Torque limiting device of ball type harmonic reducer

Abstract

The torque limiting device of the ball type harmonic reducer comprises a flexible gear, an output flange, a ball, an elastic piece, a flexible gear pressing plate and a spring flange. A flexible gear groove is formed in the end face of the flexible gear, a spring flange groove is formed in the opposite spring flange face, and the balls are clamped in the flexible gear groove and the spring flange groove. During normal operation, the elastic piece compresses the ball, so that the flexible gear and the output flange are combined into a whole, and the flexible gear transmits torque to the output flange through the ball; when the load torque is larger than the limiting torque, axial force generated by the balls pushes the elastic pieces to be compressed, the balls are made to be disengaged from the grooves of the flexible gear, then rotation slipping is generated between the flexible gear and the output flange, and torque transmission is interrupted. As the torque limiting device is integrated in the harmonic reducer, the end face space of the flexible gear and the end face space of the output flange are fully utilized, the structure is compact, and the size is small.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of harmonic reducer limit torque device. BACKGROUND

[0002] Harmonic reducer one end connects motor, the other end connects load device, mainly for reducing the rotational speed of output shaft, improves output torque.

[0003] In daily use, harmonic reducer load often because of mechanical failure is stuck, or is subjected to external sudden impact. Since harmonic reducer is precision transmission component, especially the rigidity of the tooth shape of flexible wheel, the thin wall of flexible wheel can be poor, is easily damaged by the impact force of load.

[0004] The existing solution is to add a torque limiter between the reducer and the load, including spring type, friction plate type torque limiter. But all have the following shortcomings:

[0005] 1, increase the axial length of harmonic reducer, cause the whole transmission mechanism is cumbersome. Because the application field of harmonic reducer is mostly for the field of higher space requirement, for example industrial robot, therefore the volume of harmonic reducer cannot be too large, especially axial length.

[0006] 2, connection part is more, causing transmission gap to be big, influence precision.

[0007] 3, complex structure, installation and disassembly are difficult. SUMMARY

[0008] The utility model wants to solve the technical problem to overcome the above-mentioned defects of prior art and provide a kind of ball type harmonic reducer limit torque device, it is integrated in harmonic reducer interior, under the premise of not increasing axial distance, protect the precision components in harmonic reducer from big load impact.

[0009] The technical scheme that the utility model solves above-mentioned technical problem is as follows:

[0010] Ball type harmonic reducer limit torque device includes flexible wheel, output flange, ball, elastic member, flexible wheel pressing plate, spring flange;The end surface of flexible wheel is equipped with flexible wheel groove, and the opposite spring flange face is opened with spring flange groove, and ball is clamped in flexible wheel groove and spring flange groove;Normal operation, elastic member compacts ball, so that flexible wheel and output flange are integrated, and flexible wheel transmits torque to output flange through ball;When load torque is greater than limit torque, the axial force generated by ball pushes elastic member compression, so that ball is separated from flexible wheel groove, and then rotation slip is generated between flexible wheel and output flange, so that torque transmission is interrupted.

[0011] Ideally, a cylindrical shaft is set at the center of the output flange, and an internal space is set on the outside of the cylindrical shaft. A set of elastic elements is placed in the internal space of the output flange. The end face of the flexible wheel is grooved and fitted onto the cylindrical shaft. The flexible wheel pressure plate and the cylindrical shaft on the output flange are fastened together, and the flexible wheel is positioned at the upper limit in the axial direction.

[0012] The torque limiting device of the ball-type harmonic reducer includes a flexible wheel, an output flange, balls, elastic elements, a flexible wheel pressure plate, and a spring flange. The output flange end face has an output flange groove, and the opposite spring flange face has a spring flange groove. The balls are sandwiched between the output flange groove and the spring flange groove. A cylindrical shaft is positioned at the center of the output flange. The spring flange is fitted onto the cylindrical shaft, and a set of elastic elements is fitted onto the cylindrical shaft and pressed onto the spring flange. One end of the cylindrical shaft is fastened to the flexible wheel pressure plate, and the tail of the flexible wheel is inserted into the output flange. The flexible wheel pressure plate limits the flexible wheel to its position on the output flange. During normal operation, the elastic elements press the balls, making the flexible wheel and the output flange a single unit. The flexible wheel transmits torque to the output flange via the balls. When the load torque exceeds the limiting torque, the axial force generated by the balls in the groove pushes the elastic elements to compress, causing the balls to disengage from the output flange groove. This results in rotational slippage between the flexible wheel and the output flange, interrupting torque transmission.

[0013] More specifically, the elastic element is a disc spring or a compression spring.

[0014] Compared with existing technologies, the advantages of this invention are as follows: because the torque limiting device is integrated inside the harmonic reducer, it makes full use of the space on the end face of the cup-shaped flexure and the end face of the output flange, resulting in a compact structure and small size. Furthermore, different elastic elements can be replaced or the compression amount can be changed to adjust the torque limiting range. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the torque limiting device of the ball-type harmonic reducer in Embodiment 1 of this utility model.

[0016] Figure 2 This is a schematic diagram of the torque limiting device of the ball-type harmonic reducer in Embodiment 2 of this utility model. Detailed Implementation

[0017] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Example 1

[0018] like Figure 1 As shown, the torque limiting device of the ball type harmonic reducer includes a flexible wheel 1, an output flange 4, balls 6, an elastic element 5, a flexible wheel pressure plate 2, and a spring flange 3.

[0019] The end face of the flexible wheel 1 is provided with a flexible wheel groove 11, and the circumferential surface of the opposite spring flange 3 is provided with a groove 31. The ball 6 is sandwiched in the flexible wheel groove 11 and the spring flange groove 31 between the end face of the flexible wheel and the spring flange 3.

[0020] A cylindrical shaft 41 is set at the center of the output flange 4, and an internal space 42 is set on the outside of the cylindrical shaft 41. A set of elastic elements 5 are placed in the internal space 42 of the output flange 4.

[0021] The end face of the flexible wheel 1 has a groove 12, which is fitted onto the cylindrical shaft 41 on the output flange 4. The flexible wheel pressure plate 2 is fastened to the cylindrical shaft 41 on the output flange 4 with bolts 7, thereby positioning the flexible wheel 1 in the upper axial direction.

[0022] During normal operation, the elastic element 5 inside the reducer presses the ball 6, making the flexible wheel 1 and the output flange 4 a single unit. The flexible wheel 1 transmits torque to the output flange 4 through the ball 6.

[0023] When the load torque exceeds the limit torque, the axial force generated by the ball 6 in the groove pushes the elastic element 5 to compress, causing the ball 6 to disengage from the flex wheel groove 11. Subsequently, rotational slippage occurs between the flex wheel 1 and the output flange 4, interrupting the torque transmission and thus protecting the harmonic reducer from impact damage.

[0024] The torque limiting device of this ball-type harmonic reducer can adjust the torque limiting range by replacing different elastic elements or changing the compression amount. Example 2

[0025] like Figure 2 As shown, the torque limiting device of the ball type harmonic reducer includes a flexible wheel 1, an output flange 4, balls 6, an elastic element 5, a flexible wheel pressure plate 2, and a spring flange 3.

[0026] The output flange 4 has an output flange groove 43 on its end face, and the opposite spring flange 3 has a spring flange groove 31 on its circumferential surface. The ball 6 is sandwiched between the output flange groove 43 of the output flange 4 and the spring flange groove 31 of the spring flange 3.

[0027] A cylindrical shaft 41 is set at the center of the output flange 4. A spring flange 3 is fitted onto the cylindrical shaft 41. A set of elastic elements 5 is then fitted onto the cylindrical shaft 41 and pressed onto the spring flange 3. One end of the cylindrical shaft 41 is fastened to the flexible wheel pressure plate 2. The tail 13 of the flexible wheel 1 is inserted into the output flange 4. The flexible wheel pressure plate 2 limits the flexible wheel 1 on the output flange 4. This torque limiting device is integrated into the internal space of the flexible wheel 1, which can reduce the axial length.

[0028] During normal operation, the elastic element 5 inside the reducer presses the ball 6, making the flexible wheel 1 and the output flange 4 a single unit. The flexible wheel 1 transmits torque to the output flange 4 through the ball 6.

[0029] When the load torque exceeds the limit torque, the axial force generated by the ball 6 in the groove pushes the elastic element 5 to compress, causing the ball to disengage from the groove 41 of the output flange 4. Subsequently, rotational slippage occurs between the flexure 1 and the output flange 4, interrupting the torque transmission and protecting the harmonic reducer from impact damage.

[0030] The torque limiting device of this ball-type harmonic reducer can adjust the torque limiting range by replacing different elastic elements or changing the compression amount.

Claims

1. A ball-type harmonic reducer torque limiting device, characterized by: The torque limiting device of the ball type harmonic reducer comprises a flexible gear, an output flange, balls, elastic members, a flexible gear pressing plate and spring flanges.

2. The ball-type harmonic reducer torque limiting device according to claim 1, characterized in that: The output flange is provided with an output flange groove at an end face, and the opposite spring flange face is provided with a spring flange groove.

3. The torque limiting device of the ball type harmonic reducer comprises a flexible gear, an output flange, balls, elastic members, a flexible gear pressing plate and spring flanges.

4. The ball-type harmonic reducer torque limiting device according to claim 1 or 2 or 3, characterized in that: The output flange is provided with an output flange groove at an end face, and the opposite spring flange face is provided with a spring flange groove. The elastic member is a disc spring or a compression spring.

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