JPH0635672U - Torque limiter - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a torque limiter which has excellent durability and operates by rotation in both forward and reverse directions. [Structure] Race surfaces 4, 1 provided on the outer cylinder 1 and the inner member 7
In the interval 0, the ball rolling element 15 is incorporated, and the retainer 18 of the rolling element is integrally formed on the seal member 16 fixed to the outer cylinder 1. When the inner member 7 rotates, the cage 18 rotates via the rolling elements 15, and the torque is transmitted to the outer cylinder 1. When an overload is applied to the outer cylinder 1 from this state, the rolling elements 15 idle and the torque transmission is cut off.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a torque limiter that limits the transmission torque for rotation in both directions.

[0002]

[Prior art]

 The paper feed mechanism of OA equipment (office automation equipment) and the feed mechanism such as tape ribbons and sheets have a torque limiter that shuts off the rotary torque between the input side and the output side against an excessive load. Used.

Conventionally, as this type of torque limiter, a coil spring is fitted over the input hub and the output hub, one end of this coil spring is connected to the output hub, and the inner peripheral surface of the coil spring is connected to the input hub. A spring-type torque limiter is known, which limits the transmission torque by idling the coil spring and the input hub when a large load is applied to the output side when tightened to.

[0004]

[Problems to be solved by the device]

 However, in the above-mentioned spring type torque limiter, the magnitude of the transmission torque is regulated by the tightening force between the coil spring and the input side hub, and when the load is overloaded, the input side hub idles against the coil spring and limits the torque. Therefore, the problem remains that the inner peripheral surface of the sliding coil spring and the outer peripheral surface of the input hub are likely to wear.

Further, in the above-mentioned spring type torque limiter, the coil spring and the input side hub operate as a limiter against rotation in which the coil spring and the input side hub slide, but in the reverse rotation, the coil spring and the input side hub are tightened and locked. However, there is also a problem that the applicable range is limited because there is no function to limit the transmission torque for rotation in both directions.

Therefore, an object of the present invention is to provide a torque limiter which has less wear and can transmit and cut off torque with respect to rotation in both directions with a simple structure.

[0007]

[Means for Solving the Problems]

 In order to solve the above-mentioned problems, the present invention provides a race surface on the facing surface of an inner cylinder and an outer cylinder that fits inside and outside, and inserts a rolling element incorporated between both race surfaces into the outer cylinder or the inner cylinder. The structure is such that it is held by a holding member that rotates together with the side members.

In addition, as a second means of the present invention, a sealing material that closes a gap between the race surfaces is fixed to the outer cylinder or the inner member, and the holding member is circumferentially held by the sealing material. I did.

[0009]

[Action]

 In the above structure, when the outer cylinder or the inner member rotates, the holding member rotates in the same direction via the rolling element, and the torque is transmitted to the inner member or the outer cylinder integrated with the holding member. When a load larger than this transmission torque is applied to the inner member or the outer cylinder on the driven side, the rolling element idles, the inner member and the outer cylinder rotate relatively, and the torque transmission is interrupted.

On the other hand, when the holding member is held by the seal material as in the second means, it is possible to prevent dust and the like from entering the race surfaces and to seal the lubricating oil and the like, so that the torque transmission is continued for a long time. Can be stabilized.

[0011]

【Example】

 FIG. 1 shows a torque limiter of the embodiment. As shown in the figure, the outer cylinder 1 is composed of an outer resin part 2 and an outer ring 3 which is press-fitted and fixed to the inner diameter surface of the outer resin part 2. The outer race surface 4 is formed on the inner diameter surface of the outer ring 3. Has been done. The external resin component has a hole 5 through which the drive shaft 13 is inserted in the end wall and a protrusion 6 for torque transmission. The protrusion 6 is fitted into a recess provided in a driven component (not shown). Transmits torque.

The inner member 7 is composed of a cylindrical part 8 and an inner ring 9 press-fitted and fixed to the outer diameter surface of the cylindrical part 8. An inner race surface 10 is formed on the outer diameter surface of the inner ring 9. Has been done. The cylindrical part 8 has a cylindrical hole 11 into which a drive shaft 13 is inserted, and a notch 12 is formed at an end thereof, and a pin 14 provided on the drive shaft 13 is fitted into the notch 12. Driving force is transmitted.

A plurality of ball rolling elements 15 are rotatably incorporated between the outer race surface 4 and the inner race surface 10. Sealing members 16 and 17 that close the gap between the outer ring 3 and the inner ring 9 are fixed to both ends of the inner diameter surface of the outer ring 3, and each ball rolling element 5 is held on the inner surface of one of the sealing members 16. A retainer 18 is formed. As shown in FIG. 2, the cage 18 is integrally formed on the inner surface of the sealing material 16, and is formed in a C-shaped annular shape so as to surround the ball rolling element 15. Are held at predetermined intervals in the circumferential direction.

Grease for lubricating the race surfaces 4, 10 is filled inside the both sealing members 16, 17, and the inner and outer races 3, 3, are provided between the outer resin part 2 and the cylindrical part 8. A lid plate 19 for positioning 9 is attached.

In the torque limiter of the embodiment having the above structure, when the inner member 7 is rotationally driven by the drive shaft 13, the cage 18 together with the ball rolling element 15 rotates in the same direction as the inner member 7. , The outer cylinder 1 integrated with the cage 18 is rotated. That is, the torque of the drive shaft 13 is transmitted to the external resin component 2 via the rolling element 15 and the retainer 18 to rotate the driven component.

On the other hand, when the torque applied to the external resin component 2 in the above torque transmission state becomes larger than the torque set by the rotation of the ball rolling element 15, the ball rolling element 15 idles and the inner ring 9 is formed. The outer ring 3 rotates relatively, and the torque transmission is cut off.

The magnitude of the torque transmitted by the rotation of the ball rolling element 15 is determined by the diameter and number of the ball rolling elements 15, P. C. It can be arbitrarily set depending on the size of D (pitch circle diamond), the contact angle between the ball rolling element 15 and the race surface (4, 10), and the like. For example, as shown in Table 1, ball diameter, number of balls, P. C. When D or the like is changed, the rotation speed of the cage 18 is changed, and the magnitude of the transmission torque can be changed. The rotation speed of the cage in Table 1 is the value when the rotation speed of the inner ring 9 is 100 rpm, and the radial clearance in the table is the clearance between the ball rolling element 15 and the raceways 4, 10. Is shown.

[0018]

[Table 1]

As described above, in the above torque limiter, since the torque is transmitted through the rotation of the ball rolling element 15, even if the drive shaft 13 rotates in either the forward or reverse direction, the same operation is performed. Is obtained, and the same torque can be transmitted.

FIG. 3 shows another holding structure of the cage. In this example, a plurality of projections 20 are provided on the inner surface of the sealing material 16 along the circumferential direction, and a cage 18 ′ holding the ball rolling element 15 is fitted between the projections 20 to form a cage. 18 'and the outer member are connected so as to rotate together.

Further, in the structure of FIG. 3, a protrusion 20 may be provided on the other sealing material 17 to hold the retainer 18 'from both sides.

Although the outer cylinder 1 and the retainer 18 are integrally connected in the above embodiment, the seal member 16 is fixed to the inner ring 9 of the inner member 7 so that the retainer 18 and the inner member 7 are integrated. Even if the torque is transmitted from the outer cylinder 1 to the inner member 7 by being connected to, the same effect as described above can be obtained.

The rolling element 15 is not limited to the illustrated ball, but may be a cylindrical roller or another shape.

[0024]

【effect】

 As described above, in the torque limiter of the present invention, the holding member of the rolling element is integrally connected to the outer cylinder or the inner member, and the torque is transmitted by the rotation of the rolling element. Similarly, it can transmit and cut off torque. Also, unlike the spring type torque limiter, there is no part that slides on the spring, so there is little wear and the number of parts is small and the structure is simple, so it can be made compact and at low cost. There are advantages.

[Brief description of drawings]

FIG. 1 is a sectional view showing a torque limiter of an embodiment.

FIG. 2 is a perspective view showing the same cage.

FIG. 3 is a sectional view showing a holding structure of another cage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Outer cylinder 4 Outer race surface 7 Inner member 10 Inner race surface 15 Ball rolling element 16, 17 Seal material 18, 18 'Cage

Claims (2)

[Scope of utility model registration request] 1. A race surface is provided on an opposing surface of an inner cylinder and an outer cylinder fitted inside and outside, and a rolling element incorporated between both race surfaces is integrally rotated with the outer cylinder or the inner member. A torque limiter that is held by a holding member. 2. The torque limiter according to claim 1, wherein a sealing material for closing a gap between the race surfaces is fixed to the outer cylinder or the inner member, and the holding member is circumferentially held by the sealing material. .