JP2001041230A - Thrust conical roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thrust conical roller bearing to be remarkably low in friction torque. SOLUTION: The raceway surface 4 of one annular bearing ring 2, positioned facing the other annular bearing ring 3, and the raceway surface 5 of the other annular bearing ring 3 are inclined in a taper-form manner to the respective sides opposite to each other. An intersection C1 between the extension line of inclination of one raceway surface 3 and the extension line of inclination of the other raceway surface 5 and a conical cone vertex C2 to form the peripheral surface of a conical roller 6 coincide with each other on the central axis S of a bearing 1 and with a point A in a position separated away from an orthogonal plane to the axial direction of a bearing passing through the center 0 of the spherical part 8 of the conical roller 6. Further, the curvature radius R1 of the spherical part 8 of the conical roller 6 is decreased to a value lower than the maximum radius R2 extending along the peripheral direction of the raceway surface 11 of a floating bearing ring 10 and the curvature radius R3 in a concave shape extending along the axial direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low friction torque thrust tapered roller bearing, and more particularly to a transmission roller and an input / output member of a half toroidal type traction drive continuously variable transmission, a machine tool, a resin injection molding machine, and the like. The present invention relates to a low-friction torque thrust tapered roller bearing suitable for supporting a member which rotates under a large axial load and requires low friction.

[0002]

2. Description of the Related Art In a half-toroidal traction drive continuously variable transmission, a power transmission unit is rotated as compared with other systems because a support bearing of a transmission roller rotates at a high speed while receiving a large axial load and a radial load. In order to further increase the transmission efficiency of this type of half-toroidal type continuously variable transmission having a high transmission efficiency, reduction of the friction loss of the supporting bearing is an important factor.

In this type of continuously variable transmission, the input and output disks rotate at high speeds in opposite directions while receiving a large axial load. Therefore, in order to avoid friction loss of bearings supporting these disks. There are many examples of dual cavity systems in which two sets of input and output disks are coaxially arranged back to back.

However, in the dual cavity method,
The two sets of input and output discs are arranged coaxially in the longitudinal direction, so that the transmission has a long shape in the axial direction. Although it can be applied to wheel drive vehicles, it is considered difficult to apply to front wheel drive vehicles in which the length of the transmission must be made as short as possible.

That is, in order to be applied to a front wheel drive vehicle, it is necessary to adopt a single cavity system using only one set of input and output disks, and for this purpose, the friction of a bearing supporting the input and output disks is required. Reduction of loss is an essential condition.

As described above, in the half-toroidal type continuously variable transmission, the friction loss of the transmission rollers and the bearings supporting the input / output members affects the transmission efficiency of the transmission, and the success or failure of the continuously variable transmission. Therefore, there is a strong demand for a reduction in the friction torque of the support bearing.

[0007] Thrust ball bearings and angular ball bearings are used as bearings that rotate at high speed while receiving a large axial load and that require low friction. However, in this type of bearing, the spin friction at the contact point between the ball and the raceway surface is large, and the friction torque is much larger than when a normal radial bearing rotates under a radial load.

In order to improve the drawbacks of such thrust ball bearings and angular ball bearings, a floating raceway having a raceway surface having a concave arc-shaped cross section is provided on the outer peripheral side of the ball, and the ball is placed in a normal position. A low friction torque thrust biased toward the bearing center axis so that the ball makes a pure rolling motion on the raceway except for the spin at the point of contact between the ball and the raceways of the two annular races Ball bearing (US Patent 1,42
No. 3,666).

In this bearing, the spin at the contact point between the ball and the raceway surfaces of the two annular races is substantially eliminated, and the point of contact between the raceway surface of the floating raceway and the ball forms a small ellipse. In some cases, the movement during this time is a pivoting movement, so that the friction losses are significantly lower, which results in a reduction in the friction torque of the bearing. Then, the contact angle between the ball and the two raceways is made different, the center of the contact point is set to a position different from the center of the rotation axis of the ball, and between the raceway surface of the floating race and the ball, an annular race is formed. By adding a rolling motion at a speed much slower than the rolling speed between the raceway surface and the ball, poor lubrication at the contact point due to the pivoting motion is prevented, and galling and seizure on the contact surface are prevented.

[0010] For applications that simply rotate by receiving a large axial load, tapered roller bearings can be used. However, this bearing has a large friction torque and is not suitable for high-speed rotation applications.

[0011]

In the above-mentioned conventional low-friction torque thrust ball bearing, the spin at the contact point between the ball and the raceway surface of the two annular races can be substantially eliminated, and the floating race is realized. A small amount of rolling motion is performed at the contact point between the raceway surface and the ball, so that lubricant is supplied to this contact point, and the load at this contact point is the load between the raceway surface of the annular race and the ball. And the rolling speed is low, the friction loss at this contact point is smaller than the friction loss of the entire bearing, and the friction torque of the bearing is about 2/3 to 1/2 of that of a normal thrust ball bearing. And galling and seizure at the contact point between the raceway surface of the floating race and the ball are substantially prevented.

However, there is still a large factor of friction in this low friction torque thrust ball bearing. Except for factors such as agitation of lubricant, the causes of friction in this bearing are due to spin and gentle rolling at the contact point between the raceway surface of the floating race and the ball, and the contact point between the raceway surface and the ball. , And by differential slip when a ball rolls on the raceway surface of an annular race.

Of these, the former two are not large, but in a ball bearing, the contact ellipse at the point of contact between the raceway surface and the ball is curved in a direction perpendicular to the rolling direction of the ball, and with increasing load. As the diameter of the contact ellipse increases, the friction due to differential sliding increases as well as the friction due to spin in a normal thrust ball bearing.

Therefore, when a conventional low-friction torque thrust bearing is used under a large load, the friction caused by the differential sliding becomes a major obstacle to the reduction of the friction torque. The torque will be further reduced.

The differential slip is a slip which cannot be avoided in a ball bearing caused by a raceway surface of an annular race and a rolling surface of a rolling element being a curved surface curved in a direction perpendicular to the rolling direction. Therefore, instead of a ball bearing, a roller bearing with a straight raceway surface and rolling surface is used.If conventional friction reduction technology can be applied to this roller bearing, there is no friction due to spin nor friction loss due to differential sliding. It is possible to obtain a thrust bearing with even lower friction torque than before.

A tapered roller bearing that performs a complete rolling motion without friction loss due to spin and friction loss due to differential sliding on the raceway surface is an ideal bearing in this sense. Further, since the contact on the raceway surface is a line contact, the load capacity is higher than that of a ball bearing. However, the tapered roller bearing has a disadvantage that sliding friction loss occurs between the spherical portion of the large-diameter end surface of the tapered roller and the flange surface of the inner ring (annular raceway ring). That is, if the friction loss of the flange surface can be eliminated from the tapered roller bearing, a long-life thrust bearing with low friction torque can be realized.

The present invention has been made under such a background, and an object of the present invention is to provide a thrust tapered roller bearing having extremely small friction torque.

[0018]

According to a first aspect of the present invention, there is provided a pair of annular races which are arranged opposite to each other and have annular raceways on their opposing surfaces, and a raceway of these annular races. A plurality of tapered rollers interposed rotatably between them, a floating raceway ring surrounding the outer circumference of these tapered rollers, and a retainer holding each tapered roller, each tapered roller having a peripheral surface A rolling surface that is in contact with the raceway surface of each annular race, the large diameter side end surface is a spherical surface portion that is convex outward, and the inner peripheral surface of the floating raceway ring is a raceway surface that is in contact with the spherical surface of the tapered rollers. The shape of the raceway surface along the axial direction is a concave shape that is concave in an arc shape, and the raceway surface of one annular raceway and the raceway surface of the other annular raceway facing each other are on opposite sides. It is inclined in a tapered shape, and the extension of the inclination of one raceway surface and the extension of the inclination of the other raceway surface The point C1 and the conical vertex C2 of the conical shape forming the peripheral surface of the tapered roller are separated from a plane perpendicular to the axial direction of the bearing on the central axis of the bearing and passing through the center of the spherical portion of the tapered roller. At one position, the radius of curvature R1 of the spherical portion of the tapered roller is smaller than the maximum radius R2 along the circumferential direction of the raceway surface of the floating bearing ring and the radius of curvature R3 of the concave shape along the axial direction. It is characterized by.

The intersection C1 of the extension of the inclination of the raceway surface of one annular race and the extension of the inclination of the raceway surface of the other annular race, and the conical vertex C2 of the cone forming the peripheral surface of the tapered roller And on the center axis of the bearing,
There is no spin associated with the rolling of the tapered rollers, and there is no differential slip because the raceway surface of the annular race and the rolling surface of the tapered rollers are in linear line contact.

With respect to the friction between the raceway surface of the floating race and the spherical portion of the tapered rollers, the intersection C1 and the conical vertex C2
Coincides with one point on the central axis of the bearing and at a position away from a plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered roller, so that the raceway surfaces of the pair of annular races Are different from each other, so that the spherical portion of the large end surface of the tapered roller contacts the raceway surface of the floating race ring at a position deviated from the center thereof. It is almost the same as a low friction torque thrust ball bearing.

Therefore, the friction in this bearing is
There is no friction loss due to differential sliding that occurs in the conventional low friction torque thrust ball bearing, and the thrust bearing has low friction torque.

In the bearing according to the first aspect of the present invention, the sliding friction between the inner surface of the flange and the tapered roller in the conventional tapered roller bearing is reduced by the spherical portion of the tapered roller similarly to the conventional low friction torque thrust ball bearing. It can also be said that it is replaced by a pivot motion between the raceway surface of the floating raceway.

In order to obtain low friction in the bearing of the first aspect of the present invention, the intersection C1 and the conical apex C2 are located on the central axis of the bearing.
In addition, it is premised that the attitude of the tapered rollers is maintained so as to coincide at one point at a position away from a plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered rollers. In a normal tapered roller bearing, the posture of the tapered roller is guided and maintained properly by the line or surface contact between the flange formed on the annular race and the large-diameter end surface of the tapered roller.

However, in the bearing according to the present invention, the annular race has no flange, and the spherical portion of the large-diameter end surface of the tapered roller and the race surface of the floating race are in contact at a small elliptical contact point. There is no action to guide the attitude of the tapered rollers. The attitude of the tapered rollers is guided only by the cage, and is maintained in an appropriate attitude.

In the bearing according to the first aspect of the present invention, the radius of curvature R1 of the spherical portion of the tapered roller is determined by the maximum radius R2 along the circumferential direction of the raceway surface of the floating raceway ring and the radius of curvature R3 of a concave shape along the axial direction. It is getting smaller. Therefore, a component force acts to push the tapered roller out of the bearing due to the axial load of the bearing, and this component force causes the spherical portion of the large-diameter end face of the tapered roller to reach the maximum of the raceway surface of the floating race ring. Spreading to the position of the maximum pitch radius at the point of diameter, the position of the floating race is maintained by the position of the tapered rollers.

In a conventional low friction torque thrust ball bearing,
The rolling element that comes into contact with the raceway surface of the floating bearing ring is a ball, and the radius of curvature of one surface of the two bodies in contact is determined as the radius of the ball, so that the contact surface pressure of these contact surfaces does not become excessive In order to achieve this, the radius of curvature of the raceway surface of the floating raceway along the axial direction needs to be slightly larger than the radius of the ball, but much smaller than the radius of the raceway surface.

Since the difference between the radius of curvature along the axial direction of the raceway surface and the radius of the ball is small, the contact point between the ball and the raceway surface of the floating raceway forms a long ellipse in the axial direction of the bearing. The end of the contact ellipse approaches the center of the ball's rotation axis. Also, a small radius of curvature along the axial direction means that the contact point changes sensitively to changes in the position and orientation of the annular race, and this has the advantage that the position and orientation of the floating race is easily stabilized. Spawn. However, since it is a ball bearing, the rotation axis of the ball changes even with a slight radial load, so the end of the contact ellipse may overlap the center of the rotation axis of the ball and trigger the galling of the contact surface. large.

In the bearing according to the present invention, the conical angle of the tapered rollers is smaller than the angle at which the ball is sandwiched by the conventional low-friction torque thrust ball bearing, and the number of rolling elements can be increased.
The component force acting to push the rollers per tapered roller out of the bearing is smaller than the component force acting on one ball in the case of a ball bearing. In addition, the radius of curvature of the spherical portion of the large-diameter side end surface of the tapered roller is irrespective of the diameter of the roller and is equal to or smaller than the radius of curvature along the axial direction of the raceway surface of the floating race ring, and is larger than that of the ball bearing. As a result, the contact surface pressure of the contact surface between the spherical portion of the tapered rollers and the raceway surface of the floating bearing ring is reduced, and the shape of the contact surface is smaller than that of the conventional low friction torque thrust ball bearing. The distance between the axial end of the contact ellipse and the center of the spherical portion of the tapered roller is large because the ellipse is long in the circumferential direction. Since it does not move from the center of the spherical portion, the end of the contact ellipse overlaps with the center of the spherical portion of the tapered roller, and there is little risk of galling of the contact surface.

According to a second aspect of the present invention, there is provided a pair of annular races which are arranged opposite to each other and have annular raceways on their opposing surfaces, respectively, and are freely rollable between the raceways of these annular races. A plurality of interposed tapered rollers, a floating track ring surrounding the outer circumference of the tapered rollers, and a retainer holding the respective tapered rollers, each tapered roller having a circumferential surface of the track of each annular track ring In the rolling surface which is in contact with the surface, the end surface on the large diameter side is a spherical portion convex outwardly, and the inner peripheral surface of the floating raceway is the raceway surface in contact with the spherical portion of the tapered roller, and this raceway surface is It has a cylindrical surface parallel to the axial direction, and the raceway surface of one annular raceway and the raceway surface of the other annular raceway that face each other are tapered in the opposite direction to each other, and the raceway surface of one raceway is The intersection C1 of the extension of the slope and the extension of the slope of the other track surface;
The conical vertex C2 of the conical shape forming the peripheral surface of the tapered roller is:
It is characterized in that it coincides with a point on a central axis of the bearing and at a position apart from a plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered roller.

In the bearing according to the present invention, since the contact pressure at the contact point is low, the radius of curvature of the raceway surface of the floating raceway along the axial direction is infinite, that is, the contact surface pressure becomes excessively large even when the raceway is cylindrical. Can be prevented. With a cylindrical surface, there is an advantage that machining of the raceway surface of the floating race is easier than with a concave arc shape.

When the raceway surface of the floating race is a cylindrical surface, the effect of restricting the position and posture of the floating race by the tapered rollers is lost. The change in the position of contact with the raceway surface becomes insensitive, and there is little risk of galling or seizure.

According to a third aspect of the present invention, there is provided a pair of annular races which are arranged opposite to each other and have annular raceways on their facing surfaces, respectively, and are rotatably rolled between the raceways of these annular races. A plurality of interposed tapered rollers, a floating track ring surrounding the outer circumference of the tapered rollers, and a retainer holding the respective tapered rollers, each tapered roller having a circumferential surface of the track of each annular track ring In the rolling surface which is in contact with the surface, the end surface on the large diameter side is a spherical portion convex outwardly, and the inner peripheral surface of the floating raceway is the raceway surface in contact with the spherical portion of the tapered roller, and this raceway surface is The raceway surfaces of one annular raceway ring and the raceway surface of the other annular raceway ring that are inclined with respect to the axial direction are tapered in the opposite direction to each other, and one raceway surface is inclined. C of the extension of the slope of the other track surface with the extension of the slope of the other
1 and a conical vertex C2 of the conical shape forming the peripheral surface of the tapered roller
Are coincident with each other at a point on the center axis of the bearing and at a position apart from a plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered roller.

If the raceway surface of the floating race is a conical surface inclined with respect to the axial direction, when a component force is generated to push the tapered rollers out of the bearing due to an axial load applied to the bearing, The force that presses the floating race on the raceway surface of the annular race acts by this component force, and the position and attitude of the floating race can be stabilized by this force.

According to a fourth aspect of the present invention, the raceway surface of one of the pair of annular raceways disposed opposite to each other is a plane perpendicular to the axial direction of the bearing. And

In the bearing according to the fourth aspect of the present invention, the ability to support the load in the axial direction is high. However, the load in the radial direction can hardly be supported, and if the load in the radial direction is applied, the bearing may be damaged. Therefore, when used in an application in which a small load is applied in the radial direction, it is necessary to separately provide a radial support bearing. If a separate support bearing for radial load is provided,
Rather, this bearing may not support the radial load at all, but may support only the axial load.

In particular, when used as a support bearing for a transmission roller of a half toroidal type continuously variable transmission, a radial bearing for supporting a radial load which is a reaction force of a transmission torque is used together with the transmission roller. Must be able to move in the radial direction perpendicular to the direction of the radial load due to the transmission of torque. Conventionally, the flatness of the annular raceway opposite to the transmission roller on the side opposite to the raceway surface is supported by a slide bearing or thrust needle roller bearing, thereby increasing the degree of freedom of the radial position of the transmission roller. Complex means of providing

In the bearing according to the fourth aspect of the present invention, by making the raceway surface of the annular raceway opposite to the transmission roller a flat surface, the position of the transmission roller in the radial direction is free, and the conventional slide bearing and thrust Since the function of the needle roller bearing is absorbed by this bearing, these plain bearings and thrust needle roller bearings become unnecessary, and the cost can be reduced by simplifying the structure. Also, in combination with the tapered roller bearing, the axial length of the bearing is reduced as compared with the conventionally used ball bearing, so that the structure is simplified and the space in the limited space is reduced. With this allowance, the rigidity of the member supporting the transmission roller is increased to improve the transmission efficiency of the transmission and contribute to weight reduction.

Further, in the case of a ball bearing, the transmission roller
There is a groove on the raceway surface in the vicinity of the direction in which the load is applied, which reduces the rigidity of the transmission roller. However, in the bearing of the invention of claim 4, since the raceway surface groove does not exist in the load direction, the deformation of the transmission roller during torque transmission is reduced. Small, which is also advantageous for improving the transmission efficiency of the transmission.

According to a fifth aspect of the present invention, the retainer is provided with a restricting portion for restricting the movement of the bearing in the axial direction. The invention according to claim 7 is characterized in that the retainer, the tapered rollers and the floating race are coupled irremovably from each other. The container, the tapered rollers, the floating race and one of the pair of annular races are irremovably coupled to each other. It is characterized in that one of the annular races is irremovably connected to each other.

[0040]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings.

FIGS. 1 and 2 show a first embodiment, in which a bearing 1 is provided with a pair of annular races 2 and 3 which are arranged vertically and overlap each other. The annular surfaces 3 facing each other are raceway surfaces 4 and 5, and a plurality of tapered rollers 6 are uniformly and radially arranged between the raceway surfaces 4 and 5.

The conical roller 6 has a conical peripheral surface, and the conical peripheral surface is a rolling surface 7 in contact with the raceway surfaces 4 and 5. The large-diameter end surfaces of the tapered rollers 6 are spherical spherical portions 8 that protrude outward.

A floating bearing ring 10 is provided around the outer peripheral side of the tapered roller 6, and an inner peripheral surface of the floating bearing ring 10 surrounds the tapered roller 6 and comes into contact with the spherical portion 8 of the tapered roller 6. The shape of the raceway surface 11 along the axial direction is a concave shape that is concave in an arc shape as shown in FIG.

A retainer 14 is provided between the raceway surfaces 4 and 5 of the annular races 2 and 3, and this retainer 14 has a substantially disk-like ring shape. A pocket portion 15 for surrounding and maintaining the posture in the rolling direction is formed by punching, and a column portion 16 is formed between the pocket portions 15.

As shown in FIG. 4, a blade-like support portion extending in the axial direction of the bearing 1 is provided on the side edges on both sides of each column portion 16 by utilizing the excess thickness of the punched portion of the pocket portion 15. 1
7 are formed, and the tapered rollers 6 are supported so as to be held by the support portions 17 facing each other.

As shown in FIG. 3, the intersection between the extension of the inclination of one raceway surface 4 and the extension of the inclination of the other raceway surface 5 in the annular races 2, 3 is C1, and is shown in FIG. The vertex of the cone forming the rolling surface 7 of the tapered roller 6 is C2, and the intersection C1 and the vertex C2 correspond to the center axis S of the bearing 1.
The bearing 1 passing above and passing through the center O of the spherical portion 8 of the tapered roller 6
At a point A below the horizontal plane perpendicular to the center axis S of the first point.

The radius of curvature of the spherical portion 8 of the tapered roller 6 is R1, the maximum radius of the arc along the circumferential direction of the raceway surface 11 of the floating raceway ring 10 is R2, and the maximum radius of the arc along the axial direction of the raceway surface 11 of the floating raceway ring 10 is R1. Has a radius of curvature R3, the radius of curvature R1 of the spherical portion 8 is the maximum radius R2 of the circular arc along the circumferential direction of the raceway surface 11 in the floating raceway ring 10, and the axis of the raceway surface 11 in the floating raceway ring 10. The radius of curvature of the concave curve along the direction is smaller than R3.

In such a structure, the intersections C1 of the extension lines of the inclined surfaces of the raceway surfaces 4 and 5 in the annular races 2 and 3,
Since the conical vertex C2 of the rolling surface 7 of the tapered roller 6 coincides with the point A on the central axis S of the bearing 1, the rolling surface 7 of the tapered roller 6 is , 5, complete rolling motion and no spin or differential slip associated with rolling.

As shown in FIG. 5, when an axial load W is applied to the bearing 1, since the raceway surfaces 4 and 5 are inclined, the tapered roller 6 is moved away from the center axis S of the bearing 1. A force W 'is generated to push and spread the floating raceway ring 10 so that the tapered roller 6 spreads to the position of the maximum pitch radius by the force W'. The point P of the maximum diameter of the raceway surface 11 of the floating race 10 as shown in FIG.
Touch with.

The intersection C1 and the apex C2 correspond to the bearing 1
On the central axis S of the tapered roller 6 and at a point A below a horizontal plane passing through the center O of the spherical portion 8 of the tapered roller 6,
The inclination angle of the raceway surface 4 of the one annular raceway ring 2 and the raceway surface 5 of the other annular raceway ring 3 with respect to the horizontal plane is different, so that the contact point P is located from the center O of the spherical portion 8 of the tapered roller 6. Although the position is deviated, the distance between the center O of the spherical portion 8 and the contact point P is short, so that the spherical portion 8 at the contact point P rotates with the rolling surface 7 of the tapered roller 6 as the bearing 1 rotates. This causes a spin motion involving rolling at a speed much slower than the rolling speed, and the lubricant is supplied to the surface of this contact portion, so that galling and seizure due to poor lubrication do not occur, and a small friction torque Forming a pivot that moves by means of a conventional low-friction torque thrust ball bearing.

Therefore, in the bearing 1 having this configuration, the differential slip on the raceway surface is eliminated from the conventional low-friction torque thrust ball bearing, and a low-friction torque thrust bearing can be realized.

As described above, in the bearing 1 of the present invention, the object that comes into contact with the raceway surface 11 of the floating race 10 is the spherical portion 8 of the tapered roller 6 having a larger radius of curvature R1 than the ball.
Since the contact surface pressure on the contact surface with the raceway surface 11 can be made lower than that of the ball, even if the radius of curvature R3 of the axial section of the raceway surface 11 is increased, the surface pressure on the contact surface with the spherical portion 8 is excessive. It does not become.

If the radius of curvature R3 of the axial cross section of the raceway surface 11 of the floating race 10 is increased, the stability of the position and orientation of the floating race 10 is impaired. Even if the contact angle changes, an effect of making the change of the contact position insensitive is brought about, so that it becomes difficult to generate a point where pure spin motion becomes a nucleus of galling on the contact surface. Therefore, the safety margin against galling and seizure is higher than that of the conventional low friction torque thrust ball bearing.

In a normal tapered roller bearing, the spherical portion of the large-diameter end surface of the tapered roller makes line contact or surface contact with the inner surface of the flange formed on the annular race, so that the rolling direction of the tapered roller at this contact surface Posture is kept stable.

However, in the bearing 1 of the present invention, since the raceway surface 11 of the floating race 10 and the spherical portion 8 of the tapered roller 6 are in point contact, the attitude of the tapered roller 6 is maintained at the contact point P. There is no such effect, and the tapered roller 6 is held in a stable posture by the rolling surface 7 being held by the inner periphery of the pocket portion 15 of the cage 14 and its rotation being guided.

Each tapered roller 6 is supported so as to be held by a support portion 17 formed by using the excess thickness of the punched portion of the pocket portion 15 in the cage 14 and is integrated with the cage 14. Therefore, each tapered roller 6 and the retainer 14 can be treated as an integral part, and the operation when assembling the bearing 1 to a machine or a device can be easily and efficiently performed.

FIG. 6 shows a second embodiment. In this embodiment, the raceway surface 11 of the floating race 10 is a cylindrical surface parallel to the central axis S of the bearing 1.

The radius of curvature of the spherical portion 8 of the tapered roller 6 is larger than the radius of the ball in the ball bearing, and even if the radius of curvature of the raceway surface 11 of the floating race 10 in the axial direction is larger than that of the ball bearing. The surface pressure at the contact surface between the spherical surface portion 8 and the raceway surface 11 does not become excessive, so that the radius of curvature of the raceway surface 11 can be infinite, that is, a cylindrical surface parallel to the central axis S of the bearing 1. It is.

In the case of this configuration, the tapered roller 6 is
There is no action to stabilize the position and posture of the floating race 10 by the component force pushed out. Once the floating race 10 is tilted, the component force acts in a direction to further tilt the floating race 10.

Therefore, in this embodiment, the raceway surface 5 of the annular race 3 and the outer peripheral portion 14a of the cage 14
The gap between the end faces 10a and 10b of the floating race 10 is reduced to support the floating race 10. Thereby, the movement of the floating race 10 in the axial direction is restricted, the inclination of the floating race 10 is suppressed, and the spherical portion 8 of the tapered roller 6 is formed.
The change in the contact position between the shaft and the raceway surface 11 can be reduced to prevent galling and seizure.

FIG. 7 shows a third embodiment. In this embodiment, a raceway surface 11 of a floating race 10 is tapered at a small angle θ with respect to a center axis S of a bearing 1. Surface.

In the case of this configuration, as shown in FIG.
An axial load W is applied to the bearing 1, and the tapered rollers 6
When the pressing force is generated in the direction away from the central axis S of the floating raceway 10, the floating raceway 10
Component W ′ that presses against the raceway surface 5 of the annular race 3
The position and posture of the floating race 10 can be stably held by the component force W '.

FIG. 9A shows a fourth embodiment. In this embodiment, the raceway surface 5
Are formed on a horizontal plane perpendicular to the central axis S of the bearing 1.

In this configuration, since the raceway surface 5 of the annular raceway 3 is a horizontal plane, the other annular raceway 2, the tapered rollers 6, the floating raceway 4 and the retainer 14 move on the raceway surface 5. The bearing 1 can move freely in the radial direction and does not support any radial load. The support of the radial position and the load depends on a separate radial bearing.

The bearing 1 of this embodiment is a case where the bearing 1 is applied to a transmission roller of a half toroidal type continuously variable transmission.
Compared with the conventional ball bearing 1 'illustrated in FIG. 9B, the structure is simplified, the length in the axial direction is shortened, and the resulting space is reduced by the rigidity of the trunnion supporting the transmission roller. It can be used for improvement and weight reduction.Moreover, unlike the conventional ball bearing, there is no raceway groove that reduces the rigidity of the transmission roller in the direction in which the load of the transmission roller is applied. Since it is high and the deformation of the transmission roller during torque transmission is small, this is also advantageous in improving the transmission efficiency of the transmission.

FIG. 10 shows a fifth embodiment.
10A is a cross-sectional view of a part of the bearing 1, and FIG. 10B is a cross-sectional view taken along line XX in FIG. 10A. In this embodiment, the outer circumferential portion 14 a and the inner circumferential portion b of the cage 14 are provided with the cage 1 facing the raceway surface 4 of the annular race 2.
4 is provided with a regulating portion 20 for regulating the movement in the axial direction.

In a normal tapered roller bearing, since the cage has a conical shape and is supported by the tapered rollers, its degree of freedom in the radial and axial directions is small, and the cage contacts the outer ring. There is usually no.

However, in the bearing 1 of the present invention, the cage 14
Is substantially flat, and it is difficult to maintain its axial position by the tapered rollers 6. Therefore, the retainer 14 contacts one of the annular races 2, and the column portion 16 separates the tapered rollers 6 and the raceway surface 4 from each other.
And when the lubrication is particularly poor, tapered rollers 6
May run on the pillar portion 16 and make the rotation of the bearing 1 impossible.

However, in this embodiment, the movement of the retainer 14 in the axial direction is limited by the contact of the regulating portion 20 of the retainer 14 with the raceway surface 4 of the annular race 2, and therefore, The contact position 21 between the pocket portion 15 of the tapered roller 14 and the rolling surface 7 of the tapered roller 6 can be maintained at a distance from the raceway surface 4 and close to the diameter of the tapered roller 6. The column portion 16 contacts the raceway surface 4 of the annular race 2, and the column portion 16 forms the rolling surface 7 of the tapered roller 6.
And the raceway surface 4 of the annular race 2 does not get caught between the bearing and the raceway 2, so that even if lubrication is particularly poor, it is possible to prevent the bearing 1 from rotating.

Further, in this configuration, the retainer 14 is arranged at a position away from the center of the tapered roller 6, so that the width of the pocket portion 15 is reduced as compared with the case where it is arranged at the intermediate portion of the tapered roller 6. In other words, the width of the base portion of the pillar portion 16 can be increased, whereby the strength of the pillar portion 16, particularly the base portion, is increased, and the rigidity of the retainer 14 is increased. It is possible to improve the durability of the bearing 1 by turning to increasing the number.

FIG. 11 shows a sixth embodiment.
10A is a cross-sectional view of a part of the bearing 1, and FIG. 10B is a cross-sectional view taken along line XX in FIG. 10A. In this embodiment, a restricting portion 22 that protrudes toward the raceway surface 4 of the annular race 2 is provided on a side edge of the column 16 of the retainer 14. In addition, on the inner peripheral portion 14b of the retainer 14,
A support portion 23 extending between the tapered rollers 6 and facing the column portion 16 is integrally formed. Column 16 is tapered roller 6
The support portion 23 is disposed below the center of the tapered rollers 6, and each of the tapered rollers 6 is positioned adjacent to the pillar portion 1.
6 and the support portion 23 and are held by the holder 14.

In this configuration, the restricting portion 22 contacts the raceway surface 4 of the annular race 2 so that the movement of the retainer 14 in the axial direction is restricted, and therefore, as in the fifth embodiment, The contact position 21 between the pocket portion 15 of the tapered roller 14 and the rolling surface 7 of the tapered roller 6 can be maintained at a distance from the raceway surface 4 and close to the diameter of the tapered roller 6. Of the annular raceway ring 2 or the raceway surface 4 of the annular raceway ring 2 does not contact the raceway surface 4 of the annular raceway ring 2. In addition, even when lubrication is particularly poor, it is possible to prevent the bearing 1 from being unable to rotate.

Further, in this configuration, the retainer 14 is arranged at a position away from the center of the tapered roller 6, so that the width of the pocket portion 15 is reduced as compared with the case where the cage 14 is disposed at the intermediate portion of the tapered roller 6. That is, the width of the root portion of the column 16 can be increased, whereby the strength of the root of the column 16 increases, and the rigidity of the retainer 14 increases.

In particular, in the sixth embodiment, the rigidity of the retainer 14 is further increased because the restricting portion 22 projecting toward the raceway surface 4 is integrally formed on the side edge of the column portion 16. Then, it is possible to improve the durability of the bearing 1 by allocating a margin generated thereby to increasing the number of the tapered rollers 6.

In the sixth embodiment, each of the tapered rollers 6 has a column 16 and a support 2 adjacent to each other.
3 and is integrally connected to the retainer 14, the retainer 14 and the tapered roller 6 can be treated as an integral part, and therefore, the work when assembling the bearing 1 to a machine or a device can be performed. It can be performed easily and efficiently.

FIG. 12 shows a seventh embodiment.
In this embodiment, wing-shaped support portions 17 extending in the axial direction of the bearing 1 are formed on both side edges of the column portion 16 of the retainer 14, and the tapered rollers 6 are formed by the support portions 17 facing each other. The retainer 14 and each tapered roller 6 are supported so as to be held together, and are integrated.

The outer peripheral portion 14a of the retainer 14 is integrally formed with a cylindrical portion 25 facing the outer peripheral surface of the floating race 10 with a gap therebetween. The outer circumference is enclosed. The lower end edge of the cylindrical portion 25 is a bent portion 25a that is slightly bent inward, so that the inner diameter D1 of the opening at the lower end of the cylindrical portion 25 is smaller than the outer diameter D2 of the floating bearing ring 10. .

In this configuration, the floating race 10 is held in the cylindrical portion 25 of the cage 14 to prevent it from coming off, and the cage 14, the tapered rollers 6 and the floating race 10
Can be handled as an integral part, and the operation when assembling the bearing 1 to a machine or a device can be easily and efficiently performed.

FIG. 13 shows an eighth embodiment.
In this embodiment, the retainer 14 is composed of two annular members 26 and 27 which are vertically overlapped.
In these two annular members 26 and 27, support portions 17 are formed on both side edges of the column portion 16 between the pocket portions surrounding the circumference of the tapered rollers 6, and the tapered rollers 6 are formed by the support portions 17. It is supported so that it can be held and its fall-off is prevented. The floating bearing ring 10 arranged on the outer peripheral side of the tapered roller 6 is accommodated in a space 29 inside the outer peripheral portions of the two annular members 26 and 27 which are superposed.

In this configuration, the two annular members 2
6 and 27, the cage 14, the tapered rollers 6, and the floating track ring 10 are integrally connected to each other. Therefore, as in the sixth embodiment, the cage 14, the tapered rollers 6, and the floating track The wheel 10 and the wheel 10 can be handled as an integral part, and the operation when assembling the bearing 1 to a machine or a device can be easily and efficiently performed.

FIG. 14 shows a ninth embodiment.
In this embodiment, the inner peripheral portion 14b of the retainer 14
In addition, a cylindrical portion 30 opposed to the inner peripheral surface of the annular bearing ring 3 with a gap therebetween is integrally formed. A step portion 31 is formed at a lower portion of the inner peripheral surface of the annular race ring 3, and the cylindrical portion 3 is formed.
0 is slightly bent outward so that the lower end edge thereof enters the step portion 31, so that the outer diameter D1 of the opening at the lower end of the cylindrical portion 30 is reduced by the bend.
Is larger than the inner diameter dimension D2, whereby the annular race 3 and the retainer 14 are irremovably coupled.

Further, on both side edges of the pillar portion 16 of the cage 14, support portions 17 projecting upward are formed, and the support portions 17 and the raceway surface 5 of the annular race ring 3 form tapered rollers 6.
Is supported so as to be pinched, and its separation is prevented,
Further, the floating bearing ring 10 is disposed between the outer peripheral portion 14a of the retainer 14 and the raceway surface 5 of the annular bearing ring 3 to prevent the bearing ring 10 from coming off.

In this configuration, the annular race 3, the retainer 14, the tapered rollers 6, and the floating race 10 are integrally connected. Therefore, the annular race 3, the retainer 14, the tapered rollers 6, the floating race 6, and the like. 10 can be handled as an integral part, and the work when assembling the bearing 1 to a machine or a device can be easily and efficiently performed.

FIG. 15 shows a tenth embodiment. In this embodiment, the outer peripheral portion 14
The cylindrical part 32 which opposes the outer peripheral surface of the annular bearing ring 2 with a clearance gap is integrally formed in a. Annular ring 2
A step portion 33 is formed at the upper portion of the outer peripheral surface of the cylindrical portion 32. The upper end edge of the cylindrical portion 32 is slightly bent inward so as to enter the step portion 33, and the inner diameter of the opening at the upper end of the cylindrical portion 32 due to the bending. The dimension D1 is smaller than the outer diameter dimension D2 of the annular race 2 at the lower side of the step portion 33, whereby the annular race 2 and the retainer 14 are irremovably coupled.

Further, on both side edges of the pillar portion 16 of the retainer 14, support portions 17 projecting downward are formed, and the support portions 17 support the tapered roller 6 so as to be inseparable from the retainer. Have been.

In this configuration, the annular race 2, the retainer 14, and the tapered rollers 6 are integrally connected, and thus the annular race 2, the retainer 14, and the tapered rollers 6 can be handled as an integral part. In addition, the operation for assembling the bearing 1 to a machine or a device can be easily and efficiently performed.

[0087]

As described above, according to the present invention, between the raceway surface of the pair of annular races and the rolling surface of the tapered roller,
In ball bearings, differential sliding and spin-based sliding motion, which cannot be avoided, are eliminated, and complete rolling motion with extremely small friction is achieved.Also, the spherical portion of the large-diameter side end surface of the tapered roller and the floating raceway At the contact surface with the raceway surface, there is a pivotal motion accompanied by a much slower rolling motion than at the raceway surface of the annular race, and the friction at this contact surface is extremely small, so that it is possible to provide a bearing with extremely small friction torque. it can.

Further, since the pivoting motion is slow but the rolling motion is applied to the contact surface between the spherical portion of the large-diameter side end surface of the tapered roller and the raceway surface of the floating bearing ring, the lubricant is supplied. Also, the position of the spherical raceway of the tapered roller contacting the raceway surface of the floating raceway is unlikely to change with respect to changes in the position and attitude of the floating raceway. The danger of galling and seizures between them is eliminated.

Further, when the raceway surface of one of the annular raceways is flat, when applied to a transmission roller of a half-toroidal-type continuously variable transmission, the peripheral structure is simplified, thereby being created. The extra space can be utilized for improving the performance and reducing the weight of the transmission.

The retainer and the tapered roller are irremovably coupled to each other, the retainer, the tapered roller and the floating race are irremovably coupled to each other, or the cage, the tapered roller and the floating race are coupled to each other. Or one of the annular races is permanently connected to each other, or the retainer, the tapered rollers, and one of the pair of races are permanently connected to each other. Therefore, the operation when assembling the bearing to the machine or the device can be easily and efficiently performed.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a thrust tapered roller bearing according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a state in which an annular race on an upper side of the bearing is removed and a part of a cage is cut off.

FIG. 3 is an explanatory view showing a configuration of a main part of the bearing.

FIG. 4 is a sectional view of a portion where the tapered rollers of the bearing are arranged.

FIG. 5 is an explanatory diagram for explaining the operation of the bearing.

FIG. 6 is a sectional view showing a thrust tapered roller bearing according to a second embodiment of the present invention.

FIG. 7 is a sectional view showing a thrust tapered roller bearing according to a third embodiment of the present invention.

FIG. 8 is an explanatory diagram for explaining the operation of the bearing.

FIG. 9 is a sectional view showing a thrust tapered roller bearing according to a fourth embodiment of the present invention in comparison with a conventional bearing.

FIG. 10 shows a thrust tapered roller bearing according to a fifth embodiment of the present invention, wherein (A) is a cross-sectional view of a part of the bearing,
(B) is sectional drawing which follows the XX line in the figure of (A).

FIG. 11 shows a thrust tapered roller bearing according to a sixth embodiment of the present invention, where (A) is a cross-sectional view of a part of the bearing,
(B) is sectional drawing which follows the XX line in the figure of (A).

FIG. 12 is a sectional view showing a part of a thrust tapered roller bearing according to a seventh embodiment of the present invention.

FIG. 13 is a sectional view showing a part of a thrust tapered roller bearing according to an eighth embodiment of the present invention.

FIG. 14 is a sectional view showing a part of a thrust tapered roller bearing according to a ninth embodiment of the present invention.

FIG. 15 is a sectional view showing a part of a thrust tapered roller bearing according to a tenth embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Bearing 2, 3 ... Annular raceway 4, 5 ... Raceway surface 6 ... Tapered roller 7 ... Rolling surface 8 ... Spherical part 10 ... Floating raceway ring 11 ... Raceway surface 14 ... Cage 15 ... Pocket part 16 ... Column part 17 support

Claims (9)

[Claims] 1. A pair of annular races arranged opposite to each other and having annular raceways on their facing surfaces, and a plurality of rolling races interposed between the raceways of the annular races. A tapered roller, a floating raceway ring surrounding the outer periphery of these tapered rollers, and a retainer holding each tapered roller, wherein each tapered roller has a circumferential surface in contact with the raceway surface of each annular raceway ring. The end surface on the large diameter side is a spherical surface portion convex outward, and the inner peripheral surface of the floating raceway is a raceway surface in contact with the spherical surface portion of the tapered roller, and has a shape along the axial direction of the raceway surface. Has a concave curved shape that is concave in an arc shape, and the raceway surface of one annular raceway and the raceway surface of the other annular raceway which face each other are inclined in a tapered shape on opposite sides,
The intersection C1 of the extension line of the inclination of one raceway surface and the extension line of the inclination of the other raceway surface, and the conical vertex C2 of the conical shape forming the peripheral surface of the tapered roller are on the center axis of the bearing, and At one point at a position distant from the plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered roller, the radius of curvature R1 of the spherical portion of the tapered roller is along the circumferential direction of the raceway surface of the floating race. A thrust tapered roller bearing characterized by being smaller than a maximum radius R2 and a radius of curvature R3 of a concave shape along the axial direction. 2. A pair of annular races arranged opposite to each other, each having an annular raceway surface on the opposite surface side, and a plurality of rolling races interposed between the raceway surfaces of these annular raceways. A tapered roller, a floating raceway ring surrounding the outer periphery of these tapered rollers, and a retainer holding each tapered roller, wherein each tapered roller has a circumferential surface in contact with the raceway surface of each annular raceway ring. In the surface, the end face on the large diameter side is a spherical part convex outward, and the inner peripheral surface of the floating bearing ring is a raceway surface in contact with the spherical part of the tapered roller, and this raceway plane is parallel to its axial direction. The raceway surface of one of the annular raceways facing the other and the raceway surface of the other annular raceway are tapered to the opposite sides to be tapered,
The intersection C1 of the extension line of the inclination of one raceway surface and the extension line of the inclination of the other raceway surface, and the conical vertex C2 of the conical shape forming the peripheral surface of the tapered roller are on the center axis of the bearing, and A thrust tapered roller bearing, which coincides at one point at a position distant from a plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered roller. 3. A pair of annular races arranged opposite to each other, each having an annular raceway surface on the facing surface side, and a plurality of rolling races interposed between the raceway surfaces of the annular raceways. A tapered roller, a floating raceway ring surrounding the outer periphery of these tapered rollers, and a retainer holding each tapered roller, wherein each tapered roller has a circumferential surface in contact with the raceway surface of each annular raceway ring. In the surface, the end surface on the large diameter side is a spherical portion convex outwardly, and the inner peripheral surface of the floating bearing ring is a raceway surface in contact with the spherical portion of the tapered roller, and this raceway surface is in the axial direction. The raceway surface of one annular raceway and the raceway surface of the other annular raceway which face each other are inclined in a tapered shape to the opposite sides,
The intersection C1 of the extension line of the inclination of one raceway surface and the extension line of the inclination of the other raceway surface, and the conical vertex C2 of the conical shape forming the peripheral surface of the tapered roller are on the center axis of the bearing, and A thrust tapered roller bearing, which coincides at one point at a position distant from a plane perpendicular to the axial direction of the bearing passing through the center of the spherical portion of the tapered roller. 4. The bearing surface of any one of a pair of annular races arranged opposite to each other is a plane perpendicular to the axial direction of the bearing. 4. The thrust tapered roller bearing according to 2 or 3. 5. The thrust tapered roller bearing according to claim 1, wherein the cage is provided with a regulating portion for regulating movement of the bearing in the axial direction. 6. The thrust tapered roller bearing according to claim 1, wherein the cage and the tapered roller are irremovably coupled to each other. 7. The device according to claim 1, wherein the retainer, the tapered rollers and the floating race are connected to each other so as to be inseparable from each other.
6. The thrust tapered roller bearing according to 2, 3, 4 or 5. 8. The device according to claim 1, wherein the cage, the tapered rollers, the floating race and one of the pair of annular races are irremovably coupled to each other. Or the thrust tapered roller bearing according to 5. 9. The device according to claim 1, wherein the retainer, the tapered rollers, and one of the pair of annular races are irremovably connected to each other. Thrust tapered roller bearing.