JP2014134219A - Bidirectional torque limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bidirectional torque limiter which can be efficiently assembled, and whose torque set value can be easily changed.SOLUTION: A first torque limiter 11 has a first housing 13 for storing a one-way cutch 14, and limits load torque accompanying rotation transmitted in one direction to a first torque set value or less, by using a first coil spring 15 wound around an outer face of the one-way clutch 14. On the other hand, a second torque limiter 12 has a second housing 16 for storing an inner ring 17, and limits each of load torques accompanying rotation transmitted in two directions to the same second torque set value or less, by using a second coil spring 18 wound around an outer face of the inner ring 17. Further a common shaft inserted into the one-way clutch 14 of the first torque limiter 11 and the inner ring 17 of the second torque limiter 12 is connected to the inner ring 17 of the second torque limiter 12 by means of a shaft connecting portion.

Description

  The present invention relates to a bidirectional torque limiter having a torque limit value that varies depending on the rotational direction.

  The torque limiter prevents rotation when the load torque is below the torque limit value, and starts rotation when the load torque exceeds the torque limit value. There are two-way torque limiters and one-way torque limiters. .

  The bidirectional torque limiter prevents rotation when load torque in any rotational direction is less than or equal to the torque limit value, and starts rotating when a load torque exceeding the torque limit value is applied. Some bidirectional torque limiters have the same torque limit value in any rotation direction, or have different torque limit values depending on the rotation direction (for example, Patent Document 1).

  The unidirectional torque limiter is designed to prevent rotation when the load torque is below the torque limit value in one direction and to start rotation when the load torque exceeds the torque limit value, and to permit rotation in the reverse direction. is there. One-way torque limiter is configured by winding a one-way clutch around a coil spring (see Patent Document 2).

JP-A-9-166153 JP 2001-208108 A

  However, in the bidirectional torque limiter disclosed in Patent Document 1, coil springs of the same metal material are prepared when the same torque set value is used in both directions, and different metal materials are used when different torque set values are used. The coil spring must be prepared. That is, a large number of coil springs must be prepared, and coil spring members must be selected from these. Therefore, if the torque set value is different, the structure and assembly are different, resulting in high costs. Also, once the bidirectional torque limiter is created, the torque setting value cannot be easily changed.

  On the other hand, the unidirectional torque limiter of Patent Document 2 works as a torque limiter only in one direction and cannot be used as a bidirectional torque limiter.

  An object of the present invention is to provide a bidirectional torque limiter that can be efficiently assembled and that can easily change a torque set value.

The bidirectional torque limiter according to the present invention includes a first housing that houses a one-way clutch, and a load torque associated with rotation transmitted in one direction by a first coil spring wound around the outer surface of the one-way clutch. A first torque limiter that limits the first torque set value or less;
A second torque that has a second housing that houses the inner ring and that limits the load torque associated with the rotation transmitted in both directions to the same second torque set value or less by a second coil spring wound around the outer surface of the inner ring. Limiter,
And a shaft coupling portion for coupling a common shaft inserted through the one-way clutch of the first torque limiter and the inner ring of the second torque limiter to the inner ring of the second torque limiter.

  According to the present invention, the load torque in one direction is limited to the first torque set value or less, and the reverse torque is allowed to rotate in the reverse direction. Since the second torque limiter to be limited is prepared and only these are combined, efficient assembly is possible.

  Also, a plurality of first torque limiters with different first torque setting values and second torque limiters with different second torque setting values are prepared, and a bidirectional torque limiter with different torque setting values as a whole can be obtained simply by combining them. Can be created. In addition, the torque set value can be easily changed only by changing the combination of the first torque limiter having a different first torque set value and the second torque limiter having a different second torque set value.

The block diagram of the bidirectional | two-way torque limiter which concerns on embodiment of this invention. The block diagram at the time of inserting a common shaft in the bidirectional | two-way torque limiter which concerns on embodiment of this invention. Operation | movement explanatory drawing of the 1st torque limiter in embodiment of this invention. Operation | movement explanatory drawing of the 2nd torque limiter in embodiment of this invention. Operation | movement explanatory drawing of the bidirectional | two-way torque limiter which concerns on embodiment of this invention.

  Embodiments of the present invention will be described below. FIG. 1 is a configuration diagram of a bidirectional torque limiter according to an embodiment of the present invention. FIG. 1 (a) is a cross-sectional view, and FIG. 1 (b) is a right side view.

  As shown in FIG. 1A, the bidirectional torque limiter includes a first torque limiter 11 and a second torque limiter 12. The first torque limiter 11 has a first housing 13 in which a one-way clutch 14 is accommodated. The one-way clutch 14 prevents rotation with respect to load torque in one direction and permits rotation with respect to load torque in the reverse direction.

  A first coil spring 15 is wound around the outer surface of the one-way clutch 14. An end 15 a of the first coil spring 15 is fixed to the first housing 13. By this first coil spring 15, the load torque accompanying the rotation transmitted in one direction is limited to the first torque set value or less.

  That is, since the one-way clutch 14 prevents rotation with respect to a load torque in one direction, when the load torque is equal to or lower than the first torque set value by the first coil spring 15, Prevent rotation.

  On the other hand, when the load torque exceeds the first torque set value by the first coil spring 15, the one-way clutch 14 prevents rotation with respect to the load torque, but the first coil spring 15 slips on the outer surface of the one-way clutch 14. So start to rotate.

  That is, the first torque limiter 11 functions as a unidirectional torque limiter that prevents rotation when the direction is equal to or less than the first torque set value and rotates when the value is equal to or greater than the first torque set value, and permits rotation in the opposite direction.

  Next, the second torque limiter 12 has the same torque limit value in any rotational direction, has a second housing 16, and an inner ring 17 is accommodated in the second housing 16. . A second coil spring 18 is wound around the outer surface of the inner ring 17. An end 18 a of the second coil spring 18 is fixed to the second housing 16. By this second coil spring 18, the load torque accompanying the rotation transmitted in both directions is limited to the same value or less of the second torque set value.

  As shown in FIGS. 1A and 1B, a notch 17a is provided at the end of the inner ring 17 of the second housing 16, and a shaft is connected to the notch 17a. The one-way clutch 14 of the first torque limiter 11 and the inner ring 17 of the second torque limiter 12 are formed in a cylindrical shape, a common shaft is inserted through the inner surface of the cylindrical shape, and the cut portion 17a serves as a shaft coupling portion. A common shaft is connected by locking the protruding portion of the shaft.

  FIG. 2 is a configuration diagram when a common shaft is inserted into the bidirectional torque limiter according to the embodiment of the present invention, FIG. 2A is a cross-sectional view, and FIG. 2B is a right side view. A common shaft 19 is inserted into the cylindrical inner surface of the one-way clutch 14 of the first torque limiter 11 and the inner ring 17 of the second torque limiter 12, and the protrusion 19a of the shaft 19 is locked to the notch 17a.

  The common shaft 19 slides on the cylindrical inner surface of the one-way clutch 14 of the first torque limiter 11 when a load torque is applied. As a result, the one-way clutch 14 of the first torque limiter 11 prevents rotation in one direction and permits rotation in the reverse direction.

  On the other hand, in the inner ring 17 of the second torque limiter 12, since the common shaft 19 is locked to the inner ring 17 of the second torque limiter 12, the inner ring 17 of the second torque limiter 12 is driven. Thus, in both directions, rotation is prevented when the load torque is equal to or less than the torque limit value, and rotation is started when the load torque exceeds the second torque set value.

  3 is an operation explanatory view of the first torque limiter 11, and FIG. 3A is an explanatory view when the shaft 19 is rotated in a direction in which the one-way clutch 14 of the first torque limiter 11 prevents the rotation. (B) is explanatory drawing at the time of rotating the shaft 19 in the direction which the one-way clutch 14 of the 1st torque limiter 11 permits rotation.

  As shown in FIG. 3A, when the shaft 19 rotates in a direction in which the one-way clutch 14 of the first torque limiter 11 prevents rotation, the load torque applied to the shaft 19 is equal to or less than the first torque set value C of the coil spring 15. In this case, the shaft 19 is prevented from rotating. When the load torque applied to the shaft 19 becomes equal to or higher than the first torque set value C of the coil spring 15, the shaft 19 starts to rotate. At this time, the torque limit value T1a of the first torque limiter 15 is C.

  On the other hand, as shown in FIG. 3B, when the shaft 19 rotates in the direction in which the one-way clutch 14 of the first torque limiter 11 permits rotation, the shaft 19 rotates, and thus the torque limit value T1b is zero.

  That is, the first torque limiter 11 functions as a unidirectional torque limiter that prevents rotation in one direction below the first torque set value C, rotates in the first direction above the first torque set value C, and permits rotation in the reverse direction. .

  FIG. 4 is an operation explanatory view of the second torque limiter 12, and FIG. 4A is an explanatory view when the shaft 19 is rotated so that the inner ring 17 of the second torque limiter 12 rotates in the right direction. (B) is explanatory drawing at the time of rotating the shaft 19 so that the inner ring | wheel 17 of the 2nd torque limiter 12 may rotate leftward. As described above, the second torque limiter 12 has the same torque limit value in any rotation direction.

  As shown in FIG. 4A, when the inner ring 17 of the second torque limiter 12 rotates in the right direction, the shaft 19 rotates when the load torque applied to the shaft 19 is equal to or less than the second torque set value D of the coil spring 18. To prevent. When the load torque applied to the shaft 19 becomes equal to or greater than the second torque set value D of the coil spring 18, the shaft 19 starts to rotate. The torque limit value T2a of the second torque limiter 12 at this time is D.

  Similarly, as shown in FIG. 4B, when the inner ring 17 of the second torque limiter 12 rotates in the left direction, the shaft when the load torque applied to the shaft 19 is equal to or less than the second torque set value D of the coil spring 18 is used. 19 rotation is blocked. When the load torque applied to the shaft 19 becomes equal to or greater than the second torque set value D of the coil spring 18, the shaft 19 starts to rotate. The torque limit value T2b of the second torque limiter 12 at this time is D.

  In other words, in both directions, the second torque limiter 12 functions as a bidirectional torque limiter that prevents rotation below the second torque set value D and rotates above the second torque set value D. Also have the same torque limit value (T2a = T2b = D).

  FIG. 5 is an explanatory view of the operation of the bidirectional torque limiter according to the embodiment of the present invention. FIG. 5A shows a case where the shaft 19 is rotated so that the inner ring 17 of the second torque limiter 12 rotates in the right direction. FIG. 5B is an explanatory diagram when the shaft 19 is rotated so that the inner ring 17 of the second torque limiter 12 rotates in the left direction.

  In FIG. 5A, a common shaft 19 is inserted into the cylindrical inner surfaces of the one-way clutch 14 of the first torque limiter 11 and the inner ring 17 of the second torque limiter 12, and the protruding portion 19a of the shaft 19 is inserted into the cut portion 17a. Is locked and the shaft 19 is rotated rightward. The torque limit value Ta at this time is the sum of the torque limit value T1a of the first torque limiter 11 and the torque limit value T2a of the second torque limiter 12. The torque limit value T1a is C as shown in FIG. 3A, and the torque limit value T2a is D as shown in FIG. Therefore, the torque limit value Ta for the clockwise rotation of the bidirectional torque limiter according to the embodiment of the present invention is C + D.

  On the other hand, as shown in FIG. 5B, if the shaft 19 is rotated leftward, the torque limit value Tb at this time is the torque limit value T1b of the first torque limiter 11 and the torque of the second torque limiter 12. It is the sum of the limit value T2b. The torque limit value T1b is 0 as shown in FIG. 3B, and the torque limit value T2b is D as shown in FIG. Therefore, the torque limit value Tb for leftward rotation of the bidirectional torque limiter according to the embodiment of the present invention is D.

  Thus, according to the embodiment of the present invention, the first torque limiter 11 having the torque limit value (T1b = C) only in one direction and the same torque limit value (T2a = T2b = D) in any direction. Since it is only combined with the second torque limiter 12 having the above, efficient assembly is possible. Further, the torque limit value C + D for rotation in the right direction is D, and the torque limit value for rotation in the left direction is D. In this manner, a bidirectional torque limiter having a torque limit value that varies depending on the rotation direction can be easily configured.

  Therefore, by preparing a plurality of first torque limiters having different first torque set values and second torque limiters having different second torque set values, and combining them, a plurality of types of bidirectional types having different torque set values as a whole are obtained. A torque limiter can be created. Further, the torque set value can be easily changed by simply changing the combination of the first torque limiter 11 having a different first torque set value and the second torque limiter 12 having a different second torque set value.

  The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. The novel embodiment can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. This embodiment and its modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 11 ... 1st torque limiter, 12 ... 2nd torque limiter, 13 ... 1st housing, 14 ... One-way clutch, 15 ... 1st coil spring, 16 ... 2nd housing, 17 ... Inner ring, 18 ... 2nd coil spring, 19 …shaft

Claims (1)

A first torque that has a first housing that houses a one-way clutch and that limits a load torque accompanying rotation transmitted in one direction to a first torque set value or less by a first coil spring wound around the outer surface of the one-way clutch. Limiter,
A second torque that has a second housing that houses the inner ring and that limits the load torque associated with the rotation transmitted in both directions to the same second torque set value or less by a second coil spring wound around the outer surface of the inner ring. Limiter,
A bidirectional coupling comprising: a one-way clutch of the first torque limiter; and a shaft coupling portion for coupling a common shaft inserted through the inner ring of the second torque limiter to the inner ring of the second torque limiter. Torque limiter.

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