JPH094649A - Torque limiter - Google Patents

Abstract

PURPOSE: To provide a torque limiter having both an excessive torque isolating function and a radial load supporting function with a relatively simple structure. CONSTITUTION: A torque limiter 3 is composed of an inner ring 3a fitted on a fit part 2a of a shaft sleeve 2 through a first torque transmitting member 3e, an outer ring 3b fitted on a fit part 1b of a pulley body 1 through a second torque transmitting member 3f, a plurality of balls 3c interposed between a track surface 3a1 of the inner ring 3a and a track surface 3b1 of the outer ring 3b and a holder 3d to hold the balls 3c circumferentially at an equal interval. The first torque transmitting member 3e and second torque transmitting member 3f are provided respectively with contact parts 3e3 , 3f3 moved into contact with a holder 3f by a predetermined elastic force.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a torque limiter for transmitting or blocking rotational torque between an inner rotating member and an outer rotating member.

[0002]

2. Description of the Related Art A torque limiter has a function of automatically interrupting a rotational torque from a drive side when an overload occurs on a driven side. And separate torque limiters are known. The destructive torque limiter cuts off excessive torque by shearing the shear pin, and the sliding torque limiter cuts off excessive torque by sliding between friction plates facing each other. The separable torque limiter shuts off the excessive torque by slipping a torque transmitting member such as a ball, which is interposed between opposed disks, from a recess provided on the end surface of the disk plate (withdrawing). is there. Among these, the separation type torque limiter is
It is used in a wide range of applications because it has a relatively good setting accuracy for limiting torque and has a relatively small amount of wear of the disk. Various proposals have been made regarding the separation type torque limiter (for example, Japanese Patent Publication No. 55-21895, Japanese Patent Publication No. 58-1288, Japanese Patent Publication No. 61-40846, Japanese Patent Publication No. 62-283220, Japanese Patent Publication No. 63-283220). -9736,
JP-A-1-210622).

[0003]

The torque limiter described above generally does not have a function of supporting a radial load by itself, and is often used in combination with a radial bearing. Also, it is structurally quite complex. Therefore, it is disadvantageous for applications with strict size, weight, and cost constraints.

The present invention is intended to solve the above problems by providing a torque limiter having a relatively simple structure and a function of interrupting an excessive torque and a function of supporting a radial load. Is.

[0005]

A torque limiter according to the present invention includes an inner rotating member having a raceway surface on an outer periphery thereof, an outer rotating member having a raceway surface on an inner circumference thereof, and an interposing member between both raceway surfaces. A plurality of rolling elements, a first torque transmitting member connected to the inner rotating member, and a second torque transmitting member connected to the outer rotating member. The first torque transmitting member and the second torque transmitting member are provided. Each of the torque transmission members has a contact portion that comes into contact with the rolling element with a predetermined elastic force.

Further, the torque limiter of the present invention comprises an inner rotating member having a raceway surface on the outer circumference, an outer rotating member having a raceway surface on the inner circumference, and a plurality of rolling members interposed between both raceway surfaces. A first torque including a moving body, a retainer for holding the rolling element, a first torque transmitting member connected to the inner rotating member, and a second torque transmitting member connected to the outer rotating member. The transmission member and the second torque transmission member,
Each has a contact portion that comes into contact with the cage or the rolling element with a predetermined elastic force.

In the above structure, the first torque transmitting member is arranged on the one end surface side of the inner rotating member, and the second torque transmitting member is arranged on the other end surface side of the outer rotating member. It may be an annular member.

Further, the contact portion of the first torque transmission member may be a tongue piece which contacts from one side of the rotation direction, and the contact portion of the second torque transmission member may be a tongue piece which contacts from the other side of the rotation direction.

Rolling bearing parts can be used as the inner rotating member, the outer rotating member, the rolling elements, and the retainer.

[0010]

For example, when the outer rotating member is rotationally driven in a predetermined direction, the rotational torque is changed from the outer rotating member to the second torque transmitting member to the cage (or rolling element) to the first torque transmitting member to the inner rotating member. Transmitted. On the other hand, when the rotational torque equal to or more than the limit value is input, the contact portions of the first torque transmission member and the second torque transmission member are elastically displaced,
The rotation torque is cut off due to slippage between the contact portion and the cage (or the rolling element).

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is applied to a torque limiter used for an alternator pulley of an automobile will be described below.

The alternator pulley shown in FIG. 1 mainly comprises a pulley main body 1 having a belt locking groove 1a on its outer periphery, and a torque limiter 3 interposed between the pulley main body 1 and the shaft sleeve 2. And receives the rotational power from the crankshaft of the engine via the transmission belt (V belt),
This is input to an input shaft (which is inserted into the inner circumference of the shaft sleeve 2) of an alternator (not shown).
In such a belt transmission mechanism, the torque limiter 3 supports the belt load and blocks the rotational torque when the driving side (crankshaft side) rapidly changes in rotation speed, thereby preventing the conduction belt from slipping ( If the rotational speed on the drive side fluctuates abruptly, the driven side with inertial mass cannot follow, so slippage occurs in the conductive belt.), And it also serves to suppress abrasion of the conductive belt and generation of abnormal noise.

The torque limiter 3 has an inner ring 3a fitted to the fitting portion 2a of the shaft sleeve 2 via a first torque transmitting member 3e and a second torque transmitting member 3f to the fitting portion 1b of the pulley body 1. A plurality of balls 3c interposed between the raceway surface 3a1 of the inner race 3a and the raceway surface 3b1 of the outer race 3b, and a cage 3d for holding the balls 3c at equal intervals around the circumference. . The fitting portion 1b and the fitting portion 2a are both stepped, and are between the shoulder inner circumference of the fitting portion 1b and the outer circumference of the fitting portion 2a, and the shoulder outer circumference of the fitting portion 2a and the fitting portion 1b. A seal member 4 seals between each of the inner circumference and the inner circumference.

In this embodiment, the torque limiter 3
Is an inner ring 3a, an outer ring 3b, a ball 3c, and a cage 3
the standard deep groove ball bearing consisting of d, the first torque transmission member 3e
The second torque transmission member 3f is added.
The first torque transmission member 3e and the second torque transmission member 3f are annular bodies that are press-formed from, for example, spring steel plates. The first torque transmission member 3e includes a cylindrical portion 3e1 press-fitted and fixed to the inner diameter of the inner ring 3a, an arm portion 3e2 continuously extending from one end of the cylindrical portion 3e1 to the outer diameter side, and an outer diameter side portion of the arm portion 3e2. From the one end face side to the contact portion 3e3 which is continuously extendable from the end to the inside of the bearing. The outer surface of the arm portion 3e2 is in contact with the shoulder end surface of the fitting portion 2a. Also, the second
The torque transmission member 3f includes a cylindrical portion 3f1 that is press-fitted and fixed to the outer diameter of the outer ring 3b, an arm portion 3f2 that continuously extends from the other end of the cylindrical portion 3f1 toward the inner diameter side, and a bearing from the inner diameter side portion of the arm portion 3f2. A contact portion 3f3 that extends continuously to the inside and is capable of contacting the cage 3d from the other end surface side with a predetermined elastic force.
And The outer surface of the arm portion 3f2 is the fitting portion 1
It is in contact with the shoulder end face of b.

As shown in FIG. 2, {FIG. 2 (a) is a developed view of the section A--A in FIG. 1}, the cage 3d of this embodiment.
Is a so-called caulking type, that is, two cage materials having the same shape are butted against each other from both sides of the ball 3c to accommodate the ball 3c in the pocket 3d1 and then the pocket 3d1.
This is a type in which the abutting portions between are crimped and integrated with a rivet 3d2 or the like. As the cage for the deep groove ball bearing, there is a caulking type retainer as well as a so-called crown type retainer, but it is also possible.

Further, in this embodiment, the contact portion 3e3 of the first torque transmission member 3e and the second torque transmission member 3 are formed.
Each of the contact portions 3f3 of f is a tongue that is bent inward in a V shape, and the same number as the number of balls 3c (the pockets 3d1 of the cage 3d) is arranged at circumferentially equidistant positions. . The contact portion 3e3 of the first torque transmission member 3e is formed by cutting and bending the outer diameter side portion of the arm portion 3e2 inwardly at a plurality of positions equidistantly arranged around the circumference and bending it into a V shape. The contact portion 3f3 of the second torque transmission member 3f is
The inner diameter side portion of the arm portion 3f2 is cut and raised inwardly at a plurality of positions equidistantly arranged around the circumference (see FIG. 2 (c)), and is bent and formed in a V shape. Contact part 3e3
And the contact portion 3f3 have the same shape, but their directions are opposite to each other.

2A and 2B, the contact portion 3e3 of the first torque transmission member 3e is the pocket 3 of the cage 3d.
The curved outer wall surface of d1 is elastically contacted from one side in the rotational direction, and the contact portion 3f3 of the second torque transmission member 3f is elastically contacted from the other side in the rotational direction. Therefore, the outer wall surface of each pocket 3d1 of the cage 3d is elastically sandwiched by the contact portions 3e3 and 3f3 from both sides in the rotation direction.

For example, in FIGS. 2 (a) and 2 (b), when the pulley body 1 (outer ring 3b) is rotationally driven in the X direction, the rotational torque of the pulley body 1 (outer ring 3b) → second torque transmitting member 3f → holding 3d → first torque transmission member 3e → shaft sleeve 2 (inner ring 3a), the pulley main body 1, the shaft sleeve 2, and the torque limiter 3 interposed therebetween are integrated in the X direction. Rotate. On the other hand, when a rotational torque that is equal to or greater than the limit value is input from the pulley body 1, the contact portions 3f3 and 3e3 are elastically displaced outwardly, and the contact portions 3f3 and 3e3 slide between the retainer 3d. As a result, the pulley body 1 (outer ring 3b) idles with respect to the shaft sleeve 2 (inner ring 3a), and the rotational torque is blocked. In either case of torque transmission or interruption, the belt load acting on the pulley body 1 is supported by the plurality of balls 3c interposed between the raceway surface 3a1 of the inner ring 3a and the raceway surface 3b1 of the outer ring 3b. When the input is from the shaft sleeve 2 (inner ring 3a) side, the Y direction is the torque transmission direction. That is,
The torque limiter 3 can transmit the rotational torque in either the X direction or the Y direction.

The arm portion 3f2 of the second torque transmitting member 3f
Is supported from the outside by the shoulder end surface of the fitting portion 1b, and the arm portion 3e2 of the first torque transmitting member 3e is supported from the outside by the shoulder end surface of the fitting portion 2a. 3f2 and 3e2 are contact portions 3f
Even if the retainer 3d receives a reaction force due to the elastic contact of 3 and 3e3, it does not bend outward. Therefore, the limiting torque (allowable transmission torque) is determined by the elastic force of the contact portions 3f3 and 3e3, and can be set arbitrarily and accurately according to the material, the wall thickness, the width dimension, the spring stroke S, the number of formations, etc. You can

The embodiment shown in FIG. 3 uses a spacer type retainer 3d '. Cage 3d 'of this embodiment
Is made of a resin material and is interposed between the balls 3c to hold the balls 3c at equal intervals around the circumference. First torque transmission member 3
e, the shape of the second torque transmission member 3f is the same as that of the above embodiment, but the contact portion 3e3 and the contact portion 3f3 are respectively
The difference is that it is in contact with the ball 3c. For example, in the figure, when the pulley body 1 (outer ring 3b) is rotationally driven in the X direction, the rotational torque of the pulley body 1 (outer ring 3b) →
The second torque transmission member 3f → the ball 3c → the first torque transmission member 3e → the shaft sleeve 2 (inner ring 3a) is transmitted through the route, and the pulley main body 1, the shaft sleeve 2, and the torque limiter 3 interposed therebetween are transmitted. Rotate in the X direction as a unit. On the other hand, when a rotational torque equal to or larger than the limit value is input from the pulley body 1, the contact portions 3f3 and 3e3 are elastically displaced outwardly, and slippage occurs between the contact portion 3f3 and the contact portion 3e3 and the ball 3c. Occurs, which causes
The pulley body 1 (outer ring 3b) is the shaft sleeve 2 (inner ring 3a).
Against idling, the rotational torque is cut off. In either case of torque transmission or interruption, the belt load acting on the pulley main body 1 depends on the raceway surface 3a1 of the inner ring 3a and the outer ring 3
It is supported by a plurality of balls 3c interposed between the track surface 3b1 of b and the track surface 3b1. When the input is from the shaft sleeve 2 (inner ring 3a) side, the Y direction is the torque transmission direction.

The present invention is not limited to the above-exemplified construction, and various modifications can be made. For example, the connection of the first torque transmission member 3e (second torque transmission member 3f) is not limited to press fitting, and various fixing means such as adhesion, welding, crimping, and engagement can be adopted. The shape of 3e (second torque transmission member 3f) is not limited to a ring shape, and may be a shape such as a partial ring or a divided piece. The tongue piece as the contact portion is not limited to a cut and raised shape, but a separate piece. It may be fixed, the deep groove ball bearing may be a full ball type without a cage, and a roller bearing (for example, a standard cylindrical roller bearing) may be used instead of the deep groove ball bearing. Furthermore, the torque limiter of the present invention is not limited to a belt transmission mechanism such as an alternator pulley, but can be widely used in general torque transmission mechanisms.

[0022]

Since the torque limiter of the present invention has a comparatively simple structure, it has a function of shutting off excessive torque and a function of supporting a radial load. Therefore, as compared with the conventional structure in which a radial bearing is used together, The reduction of the directional dimension, the reduction of weight, and the reduction of cost are realized, and it is particularly suitable for the application in which dimensional, weight, and cost constraints are severe.

Further, since the torque limiter can be constructed by using the standard rolling bearing as it is, it is compact and low in cost.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of an alternator pulley according to an embodiment.

2 is a developed view (FIG. A) taken along the line AA in FIG. 1, a partially enlarged view of FIG. A (FIG. B), and a side view of a second torque transmission member (FIG. C).

FIG. 3 is a sectional development view (FIG. A) and FIG. A according to another embodiment.
2 is a partially enlarged view (FIG. B) and a cross-sectional view of a bearing portion (FIG. C).

[Explanation of symbols]

 3 torque limiter 3a inner ring 3b outer ring 3c ball 3d retainer 3a1 raceway surface 3b1 raceway surface 3e first torque transmission member 3e3 contact portion 3f second torque transmission member 3f3 contact portion

Claims (5)

[Claims] 1. An inner rotating member having an outer peripheral raceway surface, an outer rotating member having an inner raceway surface, a plurality of rolling elements interposed between both raceway surfaces, and an inner rotating member. A torque limiter comprising a first torque transmission member connected to the outer rotation member and a second torque transmission member connected to an outer rotating member, wherein the first torque transmission member and the second torque transmission member are respectively provided on rolling elements. A torque limiter having a contact portion that comes into contact with a predetermined elastic force. 2. An inner rotating member having a raceway surface on the outer circumference, an outer rotating member having a raceway surface on the inner circumference, a plurality of rolling elements interposed between both raceway surfaces, and holding the rolling elements. A torque limiter including a retainer, a first torque transmission member connected to the inner rotating member, and a second torque transmission member connected to the outer rotating member. The first torque transmitting member and the second torque are provided. A torque limiter, wherein each of the transmission members has a contact portion that comes into contact with the cage or the rolling element with a predetermined elastic force. 3. The first torque transmitting member is an annular member disposed on one end surface side of the inner rotating member, and the second torque transmitting member is an annular member disposed on the other end surface side of the outer rotating member. The torque limiter according to claim 1 or 2, wherein: 4. The contact portion of the first torque transmitting member is a tongue piece that contacts from one side in the rotation direction, and the contact portion of the second torque transmitting member is a tongue piece that contacts from the other side in the rotation direction. The torque limiter according to claim 1, 2 or 3. 5. An inner rotating member, an outer rotating member, a rolling element,
The torque limiter according to claim 1, 2, 3 or 4, wherein the cage is a rolling bearing component.