JPH10267044A - Torque limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a torque limiter transmitting stable torque by a stable friction condition without deforming a friction material. SOLUTION: A drive material 1 has a flange part 2 and a shaft part 3 vertical to the flange part 2 with the shaft center passing through the center of the flange part 2. The shaft part 3 is inserted through a first friction material 8, disk-shaped driven material 5, second friction material 10 and a reinforcing plate 11 in this order. In the vicinity of a tip end of the shaft part 3, a pressure adjusting part 17 is provided, between the pressure adjusting part 17 and the reinforcing plate 11, an elastic member 14 is interposed. Pressing force by the elastic member 14 is adjusted by the pressure adjusting part 17. Here, the first friction material 8 is secured to the flange part 2 or the driven material 5, the second friction material 10 is secured to the driven material 5 or the reinforcing plate 11, so that even when a part of non-uniform friction force is provided in each friction surface, generation of a wrinkle in the friction material 8, 10 and twisting thereof are prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a torque limiter used for transmitting torque in a printer or the like.

[0002]

2. Description of the Related Art A conventionally known torque limiter has a driving member which is rotationally driven by a driving source such as a motor, and a driven member which outputs a torque less than a limit torque to the outside. As an example of such a conventional torque limiter,
The driven material has a disc-like shape with a hole formed in the center, and the driving material has a disc-shaped flange portion and a shaft portion, and there is a driving material that rotatably penetrates the hole of the driven material.

[0003] Between the flange portion of the driving material and the driven material,
A sheet-shaped first friction material made of high-strength fiber is provided. This first friction material is not fixed to either the flange portion or the driven material. Also, a sheet-like second friction material also formed of high-strength fiber is slidably in contact with the opposite surface of the driven material. The second friction material is fixed to the reinforcing plate.

The elastic member presses the driven member toward the flange portion through the reinforcing plate and the second friction member, and the pressing force is adjusted by a pressure adjusting portion.

In such a structure, the torque of the driving member is transmitted to the driven member via the first and second friction members. The limit torque at which the torque is not transmitted is adjusted by the pressure adjusting unit.

[0006]

In such a torque limiter, when torque is transmitted from the driving member to the driven member, the first friction member rotates while sliding on the flange portion and the driven member. However, the first friction material is sheet-shaped, and if there is a portion where the frictional force is strong on each friction surface, that portion is less likely to slide than the other portions, so that wrinkles may occur in that portion. And the first friction material is twisted.

In this case, since the state of the friction surface between the first friction material, the flange portion and the driven material is not stable, the value of the transmitted torque becomes unstable, and the function as a torque limiter is obtained. Disappears.

A conventional technique for solving this problem is disclosed in Japanese Utility Model Publication No. Hei 3-7622. However, this has a problem that the number of parts increases because the first friction material is formed by fixing sheet-like high-strength fibers on both surfaces of the reinforcing plate.

Accordingly, an object of the present invention is to provide a torque limiter capable of transmitting a stable torque without deforming a friction material.

[0010]

According to the first aspect of the present invention,
The driving member has a shaft portion vertically erected from the center of the disk-shaped flange portion. The driving member is rotationally driven by a driving source, and the shaft portion has a first friction material, a disk-shaped driven material, and a The two friction materials and the reinforcing plate are rotatably penetrated in this order, and an elastic member whose pressing force is adjusted by a pressure adjusting unit presses the reinforcing plate. Here, the first friction material is fixed to one of the flange portion and the driven material and is slidable with respect to the other, and the second friction material is fixed to one of the driven material and the reinforcing plate and slidable with respect to the other. It is.

Therefore, since the first and second friction members have one surface fixed to the adjacent member, when the torque is transmitted from the driving member to the driven member, the friction force increases on the friction surface. Even if there is a portion that is hard to slide, wrinkles do not occur in that portion and the friction material does not twist.

According to the second aspect of the present invention, the first friction material and the second friction material are fixed to the driven material.

Therefore, since the first friction material and the second friction material have one surface fixed to the adjacent member, the friction material is not twisted.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of a torque limiter according to the present invention will be described with reference to FIGS. First, the driving member 1 includes a disk-shaped flange portion 2 and a shaft portion 3.
Consists of The shaft portion 3 is provided perpendicular to the flange portion 2 between the flange portion 2 and the shaft portion 3. Flange part 2
A gear 4 is formed on the outer periphery of the drive member 1, and the driving member 1 is driven to rotate by a drive source such as a motor (not shown) via the gear 4.

The driven member 5 has a disk shape, and has a shaft portion 3 at the center.
A hole 6 having an inner diameter slightly larger than the outer diameter of the shaft portion 3 is formed, and the shaft portion 3 rotatably penetrates the hole 6. A gear 7 for outputting torque to the outside is formed on the outer periphery of the driven member 5.

The driving member 1 and the driven member 5 are made of engineering plastic. Representative examples include polyphenylene oxide, polyphenylene sulfide, and polyoxymethylene. Since the engineering plastic has self-lubricating properties and the shaft portion 3 and the driven member 5 are in a loose fit state, it is not necessary to provide a bearing between the shaft portion 3 and the driven member 5. Furthermore, if a lubricant or the like is impregnated, the rotation can be made smoother.

A sheet-like first friction material 8 is fixed to the surface of the flange portion 2 on the side of the driven material 5 (see FIG. 2). The fixing method is to bond with an adhesive, or
Can be directly fixed to the flange portion 2 by an insert technique without using an adhesive. The first friction material 8 has a hole 9 through which the shaft portion 3 passes. And the first friction material 8
Is slidable with respect to the driven member 5.

The surface of the driven member 5 opposite to the surface slidable with respect to the first friction material 8 is slidable with respect to the second friction material 10. The second friction material 10 has a sheet shape and is fixed to the reinforcing plate 11 (see FIG. 2). The second friction material 10 and the reinforcing plate 11 each have holes 12 and 13 having an inner diameter slightly larger than the outer diameter of the shaft portion 3 at the center, and the shaft portion 3 rotatably penetrates.

The first friction material 8 and the second friction material 10 are made of high-strength fiber. Specifically, a steel fiber, a glass fiber, a carbon fiber, a boron fiber, an alacido fiber, a fluorine fiber as a base material, a fluororesin, polychlorotrifluoroethylene,
The sheet is formed by impregnating or dipping a synthetic resin represented by epoxy or the like.

A spring 14 which is an elastic member for pressing the driven member 5 toward the flange portion 2 is fitted on the shaft portion 3. One end of the spring 14 contacts the surface of the reinforcing plate 11 to which the second friction material 10 is not fixed, and the other end of the spring 14 contacts the nut 15.

An internal thread is cut on the inner periphery of the nut 15, and the nut 15 is screwed into a screw portion 16 formed at the end of the shaft portion 3. The pressure adjusting section 17 includes a nut 15 and a screw section 16 and is used for adjusting the pressing force exerted on the driven member 5 by the spring 14.

The reinforcing plate 11 has strength and thickness enough to withstand the pressing force of the spring 14.
It is formed by an elastic material. Specifically, metal, plastic, rubber and the like are suitable.

In such a configuration, the driving member 1 is rotationally driven by a driving source such as a motor via the gear 4 of the flange portion 2. When the driving member 1 is rotationally driven, a frictional force is generated between the first friction member 8 fixed to the flange portion 2 and one surface of the driven member 5. The driving force rotates the auxiliary plate 11 via the pressure adjusting unit 17 and the spring 14, and the frictional force is generated between the second friction material 10 fixed to the auxiliary plate 11 and the other surface of the driven material 5. Occurs. Torque is transmitted to the driven member 5 by the frictional force between the two surfaces.

If the torque transmitted to the driven member 5 is larger than the load torque applied to the gear 7, the driven member 5 rotates,
If the load torque applied to the gear 7 is smaller, the driven member 5 does not rotate. The setting of the transmission torque is performed by the pressure adjusting unit 17.

As described above, if one surface of the first and second friction members 8 and 10 is fixed to another member, even if there is a portion where the frictional force between the first and second friction members 8 and 10 and the driven member 5 are uneven, Since the first and second friction members 8 and 10 are not twisted, the state of the friction surface is stable and stable torque is transmitted.

FIG. 3 shows a torque limiter according to a second embodiment of the present invention. The same portions as those described in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. In the present embodiment, the first friction material 8 is
Is fixed to the surface on the flange portion 2 side. Second friction material 1
Numeral 0 is fixed to the surface of the driven member 5 on the reinforcing plate 11 side.

In such a configuration, the transmission of the torque from the driving member 1 to the driven member 5 depends on the frictional force between the flange portion 2 and the first frictional member 8 and the reinforcing plate 11 and the second frictional member 1.
It is performed by a frictional force between zero and zero. Even if there is a portion where the frictional force is not uniform on each friction surface, the first and second friction materials 8 and 10
Is not twisted, the state of the friction surface is stable, and a stable torque is transmitted.

In practice, the first friction material 8 only needs to be fixed to the flange portion 2 or the driven member 5, and the second friction material 10 is fixed to the driven member 5 or the reinforcing plate 11. It should be fine. For example, the first friction material 8 is fixed to the driven material 5 and the second friction material 10 is
May be fixed.

[0029]

According to the first aspect of the present invention, the driving member has a shaft portion vertically erected from the center of the disk-shaped flange portion. The driving member is driven to rotate by a driving source, and the shaft portion is rotated. The first friction material, the disk-shaped driven material, the second friction material, and the reinforcing plate are rotatably penetrated in this order, and the elastic member whose pressing force is adjusted by the pressure adjusting unit presses the reinforcing plate. Here, the first friction material is fixed to one of the flange portion and the driven material and is slidable with respect to the other, and the second friction material is fixed to one of the driven material and the reinforcing plate and slid with respect to the other. Since the first and second friction members are freely fixed, one surface thereof is fixed to the adjacent member, when the torque is transmitted from the driving member to the driven member, the friction force is increased on the friction surface. Prevents wrinkles from forming on parts that are difficult to slide , It is possible to prevent the twisting of the friction material. Therefore, the state of the friction surface can be stabilized, so that stable torque can be transmitted.

According to the second aspect of the present invention, since the first friction material and the second friction material are fixed to the driven material, the first friction material and the second friction material are fixed to one surface of the adjacent member. In addition, since the torsion of the friction material can be prevented and the state of the friction surface can be stabilized, a stable torque can be transmitted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a torque limiter of the present invention.

FIG. 2 is an exploded view showing the first embodiment of the present invention.

FIG. 3 is an exploded view showing a second embodiment of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 driving member 2 flange portion 3 shaft portion 5 driven member 6 hole 8 first friction member 10 second friction member 11 reinforcing plate 14 elastic member 17 pressure adjusting portion

Claims (2)

[Claims] 1. A driving member having a disk-shaped flange portion and a shaft portion vertically erected from the center of the flange portion, the driving member being rotatably driven by a driving source, and the shaft portion rotatably penetrating therethrough. A disk-shaped driven member having a hole and outputting a rotation drive input input to the driving member; and being provided between the flange portion and the driven member, being fixed to one of the flange portion or the driven member. A first friction material that is slidable with respect to the other, a reinforcing plate having a hole that sandwiches the driven material between the first friction material and the shaft portion rotatably penetrates; A second friction material provided between the driven member and the reinforcing plate and fixed to one of the driven member and the reinforcing plate and slidable with respect to the other, an elasticity for pressing the reinforcing plate toward the flange portion. Adjusting the pressing force of the member and the elastic member And a pressure adjuster. 2. The torque limiter according to claim 1, wherein the first friction material and the second friction material are fixed to a driven material.