Rotary stop device

Abstract

A rotary stop device for a rotatably mounted shaft (12), comprising a stationary stop body (30) and a gear (14) which converts the rotary movement of the shaft (12) into a linear movement of a driven element (18) relative to the stop body (30), and comprising a stop element (24) which can be moved by the driven element into a stop position in which it bears against the stop body, characterized in that the stop element (32) is coupled to the shaft (12) in a rotationally fixed and axially displaceable manner by a linear guide.

Description

[0001] The invention relates to a rotary stop device for a rotatably mounted shaft, comprising a stationary stop body and a gear that converts the rotary movement of the shaft into a linear movement of a driven element relative to the stop body, and comprising a stop element that can be moved by the driven element into a stop position in which it rests against the stop body.

[0002] A rotary stop device of this type is known from DE 10 2020 126 785 U1, in which the stop element is a spring element that is held in a rotationally fixed manner on the shaft and is elastically deflected into the stop position by the driven element when the end of the movement of the driven element is reached. Because the stop blocks the rotary movement of the shaft in this way, the mechanical load to which the gear is exposed at the moment of impact against the stop body is limited.

[0003] The object of the invention is to create a rotary stop device that can withstand higher torques.

[0004] This object is achieved according to the invention in that the stop element is coupled to the shaft in a rotationally fixed and axially displaceable manner by a linear guide.

[0005] The linear guide stabilizes the stop element and reduces the bending moment acting on this stop element during the stop process.

[0006] Advantageous embodiments and further developments of the invention are specified in the subclaims.

[0007] In one embodiment, the gear is a spindle drive with a spindle that is non-rotatably mounted on the shaft and a nut that is in threaded engagement with the spindle as the driven element.

[0008] The stop body can be arranged on or in an end wall of a housing that accommodates the gear unit. The stop element can be arranged on the spindle so that it can be axially displaceable so that it can be moved towards the stop position by the driven element, the spindle nut. The stop element can have one or more projections that are guided in the linear guide and whose free ends abut against a respective stop body in the stop position. The linear guide can be formed by a guide disk that is keyed onto the shaft in a rotationally fixed manner and has openings in which the projections are precisely guided. In this case, the torque is transmitted to the stop element mainly or even exclusively (if the stop element itself is not held rotationally fixed on the spindle) via the guide disk.The axial distance between the guide disc and the stop bodies can be kept relatively small so that no high bending moment acts on the projections.

[0009] A spring element can be arranged between the stop element and the guide disc, elastically preloading the stop element toward the driven element so that the stop element is safely released from the stop position when the driven element moves away from the stop bodies. At the same time, the spring element can serve to limit the distance by which the stop element can move away from the guide disc.

[0010] Optionally, each stop body can be assigned a ramp surface that adjoins the stop body in the circumferential direction and rises at least to the level of the stop body. When the stop element rotates in the direction opposite to the stop direction, the free ends of the projections run onto the ramp surfaces and are thereby pushed away from the stop bodies at least far enough that they can move freely past the stop bodies. When the stop element is then rotated again in the opposite direction, the projections only strike the stop bodies again once the stop element has been moved back in the stop direction by the driven element. In this way, the function of the rotary stop device can be maintained even if the spring element breaks.

[0011] In the following, an embodiment example is explained in more detail using the drawing.

[0012] They show: Fig. 1 shows an axial section through a rotary stop device according to the invention in a first stop position; Fig. 2 a section along the line II-II in Fig. 1; Fig. 3 a development of a section along the line III-III in Fig. 2; and Fig. 4 an axial section through the rotary stop device in an opposite second stop position;

[0013] The Fig. The rotary stop device shown in Figure 1 comprises a pot-shaped housing 10, which is closed by a cover 11 and coaxially penetrated by a rotatably mounted shaft 12. The housing 10 accommodates a gear 14, which is formed by a spindle 16 fixedly keyed to the shaft 12 and a nut threadedly engaged with the spindle as the driven element 18.

[0014] The housing 10 has two guide rails 20 on the inner surface of its peripheral wall, which are encompassed by fork-shaped projections 22 projecting from the outer peripheral edge of the driven element 18. In this way, the driven element 18 is prevented from rotating relative to the housing 10 while allowing axial movement.

[0015] On both sides of the driven element 18, two mutually mirror-image stop elements 24 are arranged on the spindle 16, each having two diametrically opposed projections 26. The projections 26 of each stop element extend through openings in a guide disc 28, which is keyed onto the shaft 12 in a rotationally fixed manner. The projections 26 are guided in the openings of the guide disc 28 with the smallest possible play, thus forming a linear guide for movement of the stop elements 24 in the axial direction of the shaft 12. Two stop bodies 30 are arranged on the base of the housing 10 and on the cover 11, each forming stops for the free ends of the projections 26 in a direction of rotation of the shaft 12 and the stop elements 24.

[0016] In Fig. 1, the left of the two stop elements 24 is in its stop position, in which the projections 26 rest against the stop bodies 30. On the left side, only the upper stop body 30 can be seen, which is located behind the corresponding projection 26. The other stop body is located on the front side of the cutting plane in Fig. 1 and is therefore not visible.

[0017] On the right side in Fig. 1, the stop bodies 30 are arranged so that they limit the rotational movement of the unit consisting of shaft 12, spindle 16, stop elements 24 and guide discs 28 in the opposite direction.

[0018] A spring element 32 is attached to each of the two guide discs 28, which surrounds the shaft 12 with an annular base and has six radially projecting arms that preload the associated stop element 24 in the direction away from the guide disc 28. The arms of the spring elements 32 are arranged at an angle offset to the radial arms of the guide discs 28, which carry the projections 26. The stop element 24 on the right side in Fig. 1 is held by the spring element 32 in a position in which the projections 26 are retracted into the openings of the guide disc 28, so that they cannot strike the stop bodies 30. The arms of the spring element 32 are partially concealed here by the arms of the guide disc 28. Retaining pins 34 are attached to the stop element 24 such that, together with the base of the stop element, they form six insertion pockets into which the free ends of the arms of the spring element 32 engage. In this way, the stop element 24 is held by the spring element 32 in the axial position in which the spring element is relaxed.

[0019] On the inside of the cover 11 you can see Fig. 1 a ramp 38 running in the circumferential direction, which rises towards the stop body 30 and adjoins it in the circumferential direction.

[0020] Another spring element 32 and another ramp 38 are also mirror-inverted on the left side in Fig. 1 available. On the left side in Fig. 1, the stop element 24 is held in its stop position by the spring element 32. The spring element 32 rests against a bead 36 of the driven element 18 and is thereby held in a tensioned, flattened configuration.

[0021] Fig. Figure 2 shows the device in a section along the line II-II in Fig. 1. The cutting plane passes through the two projections 26 and through the immediately adjacent parts of the ramps 38. All other components located within the housing are covered by the guide disk 28 wedged onto the shaft 12 and are therefore in Fig. 2 is only indicated by dashed lines. One can particularly see the six arms of the spring element 32 as well as the outline of the driven element 18 with the fork-shaped projections 22 that engage the guide rails 20. Furthermore, the apex of the bead 36 is shown.

[0022] In Fig. 3 shows the course of one of the ramps 38 in a developed view.

[0023] Fig. 4 shows the device in the same sectional view as in Fig. 1, but in a state in which the driven element 18 has been moved by the spindle 16 to the opposite end of this spindle and now Fig. 4 holds the right spring element 32 and the associated right stop element 24 in the stop position for the corresponding opposite direction of rotation. The stop bodies 30 limit the rotation in the direction in which the lower projection 26 moves away from the viewer.

[0024] If the wave in the Fig. 4, the projections 26 of the right stop element 24 detach from the stop bodies 30 and run onto the ramps 38. As a result, the stop element is moved away from the guide disc 28, independent of the action of the spring element 32 there, so that the projections 26 retract into the openings of the guide disc. The pitch of the ramp 38 is dimensioned such that the axial movement of the stop element 24 is not faster than the axial movement of the driven element 18. The right spring element 32 returns to its relaxed position ( Fig. 1) and supports the movement of the stop element.

[0025] As the spindle continues to rotate, the left stop element 24 is brought back into its stop position by the bead 36 of the driven element 18 pressing centrally onto the arms of the spring element 32, which push the stop element 24 with their free ends to the left against the spring force until finally the Fig. 1 shown condition is reached.

[0026] The lever ratio on the spring element 32 is dimensioned such that the contact radius of the bead 36 of the driven element 18 and the contact radius on the stop element 24 are approximately 1:2, thus generating a significant increase in stroke on the stop element. (1 mm of axial bead movement generates 2 mm of axial stop element travel.)

[0027] The rotation stop device shown here can be used, for example, as a steering stop in a vehicle with steer-by-wire steering, or wherever a rotational movement that encompasses more than one revolution (360°) must be limited. In the case of the steering stop, the shaft 12 is the steering shaft, and the housing 10 is positively coupled in the direction of rotation to a steering system housing (not shown) of the vehicle. The rotation stop device then prevents the steering shaft from rotating endlessly in one and the same direction, which would lead to excessive stress on the electrical cables that connect switches located on the steering wheel to stationary vehicle components.

[0028] In a modified embodiment, not shown, an impact damper can be provided between the stop bodies 30 and the projections 26, for example in the form of a specially shaped spring body or a metallic cushion, which dampens the impact when the stop position is reached. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 126 785 U1

[0002]

Claims

[1] Rotary stop device for a rotatably mounted shaft (12), comprising a stationary stop body (30) and a gear unit (14) that converts the rotary motion of the shaft (12) into a linear motion of a driven element (18) relative to the stop body (30), and comprising a stop element (24) that can be moved by the driven element into a stop position in which it rests against the stop body, characterized by , that the stop element (32) is coupled to the shaft (12) by a linear guide in a rotationally fixed and axially displaceable manner. [2] Rotary stop device according to claim 1, wherein the transmission (14) is a spindle transmission with a spindle (16) fixed to rotation on the shaft (12) and a nut (18) engaged in thread with the spindle as the driven element. [3] Rotary stop device according to claim 2, in which the gearbox (14) is received in a housing (10) in which the driven element (18) is guided in a rotationally fixed but axially movable manner and on the end wall of which the stop body (30) is formed. [4] Rotary stop device according to one of the preceding claims, wherein the linear guide is formed by a guide disk (28) which is fixed to rotation on the shaft (12) and which guides an axial projection (26) of the stop element (24). [5] Rotary stop device according to claim 4, wherein the guide disk (28) has an opening through which the projection (26) penetrates. [6] Rotary stop device according to claim 4 or 5, wherein the stop element (32) has several axial projections (26) to which a stop body (30) is assigned. [7] Rotary stop device according to one of the preceding claims, comprising a spring element (32) that biases the stop element (24) into its stop position. [8] Rotary stop device according to one of the preceding claims, in which each stop body (30) has a ramp (38) rising towards the stop body in the circumferential direction, onto which a part of the stop element (24) runs when rotating against the direction of the stop. [9] Rotary stop device according to one of the preceding claims, in which at least two stop elements (24) and two stop bodies (30) are arranged such that a rotary stop is formed in each direction of rotation. [10] Rotary stop device according to one of the preceding claims, wherein the driven element (18) has an annular bead (36) which engages lever arms of the spring element (32) which in turn engage with their ends on the stop element (24) so ​​that the stroke of the stop element is increased according to the lever ratio. [11] Rotary stop device according to one of the preceding claims, in which a stop damper is integrated between the stop bodies (30) and the projections (26) which absorbs the high impact energy when the stop element with its projections (26) hits the stop bodies (30).

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