Rotation stop device

Abstract

To provide a rotation stop device that can withstand higher torques.SOLUTION: A rotation stop device for a rotatably mounted shaft 12 comprises: a stopper body 30; a transmission 14 which converts a rotational movement of the shaft 12 into a linear movement of a driven element 18 relative to the stopper body 30; and a stopper element 24 which can be moved by the driven element 18 into a stop position to bear against the stopper body 30, where the stopper element 24 is coupled to the shaft 12 by means of a linear guide so as to be fixed rotationally and displaceable in the axial direction of the shaft.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a rotation stopping device for a rotatably mounted shaft, the rotation stopping device comprising a fixed stopper body, a transmission for converting the rotational movement of the shaft into linear movement of a driven element relative to the stopper body, and a stopper element movable by the driven element to a stopping position, the stopper element abutting the stopper body at the stopping position. [Background technology]

[0002] A rotation stopping device of this type is known from German Patent Publication DE 10 2020 126 785 U1 (Patent Document 1). This conventional rotation stopping device includes a stop element consisting of a spring element that is held non-rotatably on the shaft and is elastically deflected by the driven element to a stopping position when the driven element reaches the end of its range of movement. In this way, the stop element prevents the shaft from rotating, thereby limiting the mechanical load that the transmission will experience when it hits the stop body. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] German patent publication DE102020126785U1 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a rotation stopping device that can withstand higher torque. [Means for solving the problem]

[0005] According to the invention, this object is achieved by connecting the stop element to the shaft in a rotatable and axially displaceable manner via a linear guide, which stabilizes the stop element and reduces the bending moment acting on the stop element in the event of a collision.

[0006] Advantageous and further embodiments of the invention are described in the dependent claims. In one embodiment, the transmission is a spindle transmission with a spindle fixedly mounted on the shaft and a nut as the driven element, which is screwed onto the spindle.

[0007] In one embodiment of the present invention, the stop body can be arranged on or in an end wall of a housing that accommodates the transmission. Also, in one embodiment of the present invention, the stop element can be axially displaceable on the spindle so that it can be displaced toward the stop position by the driven element, i.e., the spindle nut. The stop element can be guided in a linear guide and have one or more protrusions whose free ends abut against the corresponding stop body in the stop position. The linear guide can be formed by a guide disk that is wedged non-rotatably onto the shaft and has openings in which the protrusions are precisely guided. In this case, torque is transmitted to the stop element primarily, or via the guide disk (if the stop element itself is not non-rotatably held on the spindle). The axial distance between the guide disk and the stop element can be relatively small to prevent large bending moments from acting on the protrusions.

[0008] A spring element can be arranged between the stop element and the guide disc, which elastically preloads the stop element in the direction of the driven element so that the stop element is safely released from its stopping position when the driven element moves away from the stop body, and at the same time can be used to limit the distance the stop element can move away from the guide disc.

[0009] As an option of the present invention, each stop element can be associated with a ramp adjacent to the stop element in the circumferential direction and rising to at least the height of the stop element. When the stop element rotates in the direction opposite to the stopping direction, the free end of the projection rides up on the ramp and is pushed out of the stop body, at least to the extent that it can pass freely through the stop body. When the stop element then rotates again in the opposite direction, the projection will not collide with the stop body again until the stop element is returned to the stopping direction by the driven element. In this way, the function of the rotation stop is maintained even if the spring element breaks. [Effects of the Invention]

[0010] According to the present invention, it is possible to provide a rotation stopping device that can withstand higher torque. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is an axial cross-sectional view of a rotation stopping device according to the present invention in a first stopping position. [Figure 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Figure 3] FIG. 3 is a development view of a cross section taken along line III-III in FIG. 2. [Figure 4] 3 is an axial cross-sectional view of the rotation stopping device according to the present invention at a second stop position opposite to the first stop position. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] The embodiments will be described in more detail below with reference to the drawings. The anti-rotation device shown in Fig. 1 has a pot-shaped housing 10, which is closed by a cover 11, and a rotatably mounted shaft 12 coaxially penetrating the housing 10. The housing 10 accommodates a transmission 14, which is composed of a spindle 16 firmly keyed to the shaft 12 and a nut (driven element 18) that threads onto the spindle 16.

[0013] Two guide strips 20, 20 are provided on the inner surface of the peripheral wall of the housing 10, and these guide strips 20, 20 are clamped by fork-shaped protrusions 22 protruding from the outer periphery of the driven element 18. This prevents the driven element 18 from rotating relative to the housing 10, but allows it to move axially.

[0014] Two stopper elements 24, 24 are arranged on the spindle 16 on either side of the driven element 18, in a mirror image relationship, and each stopper element 24 has two protrusions 26, 26 projecting in diametrically opposite directions. The protrusions 26 of each stopper element 24 engage with openings in a guide disk 28 that is keyed and fixed (non-rotatable) to the shaft 12. The protrusions 26 are guided with minimal play in the openings of the guide disk 28, thereby forming a linear guide for the movement of the stopper elements 24 in the axial direction of the shaft 12. Two stopper bodies 30, 30 are arranged on the bottom and cover 11 of the housing 10, respectively, and serve as stops for the free ends of the protrusions 26 in one rotational direction of the shaft 12 and the stopper elements 24.

[0015] In Fig. 1, of the two stopper elements 24, 24, the left stopper element 24 is in a stopped position, with the protrusion 26 in contact with the stopper body 30. Only the upper stopper body 30 located behind the corresponding protrusion 26 is visible on the left side of Fig. 1. The other stopper body 30 is not visible because it is located in front of the cross section of Fig. 1.

[0016] On the right side of FIG. 1, a stopper body 30 is arranged to limit the rotational movement of the unit consisting of shaft 12, spindle 16, stopper element 24 and guide disc 28 in the opposite direction.

[0017] Each of the two guide discs 28, 28 is provided with a spring element 32 whose annular base surrounds the shaft 12. As shown in FIG. 2, six radially protruding arms pretension the corresponding stop element 24 in a direction away from the guide disc 28. The arms of the spring element 32 are arranged at an angle offset from the radial arms of the guide disc 28, which carry the protrusions 26. The stop element 24 on the right side of FIG. 1 is provided with a spring element 32 whose annular base surrounds the shaft 12. The stop element 24 shown in FIG. 1 is held in a position where the protrusions 26 are retracted into the openings of the guide disc 28 by the spring element 32. Therefore, the protrusions 26 do not collide with the stopper body 30. In FIG. 1, the arms of the spring element 32 are partially covered by the arms of the guide disc 28. A retaining pin 34 is attached to the stop element 24, which, together with the base of the stop element 24, forms six insertion pockets into which the free ends of the arms of the spring element 32 engage. In this way, the stopper element 24 is held by the spring element 32 in its relaxed axial position.

[0018] As shown in FIG. 1, the cover 11 is provided on its inner side with inclined portions (inclined surfaces) 38 that extend in the circumferential direction, rise toward the stopper body 30, and are adjacent to each other in the circumferential direction.

[0019] 1, a further spring element 32 and ramp 38 are arranged in a mirror image relationship. On the left side of Fig. 1, the stop element 24 is held in a stopped position by a spring element 32. The spring element 32 is supported by a bead 36 on the driven element 18 and is held flat under tension.

[0020] FIG. 2 shows a cross-section of the device along line II-II in FIG. 1. The cross-section along line II-II in FIG. 1 passes through the two protrusions 26, 26 and the portion of the ramp 38 immediately adjacent to them. All other components within the housing 10 are shown only in dashed lines in FIG. 2, since they are covered by the guide disk 28 keyed to the shaft 12. In particular, the six arms of the spring element 32 and the contour shape of the driven element 18 with the fork-shaped protrusion 22 surrounding the guide strip 20 can be seen. The apex of the bead 36 is also shown. FIG. 3 shows the shape of one of the ramps 38 in an exploded view.

[0021] Figure 4 shows the device in the same cross section as Figure 1, but with driven element 18 moved by spindle 16 to the opposite end of spindle 16, holding spring element 32, on the right side of Figure 4, and connected stop element 24, on the right side, in a corresponding opposite rotational stop position. Stop body 30 limits rotation of lower projection 26 away from the viewer.

[0022] 4, when the shaft 12 is rotated in the direction opposite to the stopping direction, the protrusion 26 of the right-side stopper element 24 disengages from the stopper body 30 and rides onto the inclined portion 38. As a result, the stopper element 24 also disengages from the guide disc 28 independently of the action of the spring element 32, and the protrusion 26 is pulled into the opening of the guide disc 28. The inclination of the inclined portion 38 is dimensioned so that the axial movement of the stopper element 24 is not faster than the axial movement of the driven element 18. The right-side spring element 32 returns to its original released position, as shown in FIG. 1, and supports the movement of the stopper element 24.

[0023] As the spindle 16 continues to rotate, the left stop element 24 returns to its rest position as the bead 36 of the driven element 18 presses against the center of the arm of the spring element 32. The arm of the spring element 32 pushes the stop element 24 leftward against the spring force, eventually returning it to the state shown in FIG.

[0024] The leverage of the spring element 32 is dimensioned so that the contact radius of the bead 36 of the driven element 18 and the contact radius of the stopper element 24 are approximately 1:2, which significantly increases the stroke of the stopper element 24. For example, a 1 mm axial movement of the bead 36 results in a 2 mm axial movement of the stopper element 24.

[0025] The rotation stopping device of this embodiment can be used, for example, as a steering stopper in a vehicle equipped with steer-by-wire steering, or anywhere that requires limiting rotational movement beyond one rotation (360°). When applied as a steering stopper, the shaft 12 of the above-described embodiment is a steering shaft, and the housing 10 is securely connected in the rotational direction to a steering system housing of the vehicle (not shown). The rotation stopping device of this embodiment prevents the steering shaft from rotating infinitely in the same direction. The rotation stopping device of this embodiment also prevents excessive load from being applied to an electrical cable connecting a switch located on the steering wheel to a fixed component of the vehicle.

[0026] In a modified embodiment not shown, a shock absorbing member such as a specially shaped spring body or a metal cushion can be provided between the stopper body 30 and the protrusion 26, thereby absorbing the shock when the stop position is reached. [Explanation of symbols]

[0027] 10. Housing 11...Cover 12...Shaft 14...Transmission 16...Spindle 18...Driven element (nut) 20...Guide strip 22...Fork-shaped protrusion 24...Stopper element 26…Protrusion 28...Guide disc 30...Stopper body 32...Spring element 34...Retaining pin 36...Bead 38…Slanted part (slanted surface)

Claims

1. A device for stopping rotation of a rotatably mounted shaft (12), comprising: a fixed stopper body (30); a transmission (14) that converts rotational motion of the shaft (12) into linear motion of a driven element (18) relative to the stopper body (30); a stopper element (24) that is moved by the driven element (18) to a stop position where it abuts against the stopper body (30); The stopper element (24) is rotatably fixed to the shaft (12) by a linear guide and is connected to the shaft so as to be movable in the axial direction.

2. 2. The rotation stopping device according to claim 1, wherein the transmission (14) is a spindle transmission mechanism including a spindle (16) non-rotatably attached to the shaft (12) and a nut threaded onto the spindle as the driven element (18).

3. The transmission (14) is housed in a housing (10), Within the housing, the driven element (18) is guided in a rotationally fixed manner but axially movable along the shaft; 3. The rotation stopping device according to claim 2, wherein the stopper body (30) is formed on an end wall of the housing.

4. The rotation stopping device according to any one of claims 1 to 3, wherein the linear guide is formed by a guide disk (28) which is wedged non-rotatably onto the shaft (12) and which guides an axial protrusion (26) of the stopper element (24).

5. 5. The rotation stopping device according to claim 4, wherein the guide disc (28) has an opening in which the protrusion (26) engages.

6. 5. A rotation stopping device according to claim 4, wherein the stopper element (24) has a plurality of axial projections (26), each of which is assigned to a stopper body (30).

7. A rotation stopping device according to any one of claims 1 to 3, comprising a spring element (32) for biasing the stop element (24) into a stopping position.

8. A rotation stopping device according to any one of claims 1 to 3, wherein each of the stopper bodies (30) is provided with an inclined portion (38) that rises circumferentially toward the stopper body, and when rotating in the direction opposite to the stopping direction, a part of the stopper element (24) runs on the inclined portion.

9. A rotation stopping device according to any one of claims 1 to 3, wherein at least two of the stopper elements (24) and at least two of the stopper bodies (30) are arranged so that a rotation stop is formed in each rotation direction.

10. 8. The rotation stopping device of claim 7, wherein the driven element (18) has an annular bead (36) that engages with the lever arm of the spring element (32), and the end of the lever arm engages with the stopper element (24), thereby increasing the stroke of the stopper element according to a leverage ratio.

11. 5. The rotation stopping device according to claim 4, wherein an impact absorbing body is integrated between the stopper body (30) and the protrusion (26), and the impact absorbing body absorbs high impact energy when the protrusion (26) collides with the stopper body (30).

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