JP2009180278A - Torque limiter structure - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a torque limiter structure capable of maintaining preset torque by regulating the degree of the flexibility of a spring of a spring receiving plate for receiving the other end of the spring by a fastening shaft having a locking part when incorporating a gear, the spring and the spring receiving plate into a base member, in a torque limiter. <P>SOLUTION: The torque limiter transmits the rotational torque of a specific range by a frictional force to a driven body by a driving force of a rotary body from the outside, and has the gear 4 transmitting driving, the spring 6, the spring receiving plate 7, the fastening shaft 8, and a base member 2 having a shaft 2b having a fastening shaft inserting hole 2e capable of inserting the fastening shaft 8. By allowing the locking part 2c of the fastening shaft 8 to abut on the spring receiving plate 7, the degree of the flexibility of the spring 6 is regulated, and the slip-out of the spring from the fastening shaft inserting hole 2e is prevented. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a structure of a torque limiter for transmitting a certain range of torque.

  As a structure related to the assembly of the torque limiter, a shaft body having a flange at one end is inserted by inserting the first rotating body, slip material, elastic body and second rotating body, and the first rotating body or the second rotating body In the torque limiter that transmits the rotational force to the second rotating body or the first rotating body through the slip material, a fastener having a flange and having a through hole in the central portion is provided, and the through hole of the fastener is provided. Press-fit the other end of the shaft. Alternatively, by providing a male screw on the outer peripheral surface of the other end portion of the shaft body, providing a fastener having a flange, and having a screw hole in the central portion, and screwing the male screw into the screw hole of the fastener. The first rotating body, the slip material, the elastic body, and the second rotating body are loaded on the shaft body. Torque limiter assembly methods are disclosed in the literature.

  However, in the technique disclosed in the literature, when the first rotating body, the slip material, the elastic body, and the second rotating body are loaded on the shaft body having a flange, a method of incorporating a fastener into the shaft body by press fitting, In the method in which a screw hole is provided in the body and a screw hole is provided in the body and screwed into the body, the torque limiter itself is rotated and the press-fitting point of the shaft body and the fastener is removed or the screw is loosened. Due to this, the pressure on the spring changes, and there is a possibility that the torque within a certain set range cannot be transmitted.

In addition, in the method in which the fastener is press-fitted into the shaft body, for example, it is difficult to recombine springs having different spring pressures due to a spring failure or a change in transmission torque. In addition, in the method of assembling by screwing the shaft body with the male screw and the screw hole in the fastener, recombination of the springs is possible, but to set the specific torque after recombination, measure the torque again. There is a need.
JP-A-8-42587

  Therefore, in view of the above-described problems, the present invention does not move the fastener of the torque limiter from the shaft body when the first rotating body, slip material, and elastic body are incorporated into the shaft body with the fastener. It is an object of the present invention to provide a torque limiter structure that can be maintained and that can maintain a set torque without performing torque measurement after re-assembly by exchanging a spring.

  In a torque limiter that transmits a driving torque of a rotating body from outside to a driven body via a frictional force, a gear that transmits driving, a spring that biases a side surface of the gear, a spring, and the like A spring receiving plate for receiving an end, a stop shaft provided with a locking portion at both ends, and a base member having a shaft portion provided with a stop shaft insertion hole into which the stop shaft can be inserted. The abutment portion is brought into contact with the spring receiving plate, thereby restricting the degree of freedom of the spring and preventing the spring from being removed from the stop shaft insertion hole.

  According to the structure of the torque limiter of the present invention, when the gear arranged between the spring receiving plate and the flange of the base member is transmitted with torque from the base member to the gear by the frictional force pressed against the flange by the urging force of the spring. The degree of freedom of the spring is regulated by a stop shaft having a locking portion for the spring receiving plate that receives the other end of the spring. That is, the locking portion provided on the stop shaft abuts on the spring receiving plate, and the spring receiving plate that receives the spring end at a predetermined location regulates the degree of freedom of the spring, and the stop shaft is removed from the stop shaft insertion hole. It becomes possible to prevent.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a plan view showing the appearance of a torque limiter 1 of the present invention. Next, FIG. 2 is a plan view of the base member 2 according to the torque limiter 1 of the present invention. Next, FIG. 3 is a plan view of the gear 4 according to the torque limiter 1 of the present invention. Next, FIG. 4 is a plan view of the resin washer 3 according to the torque limiter 1 of the present invention. Next, FIG. 5 is a plan view of the washer 5 according to the torque limiter 1 of the present invention. Next, FIG. 6 is a plan view of the spring receiving plate 7 according to the torque limiter 1 of the present invention. Next, FIG. 7 is a plan view of the stop shaft 8 according to the torque limiter 1 of the present invention. Next, FIG. 8 is a plan view showing an example of use in which the torque limiter 1 of the present invention is combined with a motor M and an external gear G. FIG.

  As shown in FIGS. 1 and 8, the structure of the torque limiter 1 for transmitting a torque within a certain range according to the present invention is driven by a base member 2 that rotates by receiving an external drive, a resin washer 3, and an external drive. Is constituted by a gear 4, a washer 5, a spring 6, a spring receiving plate 7, and a stop shaft 8, and a structure in which external driving is transmitted by frictional resistance between the base member 2 and the gear 4. ing.

  First, the base member 2 shown in FIG. 2 includes a shaft portion 2b having a cut surface 2c formed on a part of the outer periphery and a D-shaped cross section, and a motor as a rotating body from the outside at the center of one end of the shaft portion 2b. An input / output receiving hole 2d into which a drive shaft such as M can be inserted, a flange 2a having a diameter larger than the diameter of the shaft 2b, and a flange 2a of the shaft 2b are provided at one end of the shaft 2b. On the end side, there is a stop shaft insertion hole 2e penetrating in the direction perpendicular to the center direction of the shaft portion 2b, and is integrally formed of a resin material.

  Next, the gear 4 shown in FIG. 3 has a gear center hole 4a into which the shaft portion 2b of the base member 2 can be inserted and slidable around the shaft portion 2b, and gear center holes 4a on both side surfaces of the gear 4. And the gear teeth 4c have a record-like annular groove 4b and are integrally formed of a resin material.

  Next, the resin washer 3 shown in FIG. 4 has a substantially same outer diameter as the flange 2a of the base member 2, can insert the shaft portion 2b of the base member 2 at the center, and can slide around the shaft portion 2b. The center hole 3a is formed of a resin material having self-lubricating properties.

  Next, the washer 5 shown in FIG. 5 has substantially the same outer diameter as the range up to the gear teeth 4c of the gear 4, and has the same shape as the cross section of the shaft portion 2b in which the cut surface 2c of the base member 2 is formed at the center. The shaft portion 2b of the base member 2 can be inserted, and is prevented from rotating with respect to the shaft portion 2b by the cut surface 2c of the shaft portion 2b.

  Next, the spring receiving plate 7 shown in FIG. 6 has an outer diameter substantially the same as the flange 2a of the base member 2, and a receiving plate center having the same shape as the cross section of the shaft portion 2b in which the cut surface 2c of the base member 2 is formed at the center. The shaft portion 2b of the base member 2 can be inserted, and is prevented from rotating with respect to the shaft portion 2b by the cut surface 2c of the shaft portion 2b.

  Next, the stop shaft 8 shown in FIG. 7 is a pin shaft having a length L substantially equal to the diameter of the spring receiving plate 7, and has cut surfaces 8 a as locking portions cut into the same D shape at both ends. The length L2 of the non-processed portion excluding the length of the processed portion that is the cut surface 8a at both ends from the entire length L1 of the retaining shaft 8 is set to be equal to or less than the diameter of the shaft portion 2b of the base member 2. .

  Next, the spring 6 shown in FIG. 1 has an inner diameter into which the shaft portion 2b of the base member 2 can be inserted, and the outer diameter is set to be equal to or smaller than the outer diameter of the spring receiving plate 7, and the spring pressure is changed by changing the wire diameter or the number of turns. By adjusting, the transmission torque of the torque limiter can be set.

  The method of assembling the torque limiter 1 of the present invention is such that the resin washer 3, the gear 4 and the washer 5 are directed from the one end of the shaft portion 2b of the base member 2 toward the flange 2a formed on the other end side. The spring 6 is inserted into the shaft portion 2b in that order and incorporated, and the spring 6 is inserted into the shaft portion 2b while being compressed by the spring receiving plate 7. The stopper shaft 8 is inserted into the stopper shaft insertion hole 2e by moving the stopper shaft insertion hole 2e on the shaft portion 2b of the base member 2 to the flange 2a side, and the stopper shaft cut surfaces 8a at both ends of the stopper shaft 8 are inserted. The base member 2, the resin washer 3, the gear 4, the washer 5, the spring 6, and the spring receiving plate 7 are assembled integrally with each other in contact with the surface of the spring receiving plate 7. By the urging force, and the flange 2a, the resin washer 3, the gear 4, the washer 5 it is made possible to transmit the rotational torque to the base member 2 and the gear 4 by surface friction.

  Further, as shown in FIG. 1D, when the cut surface 8a of the stop shaft 8 abuts against the surface of the spring receiving plate 7 to restrict the movement of the spring receiving plate 7, the stop shaft 8 shown in FIG. The portion of the length L2 of the unprocessed portion enters the receiving plate center hole 7a of the spring receiving plate 7, thereby preventing the stop shaft 8 from coming out of the stop shaft insertion hole 2e of the base member 2.

  Further, the stop shaft 8 can be removed from the stop shaft insertion hole 2e of the base member 2 by compressing the spring 6 with the spring support plate 7 to release the contact between the stop shaft 8 and the spring support plate 7. Therefore, the assembled torque limiter 1 can be easily disassembled, and the transmission torque can be easily changed by recombination with the spring 6 having a different spring pressure.

  Furthermore, because of the annular grooves 4b provided on both side surfaces of the gear 4, the contact with the resin washer 3 and the washer 5 pressed against the side surface of the gear 4 becomes point contact with the apexes of the height of the plurality of annular grooves 4b. Contact with the resin washer 3 and the washer 5 is ensured, and stable torque can be transmitted.

  With the configuration of the torque limiter 1 described above, the rotational torque from the motor M as the rotating body shown in FIG. 8 is transferred from the gear 4 to the external gear G as the driven body by the surface friction of the flange 2a, the resin washer 3, and the gear 4. When a torque load greater than the surface friction is transmitted, slippage occurs between the gear 4 and the flange 2a, and an overload to the motor M is prevented.

These are the external appearance top views which show the structure of the torque limiter based on the Example of this invention, (a) is a left view, (b) is a front view, (c) is a right view, d) is a part of a cross-sectional view taken along line AA in FIG. (A) is a right view of the base member which concerns on the Example of this invention, (b) is a front view, (c) is a right view. (A) is a front view of the gear which concerns on the Example of this invention, (b) is a right view. (A) is a front view of the resin washer which concerns on the Example of this invention, (b) is a right view. (A) is a front view of the washer which concerns on the Example of this invention, (b) is a right view. (A) is a front view of the spring receiving plate based on the Example of this invention, (b) is a right view. (A) is a front view of the stop axis | shaft which concerns on the Example of this invention, (b) is a right view. These are the top views which show the Example which combined the motor and the external gear with the torque limiter which concerns on the Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Torque limiter 2 Base member 2a Flange 2b Shaft part 2c Cut surface (locking part)
2d I / O receiving hole 2e Stop shaft insertion hole 3 Resin washer 3a Resin washer center hole 4 Gear 4a Gear center hole 4b Annular groove 4c Gear tooth 5 Washer 5a Washer center hole 6 Spring 7 Spring receiving plate 7a Receiving plate center hole 8 Stopping shaft 8a Stop shaft cut surface G External gear (driven body)
M motor (rotating body)
L1 Total length of stop shaft L2 Length of unmachined part

Claims (1)

In the torque limiter that transmits the rotational torque of a certain range to the driven body via the frictional force from the outside to the driven body,
A gear that transmits drive;
A spring that biases the side of the gear;
A spring receiving plate for receiving the other end of the spring;
A stop shaft provided with locking portions at both ends;
A base member having a shaft portion provided with a stop shaft insertion hole into which the stop shaft can be inserted;
With
A structure of a torque limiter characterized by restricting the degree of freedom of the spring and preventing the retaining shaft from coming out of the retaining shaft insertion hole by bringing the retaining portion of the retaining shaft into contact with the spring receiving plate.

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