Clamping element freewheel with safety device

Abstract

Clamping element freewheel (24) with an inner ring (26), an outer ring (10), a number of clamping elements (28) which are received in an annular gap between the inner ring (26) and the outer ring (10), and with a locking device (14) for torque-resistant connection of the outer ring (10) with an adjoining component (16), characterized in that the locking device (14) is formed by a ring of projections (18) formed in one piece with the outer ring (10), which project axially from an end face of the outer ring and are distributed on the circumference of the outer ring.

Description

[0001] The invention relates to a sprag freewheel with an inner ring, an outer ring, a number of sprags which are accommodated in an annular gap between the inner ring and the outer ring, and with a securing device for the torque-resistant connection of the outer ring to an adjoining component.

[0002] Such sprag freewheels are generally used to selectively transmit torque from one component to another in only one direction. If a first component is connected to the outer ring of the freewheel and a second component is connected to the inner ring, the first component can rotate relative to the second component in one direction around the axis of the inner ring. If, however, a torque acts on the first component in the opposite direction, the freewheel locks, preventing rotation of that component.

[0003] Generally, the freewheel is a purchased part that is only connected to the first and second components during assembly. The locking effect of the freewheel only comes into effect if a sufficiently strong connection can be established between the first component and the outer ring of the freewheel.

[0004] Typically, the outer ring of the freewheel is in the form of a cylindrical sleeve that can be press-fitted into a corresponding bore in the first component. However, due to thermal expansion, the press-fit connection may no longer be able to withstand higher torque, meaning that rotation of the first component in the locking direction can no longer be reliably prevented.

[0005] WO 2020 / 120661 A1 describes a sprag freewheel of the type mentioned above, in which a locking device on the outer ring ensures that the connection between the outer ring and the adjoining component can withstand a higher torque. The locking device can be formed, for example, by the outer ring having a radially projecting flange at one end, on which wrench flats or other locking contours are formed that can be brought into engagement with complementary contours on the component. During the manufacture of the sprag freewheel, the radial flange must then be formed on the outer ring in a first step, and the outer edge of this flange must be machined in a second step.

[0006] The object of the invention is to create a sprag freewheel with a safety device that is easier to manufacture.

[0007] This object is achieved according to the invention in that the securing device is formed by a ring of projections formed in one piece with the outer ring, which project axially from an end face of the outer ring and are distributed over the circumference of the outer ring.

[0008] A precursor for the outer ring with the safety device can then be easily manufactured in a deep-drawing and punching process. The result is a cylindrical sleeve with a base at one end, from which an inner section is punched out, leaving projections that initially point radially inward from the edge of the sleeve. In a further forming step, these projections can then be bent in the axial direction. The number and dimensions of the projections can be adapted within a wide range to the limit torque that the safety device must withstand.

[0009] Advantageous embodiments of the invention are specified in the subclaims.

[0010] In one embodiment, the outer ring can have a radially inwardly facing collar in the spaces between the individual projections, which increases the deformation stiffness of the outer ring.

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

[0012] They show: Fig. 1 an outer ring of a sprag freewheel according to the invention in a side view; Fig. 2 the outer ring Fig. 1 in a front view from the direction of arrows II-II; Fig. 3 a section through the sprag freewheel together with a part of a lever-like component that is connected to the outer ring of the freewheel in a torque-resistant manner; and Fig. 4 a view of the lever-like component alone.

[0013] In Fig. 1 shows a side view of a substantially cylindrical outer ring 10 of a sprag freewheel. The outer ring has a radially outwardly projecting flange 12 at one end and a securing device 14 at the opposite end, which serves to provide a torque-resistant connection between the outer ring 10 and a Fig. 3 and Fig. 4. The securing device 14 is formed in this example by eight tab-like projections 18 that project in the axial direction of the outer ring 10 and are distributed at equal angular intervals on the circumference of the outer ring.

[0014] At the end that forms the securing device 14, the edge of the sleeve forming the outer ring 10 is slightly rounded. In the front view in Fig. 2 it can be seen that the peripheral wall of the sleeve merges over this rounding into a radially inwardly pointing collar 20, which, however, is interrupted by a gap 22 at the positions of the projections 18.

[0015] The outer ring 10 with the Fig. 1 and Fig. The shape shown in Figure 2 can be produced, for example, by a combined punching and deep-drawing process, in which a cylindrical pot is formed by deep-drawing, from whose base the inner part is then punched out, leaving only the individual segments of the collar 20 and the tabs that later form the projections 18, but initially also point radially inward. In a further forming step, the projections 18 are then bent into the axial orientation.

[0016] Fig. Figure 3 shows the lever-like component 16 and—in a sectional view—a complete sprag clutch 24, which comprises the outer ring 10, an inner ring 26, and sprags (clamping rollers) 28. The inner ring 26 has keyways 30 on its inner circumferential edge, with which it can be keyed onto a shaft (not shown).

[0017] In the example shown, the inner circumferential surface of the outer ring 10 forms a clamping contour 32 for the clamping bodies 28. This clamping contour can be efficiently produced in the deep-drawing process mentioned. The securing device 14 formed by the projections 18 is in Fig. 3 is not visible, but parts of the Bund 20 can be seen.

[0018] In Fig. 4 it can be seen that the component 16 has a ring of circular arc-shaped slots 34, the positions and outline shapes of which correspond to the positions and contours of the projections 18 in Fig.2. Component 16 can therefore be attached flat to outer ring 10 by welding or other means, so that projections 18 engage slots 34, thus creating a particularly torque-resistant connection between outer ring 10 and component 16. At the same time, slots 34 and locking device 14 allow simple and precise centering of the sprag clutch. Slots 34 can be produced by laser cutting or, for example, in the case of aluminum components 16, by stamping. 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] WO 2020 / 120661 A1

[0005]

Claims

[1] Sprag freewheel (24) with an inner ring (26), an outer ring (10), a number of sprags (28) which are accommodated in an annular gap between the inner ring (26) and the outer ring (10), and with a securing device (14) for the torque-resistant connection of the outer ring (10) to a component (16) adjoining it, characterized by that the securing device (14) is formed by a ring of projections (18) formed in one piece with the outer ring (10), which project axially from an end face of the outer ring and are distributed over the circumference of the outer ring. [2] Sprag freewheel (24) according to claim 1, wherein the outer ring (10) has, at the end at which the securing device (14) is located, a radially inwardly projecting collar (20) which is interrupted by gaps (22) in which the projections (18) are located. [3] Sprag freewheel (24) according to claim 1 or 2, wherein the outer ring (10) is a deep-drawn part, the projections (18) of which are bent after deep-drawing from an initially radially inwardly facing orientation into an axial orientation. [4] Sprag freewheel (24) according to claim 3, wherein a clamping contour (32) is formed on the inner surface of the outer ring (10).

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