Clamping roller freewheel for an adjustment device in a motor vehicle
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- ADIENT YANFENG SEATING MECHANISMS CO LTD
- Filing Date
- 2010-07-08
- Publication Date
- 2026-07-09
AI Technical Summary
Existing clamping roller freewheels face limitations in achieving high locking torque without increasing size or adding components, with half the rollers being passive in one direction, and there is a need for improved torque distribution during rotation.
Each roller is assigned two opposite V-shaped clamping bevels, allowing it to act in both clamping directions, with a cage transferring relative movement to ensure all rollers engage under high loads, and a driver and transmission device manage rotational play.
The solution enhances locking torque by engaging all rollers in both directions, maintaining size constraints, and reduces rotational play for efficient torque transfer.
Smart Images
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Abstract
Description
[0001] The invention relates to a clamping roller freewheel for an adjustment device in a motor vehicle, in particular in a motor vehicle seat, the clamping roller freewheel comprising a) a housing having a cylindrical inner surface that defines an axis, b) at least one pair of rollers having two rollers, the rollers being in contact with the inner surface, c) an output shaft that is centered on the axis, and d) a clamping element located on the side of the rollers opposite the inner surface and rotatably connected to the output shaft.
[0002] Such a clamping roller freewheel is known from DE 10 2009 028 213 A1. These clamping roller freewheels are preferably used for indexing devices, such as those known from EP 1 152 168 B1 and DE 195 40 631 C2.
[0003] For further information on the state of the art, reference is made to EP 497 007 B1; however, in this document, the clamping ramps are located on the housing and not on the clamping element. The clamping element has a cylindrical outer surface.
[0004] For these types of sprag clutches, a high locking torque is desired, ideally greater than 60 Nm, taking the Hertzian contact stress into account. The minimum breaking torque should exceed 200 Nm. The goal is also for the locking torque to initially exhibit a smaller slope across the rotation angle and then, above a certain angle, a steeper slope. Above a further rotation angle, the clamping force should be maintained as high and constant as possible before permanent deformation and damage occur.
[0005] The previously known sprag clutch has n rollers. Half of these are responsible for one direction of rotation, the other half for the other direction. The locking torque in one direction is therefore only generated by half (n / 2) of the rollers. The other half of the rollers are passive. To increase the locking torque, one could increase the number (n) of rollers in the sprag clutch. However, one would not want to increase the dimensions of the sprag clutch. The space inside the sprag clutch is limited.
[0006] This is where the invention comes in. Its aim is to improve and increase the locking torque of a clamping roller freewheel such as that of the type mentioned above, while maintaining the size of the clamping roller freewheel and, if possible, without further additional components or costly precautions.
[0007] This problem is solved by a clamping roller freewheel with the features of claim 1.
[0008] In this clamping roller freewheel, each individual roller has two clamping ramps. These ramps are opposite in direction and form a V-shape. Each roller can engage with either of its two clamping ramps, allowing it to clamp in both directions.
[0009] The clamping roller freewheel according to the invention has the advantage that, when it comes into the clamping state, it initially behaves like the clamping roller freewheel according to the prior art. If a rotational movement occurs at the pinion, first the rollers, namely 50% of the total number n of rollers, come into clamping or clamping position, which are in contact with that clamping slope of their two clamping slopes that blocks in the clamping direction. In the initial position, the two rollers of a roller pair bear against the clamping slope of their two that are furthest apart.
[0010] If the pinion is then rotated a further angle, the other rollers also come into a clamping position. In this process, the cage transmits the relative movement of the already clamped roller of the roller pair to the other roller of the roller pair. Under higher torques, particularly in a crash, both rollers of a roller pair are therefore clamped via the double clamping contour according to the invention. Since very high spreading forces now act on the housing, a limit is preferably set after a predetermined further rotation angle.
[0011] The clamping roller freewheel according to the invention therefore operates in two successive angular ranges. In the first angular range, it operates according to the prior art, absorbing the occurring moments without permanent deformation. Under higher loads, such as in a crash, upon reaching the second angular range, the rollers of the opposite direction of rotation are also engaged with the rollers already clamped, resulting in a higher locking torque. This is achieved by the double clamping contour. Each of the rollers is positioned prismatically between a left clamping slope and a right clamping slope. The rollers themselves are located in a cage and are preferably held in a preferred position by spacers, so that immediate clamping occurs in every direction of rotation. Complete backlash-free operation can be achieved if the spacers are elastic or at least partially elastic.
[0012] In a preferred embodiment, the clamping roller freewheel also has a release wheel that is centered on the axis and a drive element arranged between the release wheel and the cage. A torque for the drive can be applied externally via the release wheel and then tapped off at the pinion. The drive element ensures that a rotation of the release wheel ultimately also causes the cage to rotate, and vice versa. The drive element preferably has a clearance angle α, meaning that a rotation of the release wheel is only transmitted to the cage when the release wheel has rotated by the clearance angle, and vice versa.
[0013] In a further advantageous embodiment, the clamping roller freewheel also has a transmission device located between the release wheel and the pinion. This device ensures that the release wheel and pinion are rotatably connected. It preferably has a transmission clearance angle b, which ensures that a rotational movement at the release wheel is only transmitted to the pinion once the transmission clearance angle b has been exhausted, and vice versa.
[0014] Preferably, the drive mechanism and the transmission mechanism have coupling elements. For example, the cage has pins and the release wheel has windows. The pins engage in the windows. A clearance angle is formed between the pins and the windows in the circumferential direction. For the transmission mechanism, it is preferably such that the pinion is connected to a splined shaft profile that engages in a central opening of the release wheel. This opening has stop surfaces for the splined shaft profile, again taking the clearance angle into account.
[0015] Further advantages and features of the invention will become apparent from the remaining claims and the following description of a non-restrictive embodiment of the invention, which is now described with reference to the drawing. This drawing shows:
[0016] Fig. 1: A perspective assembly image of the clamping roller freewheel,
[0017] Fig. 2: A perspective view of the clamping roller freewheel when viewed from a rear oblique angle towards the release wheel,
[0018] Fig. 3: a sectional view with a radial section plane and greatly enlarged, showing a detail with a pair of rollers and the immediately surrounding components, and
[0019] Fig. 4: An axial view of the clamping roller freewheel with a top view of the release wheel.
[0020] The clamping roller freewheel has a pinion gear. 20 , which is based on an output wave 21 sits and around a pivot axis 22 It is rotatable. When the clamping roller freewheel is mounted, this pinion protrudes. 20 Freely on one side. The pinion 20 is over a collar area with a splined shaft profile 24connected. It has a stub at its other end to which fasteners can be attached to hold and close the clamping roller freewheel. The collar area forms a housing. 26 in contact and can rotate with a bearing area around the collar area.
[0021] The case 26 has a cylindrical inner surface 28 , which are centered on the axis 22 is the case 26 It is pot-shaped and faces away from the pinion. 20 open. Into the open space of the enclosure 26 A clamping element fits 30 It has a hole that matches the splined shaft profile. 24 is adapted so that the clamping element 30 rotationally fixed to the pinion 20 and thus the output wave 21 is connected. The clamping element 30 It has the shape of a perforated disc. On its radial outer surface, it has a number n of V-shaped arrangements. 32These each have a left and a right clamping bevel. The V-shaped arrangement 32 Each surface is symmetrical about a radial. The radial outer surface of the clamping element is also referred to as the inner surface. 28 opposite side.
[0022] The clamping roller freewheel has a total of n rollers. 34 , forming n / 2 pairs of rollers. Each V-shaped arrangement 32 is a role 34 assigned. In the normal or initial state, the roles are 34 a pair of rollers on the widely separated clamping ramps of their V-shaped arrangements 32 These clamping ramps will be referred to as outer clamping ramps in the following. The rollers 34 Therefore, in their initial state, they do not have contact with adjacent clamping slopes of the V-shaped arrangements. 32 of a pair of rollers. These clamping ramps will be referred to as inner clamping ramps in the following.
[0023] In a preferred embodiment, the two V-shaped arrangements 32 with one outer and one inner clamping bevel in the shape of a W.
[0024] The clamp roller freewheel still features a cage. 40 It has a disc-shaped base. Drive lugs spring from this base in an axial direction. 42 before. They intervene between pairs of roles. 34 Between two drive wheels 42 Each is a distance element 44 intended to be in the same direction as the drive lugs 42 protrudes from the disc. It is located between the two rollers. 34 of a pair of rollers. The drive lugs 42 form at least one support surface in the circumferential direction 43 out. At a planting area 43 Each roll is located 34 to.
[0025] On the other side of the disc-shaped base of the cage 40 jump cones46 before. The cage 40 It has a central hole with which it can rotate around the splined shaft profile.
[0026] Outside the cage 40 , seen from the pinion 20 , there is a release wheel 50 It has external teeth through which a torque is transmitted to the release wheel. 50 It can be introduced, for example, by means of a drive such as the one mentioned above. The release wheel 50 It is disc-shaped. It has a central opening which, together with the splined shaft profile, 24 This forms a transmission device. This transmission device has a transmission clearance angle, which will be discussed later. The release wheel has windows. 52 , into which the cones 46 intervene. Cones 46 and windows 52 Together they form a drive mechanism. This has a drive clearance angle a.
[0027] Fig. Figure 3 shows the initial state. In the initial state, each of the two rollers of the considered roller pair rests on the outer clamping slope of its V-shaped arrangement. 32 The distance from the inner clamping slope of the associated V-shaped arrangement. 32 X is the value. The two V-shaped arrangements 32 The roller pairs share a W-shaped profile. The outer clamping arms do not run straight outwards, but rather transition from an initial incline at the junction of the two clamping ramps of a V-shaped arrangement to a shallower incline, so that they form a smaller angle with the inner surface there. 28 , which is radially opposite. They extend further outwards into a stop flank that forms a projection. 56 This is located between two pairs of rollers. This stop flank is significantly steeper than the clamping flanks and limits the possible travel of the rollers.34 .
[0028] Alternatively, the spacer element can be omitted, the rollers 34 The two roles of a pair then have direct contact. But even in the case of direct contact between the two roles, a reduced element can be used instead of the distance element. 44 It is intended that it will be located in the triangle between the two roles. 34 of the pair and the inner surface 28 is located and the roles 34 Pre-loaded inwards. Preferably the contact surfaces 43 They are designed to preload or press the rollers radially inwards. It is desirable and advantageous for the rollers to be preloaded radially inwards.
[0029] The described drive device, which is located at the transition point of the release wheel 50 and cage 40 is present, and the transmission device, which replaces the transition release wheel 50 and pinion 20The rotational play required for clamping is enabled by this. Without rotational play, a drive torque would be lost from the pinion. 20 directly via the release wheel 50 on the cage 40 transferred and the roles 34 got out of clamping.
[0030] In contrast, when actuating the clamping roller freewheel, rotational play is rather undesirable, as it leads to losses in the output. Preferably, the release wheel is engaged after actuation. 40 The rotation is held in place by a small frictional torque, so that when actuated again in the same adjustment direction, the backlash is almost zero and losses are largely avoided. Only when the direction changes during actuation must the rotational play be completely bridged before any drive action can occur. The rotational play is characterized by the switching angle and is, for example, 4.5°.
[0031] Depending on the load condition and direction of actuation of the clamping roller freewheel, either the rollers 34 over the cage 40 or the pinion 20 first from the release wheel 50 taken along. Therefore, the rotational movements described above could have the same values from a design perspective. Preferably, however, the coordination is such that the rollers are engaged first. 34 be taken along. In the opposite case, a jam could occur, because the pinion 20 with the clamping element 30 is connected in a rotationally fixed manner. This is because the roller pairs are each in a preferred position, namely on the outer clamping ramp, and are actuated via the cage. 40 only the running up of the rollers 34 The spacer element prevents the outer clamping slopes from being avoided. 44 Normally the roles 34 away from the inner clamping slopes, see distance X. Simultaneously, this is done via the spacer element. 44also the advance of the second roller of the roller pair when the first roller is removed from the cage 40 will be postponed.
[0032] The spacer element 44 It can be elastic, rigid, or both elastic and rigid. Preferably, the spacer element 44 rigid at the point that forms the center of the two roles 34 the roller pair connects. This ensures the distance between the rollers of the roller pair. Otherwise, the spacer element cannot be used. 44 preferably be elastic, for example in the triangular area between the two rollers of the roller pair and the inner surface 28 .
[0033] The freewheel angle a and / or the transmission free angle b are in the range of 2° to 10°, especially around 5°.
[0034] A typical operating sequence is as follows: It engages the pinion gear. 20 a torque is applied and the pinion is engaged. 20 opposite the fixed housing 26When rotated, the roller that clamps in the direction of rotation is located after approximately 2° of pinion rotation. 34 The pair of rollers is clamped at approximately 1°. The second roller 34 of the respective pair of roles gets over the cage 40 also clamped. After a 2.5° pinion rotation, the release wheel is engaged. 50 from the pinion 20 taken along. After a further 2.5° turn, the release wheel runs. 50 against the cones 46 of the cage 40 After a 7° pinion rotation, the rollers that were originally jammed in the direction of rotation come against their respective projections. 56 .
[0035] The drawing in Fig. Figure 3 is to scale. The individual dimensions can be extracted from it and determined by the fact that the rollers 34 have a diameter of 5 mm. In this way, dimension X can also be determined.
[0036] The clamping roller freewheel for an adjustment device in a motor vehicle, in particular in a motor vehicle seat, features: – a case 26 , – a cylindrical surface that defines an axis and is either formed by a cylindrical inner surface 28 of the case 26 or is formed on a cylindrical surface of a bearing ring, – at least one role 34 , whereby the role 34 comes into contact with the cylindrical surface, – an exit wave 21 , which are centered on the axis 22 is, – a clamping contour that comes into contact with the roller 34 comes, which is located on the side of the roller opposite the cylindrical surface. 34 is located and with the output wave 21 is rotatably connected, the clamping contour being a double clamping contour which has a left clamping slope and a right clamping slope.
[0037] The clamping roller freewheel for an adjustment device in a motor vehicle, in particular in a motor vehicle seat, features: – a case 26 , which has a cylindrical inner surface 28 has an axis 22 defined – at least one pair of roles that includes two roles 34 exhibits, whereby the roles 34 coming into contact with the inner surface 28 condition, – an exit wave 21 , which are centered on the axis 22 is, – a clamping element 30 , which is located on the inner surface 28 opposite side of the rolls 34 is located and that with the output wave 21 is rotary-connected, – characterized by the fact that the clamping roller freewheel continues to have a cage 40 exhibits a circumferential effect for each role 34 at least one installation area each 43 exhibits, in which a role 34is attached, and that the clamping element 30 for each role 34 a V-shaped arrangement 32 with a left clamping slope and a right clamping slope.
[0038] The applicant reserves the right to combine features and sub-features of individual claims and / or individual sentences of the description in any way he or she may, even if such a combination is not immediately apparent from the context. QUOTES INCLUDED IN THE DESCRIPTION
[0039] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0040] DE 102009028213 A1
[0002] EP 1152168 B1
[0002] DE 19540631 C2
[0002] EP 497007 B1
[0003]
Claims
[1] Clamping roller freewheel for an adjustment device in a motor vehicle, in particular in a motor vehicle seat, the clamping roller freewheel has: – a case ( 26 ) or a bearing ring, which has a cylindrical outer surface ( 28 ) have an axis ( 22 ) defined, – at least one role ( 34 ), – an output wave ( 21 ), which are centered on the axis ( 22 ) is, – a clamping contour located on the cylindrical surface ( 28 ) opposite side of the roll ( 34 ) is located and via the housing or bearing ring with the output shaft ( 21 ) is connected via a rotary joint. – characterized by , that the clamping contour is a double clamping contour, wherein at least one roller ( 34) is assigned to the double clamping contour and the double clamping contour has a left and right clamping area, whereby the interaction of at least one roller ( 34 ) with the left or right clamping area, depending on the direction of rotation, and the cylindrical outer surface ( 28 A clamping effect occurs. [2] Clamping roller freewheel according to claim 1, characterized in that the double clamping contour is a V-shaped arrangement ( 32 ) and that preferably the gap between the straight or arc-shaped legs of the V-shaped arrangement and the cylindrical outer surface becomes smaller the further one leaves the valley of the V-shaped arrangement. [3] Clamping roller freewheel according to claim 1 or 2, characterized in that the clamping roller freewheel has at least one pair of rollers with two rollers ( 34 ) has, each with a role ( 34) of the roller pair is directly clamped in one direction of rotation, the other roller ( 34 ) is just not clamped when rotating in the same direction, which is either due to direct contact between both rollers ( 34 ) is caused to each other / or by a spacer element ( 44 ) is caused, which occurs between the roles ( 34 ) of the role pair. [4] Clamping roller freewheel according to one of the preceding claims, characterized in that the clamping roller freewheel further comprises a cage which extends circumferentially for each roller ( 34 ) at least one planting area ( 43 ) has a roller at the clamping point ( 34 ) is pending. [5] Clamping roller freewheel according to claim 3 or 4, characterized in that a spacer element ( 44 ) is intended to ensure that there is an exchange between the two roles ( 34 ) of the pair of rollers, and that the distance element ( 44) as a separate one, not with the cage ( 40 ) connected element or as connected to the cage ( 40 ) connected element is formed. [6] Clamping roller freewheel according to one of the preceding claims 3 to 5, characterized in that the spacer element ( 44 ) is either rigid or has elastic areas in addition to rigid ones. [7] Clamping roller freewheel according to one of the preceding claims, characterized in that the double clamping contour has a V-shaped arrangement ( 32 ) exhibits, and that preferably two adjacent V-shaped arrangements of a pair of rollers together form a W-shaped arrangement. [8] Clamping roller freewheel according to one of the preceding claims, characterized in that between two adjacent V-shaped arrangements ( 32 ) different role pairs an advantage ( 56 ) is located. [9] Clamping roller freewheel according to one of claims 2 to 8, characterized in that the drive device has a free drive angle, that the transmission device has a free transmission angle, and that the free transmission angle is not smaller than the free drive angle or vice versa.