Overrunning clutch with bearing

Abstract

Overrunning clutch (100) with an inner race (10), an outer race (20) which coaxially surrounds the inner race (10) at a distance so that an annular gap (30) is formed between the races (10, 20), a set of clamping elements (60) received in the annular gap (30) and a cage for the clamping elements (60) received in the annular gap (30), wherein one of the races (10, 20) forms a clamping contour (22) for the clamping elements (60) which delimits the annular gap (30), wherein the overrunning clutch (100) has a sliding bearing (40) radially supported on this race (10, 20) for radially supporting the other of the races (10, 20), wherein the sliding bearing (40) is formed by the cage or the sliding bearing (40) comprises a plurality of separate sliding elements (52) arranged in the cage (62).

Description

[0001] The present invention relates to a one-way clutch with an inner race, an outer race which coaxially surrounds the inner race at a distance so that an annular gap is formed between the races, and with a set of clamping elements received in the annular gap, one of the races forming a clamping contour for the clamping elements which delimits the annular gap.

[0002] Overrunning clutches of this type are known in a wide variety of designs and are used, for example, to mechanically couple two alternatively usable drive sources, such as a bicycle crank and an electric motor, to the same output, thereby preventing feedback from the faster-running drive source on the slower-running or possibly switched-off drive source. The overrunning clutch can also function as a bearing sleeve, supporting a shaft connected to at least one of the driving and driven elements.

[0003] In an alternative design of one-way clutches, neither the inner race nor the outer race has a clamping contour. Instead, clamping elements are pivotably mounted in the annular gap so that, depending on the direction of the torque, they move into a clamping or a release position. However, one-way clutches of the type considered here have the advantage of being easier to manufacture and assemble. For example, the outer race can be formed by a deep-drawn sleeve, in which the clamping contour is simultaneously formed during the deep-drawing process.

[0004] In most applications, it is desirable for the two elements coupled by the overrunning clutch to also be radially supported against each other. Unlike sprag clutches with round inner and outer rings, where bearing rollers can be arranged in the same track as the sprags, as described in DE 10 2022 109 860 B3, rolling bearing rollers in a track with clamping contours is not possible.

[0005] From DE 10 2019 128 700 A1, a one-way clutch of the type mentioned at the outset is known, in which the race that forms the clamping contour has a cylindrical circumferential wall section axially adjoining the clamping contour, which, with a corresponding circumferential wall section of the other race, forms an annular space that axially extends the annular gap, wherein an axial bearing integrated into the one-way clutch is accommodated in this annular space.

[0006] The object of the invention is to provide a freewheel clutch with which a particularly compact radial bearing arrangement can be realized.

[0007] This object is achieved according to the invention by a one-way clutch with an inner race, an outer race which surrounds the inner race coaxially at a distance so that an annular gap is formed between the races, a set of clamping elements received in the annular gap and a cage for the clamping elements received in the annular gap, wherein one of the races forms a clamping contour for the clamping elements which delimits the annular gap, wherein the overrunning clutch has a plain bearing radially supported on this race for the radial mounting of the other of the races, wherein the plain bearing is formed by the cage or the plain bearing comprises several separate sliding elements arranged in the cage.

[0008] According to the invention, a plain bearing is structurally integrated into the one-way clutch, eliminating the need for an additional radial bearing separate from the one-way clutch. The plain bearing provides radial support and guidance for the two races in the area of ​​the cage, and thus directly within the one-way clutch. The bearings are supported by the cage or, if present, the sliding elements. In embodiments with sliding elements, these are arranged in the cage, in particular in the annular space spanned by the cage in the axial, circumferential, and radial directions. The plain bearing is then, in particular, made up of several parts.

[0009] The invention creates a one-way clutch that allows the components of the one-way clutch that form the races to be radially supported relative to each other exclusively via the plain bearing. The one-way clutch enables relative support of the races without axially offset bearings, thereby gaining more axial installation space. The axial installation space can be used for the clamping elements and the plain bearing sliding surfaces.

[0010] The one-way clutch is configured to couple / uncouple a rotational movement of an inner race and an outer race, which coaxially surrounds the inner race and is spaced apart by the annular gap. One of the races can be connectable to a drive element or a drive shaft. The other of the races can be connectable to an output element or an output shaft. The races can have the same axial width or different axial widths.

[0011] In many applications, a plain bearing is sufficient for the radial support of the races, especially since when the one-way clutch is locked (the clamping or locking case), the clamping elements clamped between the races themselves provide (additional) radial support. For example, in a one-way clutch on the drive of an e-bike, when the one-way clutch is in the freewheeling state (the freewheeling case), the radial load is essentially provided solely by the mounted gear.

[0012] Advantageous embodiments and further developments of the overrunning clutch according to the invention are specified below and in the subclaims.

[0013] In some embodiments, the clamping elements are clamp rollers. The clamp rollers may have a length greater than their diameter. The clamp rollers may also be referred to as needle rollers or cylindrical rollers.

[0014] The clamping contour can be configured to create a force-locking connection between the respective clamping elements and the clamping contour when the overrunning clutch is locked. In some embodiments, the outer race forms the clamping contour. In other embodiments, the inner race forms the clamping contour.

[0015] In some embodiments, the plain bearing is made of plastic or sintered metal. The plain bearing can be formed from an injection-molded or castable polymeric material. The plain bearing can be formed by sintering a metallic material.

[0016] The overrunning clutch comprises the cage for the clamping elements. The cage can be configured to accommodate the clamping elements. The cage can be ladder-shaped in the circumferential direction of the annular gap. In other words, the cage can be configured to accommodate a clamping element between two ladder-rung-like sections. In particular, the cage can comprise ladder-like sections located axially outside the clamping elements. These sections can form support sections on which the plain bearing is radially supported on the raceway that forms the clamping contour.

[0017] The cage can comprise individual spring elements. The cage can be configured to spring-load the clamping elements (in particular clamping rollers) via a respective spring element, in particular in the direction of a clamping position that the clamping element assumes on the clamping contour in the locked state. The spring elements can be arranged on respective ladder-rung-like sections of the cage. The cage can be configured to be spring-loaded via a (central) spring element or friction element. The cage can be configured to spring-load the clamping elements together, for example via the (central) spring element or friction element.

[0018] Preferably, the other of the races (i.e. the race that does not form the clamping contour) forms at least one raceway bearing sliding surface for the plain bearing. Preferably, the plain bearing forms at least one plain bearing sliding surface, which forms at least one mating sliding surface to the at least one raceway bearing sliding surface. One (or the) raceway bearing sliding surface is assigned to the respective plain bearing sliding surface. The respective raceway bearing sliding surface is in particular circular. It can in particular delimit the annular gap. The respective mating sliding surface to the raceway bearing sliding surface, formed by the respective plain bearing sliding surface, can in particular be in the shape of a circular segment or circular, in particular in the shape of a cylindrical segment or cylindrical. The respective plain bearing sliding surface is designed to slide on the assigned raceway bearing sliding surface in the freewheeling case.The respective plain bearing sliding surface can have the curvature of the associated race bearing sliding surface.

[0019] Various embodiments are presented below, which can differ particularly with regard to the arrangement of plain bearing sliding surfaces. In particular, plain bearing sliding surfaces can be provided in a track with the clamping elements. These plain bearing sliding surfaces can be formed by the cage or, if present, by the sliding elements. Furthermore, for example, plain bearing sliding surfaces can be provided axially outside the clamping elements. These can in particular be formed by the cage. A raceway bearing sliding surface can be assigned to the plain bearing sliding surfaces. In particular, a common, cylindrical raceway bearing sliding surface can be assigned to all plain bearing sliding surfaces. This simplifies production.However, separate raceway bearing sliding surfaces can also be assigned to plain bearing sliding surfaces provided axially outside the clamping elements, for example separate raceway bearing sliding surfaces on axially opposite sides of the clamping elements.

[0020] In embodiments, the plain bearing forms a plurality of plain bearing sliding surfaces which, in a track (i.e., consecutive in the circumferential direction), form mating sliding surfaces arranged with the clamping elements in the annular gap to the at least one raceway bearing sliding surface. The raceway that does not form the clamping contour is thus used as the raceway bearing sliding surface for the plain bearing. This enables radial mounting of the two raceways in the same track or in a track with the clamping elements. In particular, the full axial width of the track of the clamping elements is available for the plain bearing sliding surfaces. For example, the axial extent of the plain bearing sliding surfaces can correspond at least to the axial extent of the clamping elements.

[0021] In embodiments, the plain bearing sliding surfaces each extend in the shape of a circular segment over a circular segment of the raceway bearing sliding surface. The plain bearing sliding surfaces can in particular be designed in the shape of a cylindrical segment. In other words, the plain bearing sliding surfaces can extend along a respective section of the raceway bearing sliding surface, in particular a respective circumferential section of the corresponding raceway. The plain bearing sliding surfaces can each be arranged between two clamping elements. Two plain bearing sliding surfaces can each be arranged separated from one another by a plurality of clamping elements. The plain bearing sliding surfaces can be arranged with a radial bearing clearance relative to the raceway bearing sliding surface. The respective radial bearing clearance of the plain bearing sliding surfaces relative to the raceway bearing sliding surface can be uniform. The radial bearing clearances of the plain bearing sliding surfaces relative to the raceway bearing sliding surface can be identical.The plain bearing sliding surfaces can be arranged at a uniform distance from the raceway bearing sliding surface along the raceway bearing sliding surface, whereby the distance corresponds to a bearing clearance.

[0022] In embodiments, the plain bearing comprises a plurality of bearing sections, in each of which the plain bearing forms at least one of the plain bearing sliding surfaces on one side and is radially supported on the raceway that forms the clamping contour on a (radially) opposite side. The bearing sections can each be arranged between two clamping elements. In the bearing sections, the plain bearing can form at least one of the plain bearing sliding surfaces on one side.

[0023] Preferably, bearing sections, each with at least one plain bearing sliding surface, and clamping sections, each with at least one clamping element, follow one another in the track, wherein the clamping elements are arranged in the clamping sections, and wherein the number of clamping elements per clamping section differs from one another by at most 1 (one). In other words, the bearing sections can be evenly distributed. The plain bearing sliding surfaces can be distributed between the clamping elements. For example, a plain bearing sliding surface can be arranged in each space between two adjacent clamping elements.

[0024] In embodiments, the plain bearing comprises a plurality of separate sliding elements, each of which forms at least one of the plain bearing sliding surfaces on one side and is supported radially on a (radially) opposite side on the race that forms the clamping contour. The sliding elements can also be referred to as sliding shoes. They can be made, for example, from sintered metal, plastic, or another material with good sliding properties. The plurality of separate sliding elements can each be arranged between two clamping elements. The sliding elements can be distributed symmetrically in the plain bearing. The plain bearing can comprise at least three, for example three or four, symmetrically arranged, separate sliding elements, wherein the sliding elements can be arranged, for example, between two adjacent clamping elements. Between each two sliding elements, a plurality of clamping elements can be arranged, for example, at least three clamping elements.

[0025] In embodiments, the raceway forming the clamping contour forms pockets in which the sliding elements are received in a form-fitting manner. The sliding elements can be received in a form-fitting manner in the clamping contour. The pockets can be formed symmetrically distributed in the clamping contour. The pockets can have the same shape as respective sections of the clamping contour assigned to a clamping element. The pockets and the sections of the clamping contour assigned to the respective clamping elements can be formed at uniformly distributed circumferential positions of the respective raceway. In other words, in embodiments, the clamping contour has uniformly shaped clamping contour sections, wherein the clamping elements are arranged on a respective one of the clamping contour sections, and wherein the pockets are each formed by a respective one of the clamping contour sections that is free of a clamping element.

[0026] The raceway forming the clamping contour can be manufactured by tensile and compression forming a metal blank. In embodiments, the raceway forming the clamping contour is a deep-drawn part in which the clamping contour and the pockets are produced in a single deep-drawing process. However, the raceway forming the clamping contour can also be manufactured in other ways, e.g., by milling, broaching, or stacking. For example, the raceway can be formed by several laminations stacked on top of one another and held firmly together, and / or the clamping contour and, if applicable, the pockets can be formed by milling or broaching.

[0027] In some embodiments, the overrunning clutch comprises the sliding elements, and the sliding elements and the cage are separate components. This improves the spring function of the cage for spring-loading the clamping elements. The sliding elements can be distributed symmetrically in the plain bearing. The sliding elements can be arranged so that they can move relative to the cage. The cage can be guided with play on the raceway, which forms the clamping contour, and can be spring-loaded, for example.

[0028] In some embodiments, the cage forms the plain bearing. This enables a particularly simple design of the overrunning clutch with radial bearings. The cage can be in contact with both races. The cage can be configured to radially support one race against the other race. The cage can comprise the aforementioned support sections.

[0029] In embodiments, the other of the races (i.e. the race that does not form the clamping contour) forms at least one raceway bearing sliding surface for the plain bearing, wherein the plain bearing forms at least one plain bearing sliding surface that forms a mating sliding surface, arranged axially outside the clamping elements, to the at least one raceway bearing sliding surface. I.e., this plain bearing sliding surface can be located axially outside the track of the clamping elements. Preferably, the plain bearing forms plain bearing sliding surfaces that form mating sliding surfaces, arranged axially outside the clamping elements, to the at least one raceway bearing sliding surface. These plain bearing sliding surfaces can, for example, be separate plain bearing sliding surfaces on axially opposite sides of the clamping elements.

[0030] In embodiments, the plain bearing has support sections on which the plain bearing is radially supported in the axial direction outside the clamping elements on the raceway that forms the clamping contour. For example, the support sections can be located outside the clamping elements in the axial direction. I.e., the support sections can be located axially outside the track of the clamping elements. The support sections can radially support the raceway that forms the clamping contour against the other of the raceways. For example, the support sections can bear against the raceway other than the raceway that forms the clamping contour in such a way that sliding of the support sections on the raceway is possible. For example, the support sections can be received in the clamping contours with a form-fitting fit.The support sections can form the above-mentioned plain bearing sliding surfaces, which form counter sliding surfaces arranged in the axial direction outside the clamping elements to the at least one race bearing sliding surface.

[0031] The following examples are explained in more detail using the drawings. They show: Fig. 1a a partial sectional view of a clamping roller overrunning clutch with a plain bearing according to an embodiment, wherein the clamping elements are each individually spring-loaded; Fig. 1b is a partial sectional view of the clamp roller overrunning clutch showing a support portion of the plain bearing located axially outside the clamping elements; Fig. 2 a partial sectional view of a clamping roller overrunning clutch with a plain bearing formed by a cage according to an embodiment with central spring support of the clamping rollers by the cage; Fig. 3 is a partial sectional view of a clamping roller overrunning clutch with a cage and with a plain bearing according to an embodiment in which the plain bearing comprises several separate sliding elements in the form of sliding shoes; and Fig. 4 a partial sectional view of a clamping roller overrunning clutch with a plain bearing according to an embodiment in which the inner race forms the clamping contour.

[0032] In the figures, identical or corresponding elements are identified by the same reference numerals.

[0033] The Fig. 1a and Fig. 1b show partial sectional views of a one-way clutch 100 according to one embodiment. As in Fig. As shown in Figure 1a, the one-way clutch 100 comprises an inner race 10 and an outer race 20. The races have the same axial width. The outer race 20 surrounds the inner race 10 coaxially at a distance. The outer race 20 is surrounded by a housing 200. An annular gap 30 is formed between the races 10, 20. A plain bearing 40 is arranged in the annular gap 30. The plain bearing 40 is made of plastic. The plain bearing 40 is supported radially on the outer race 20. The plain bearing 40 is designed as a cage.

[0034] A set of clamping elements 60 is accommodated in the cage. The clamping elements 60 are clamping rollers. The outer race 20 forms a clamping contour 22 for the clamping elements 60, which defines the annular gap 30. The clamping contour 22 has uniformly shaped clamping contour sections 24. The clamping elements 60 are arranged on a respective one of the clamping contour sections 24. The clamping elements 60 are each spring-loaded against the clamping contour 22, in particular a respective clamping contour section 24, by individual springs 44 of the cage. When the inner race 10 rotates relative to the outer race 20 in the clamping direction, the clamping elements 60 prevent a relative rotational movement of the races 10, 20 through static friction and clamping of the clamping elements 60 against the clamping contour 22 of the outer race 20 and against the inner race 10.Upon rotation of the inner race 10 relative to the outer race 20 in the freewheeling direction, the clamping elements 60 are released and are arranged with play on the respective clamping contour sections 24. The clamping elements 60 then allow rotation of the races 10, 20 relative to one another.

[0035] The inner race 10 forms a circular race bearing sliding surface 12 for the plain bearing 40, which delimits the annular gap 30. The inner race 10 is radially supported by the plain bearing 40. The plain bearing 40 forms several plain bearing sliding surfaces 42. The plain bearing sliding surfaces 42 are arranged in a track with the clamping elements 60 in the annular gap 30. The plain bearing sliding surfaces 42 form counter sliding surfaces to the race bearing sliding surface 12. The plain bearing sliding surfaces 42 extend in the shape of a circular segment over a respective circular segment of the race bearing sliding surface 12. As in Fig. As shown in Figure 1b, the plain bearing 40 has support sections 46 located axially outside the clamping elements 60. The support sections 46 are each positively connected to the clamping contour 22. The plain bearing 40 is supported radially by the support sections 46 on the outer race 20, which forms the clamping contour 22. The support sections 46 form two additional, annular plain bearing sliding surfaces 47. The plain bearing sliding surfaces 47 of the support sections 46 extend circularly along the race bearing sliding surface 12 of the inner race 10.

[0036] Fig. 2 shows a partial sectional view of a one-way clutch 100 according to one embodiment. The plain bearing 40 is made of plastic and is designed as a cage. A set of clamping elements 60 is accommodated in the cage. The clamping elements 60 are clamping rollers. The plain bearing 40 comprises a plurality of bearing sections 50. On each of the bearing sections 50, the plain bearing 40 forms at least one of the plain bearing sliding surfaces 42 on one side. On a side of the bearing sections 50 radially opposite the respective plain bearing sliding surfaces 42, the plain bearing 40 is radially supported on the raceway 20, which forms the clamping contour 22. The bearing sections 50 each extend across the axial width of the raceways 10, 20. The bearing sections 50 are each arranged between two clamping elements 60.

[0037] Fig. 3 shows a partial sectional view of a one-way clutch 100 according to one embodiment. The one-way clutch 100 comprises a cage 62 and a plain bearing 40 made of several separate sliding elements 52, which can also be referred to as sliding shoes. The cage 62 is made of plastic, and the sliding elements 52 are made of sintered metal, plastic, or another material with good sliding properties. A set of clamping elements 60 is accommodated in the cage 62. The clamping elements 60 are clamping rollers. The sliding elements 52 each form at least one of the plain bearing sliding surfaces 42 on one side. The sliding elements 52 and the cage 62 are separate components, and the cage 62 is movable with play in the circumferential direction relative to the sliding elements 52. The inner race 10 is radially supported by the sliding elements 52 of the plain bearing 40. The inner race 10 forms a race bearing sliding surface 12 for the plain bearing 40, which delimits the annular gap 30.The plain bearing sliding surfaces 42 form counter-sliding surfaces to the raceway bearing sliding surface 12. The plain bearings 40 each slide on the raceway bearing sliding surface 12. The plain bearing sliding surfaces 42 are arranged in a track with the clamping elements 60 in the annular gap 30. The sliding elements 52 are supported radially on the outer raceway 20 on a side opposite the respective plain bearing sliding surfaces 42. The outer raceway 20 forms the clamping contour 22. The clamping contour 22 has uniformly shaped clamping contour sections 24. The clamping elements 60 are arranged on a respective one of the clamping contour sections 24. The clamping contour 22 forms pockets 26 in which the sliding elements 52 are received in a form-fitting manner. The pockets 26 are each formed instead of a clamping contour section 24 of the clamping contour 22. The sliding elements 52 are each arranged between two adjacent clamping elements 60.Four clamping elements 60 are arranged between two adjacent sliding elements 52.

[0038] In the above embodiments, the outer race 20 forms the clamping contour 22. Alternatively, the inner race 10 can form the clamping contour, and the outer race 20 can form a circular race bearing sliding surface 12 for the plain bearing 40, which delimits the annular gap 30. As in Fig. 4, the plain bearing 40 is then supported radially on the inner race 10. The plain bearing 40 then supports the outer race 20, for example, on support sections 46, which are located axially outside the clamping elements 60 (analogous to the illustration in Fig. 1b). Deviating from Fig. 4, the cage forming the plain bearing 40 can also form plain bearing sliding surfaces 42 arranged in the same track as the clamping elements 60, which form counter sliding surfaces to the raceway bearing sliding surface 12 (analogous to the illustration in Fig.1a). In embodiments with sliding shoes and pockets, the pockets are then formed accordingly on the inner race 10. 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 2022 109 860 B3

[0004] DE 10 2019 128 700 A1

[0005]

Claims

[1] Overrunning clutch (100) with an inner race (10), an outer race (20) which surrounds the inner race (10) coaxially at a distance so that an annular gap (30) is formed between the races (10, 20), a set of clamping elements (60) received in the annular gap (30) and a cage for the clamping elements (60) received in the annular gap (30), wherein one of the races (10, 20) forms a clamping contour (22) for the clamping elements (60) which delimits the annular gap (30), wherein the overrunning clutch (100) has a sliding bearing (40) radially supported on this race (10, 20) for radially supporting the other of the races (10, 20), wherein the sliding bearing (40) is formed by the cage or the sliding bearing (40) comprises a plurality of separate sliding elements (52) arranged in the cage (62). [2] One-way clutch (100) according to claim 1, wherein the clamping elements (60) are clamping rollers. [3] Overrunning clutch (100) according to claim 1 or 2, wherein the outer race (20) forms the clamping contour (22). [4] Overrunning clutch (100) according to claim 1 or 2, wherein the inner race (10) forms the clamping contour. [5] Overrunning clutch (100) according to one of the preceding claims, wherein the plain bearing (40) is made of plastic or sintered metal. [6] Overrunning clutch (100) according to one of the preceding claims, wherein the other of the races (10, 20) forms at least one race bearing sliding surface (12) for the plain bearing (40), wherein the plain bearing (40) forms a plurality of plain bearing sliding surfaces (42) which form counter sliding surfaces to the at least one race bearing sliding surface (12) arranged in a track with the clamping elements in the annular gap (30). [7] Overrunning clutch (100) according to claim 6, wherein the plain bearing sliding surfaces (42) each extend in the shape of a circular segment over a circular segment of the race bearing sliding surface (12). [8] Overrunning clutch (100) according to claim 6 or 7, wherein the plain bearing (40) comprises a plurality of bearing sections (50), in each of which the plain bearing (40) forms at least one of the plain bearing sliding surfaces (42) on one side and is radially supported on an opposite side on the race (10, 20) which forms the clamping contour (22). [9] Overrunning clutch (100) according to one of claims 6 to 8, wherein the plain bearing (40) comprises the plurality of separate sliding elements (52) and these each form at least one of the plain bearing sliding surfaces (42) on one side and are radially supported on an opposite side on the race (10, 20) which forms the clamping contour (22). [10] Overrunning clutch (100) according to claim 9, wherein the race (10, 20) forming the clamping contour (22) forms pockets (26) in which the sliding elements (52) are received in a form-fitting manner. [11] Overrunning clutch (100) according to claim 10, wherein the race (10, 20) forming the clamping contour (22) is a deep-drawn part in which the clamping contour (22) and the pockets (26) have been produced in a common deep-drawing process. [12] Overrunning clutch (100) according to claim 10 or 11, wherein the clamping contour (22) has uniformly shaped clamping contour sections (24), wherein the clamping elements (60) are arranged on a respective one of the clamping contour sections (24), and wherein the pockets (26) are each formed by a respective one of the clamping contour sections (24) free of a clamping element (60). [13] Overrunning clutch (100) according to one of claims 1 to 8, wherein the cage forms the plain bearing (40). [14] Overrunning clutch (100) according to one of the preceding claims, wherein the other of the races (10, 20) forms at least one race bearing sliding surface (12) for the plain bearing (40), wherein the plain bearing (40) forms at least one plain bearing sliding surface (47) which forms a counter sliding surface arranged in the axial direction outside the clamping elements (60) to the at least one race bearing sliding surface (12). [15] Overrunning clutch (100) according to one of the preceding claims, wherein the plain bearing (40) has support sections (46) on which the plain bearing (40) is radially supported in the axial direction outside the clamping elements (60) on that race (10, 20) which forms the clamping contour (22).

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