WO2025197645A1 - Rotation transmission device - Google Patents

Abstract

A rolling bearing (3) is disposed between an inner ring (1) and an outer ring (2) of this rotation transmission device. A retainer (6) has a flange part (6a) extending in the radial direction from between a cam ring part (1b) and an inner raceway ring (3a). The cam ring part (1b) has a restriction surface (1e) that receives the flange part (6a) in the axial direction, and a retainer seat surface (1f) that receives the flange part (6a) in the radial direction. A ring-shaped spacer (18) is provided on a non-restriction surface (1e) side of the flange part (6a). The inner ring (1) has a spacer seat surface (1g) that receives the spacer (18) in the radial direction, and the cam ring part (1b) has a step surface (1h) that receives the spacer (18) in the axial direction. The spacer (18) is axially sandwiched between the step surface (1h) and the inner raceway ring (3a). Thus, the axial length of the inner ring (1) is shortened while avoiding interference from the retainer (6) and the outer ring (2).

Description

Rotation Transmission Device

This invention relates to a rotation transmission device that transmits and cuts off rotational torque.

Conventionally, there is a rotation transmission device in which a rolling bearing and multiple engaging elements are arranged between the inner and outer rings, and these engaging elements are held at multiple locations circumferentially by an annular cage.When an electromagnet is excited or de-excited, the cage is moved to an engaged position, transmitting rotational torque between the inner and outer rings via the engaging elements.When the electromagnet is excited or de-excited, the cage is moved to a released position, interrupting the transmission of rotational torque.

In the rotation transmission devices disclosed in Patent Documents 1 and 2, the inner ring has a bearing seat that fits into the inner raceway of the rolling bearing, and a cam ring portion that is larger in diameter than the bearing seat. Multiple engaging elements are arranged between the cam ring portion and the inner circumference of the outer ring. The inner ring is made of metal. The cam ring portion has a cam surface that contacts the engaging elements. To improve the surface hardness of this cam surface, the cam surface of the cam ring portion is subjected to heat treatment such as carburizing. Because forming pockets for accommodating the engaging elements at multiple locations around the circumference by machining would be costly, the cage is generally made of a single part formed by press working such as punching and drawing. The cage is positioned axially and radially relative to the inner ring.

In the case of the rotation transmission device of Patent Document 1, the cage has a flange with an L-shaped cross section between the cam ring portion and the inner raceway. The cam ring portion has a restriction surface that receives the cage flange in the axial direction, a cage seat surface that receives the flange in the radial direction, and a shoulder end surface that receives the inner raceway in the axial direction. The cage flange abuts against the inner raceway in the axial direction at a plate thickness surface located at the tip of the axial side portion of the L-shaped cross section. The cage is positioned radially by the cage seat surface, and is sandwiched axially between the cam ring portion's restriction surface and the inner raceway.

In the case of the rotation transmission device of Patent Document 2, the cage has a flange extending radially between the cam ring portion and the inner raceway ring. The cam ring portion has a restriction surface that axially receives the cage flange, a cage seat surface that radially receives the flange, and a shoulder end surface that axially receives the inner raceway ring. The inner ring has a retaining ring groove in an intermediate position between the cage seat surface and the shoulder end surface. The cage is positioned radially by the cage seat surface, and axially by the restriction surface of the cam ring portion and a retaining ring attached to the retaining ring groove.

Japanese Patent Application Laid-Open No. 2006-275247 Japanese Patent Application Laid-Open No. 2009-216213

When the flange of the cage is press-formed into an L-shaped cross section, as in the rotation transmission device of Patent Document 1, it is difficult to reduce the radius of curvature of the bend in order to prevent cracks in the bend extending from the radial edge to the axial edge. Furthermore, the inner diameter surface of the axial edge must have sufficient axial length to guide the cage, which results in a large axial length for the flange. As a result, the axial length between the restricting surface of the cam ring and the inner raceway ring (bearing seat surface) becomes large.

By using a flange that extends radially, as in the retainer of the rotation transmission device in Patent Document 2, it is possible to reduce the axial length of the flange.

However, when a retaining ring is placed on the side of the retainer flange opposite the restriction surface, as in the rotation transmission device of Patent Document 2, if the inner ring has an excessively thin portion, deformation and cracks will occur in the thin portion due to the heat treatment described above, so it is necessary to ensure sufficient thickness in the axial and radial directions near the retainer seat surface and the retaining ring groove. As a result, the axial length between the retaining ring groove and the shoulder end face cannot be reduced, and the axial length between the restriction surface of the cam ring portion and the inner raceway ring (bearing seat surface) ends up being large.

On the other hand, if the axial length between the restricting surface of the cam ring and the bearing seat surface is made too short, it will be impossible to ensure an axial gap between the retainer and the retaining ring that restricts the outer raceway of the rolling bearing, resulting in interference between the retainer on the inner ring side and the outer ring side.

In light of the above background, the problem that this invention aims to solve is to shorten the axial length of the inner ring while avoiding interference between the outer ring and the cage that holds multiple engaging elements between the cam ring portion of the inner ring and the outer ring.

In order to achieve the above object, the present invention provides a bearing comprising an inner ring, an outer ring surrounding the inner ring, a rolling bearing arranged between the inner ring and the outer ring, and a clutch mechanism for transmitting and blocking rotational torque, wherein the rolling bearing has an inner raceway, an outer raceway, and a plurality of rolling elements arranged between the inner and outer raceways, the inner ring has a bearing seat that fits into the inner raceway and a cam ring portion that is larger in diameter than the bearing seat, the clutch mechanism has a plurality of engaging elements arranged at predetermined intervals in the circumferential direction between the cam ring portion and the outer ring, and a retainer that holds these engaging elements, The rotation transmission device employs configuration 1, in which the retainer has a flange extending radially between the cam ring portion and the inner raceway, the cam ring portion having a cam surface that contacts the engaging element, a restriction surface that receives the flange in the axial direction, and a retainer seat surface that receives the flange radially, and further includes a spacer on the side opposite the restriction surface of the flange, the spacer being ring-shaped, the inner ring having a spacer seat surface that receives the spacer radially, the cam ring portion having a stepped surface that receives the spacer axially, and the spacer being sandwiched axially between the stepped surface and the inner raceway.

In the above configuration 1, the ring-shaped spacer is positioned radially by the spacer seat surface of the inner ring, and is positioned axially by the stepped surface of the cam ring portion and the inner raceway ring of the rolling bearing. Therefore, the cage is positioned axially by the restriction surface of the cam ring portion that axially receives the collar portion of the cage, and the spacer that is restricted by the inner raceway ring at a position adjacent to the non-restriction surface side of the collar portion. Because no groove such as a retaining ring groove is used to position the spacer, there is no groove shoulder sandwiched between the spacer and the inner raceway ring, thereby reducing the axial length of the inner ring. Furthermore, because the spacer adjacent to the collar portion of the cage is sandwiched between the stepped surface of the cam ring portion and the inner raceway ring, it is possible to ensure an appropriate axial distance between the outer raceway ring and the cage, and interference between the cage and the outer ring side is avoided.

In the above configuration 1, configuration 2 can be adopted, in which the spacer seat surface and the bearing seat surface are formed as the same plane that is continuous in the axial direction.

With configuration 2 above, there is no step between the spacer seat surface and the bearing seat surface, which avoids complicating the inner ring shape.

In the above configurations 1 and 2, configuration 3 can be adopted, in which a retaining ring is attached to the outer ring between the cage and the outer raceway ring, and the spacer and the retaining ring are located at the same axial position.

With configuration 3 above, the axial length of the spacer seat surface can be minimized to achieve the minimum spacer width necessary to prevent interference between the cage and the outer ring-side retaining ring.

In any one of the above configurations 1 to 3, configuration 4 can be adopted, in which the spacer is made of a single part that has been pressed or coiled.

In any one of the above configurations 1 to 4, configuration 5 can be adopted, in which the clutch mechanism has an electromagnet, an armature that is attracted in the axial direction by the electromagnet, and a recoil spring that urges the armature in the axial direction away from the electromagnet, and is configured to switch between transmitting and blocking the rotational torque in response to axial movement of the armature by the electromagnet or the recoil spring.

In any one of the above configurations 1 to 5, configuration 6 can be adopted, in which at least one of the inner and outer rings is connected to a rotating shaft provided in the drive system or steering device of a vehicle, ship, or construction machine.

As described above, by adopting the above-mentioned configuration 1, this invention makes it possible to shorten the axial length of the inner ring while avoiding interference between the outer ring and the cage that holds multiple engaging elements between the cam ring portion of the inner ring and the outer ring.

1 is a cross-sectional view showing a rotation transmission device according to an embodiment of the present invention when excited; 2 is a cross-sectional view showing a cross section taken along line II-II in FIG. Enlarged view of the collar of the cage in Figure 1 FIG. 1 is a perspective view showing an example of a spacer according to an embodiment; FIG. 10 is a perspective view showing another example of a spacer according to an embodiment.

A rotation transmission device according to an exemplary embodiment of the present invention will be described with reference to Figures 1 to 3 of the accompanying drawings.

This rotation transmission device, shown in Figures 1 and 2, comprises an inner ring 1, an outer ring 2 surrounding the inner ring 1, a rolling bearing 3 disposed between the inner ring 1 and the outer ring 2, and a clutch mechanism that transmits and blocks rotation between the inner ring 1 and the outer ring 2.

Here, the direction along the central axis of relative rotation of the inner ring 1 and outer ring 2 is referred to as the "axial direction," and the direction perpendicular to that central axis is referred to as the "radial direction." Furthermore, the circumferential direction centered on that central axis is referred to as the "circumferential direction." The axial direction corresponds to the left-right direction in Figure 1, so below, one axial direction will be referred to simply as the "left" in Figure 1, and the other axial direction opposite to the one axial direction will be referred to simply as the "right" in Figure 1.

The inner ring 1 is connected to a rotating shaft 100 of another machine. The outer ring 2 is connected to a rotating shaft 101 of another machine. The other machine is, for example, a drive system of a vehicle, ship, or construction machine, and the rotating shafts 100, 101 are shafts that transmit power.

The inner ring 1 and outer ring 2 are each made of a metal member formed into a hollow shaft. These metal members are made, for example, from forged steel, and their surfaces are hardened by heat treatment such as carburizing.

A joint portion that connects to the rotating shaft 100 is formed on the inner circumference of the inner ring 1. A joint portion that connects to the rotating shaft 101 is formed on the right end of the inner circumference of the outer ring 2. Each of these joint portions is a spline hole portion.

The rolling bearing 3 is a non-separable radial bearing having an inner raceway 3a, an outer raceway 3b, and multiple rolling elements 3c arranged between the inner and outer raceways 3a and 3b. Axial displacement of the inner and outer raceways 1 and 2 is prevented by the multiple rolling elements 3c engaging axially with the non-separable raceways 3a and 3b. In the illustrated example, the rolling bearing 3 is configured as a deep groove ball bearing.

The inner ring 1 has a bearing seat 1a that fits into the inner raceway ring 3a, a cam ring portion 1b that has a larger diameter than the bearing seat 1a, and a cylindrical portion 1c that has a smaller diameter than the cam ring portion 1b. In other words, the cam ring portion 1b is located radially outward from the bearing seat 1a, and the cylindrical portion 1c is located radially inward from the cam ring portion 1b. The bearing seat 1a is located to the right of the cam ring portion 1b, and the cylindrical portion 1c is located to the left of the cam ring portion 1b.

A retaining ring 4, which prevents the inner raceway ring 3a from coming loose relative to the inner ring 1, is attached adjacent to the right side of the bearing seat surface 1a.

The clutch mechanism is designed to be able to electromagnetically switch between an engaged state, in which rotational torque is transmitted between the inner ring 1 and the outer ring 2, and a disengaged state, in which transmission of rotational torque between the inner ring 1 and the outer ring 2 is interrupted.

The clutch mechanism comprises a cam surface 1d formed on the outer periphery of the cam ring portion 1b, a cylindrical surface 2a formed on the inner periphery of the outer ring 2, an engaging element 5 arranged between the cam surface 1d and the cylindrical surface 2a, a retainer 6 that holds the engaging element 5, a centering spring 7 that is prevented from rotating by the inner ring 1 and the retainer 6, an electromagnet 8, an armature 9 that is prevented from rotating relative to the retainer 6 and is arranged so as to be movable in the axial direction, and a separation spring 10 that urges the armature 9 to the right, away from the electromagnet 8.

The cylindrical surface 2a extends circumferentially. The cam surface 1d forms a wedge space with the cylindrical surface 2a. This wedge space gradually narrows from the circumferential center of the cam surface 1d toward both circumferential ends. That is, the radial distance between the cam surface 1d and the cylindrical surface 2a gradually decreases from the position of the engaging element 5 in Figure 2, which is located in the circumferential center of the cam surface 1d, toward one circumferential direction (counterclockwise in Figure 2), and also gradually decreases from the position of the engaging element 5 toward the other circumferential direction (clockwise in Figure 2). Multiple cam surfaces 1d are formed on the outer periphery of the inner ring 1, spaced apart circumferentially. That is, multiple wedge spaces are formed, and an engaging element 5 is disposed in each wedge space. Note that while an example in which the cam surface 1d is configured from a single plane has been shown, the cam surface may also be configured from multiple surfaces or a single curved surface.

As the retainer 6 rotates relative to the inner ring 1, the engaging element 5 engages with the cylindrical surface 2a and cam surface 1d, transmitting rotational torque between the inner ring 1 and outer ring 2. The engaging element 5 is formed in the shape of a cylindrical roller.

The cage 6 is an annular member with pockets formed at multiple locations around the circumference to accommodate the engaging elements 5. The cage 6 is formed by press working.

By contacting the retainer 6 in the circumferential direction, the engaging element 5 has its circumferential position relative to the cam surface 1d restricted and is forced to rotate together with the retainer 6.

The cage 6 can move coaxially with respect to the inner ring 1 in the circumferential direction between a predetermined engagement position and a release position. The engagement position is a position where the engaging element 5 is moved circumferentially from the circumferential center of the cam surface 1d to engage the cam surface 1d with the cylindrical surface 2a. The release position is a position where the engaging element 5 is moved toward the circumferential center of the cam surface 1d to release the engagement of the engaging element 5 with the cam surface 1d and the cylindrical surface 2a.

The cage 6 has a flange 6a located to the right of the multiple engaging elements 5. The flange 6a is made of a metal plate extending radially. The flange 6a contributes to improving the rigidity of the cage 6.

The centering spring 7 is made of an elastic member that elastically holds the retainer 6 in the released position. The centering spring 7 is elastically deformed by the relative rotation of the retainer 6 with respect to the inner ring 1, and its restoring elasticity causes the retainer 6 to return to its original rotation.

The centering spring 7 has extensions 7a extending radially outward from both circumferential ends of the arc-shaped spring portion. The centering spring 7 is passed through the outer periphery of the cylindrical portion 1c at its arc-shaped spring portion and is supported axially on the left end face of the cam ring portion 1b. The pair of extensions 7a pass through notches formed on the left side face of the cam ring portion 1b and are inserted into notches 6b formed in the left annular portion of the retainer 6. The pair of extensions 7a can press the notches in the cam ring portion 1b and the notches 6b in the retainer 6 in opposite circumferential directions. As a result, the centering spring 7 is capable of elastically holding the retainer 6 in the released position, while being prevented from rotating by the inner ring 1 so as to rotate integrally with the inner ring 1, and is also prevented from rotating by the retainer 6.

The clutch mechanism has a spring retainer member 11 adjacent to the left side of the centering spring 7. The spring retainer member 11 is a ring member that is passed around the outer periphery of the cylindrical portion 1c. A retaining ring is attached to the outer periphery of the cylindrical portion 1c to restrict leftward movement of the spring retainer member 11.

The armature 9 consists of an annular member that is fitted onto the outer periphery of the cylindrical portion 1c so as to be freely slidable in the axial direction. The armature 9 faces the electromagnet 8 in the axial direction.

The spring retaining member 11 is prevented from rotating by the retainer 6 and armature 9. The spring retaining member 11 is inserted axially into an engagement window 9a formed in the armature 9 and has an engagement protrusion 11a that fits into the notch 6b on the left side of the retainer 6. Circumferential engagement is possible between the engagement window 9a and the engagement protrusion 11a, and between the engagement protrusion 11a and the notch 6b throughout the entire axial reciprocating stroke of the armature 9, and this engagement allows the retainer 6, armature 9, and spring retaining member 11 to move circumferentially together. The armature 9 and retainer 6 may also be prevented from rotating by providing an engagement protrusion on the retainer 6 that is inserted into the engagement window 9a of the armature 9, rather than using a spring retaining ring.

The clutch mechanism has a rotor 12 that faces the electromagnet 8 and armature 9 in the axial direction, and a rotor guide 13 that connects the rotor 12 to the outer ring 2. The rotor 12 and rotor guide 13 can rotate integrally with the outer ring 2. A needle bearing 14 is fitted onto the inner periphery of the rotor 12 to support the rotating shaft 100.

The armature 9 is elastically held in a predetermined set position (the position shown in Figure 1) by the separation spring 10, and is magnetically attracted from that set position by energizing the electromagnet 8. The set position is set at a position where the armature 9 abuts the left end face of the retainer 6 in the axial direction. The set position of the armature 9 can also be set at a position where it abuts against a retaining ring attached to the outer periphery of the cylindrical portion 1c.

The separation spring 10 is a spring member that biases the armature 9 to the right. The separation spring 10 is disposed between a recess on the left side of the armature 9 and the annular right side of the rotor 12. The separation spring 10 stores energy when the armature 9 is moved to the left from the set position. The separation spring 10 is, for example, a wave washer-shaped or coil-shaped metal spring.

When current is applied to the solenoid coil, the electromagnet 8 switches from a de-energized state to an excited state. When it enters an excited state, a magnetic circuit is created that passes through the rotor 12 and armature 9 and magnetically attracts the armature 9 to the right side of the rotor 12. Note that if the relative rotational speed of the inner ring 1 and outer ring 2 is low, or if there is no concern about damaging the electromagnet 8 even if the armature 9 is attracted to the right end surface of the electromagnet 8, the rotor 12 and rotor guide 13 can be omitted.

The electromagnet 8 is fixed to the right side of the annular base plate 15. The base plate 15 is attached to a stationary part 102 attached to another machine. A retaining ring 16 is attached to the stationary part 102 to prevent the base plate 15 from coming loose.

When the electromagnet 8 is not excited, the armature 9 is supported at a set position away from the rotor 12 by the recoil spring 10, preventing circumferential force from being transmitted between the rotor 12 on the outer ring 2 side and the armature 9. Therefore, the retainer 6, which is prevented from rotating relative to the armature 9 and inner ring 1, is elastically held by the centering spring 7 in a released position where the engaging element 5 does not engage the cylindrical surface 2a of the outer ring 2 and the cam surface 1d of the inner ring 1. Therefore, regardless of whether the inner ring 1 or the outer ring 2 rotates counterclockwise or clockwise in Figure 2, the rotational torque is not transmitted between the inner ring 1 and the outer ring 2 via the engaging element 5, and the inner ring 1 and the outer ring 2 rotate relatively freely (freely). In other words, the clutch mechanism is in a disengaged state that blocks the transmission of rotational torque between the inner ring 1 and the outer ring 2. In this disengaged state, the rotation of the inner ring 1 is transmitted to the retainer 6 via the centering spring 7, allowing the retainer 6 and engaging element 5 to rotate together. Additionally, the armature 9 is prevented from rotating relative to the retainer 6, so the armature 9 can also rotate together.

When at least one of the inner ring 1 and the outer ring 2 rotates and these two rings 1, 2 rotate relative to each other, and the electromagnet 8 switches from a de-energized state to an energized state, the armature 9 is attracted to the rotor 12 against the separation spring 10. The frictional resistance acting on the attracting surfaces of the rotor 12 and armature 9 is applied as a circumferential force in a direction that moves the retainer 6 from the released position to the engaged position via the spring pressure member 11. This frictional resistance is pre-set to a value greater than the spring force of the centering spring 7. As a result, the centering spring 7 is pushed circumferentially by the retainer 6, causing it to elastically deform, and the retainer 6 to rotate relative to the inner ring 1. This causes the retainer 6 to rotate relative to the inner ring 1, and moves the engaging element 5 toward the narrow portion of the wedge space between the cylindrical surface 2a of the outer ring 2 and the cam surface 1d of the inner ring 1. As a result, the cage 6 moves to the engagement position, engaging the engaging element 5 with the cam surface 1d of the inner ring 1 and the cylindrical surface 2a of the outer ring 2. This switches the rotation transmission device to an engaged state in which rotational torque is transmitted between the inner ring 1 and outer ring 2.

In this engaged state, when the electromagnet 8 is switched to a de-energized state, the biasing force of the separation spring 10 separates the armature 9 from the rotor 12 and returns it to the set position. As a result, the spring force of the centering spring 7 causes the retainer 6 to rotate relative to the inner ring 1 in the opposite direction to when engaged. This causes the retainer 6 to move to the release position, releasing the engagement of the engaging element 5 with the cam surface 1d of the inner ring 1 and the cylindrical surface 2a of the outer ring 2. This returns the rotation transmission device to a disengaged state.

As mentioned above, to ensure proper engagement and release between the cylindrical surface 2a of the outer ring 2 and the cam surface 1d of the inner ring 1, it is important that the cage 6 is stable in position and that the inner ring 1 is coaxial with the cylindrical surface 2a. For this reason, the rolling bearing 3 is positioned close to the cam ring portion 1b, and the cage 6 is positioned axially and radially to prevent interference between the rolling bearing 3 and the cage 6.

As shown in Figures 1 and 3, the outer raceway 3b of the rolling bearing 3 is restricted from moving to the left by a retaining ring 17 attached to the inner periphery of the outer ring 2. The retaining ring 17 protrudes between the cage 6 and the outer raceway 3b, and is adjacent to the left side of the outer raceway 3b.

The inner diameter surface of the flange 6a of the retainer 6 is located between the cam ring portion 1b and the inner raceway ring 3a. The cam ring portion 1b has a restriction surface 1e that receives the flange 6a in the axial direction, and a retainer seat surface 1f that receives the flange 6a in the radial direction. The retainer 6 is guided radially by the retainer seat surface 1f on the inner diameter surface of the flange 6a. Movement of the retainer 6 to the left is restricted as the flange 6a catches on the restriction surface 1e.

Furthermore, a spacer 18 is arranged adjacent to the right side surface (opposite the restricting surface 1e) of the flange portion 6a. The spacer 18 is ring-shaped and extends circumferentially. The inner ring 1 has a spacer seating surface 1g that receives the spacer 18 radially, and a stepped surface 1h that receives the spacer 18 axially. The spacer 18 is positioned radially by fitting into the spacer seating surface 1g. The spacer 18 is sandwiched axially between the stepped surface 1h and the inner raceway ring 3a. Movement of the spacer 18 to the left is restricted by the stepped surface 1h. Movement of the inner raceway ring 3a to the left is restricted by the spacer 18 received on the stepped surface 1h. Movement of the spacer 18 to the right is restricted by the inner raceway ring 3a. Furthermore, even if the spacer 18 is pushed to the right by the flange 6a of the retainer 6, which determines the set position of the armature 9, and the inner raceway 3a is pushed to the right, the rightward movement of the inner raceway 3a is restricted by the retaining ring 4.

By sandwiching the spacer 18 between the stepped surface 1h and the inner raceway ring 3a, the inner ring wall portion that protrudes between the spacer seat surface 1g and the inner raceway ring 3a is eliminated, shortening the axial length of the inner ring 1, while allowing the axial position of the rolling bearing 3 to be set at a position that ensures an axial gap between the retaining ring 17 and the right side surface of the cage 6. In other words, if the spacer 18 were omitted and the inner raceway ring 3a were abutted against the stepped surface 1h, the retaining ring 17 would interfere with the cage 6. If the retaining ring 17 were omitted, there would be a concern that the outer ring 2 would shift to the right relative to the rolling bearing 3.

The spacer 18 and the retaining ring 17 are of the same width. The left side of the spacer 18 and the left side of the retaining ring 17 face each other radially. Therefore, the spacer 18 and the retaining ring 17 are located at the same axial position. In other words, it is only necessary to ensure a minimum axial distance between the step surface 1h and the inner raceway ring 3a, just enough to accommodate the retaining ring 17, thereby reducing the width of the spacer seat surface 1g.

The spacer seating surface 1g is formed as a cylindrical surface extending in the circumferential direction. The spacer seating surface 1g and the bearing seating surface 1a are formed as the same surface that is continuous in the axial direction.

Forming a protruding inner ring wall between the spacer seating surface and the inner raceway ring 3a is not desirable, as it would increase the axial length of the inner ring. It is possible to make the diameter of the spacer seating surface larger than the diameter of the bearing seating surface 1a. In this case, a step would be created between the spacer seating surface and the bearing seating surface 1a, making the inner ring shape more complex than that of the inner ring 1.

The ring shape of the spacer 18 needs only to extend circumferentially to a range that allows the spacer 18 to be positioned radially by fitting with the spacer seat surface 1g. As shown in Figure 4, it may be a circular annular plate that continues around the entire circumferential direction, or as shown in Figure 5, it may be an arcuate plate that extends circumferentially.

The spacer 18 shown in Figure 4 is made from a single pressed part. The spacer 18 shown in Figure 5 is made from a single coiled part. If the diameter of the spacer 18 is large enough to be formed by coiling, it can be made by coiling. If the diameter of the spacer 18 is small enough that it cannot be formed by coiling, it can be made by pressing. Using a spacer 18 made by coiling means that the spacer 18 can be manufactured more cheaply, as no mold costs are required.

As described above, the rotation transmission device shown in Figures 1 to 3 comprises an inner ring 1, an outer ring 2 surrounding the inner ring 1, a rolling bearing 3 arranged between the inner ring 1 and the outer ring 2, and a clutch mechanism that transmits and blocks rotational torque. The rolling bearing 3 has an inner raceway 3a, an outer raceway 3b, and a plurality of rolling elements 3c arranged between the inner and outer raceways 3a and 3b. The inner ring 1 has a bearing seat 1a that fits into the inner raceway 3a, and a bearing seat 1a that is provided with a larger diameter than the bearing seat 1a. The clutch mechanism has a plurality of engaging elements 5 arranged at predetermined intervals in the circumferential direction between the cam ring portion 1b and the outer ring 2, and a retainer 6 that holds these engaging elements 5. The retainer 6 has a flange 6a that extends radially between the cam ring portion 1b and the inner raceway ring 3a, and the cam ring portion 1b has a cam surface 1d that contacts the engaging elements 5, a restriction surface 1e that receives the flange 6a in the axial direction, and a retainer seat surface 1f that receives the flange 6a radially.

This rotation transmission device, in particular, further comprises a spacer 18 adjacent to the anti-restriction surface 1e side of the rib portion 6a, the spacer 18 being ring-shaped, the inner ring 1 having a spacer seat surface 1g that receives the spacer 18 radially, the cam ring portion 1b having a stepped surface 1h that receives the spacer 18 axially, and the spacer 18 being sandwiched axially between the stepped surface 1h and the inner raceway ring 3a, so that the ring-shaped spacer 18 is positioned radially by the spacer seat surface 1g and is positioned axially by the stepped surface 1h and the inner raceway ring 3a. Therefore, the cage 6 is positioned axially by the restriction surface 1e that receives the rib portion 6a axially, and the spacer 18 that is restricted by the inner raceway ring 3a at a position adjacent to the anti-restriction surface 1e side of the rib portion 6a. Because no groove such as a retaining ring groove is used to position the spacer 18, there is no groove shoulder sandwiched between the spacer 18 and the inner raceway 3a, thereby shortening the axial length of the inner ring 1. Furthermore, because the spacer 18 adjacent to the flange 6a is sandwiched between the stepped surface 1h and the inner raceway 3a, it is possible to ensure an appropriate axial distance between the outer raceway 3b and the cage 6, thereby avoiding interference between the cage 6 and the outer ring 2.

In this way, this rotation transmission device can shorten the axial length of the inner ring 1 while avoiding interference between the outer ring 2 and the cage 6, which holds multiple engaging elements 5 between the cam ring portion 1b of the inner ring 1 and the outer ring 2.

Furthermore, in this rotation transmission device, the spacer seating surface 1g and the bearing seating surface 1a are formed as the same plane that is continuous in the axial direction, so there is no step between the spacer seating surface 1g and the bearing seating surface 1a, and the shape of the inner ring 1 does not have to be complicated.

Furthermore, in this rotation transmission device, a retaining ring 17 adjacent to the outer raceway ring 3b is attached to the outer raceway ring 2 between the retainer 6 and the outer raceway ring 3b, and the spacer 18 and retaining ring 17 are located at the same axial position, which allows the width of the spacer 18 to be minimized so that the retainer 6 and the retaining ring 17 on the outer raceway ring 2 side do not interfere with each other, and the axial length of the spacer seat surface 1g can be minimized.

This rotation transmission device has been shown as being applied to a rotating shaft in the drive system of a vehicle, ship, construction machinery, etc., but it can also be modified to serve as a braking rotation transmission device that blocks the transmission of rotation from a rotating shaft, such as a steering lock for the steering device of such construction machinery. In this case, a rotating shaft such as a steering shaft is connected to one of the inner or outer rings, and the other is prevented from rotating relative to a stationary part of the other machine.

In addition, while this rotation transmission device has been shown as an example in which the cylindrical surface 2a is formed on the outer ring 2 and the cam surface 1d is formed on the inner ring 1, it is also possible to form the cylindrical surface on the inner ring and the cam surface on the inner periphery of the outer ring. It is also possible to use sprags as the engaging elements, and control the tilt position of the sprags by the relative rotation of the cage.

Furthermore, while this rotation transmission device has been exemplified as an excitation-activated type in which the clutch mechanism transitions to a state in which rotational torque can be transmitted when the electromagnet 8 is excited, it is also possible to change the clutch mechanism to a de-excitation-activated type in which the clutch mechanism transitions to a state in which rotational torque can be transmitted when the electromagnet is de-excited.

The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. Therefore, the scope of the present invention is indicated by the claims rather than the above description, and it is intended to include all modifications that are equivalent in meaning to and within the scope of the claims.

1 Inner ring 1a Bearing seat surface 1b Cam ring portion 1d Cam surface 1e Restricting surface 1f Cage seat surface 1g Spacer seat surface 1h Step surface 2 Outer ring 2a Cylindrical surface 3 Rolling bearing 3a Inner raceway ring 3b Outer raceway ring 3c Rolling element 5 Engagement element 6 Cage 6a Flange portion 7 Centering spring 8 Electromagnet 9 Armature 10 Separation spring 17 Retaining ring 18 Spacer 100, 101 Rotating shaft

Claims (6)

The bearing comprises an inner ring, an outer ring surrounding the inner ring, a rolling bearing disposed between the inner ring and the outer ring, and a clutch mechanism for transmitting and interrupting rotational torque,
The rolling bearing has an inner raceway, an outer raceway, and a plurality of rolling elements disposed between the inner and outer raceways,
The inner ring has a bearing seat that fits into the inner raceway ring, and a cam ring portion that is provided with a larger diameter than the bearing seat surface,
the clutch mechanism includes a plurality of engaging elements arranged at predetermined intervals in the circumferential direction between the cam ring portion and the outer ring, and a retainer that holds these engaging elements,
the retainer has a flange portion extending radially between the cam ring portion and the inner raceway ring,
In a rotation transmission device, the cam ring portion has a cam surface that contacts the engaging element, a restriction surface that receives the flange portion in the axial direction, and a retainer seat surface that receives the flange portion in the radial direction,
A spacer is further provided on the opposite side of the flange portion to the restriction surface,
The spacer is ring-shaped,
the inner ring has a spacer seat surface that receives the spacer in the radial direction,
the cam ring portion has a stepped surface that receives the spacer in the axial direction,
A rotation transmission device, characterized in that the spacer is sandwiched in the axial direction between the stepped surface and the inner raceway ring. The rotation transmission device described in claim 1, wherein the spacer seating surface and the bearing seating surface are formed as a single plane that is continuous in the axial direction. a retaining ring is attached to the outer ring between the cage and the outer raceway;
3. The rotation transmission device according to claim 1, wherein the spacer and the retaining ring are provided at the same axial position. A rotation transmission device according to any one of claims 1 to 3, wherein the spacer is made of a single part that is pressed or coiled. A rotation transmission device as described in any one of claims 1 to 4, wherein the clutch mechanism has an electromagnet, an armature that is attracted in the axial direction by the electromagnet, and a recoil spring that urges the armature in the axial direction away from the electromagnet, and is configured to switch between transmitting and cutting off the rotational torque in response to axial movement of the armature by the electromagnet or the recoil spring. A rotation transmission device according to any one of claims 1 to 5, wherein at least one of the inner and outer rings is connected to a rotating shaft provided in a drive system or steering device of a vehicle, ship, or construction machine.