distributed circumferentially around the axis, and the rear mounting (5) comprises a second fixing geometry (20) being a negative of the first fixing geometry, wherein the first and second fixing geometries form an overlapping region.)

1. A linear actuator (1) comprising: a support frame (2); an outer tube (3) connected to the support frame (2); an electric motor (7); a transmission (14); and a main shaft (13) connected to the transmission (14); a spindle nut (16) on the spindle (13); an inner tube (4) connected to the spindle nut (16), and the spindle nut (16) and the inner tube (4) are guided inside the outer tube (3); and a rear mounting (5) fixed to a rear end of the support frame (2), characterized in that the support frame (2) comprises a first fixing geometry (18) having a plurality of first fingers (19) distributed circumferentially around a longitudinal axis of the main shaft (13), and the rear mounting (5) comprises a second fixing geometry (20) being a negative form of the first fixing geometry (18), wherein the first fixing geometry (18) and the second fixing geometry (20) form an overlapping region.

2. Linear actuator according to claim 1, characterized in that a spring ring (28) is arranged in the overlap region.

3. Linear actuator according to claim 2, characterized in that the spring ring (28) is positioned in the overlap region between at least a first protrusion (19a) at the first fixing geometry (18) on a side (25) facing away from the rear mounting (5) and at least a second protrusion (21a) at the second fixing geometry (20) on a side (26) facing away from the support frame (2).

4. Linear actuator according to claim 3, characterized in that the first fixed geometry (18) comprises an inclined front surface (24) facing the rear mounting (5).

5. Linear actuator according to claim 3 or 4, characterized in that the spring ring (28) is axially fixed on the second fixed geometry (20).

6. Linear actuator according to claim 5, characterized in that the spring ring (28) is positioned on the second fixed geometry (20) between the second protrusion (21a) and a holding geometry (27).

7. Linear actuator according to any of claims 2 to 6, characterized in that the spring ring (28) comprises a gap along its circumference.

8. Linear actuator according to any of claims 2 to 7, characterized in that the rear mounting (5) comprises at least two parts (29, 30) held together by the spring ring (28).

9. Linear actuator according to any of claims 1 to 8, characterized in that the first fixed geometry (18) and the second fixed geometry (20) are mountable to each other in at least two different angular positions.

10. Linear actuator according to any of claims 1 to 9, characterized in that the first fingers (19) have the same width in the circumferential direction and the second fixed geometry comprises a corresponding number of second fingers (21) having the same width in the circumferential direction, the width of the second fingers (21) in the circumferential direction being equal to the width of the gaps (22) between the first fingers (19) in the circumferential direction.

Technical Field

The present invention relates to a linear actuator comprising a reversible electric motor and a transmission. The transmission includes a worm driven by the motor and engaged with a worm gear. The worm gear is rotatably fixed to a main shaft disposed in the outer tube. The spindle nut is threadedly engaged with the spindle and is fixed against rotation via engagement with the outer tube. The inner tube is connected to the spindle nut. As the spindle rotates, the inner tube moves along the longitudinal axis of the spindle, moving into or out of the outer tube. The direction of movement depends on the direction of rotation of the spindle. For mounting the linear actuator, the rear end is equipped with a rear mounting and the front end of the inner tube is equipped with a front mounting.

Background

The rear mount of the linear actuator is conventionally a separate component which is fixed to the linear actuator by screws, see WO2012/083951 a1 to link a/S, or held in place by a housing which encloses a part of the linear actuator, see for example WO2011/057631 a1 to link a/S. These types of rear mounts require a large number of assembly operations.

Disclosure of Invention

The invention is based on the object of providing a simple way of mounting a rear mounting to a linear actuator without a housing.

This object is solved by a linear actuator according to the preamble of claim 1, wherein the support frame comprises a first fixed geometry having a plurality of first fingers distributed circumferentially around an axis, and the rear mounting comprises a second fixed geometry being a negative version of the first fixed geometry, wherein the first fixed geometry and the second fixed geometry form an overlapping region.

Such a configuration simplifies the mounting of the rear mounting member to the support bracket. It will only be necessary to insert the second fixing geometry into the first fixing geometry to define the relative position between the rear mounting and the support bracket. Thereafter or simultaneously, a connection may be established between the rear mounting and the support frame.

In one embodiment of the invention, the spring ring is arranged in said overlapping area. The spring ring may be used to prevent lateral movement between the support bracket and the rear mount in a direction perpendicular to the longitudinal axis of the main shaft. Furthermore, the spring ring may be used as a fixing means.

In one embodiment of the invention, the spring ring is positioned in the overlap region between at least a first projection on the side facing away from the rear mounting at the first fixing geometry and at least a second projection on the side facing away from the housing at the second fixing geometry. In this way, the rear mounting member is fixed in the support frame against tensile force. When a pulling force is generated, the spring ring is clamped between the two protrusions and prevents any movement of the rear mounting in a direction away from the support frame.

In one embodiment of the invention, the first fixing geometry comprises an inclined front surface facing the rear mounting. In this case, the spring ring may be preassembled on the second fixed geometry and then the rear mount pushed onto the support bracket. The inclined front surface of the first fixing geometry then widens the spring ring so that it can pass the first projection and snap radially inwards behind it. In this way, not only a well-defined geometrical relationship between the support frame and the rear mounting can be established, but also the rear mounting can be fixed to the support frame at the same time.

In one embodiment of the invention, the spring ring is axially fixed to the second fixed geometry. The position of the spring ring relative to the longitudinal axis of the spindle cannot change during installation. The spring ring can thus be widened when the second geometry is pushed into the first geometry, so that no additional devices are required.

In one embodiment of the invention, the spring ring is positioned on the second fixed geometry between the second protrusion and the retaining geometry. The retaining geometry can be formed, for example, by a further projection which is arranged on the side of the second projection facing away from the support frame.

In one embodiment of the invention, the spring ring includes a gap along its circumference. The spring ring may be made of metal or plastic spring wire, for example. When there is a gap along the circumference, the inner diameter of the spring ring can be widened without deforming the material of the spring ring.

In one embodiment of the invention, the rear mount comprises at least two parts held together by the spring ring. In this case, the spring ring is a mounting aid for mounting the rear mounting before connecting the rear mounting to the support frame.

In one embodiment of the invention, the first and second fixed geometries may be mounted to each other in at least two different angular positions. The angular positions may for example be offset by 90 ° with respect to each other.

In one embodiment of the invention, the first fingers have the same width in the circumferential direction and the second fixed geometry comprises a corresponding number of second fingers having the same width in the circumferential direction, the width in the circumferential direction of the second fingers being equal to the width in the circumferential direction of the gaps between the first fingers. The first and second fingers are preferably evenly distributed in the circumferential direction. Furthermore, it is preferable that the width of the gap and the width of the finger are equal.

Drawings

Embodiments of the invention will now be described in more detail with reference to the accompanying drawings, in which:

figure 1 shows a perspective view of a linear actuator,

figure 2 shows a perspective view of a linear actuator with a longitudinal partial cross-section,

figure 3 shows a front view of the linear actuator,

FIG. 4 shows an exploded perspective view of the rear mounting member and the support bracket, an

Fig. 5 shows an exploded perspective view of the rear mount and support bracket from another angle.

Detailed Description

Fig. 1 shows a perspective view of a linear actuator 1, which linear actuator 1 comprises a support frame 2, an outer tube 3 and an inner tube 4 guided in the outer tube 3. For mounting the linear actuator, the rear end is equipped with a rear mounting 5 and the front end of the inner tube 4 is equipped with a front mounting 6. As can be seen from fig. 1 and 2, the linear actuator 1 comprises an electric motor 7, typically a reversible electric motor, which may be a DC or AC motor for low or mains voltage. The motor 7 is mounted to the bottom of the support frame 2 and the rear mount 5 is mounted to the rear end of the support frame 2.

The linear actuator 1 comprises a socket 8 for connecting the linear actuator 1 to a power supply or an electrical controller. The outer tube 3 comprises a rectangular cross-section, in particular a square cross-section, i.e. the outer tube 3 comprises four walls 9, 10, 11, 12.

The linear actuator 1 further comprises a main shaft 13, which main shaft 13 is driven by the electric motor 7 via a transmission 14 being a worm gear, wherein an extension of the shaft of the electric motor 7 is designed as a worm (not shown) which engages with a worm gear 15 mounted on the main shaft 13.

A spindle nut 16 with an internal thread engages with the external thread of the spindle 13. The spindle nut 16 is guided inside the outer tube 3 and is fixed against rotation.

The foremost part of the spindle nut 16 is adapted to receive the inner tube 4. More specifically, the rear portion of the inner tube 4 may be fastened to the spindle nut 16 via corresponding threads on both portions, or the spindle nut 16 may have a protruding rim or shoulder on which the inner tube 4 may be received. Activation of the motor 7 will rotate the spindle 13 via the transmission 14, whereby the spindle nut 16 and the inner tube 4 will travel in a certain direction along the longitudinal axis of the spindle 13, depending on the direction of rotation of the motor 7.

The front end of the outer tube 3 comprises a bushing 17 for guiding the inner tube 4. The bushing 17 may be designed with seals to prevent dust and moisture from entering between the bushing 17 and the outer tube 3 and the inner tube 4, respectively.

The rear mounting 5 is a separate component from the support frame 2, as can be seen in fig. 4 and 5. Fig. 4 and 5 show only the rear mounting 5 and the support frame 2, without showing the outer tube 3 and the motor 7.

The support frame 2 comprises at its rear end a first fixed geometry 18 having a plurality of first fingers 19 distributed in a circumferential direction along the longitudinal axis of the main shaft 13. The rear mounting 5 comprises a second fixing geometry 20, which is a negative of the first fixing geometry 18. In other words, the second fixed geometry 20 comprises a number of second fingers 21 corresponding to the number of first fingers 19. In the present case, there are four first fingers 19 and four second fingers 21.

In the first fixed geometry 18, there are gaps 22 between the first fingers 19. The width of the gap 22 in the circumferential direction corresponds to the width of the second finger 21 in the circumferential direction. In other words, the second finger 21 fits exactly into the gap 22 of the first fixed geometry 18. In a similar manner, the second fixed geometry 20 comprises a plurality of second gaps 23. The width of the second gap 23 in the circumferential direction corresponds to the width of the first finger 19 of the first fixed geometry 18.

The first fixed geometry 18 includes an inclined front surface 24. At the back side of the inclined front surface 24, the first finger 19 comprises a collar 25, which is substantially perpendicular to the longitudinal axis of the main shaft 13.

In a similar manner, the second finger 21 comprises a side 26 facing away from the support 2, which is substantially perpendicular to the longitudinal axis of the main shaft 13. A further holding geometry 27 is assigned to each second finger 21.

A spring ring 28 is held between the second finger 21 and the holding geometry 27. In other words, the spring ring 28 is axially fixed to the rear mounting 5. Thus, the second finger 21 and the retaining geometry 27 form a slit in which the spring ring 28 is fixed.

The rear mounting 5 comprises two parts 29, 30 which are held together by a spring ring 28 before mounting the rear mounting 5 to the support frame 2.

The preassembled rear mount 5 (i.e. the two parts 29, 30 held together by the spring ring 28) is inserted into the rear end of the support frame 2 so that the second finger 21 enters the first gap 22. During movement of the rear mounting 5 into the support frame 2, the spring ring 28 is in contact with the inclined surface 24. When the rear mounting 5 is pushed with sufficient force, the spring ring 28 widens or yields, i.e. increases its inner diameter, so that the spring ring 28 can pass the projection 19a of the first finger 19 and snap radially inwards after it has passed the first projection 19 a. The first fixing geometry 18 and the second fixing geometry 20 now form an overlap region between the first protrusion 19a of the first fixing geometry 18 and the second protrusion 21a of the second fixing geometry 20. The prestress of the spring ring 28 and the stiffness of the first finger 19 can also be designed such that the first finger 19 can deflect when the rear mounting 5 is pushed into the support frame 2.

As can be seen in fig. 1 and 2, the spring ring 28 is now positioned between the first projection 19a of the support frame 2 and the second projection 21a of the rear mounting 5. When the rear mounting 5 is subjected to a pulling force, i.e. a force trying to pull the rear mounting 5 out of the support frame 2, the spring ring 28 is clamped between the first protrusion 19a and the second protrusion 21a and prevents the rear mounting 5 from being pulled out of the support frame 2.

In one embodiment, the spring ring 28 is discontinuous along its circumference with gaps. In this way, the diameter of the spring ring 28 may be increased without stretching the material of the spring ring 28. The spring ring 28 may be made of metal or plastic spring wire.

In the present embodiment, the spring ring 28 is arranged outside the support frame 2. It is also possible to arrange the spring ring 28 inside the cage 2 so that it can yield to a smaller diameter.

All gaps 22 have an equal width in the circumferential direction. As does the width of the first finger 19. Thus, the rear mount 5 may be mounted to the support frame 2 in a first orientation as shown and in a second orientation in which the rear mount 5 is rotated 90 ° relative to the longitudinal axis of the main shaft 13.

The second protrusion 21a may be realized by the second finger 21 itself.

The rear mounting 5 comprises a cylindrical extension 31 adapted to a cylindrical accommodation 32 in the support frame 2. The extension 31 facilitates insertion of the rear mounting 5 into the support frame 2.