JPH06313450A - Torque limiter - Google Patents

Abstract

PURPOSE:To provide a torque limiter capable of absorbing the concentric error and the declination error between a driving shaft and a driven shaft. CONSTITUTION:A drive boss 12 to be connected to the rotary shaft 9 of a stepping motor 8 and a thrust boss 13 to be connected to a shaft 3 are rotatably connected to each other. And a disc part 25 of the thrust boss 13 is pinched between a main body 16 of the drive boss 12 and a disc 19 through a space, and a boss part 15 of the thrust boss 13 is loosely inserted into a hole 18 of the disc 19. A plurality of ball plungers are provided around an axis O1 of the rotation of the main body 16 of the drive boss 12 at equal distances, the tip is protruded to the space. The thrust boss 13 is pressed to the disk 19 by the ball protruded on the tip of the ball plunger 41. The drive boss 12 and the thrust boss 13 are relatively moved so that the mutual rotational centers O1, O2 may be made eccentric, moreover, they are allowed to relatively incline so as to be declined.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission device for transmitting a rotational force of a driving shaft to a driven shaft, and a torque limiter for idling the driving shaft when a torque applied to the driven shaft exceeds a predetermined torque. Regarding

[0002]

2. Description of the Related Art Conventionally, as a comparatively small type of torque limiter of this type, for example, one shown in FIG. 6 has been put into practical use. That is, the torque limiter 61
Has a holder 64 provided inside a sealed chamber 63 in which the powder 62 is enclosed, and a shaft 65 penetrating the center of rotation of the holder 64 and rotatably supported by the holder 64. Further, the shaft 65 has the closed chamber 63.
The serration 66 is formed in the portion located inside.

When such a torque limiter 61 is used in a drive system of an apparatus, for example, the holder 64 rotates while the holder 64 is connected to the rotation shaft of the motor and the shaft 65 is connected to the shaft for power transmission. Then, the rotational force is transmitted to the shaft 65 via the powder 62. At this time, torque is applied to the shaft 65 side, and the torque is applied between the holder 64 and the shaft 65,
That is, when the torque exceeding the shear resistance of the powder 62 acting around the shaft 65 in the closed chamber 63 is reached, the holder 64 idles. Therefore, it is possible to prevent the motor from being overloaded.

[0004]

However, in such a conventional torque limiter 61, the shaft 6
When the torque limiter 61 is used, the rotating shaft of the motor connected to the holder 64 and the shaft 65 is provided because the structure of 5 is rotatably supported by the holder 64 by penetrating the rotation center of the holder 64. Etc. and the axes of the two shafts such as the shaft for power transmission must be aligned. Therefore, in the device using the torque limiter 61, a driving shaft (motor or the like) and a driven shaft (power transmission shaft)
High precision was required for processing and assembling the parts constituting the. On the other hand, in order to avoid this, the torque limiter 61
And a driving shaft or a driven shaft, a coupling for absorbing the concentricity error and the declination error of these two shafts must be separately provided, which causes a problem of high cost of the device.

The present invention has been made in view of such conventional problems, and an object thereof is to provide a torque limiter capable of absorbing a concentric error and a declination error between a driving shaft and a driven shaft. And

[0006]

In order to solve the above-mentioned problems, the present invention has a relatively rotatable first joint member and a second joint member, and is capable of controlling the rotational force of a driving shaft. A transmission device for transmitting to a driven shaft via both joint members, wherein when the torque applied to the driven shaft is equal to or greater than a predetermined torque, the first joint member and the second joint member are mutually In the idling torque limiter, the first joint member has a first wall and a second wall facing each other, and
Is provided with a first boss portion to which either one of the driving shaft and the driven shaft is connected, a hole is opened in the second wall, and the second joint member is the second coupling member. A disc portion sandwiched between the first wall and the second wall through a space; and a disc portion protruding from the disc portion and loosely inserted in the hole, and the other one of the driving shaft and the driven shaft A second boss portion connected to the first joint member via a spring, and in the space from the side of the first wall toward the side of the second wall. A plurality of pressing members that are urged and pressed against the disk portion while being allowed to move with respect to the disk portion are arranged at equal intervals around the axis of rotation of the first joint member.

Further, the pressing member projects at the tip of the case screwed into the screw hole penetrating the first wall, and is urged in the projecting direction by a spring housed inside the case. It is desirable to be a free ball.

[0008]

In the above structure, the disc portion of the second joint member is pressed against the second wall by the pressing member between the first wall and the second wall of the first joint member. Therefore, when the drive shaft is connected to the first boss portion of the first joint member and the driven shaft is connected to the second boss portion of the second joint member, the rotational force of the drive shaft is increased. When the first joint member is rotated by the second joint member, the second joint member is rotated by the frictional resistance generated between the disc portion and the second wall, whereby the rotational force of the driving shaft is applied to the driven shaft. Transmitted. Further, when torque is applied to the driven shaft during such transmission operation and the torque becomes larger than the friction resistance, the pressing member slides or rolls with respect to the disc portion and moves relatively in the rotational direction. As a result, the second wall and the disk portion, that is, the first and second joint members idle with each other.

Here, the disc portion of the second joint member is the first
A second boss portion that is sandwiched by a space between the first wall and the second wall of the joint member, and that projects from the disc portion;
Since it is loosely inserted in the hole opening in the second wall, the first
The joint member and the second joint member are allowed to move relative to each other such that the axes of rotation of each other are eccentric to each other, and are allowed to relatively tilt to be declined from each other. Moreover, since the plurality of pressing members are arranged at equal intervals around the axis of rotation of the first joint member, the disc portion of the second joint member and the second wall of the first joint member are Are kept pressed against each other.

Therefore, even when there is a concentricity error and a declination error between the center of the driving shaft and the center of the driven shaft, the first joint member and the second joint member are separated from each other. ,
The axes of rotation of each other are eccentric or declined to absorb the error and rotate or idle each other.

Further, the pressing member projects at the tip of the case screwed into the screw hole penetrating the first wall, and is urged in the projecting direction by a spring housed inside the case. In the case of a free ball, the above-mentioned frictional resistance generated between the first joint member and the second joint member by screwing the case toward the space or screwing the case in the opposite direction. Can be easily adjusted. Moreover, since the balls are rollable, the frictional resistance against the second joint member during idling is extremely small.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view showing a main part of a drive mechanism of a belt that conveys a lead frame in a semiconductor component manufacturing apparatus, and a vertical wall 1 has a mounting hole 2 formed therein. An end portion on the other end side of a shaft 3 which is a driven shaft having a pulley around which the belt is wound is attached to one end side (not shown) is rotatably supported in a mounting hole 2 via a bearing 4. There is. The shaft 3 has an E on the vertical wall 1 side.
The ring 5 is externally fitted to prevent the ring 5 from slipping out in one direction, and a collar is provided between the vertical wall 1 and the E ring 5.

A support member 6 is fixed to the vertical wall 1 on the lower side of the shaft 3, and the support member 6 is provided on the support member 6 substantially parallel to the vertical wall 1 in the extending direction of the shaft 3.
Is stuck. A stepping motor 8 is provided on the support wall 7.
Is fixed and is the stepping motor 8 that is the driving shaft.
The end of the rotary shaft 9 extends from the hole 10 opened in the support wall 7 toward the shaft 3.

The rotary shaft 9 and the shaft 3 are connected via the torque limiter 11 according to the present invention. The torque limiter 11 is the first fixed to the rotary shaft 9.
Drive boss 12 which is a joint member of the above, and a thrust boss 13 which is a second joint member fixed to the shaft 3, and the drive boss 12 and the thrust boss 13 are rotatably connected to each other. ing.

The drive boss 12 has a drive boss body 16 located at the center of one end surface of the disk portion 14 and having a first boss portion 15 protruding therefrom, and the same as the disk portion 14 on the other end surface side. It has a thin-walled disc 19 fixed in parallel with the disc portion 14 via a cylindrical spacer 17 having an outer diameter dimension and having a hole 18 opened in the central portion. The disc portion 14 and the disc 19 respectively form the first wall and the second wall of the present invention. A rib 20 protruding toward the drive boss main body 16 is formed at the opening edge of the hole 18 in the disc 19. The drive boss 12 has the rotary shaft 9 fitted in a mounting hole 12a penetrating the rotary shaft O ₁ .

As shown in FIGS. 4 and 5, the disk portion 14 of the drive boss main body 16 is provided with three screw holes 21 ... At equal intervals around the rotation axis O _1. A ball plunger 41 is screwed into each of the screw holes 21. The disc portion 14 is provided with holes 22 ... Through which screws (not shown) for fixing the disc 19 are passed. Further, the first boss portion 15 is provided with screw holes 23 ... In which a tightening screw for fixing the rotating shaft 9 is screwed (not shown).

The ball plunger 41 is generally commercially available and has the structure shown in FIG.
That is, the ball plunger 41 has a case 42 having an external thread on its outer peripheral surface, a coil spring 44 housed in the case 42 and having a push plate 43 at its end, and a coil spring 44 urged by the push plate 43. Case 4
2 and a ball 45 that is a pressing member protruding to the tip of And the ball plunger 41 is
The tip end side of the drive boss body 16 is projected toward the thrust boss 13 side.

As shown in FIG. 2, the thrust boss 13 has the shaft 3 internally fitted and fixed in a mounting hole 13a penetrating the rotation center 0 ₂ , and the disc portion 25 and its rotation axis 0. _{The second} boss portion 26 located at ₂ and protruding. Further, the disc portion 25 is sandwiched between the drive boss body 16 and the disc 19 through a space d, and the second boss portion 26 is loosely inserted in the hole 18 of the disc 19.
Therefore, the drive boss 12 and the thrust boss 13 are allowed to move relative to each other such that the axes of rotation O ₁ and O ₂ possessed by each other are eccentric to each other, or are allowed to relatively tilt to be declined. There is. Also, the thrust boss 13 is
The disk portion 25 is pressed against the rib 20 of the disk 19 by the tips of the three ball plungers 41 that project from the drive boss 12 side, that is, the balls 45.

In the present embodiment having the above-mentioned structure, when the stepping motor 8 is operated and the drive boss 12 is rotated, the thrust boss 13 is rotated by the frictional resistance generated between the disk portion 25 and the disk 19. It This allows
Rotational force is transmitted to the shaft 3 connected to the thrust boss 13 side, and a belt (not shown) that conveys the lead frame is driven. On the other hand, at the time of this transmission operation, when the belt or the like is disturbed and torque is applied to the shaft 3 and the torque becomes larger than the frictional resistance, the ball 45 of the ball plunger 41 rolls to drive the drive boss 12. The thrust boss 13 and the thrust boss 13 idle each other. Therefore, it is possible to prevent the stepping motor 8 from being burdened by the idling operation.

Here, as described above, the drive boss 1
2 and thrust boss 13 have axes of rotation O ₁ ,
It is allowed that the O _{2 s} are relatively moved so as to be eccentric to each other and that they are relatively inclined to be declined. Therefore, when the rotation shaft 9 of the stepping motor 8 and the shaft 3 are connected, if there is a concentricity error and a declination error between them, the drive boss 12 and the thrust boss 13 move relatively, Alternatively, the error is absorbed by tilting. Moreover, since the plurality of ball plungers 41 are arranged at equal intervals around the rotation axis O ₁ of the drive boss 12, the disk portion 25 of the thrust boss 13 and the disk 19 (rib 20) of the drive boss 12 are formed. And are always pressed against each other. Therefore, even if there is a concentricity error and a declination error between the rotating shaft 9 and the shaft 3, the transmission operation and the idling operation described above are performed while absorbing the errors.

Therefore, when the torque limiter 11 is used, it is not necessary to match the axial centers of the rotary shaft 9 and the shaft 3 with each other, and the mounting hole 2 of the vertical wall 1 is machined and the support wall 7 and It is possible to reduce the accuracy of assembly of the stepping motor 8 and the like, and it is possible to eliminate the need for a coupling for absorbing the concentricity error and the declination error of the two axes. Therefore, the cost of the device can be reduced.

Further, since the torque limiter 11 has a simple structure, it can be easily miniaturized, and since high precision is not required for processing and assembling each component, it can be manufactured at low cost. it can.

On the other hand, in the torque limiter 11 of the present embodiment, the disk portion 25 of the thrust boss 13 is pressed against the disk 19 of the drive boss 16 by the ball 45 which is pressed against the thrust boss 13 and is freely rotatable. As a result, the components at such locations are less consumed during the idling operation, and the durability of the torque limiter 11 can be improved. Moreover, since the ball 45 constitutes the ball plunger 41 which is screwed into the drive boss body 16 of the drive boss 12, the ball 45 is formed in the space d.
It is possible to easily change the frictional resistance generated between the drive boss 12 and the thrust boss 13 at the time of transmission by screwing the screw toward the rear end or retracting it in the opposite direction. Therefore, the operating characteristics of the torque limiter 11 can be easily adjusted.

In this embodiment, the disk portion 25 of the thrust boss 13 is pressed by the rib 20 protruding from the disk 19 of the drive boss 12.
Need not necessarily be provided. Further, in the present embodiment, the pressing member pressed against the disk portion 25 is a ball 4 which can roll.
However, instead of this, a plurality of other members are arranged at equal intervals around the axis of rotation O ₁ of the drive boss body 16, and the member is the disk portion 25.
It may be pressed against.

[0025]

As described above, in the present invention,
When the torque applied to the driven shaft exceeds a predetermined torque in a transmission device that transmits the rotational force of the driving shaft to the driven shaft,
In a torque limiter having a first joint member and a second joint member that rotate idle with each other, the first and second joint members move relative to each other such that their rotation axes are eccentric, and The disc portion of the second joint member is allowed to relatively incline so as to be deviated, and the plurality of pressing members are arranged on the first joint member at equal intervals around the axis of rotation thereof. , The first joint member is always pressed against the first wall.

Therefore, even if there is a concentricity error and a declination error between the driving shaft and the driven shaft, the transmission motion of the first and second joint members is absorbed while absorbing such errors. And, the idling operation can be performed.

Therefore, in using it, it is not necessary to match the axial centers of the two axes of the driving shaft and the driven shaft, so that the processing precision required for the portion related to the two shafts,
It is possible to avoid an increase in assembly accuracy. Moreover, the coupling for absorbing the concentricity error and the declination error of the two axes can be eliminated. Therefore, the cost of the device can be reduced.

Further, the torque limiter according to the present invention is
Since the structure is simple, miniaturization is easy, and since high precision is not required for processing and assembling each component, it can be manufactured at low cost.

Further, the pressing member is projected at the tip of the case screwed into the screw hole penetrating the first wall of the first joint member, and is attached in the projecting direction by the spring housed inside the case. It is a ball that can be rolled freely.
Therefore, the pressing member is less consumed during idling operation, and the durability of the torque limiter can be improved. Further, the friction resistance generated between the first joint member and the second joint member during the power transmission can be easily changed by screwing the case in or out. Therefore, the operating characteristics of the torque limiter can be easily adjusted.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is an enlarged view of part A in FIG.

FIG. 3 is a sectional view of a ball plunger.

FIG. 4 is a plan view showing a drive boss body.

5 is a cross-sectional view taken along the line BB of FIG.

FIG. 6 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 3 shaft (driven shaft) 9 rotating shaft (driving shaft) 12 drive boss (first joint member) 13 thrust boss (second joint member) 14 disk portion (first wall) 15 first boss portion 18 Hole 19 Disc (second wall) 25 Disc portion 26 Second boss portion 41 Ball plunger 45 Ball (pressing member) d Space

Claims (2)

[Claims] 1. A transmission device having a relatively rotatable first joint member and a second joint member, for transmitting the rotational force of a driving shaft to a driven shaft through both joint members. , When the torque applied to the driven shaft exceeds a predetermined torque,
In a torque limiter in which the first joint member and the second joint member idle each other, the first joint member has a first wall and a second wall facing each other, and The wall is provided with a first boss portion to which one of the driving shaft and the driven shaft is connected, and a hole is opened in the second wall, and the second joint member is the first A disk part sandwiched by a space between the wall and the second wall, and a disk part protruding from the disk part and loosely inserted in the hole, and the other one of the driving shaft and the driven shaft is A second boss portion to be connected, and is supported by the first joint member via a spring, and is attached from the first wall side toward the second wall side in the space. The pressing member pressed against the disk part while being biased and allowed to move with respect to the disk part is the first joint member. Torque limiter, characterized in that a plurality of equally spaced around the rotation axis. 2. The pressing member projects at the tip of a case screwed into a screw hole penetrating the first wall,
The torque limiter according to claim 1, wherein the ball is a rollable ball urged in a protruding direction by a spring housed inside the case.