JPH0587155A - Normal/reverse rotating torque limiter - Google Patents

Abstract

PURPOSE:To display the function as a torque limiter in either direction of normal/reverse rotation of driving force by one torque limiter. CONSTITUTION:One end of a coil spring 4 fitted around a spring seat ring 1 and a C-ring spring 2 is engaged with the spring seat ring 1, and the other end is engaged with an outer ring 3 to make the inner diameter of the coil spring constant. Torque adjustment is performed by rotating the outer ring 3 by the required angle.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a forward / reverse rotation torque limiter used in a drive unit of an office machine or the like.

[0002]

2. Description of the Related Art In functions such as a motor safety device and a gear backlash stop function in a drive unit of an office machine or the like, torque is transmitted when a load larger than a certain level is applied in both forward and reverse directions. There is a case where a torque limiter that cuts off the torque and transmits the torque only when the load is smaller than that is required.

In such a case, conventionally, it has been customary to separately provide one-way torque limiters for forward rotation and one for reverse rotation.

[0004]

However, providing two types of torque limiters, one for forward rotation and the other for reverse rotation, not only causes high cost, but also has a problem that the mounting space is limited.

Therefore, it is an object of the present invention to enable a single torque limiter to exert a function as a torque limiter for both forward and reverse rotations.

[0006]

In order to solve the above-mentioned problems, the present invention comprises a spring seat ring, a C ring spring, a coil spring and an outer ring, and the spring seat ring is non-rotatably fitted onto a torque transmission shaft. C ring spring is loosely fitted to the torque transmission shaft, and
The coil spring is wound around the outer diameter surface of the ring spring, the outer ring is fitted on the outer side of the coil spring, and the outer ring is fixed to the spring seat ring. One end of the coil spring is the spring seat ring and the other end is the outer ring. And a torque transmission member is engaged with the C ring spring.

[0007]

The coil spring has a constant inner diameter because one end thereof is engaged with the spring seat ring and the other end thereof is engaged with the outer ring. Therefore, the frictional force with the outer diameter surface of the C ring spring is equal to that of the C ring. It is constant in both forward and reverse rotations.
Therefore, the magnitude of the torque transmitted from the torque transmission member to the torque transmission shaft or in the opposite direction becomes constant according to the frictional force.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The forward / reverse rotation torque limiter of the embodiment shown in the accompanying drawings comprises a spring seat ring 1, a C ring spring 2, an outer ring 3 and a coil spring 4.

The spring seat ring 1 is externally fitted to the torque transmission shaft 5, and is non-rotatably engaged by a pin 6 fixed to the torque transmission shaft 5 in a radial direction.

In this spring seat ring 1, a small-diameter step portion 8 and a large-diameter step portion 9 are formed in two steps on the outer diameter surface of the rear half of the cylindrical portion 7, and the outer diameter of the cylindrical portion 7 is formed in each step portion 18 and 19. Engagement groove 1 reaching depth
0 is formed in the axial direction. A flat surface 18 'is formed on the opposite side of the engagement groove 10.

The C-ring spring 2 is formed by a steel plate having a spring property into a C-ring shape with a part thereof separated, and an engaging edge 11 for engagement is formed on the outer end thereof. In the natural state, the C ring spring 2 has an outer diameter that matches the outer diameter of the cylindrical portion 7 of the spring seat ring 1, and is loosely fitted around the torque transmission shaft 5 with a required gap. The inner end of the C ring spring 2 is brought into contact with the end face of the spring seat ring 1, and the uneven edge 11 thereof is engaged with a torque transmission member 12 such as a gear rotatably fitted around the torque transmission shaft 5. It

The coil spring 4 is made of a wire having a quadrangular cross section, and has an inner diameter that matches the outer diameter of the cylindrical portion of the spring seat ring 1 in a natural state. An axial engagement protrusion 13 is provided at one end of the coil spring 4, and a radial engagement protrusion 14 is provided at the other end.

The outer ring 3 is fitted in the small-diameter step portion 8 of the spring seat ring 1, a plurality of screw holes 15 are formed along one end, and an engaging recess 16 is formed at one end of the other end. It is formed.

The outer ring 3 is fitted on the outer side of the coil spring 4 with a required gap, and is fixed around the small-diameter step portion 8 by a screw 17 screwed into the screw hole 15.

Further, the outer diameter surface of the outer ring 3 is formed with flat surfaces 18 (see FIG. 2) extending over both ends thereof.

One of the engaging protrusions 13 of the coil spring 4 is engaged with the engaging groove 10 of the spring seat ring 1, and the other engaging protrusion 14 is engaged with the engaging recess 16 of the outer ring 3. It

The forward / reverse rotation torque limiter of the embodiment is constructed as described above, and its operation will be described below.

The driving force is transmitted from the torque transmission shaft 5 to the torque transmission member 12 or the opposite direction. To adjust the upper limit of the transmission torque, loosen the screw 17 and rotate the outer ring 3. At this time, the flat surface 18 of the outer ring 3,
The flat surface 18 'of the spring seat ring 1 is used as a slip stopper. When the outer ring 3 is rotated clockwise relative to the spring seat ring 1, the diameter of the coil spring 4 is reduced and the C ring spring 2 is compressed (see FIG. 3). As a result, the frictional force between the C ring spring 12 and the coil spring 4 increases, and the upper limit of the transmission torque increases. Conversely, when the outer ring 3 is rotated counterclockwise with respect to the spring seat ring 1, the diameter of the coil spring 4 is expanded, the frictional force between the outer ring 3 and the C ring spring 2 is reduced, and the upper limit of the transmission torque is reduced.

Adjusting as described above, the frictional force between the coil spring 4 and the C-ring spring 2 is kept constant, and normal rotation,
When the reverse rotation torque is transmitted, a torque having a certain upper limit is transmitted in any direction, and when the upper limit is exceeded, the torque transmission is cut off.

[0020]

As described above, according to the present invention, one torque limiter having a simple structure exerts a function as a torque limiter with respect to both forward rotation and reverse rotation, so that it is economical. At the same time, it is advantageous in terms of installation space.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment.

FIG. 2 is a sectional view taken along line II-II in FIG.

FIG. 3 is a sectional view of the embodiment when a high torque is set.

FIG. 4 is an exploded perspective view of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Spring seat ring 2 C ring spring 3 Outer ring 4 Coil spring 5 Torque transmission shaft 6 Pin 7 Cylindrical part 8 Small diameter step 9 Large diameter step 10 Engagement groove 11 Rough edge 12 Torque transmission member 13, 14 Engagement projection 15 Screw Hole 16 Engagement recess 17 Screw 18, 18 'Flat surface

Claims (1)

[Claims] 1. A spring seat ring, a C ring spring, a coil spring, and an outer ring, wherein the spring seat ring is non-rotatably fitted onto the torque transmission shaft, and the C ring spring is loosely fitted onto the torque transmission shaft. The coil spring is wound around the outer diameter surfaces of the spring seat ring and the C ring spring, the outer ring is fitted on the outer side of the coil spring and the outer ring is fixed to the spring seat ring, and one end of the coil spring is used as the spring seat ring. A forward / reverse rotation torque limiter in which the other ends are respectively engaged with the outer ring and the torque transmission member is engaged with the C ring spring.