JPH1127928A - Torque limiter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To transfer torque stably for a long time with a compact torque limiter by forming either one of a first interlocking main body being mounted to a drive shaft or a second interlocking body being supported rotatably with a rare-earth magnet with at least a specific energy product being magnetized to multiple poles in circumferential direction, and forming the other with a hysteresis material. SOLUTION: A first interlocking main body 12, that is formed cylindrically by Nd-Fe-B rare-earth magnet with pole anisotropy for obtaining an energy product (BH) max exceeding 25 (MGOe) and where at least 12 multiple poles are magnetized in circumferential direction is adhered to the outer periphery surface of a first rotary substrate 3 in rotor state being mounted to a drive shaft 2. A second rotary substrate 4 is constituted of a closed-end cylindrical member 4a and a lid body 4b for covering the opening edge and is rotatably and coaxially supported on the first rotary substrate 3. A second cylindrical interlocking main body 6, that is made of a hysteresis material that opposes the first interlocking main body 12 through an interval 7 of at least 0.3 mm, is forced into and is mounted to the inner periphery surface of the closed-end lid-shaped member 4a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hysteresis type torque limiter used for driving a paper feed roller or the like in OA equipment.

[0002]

2. Description of the Related Art FIG. 6 is a longitudinal sectional view showing a hysteresis type torque limiter disclosed in JP-A-6-221341. This torque limiter 1 is made of a first oil-impregnated sintered aluminum material fixed to a drive shaft 2.
Of the rotating base 3 and a polypropylene resin,
A second rotating base 4 coaxially and rotatably supported by the rotating base 3 and a circle forming a first cylindrical connecting body 5 adhered to the outer peripheral surface of the first rotating base 3. A cylindrical permanent magnet multipolarly magnetized in the circumferential direction;
And a cylindrical hysteresis material formed of a semi-rigid magnetic material forming a cylindrical second connection main body 6 press-fitted into the inner peripheral surface of the first connection main body 5. Second
The inner peripheral surface of the connecting main body 6 of Japanese Patent Application Laid-Open No. 7-791
As shown in Japanese Patent Application Publication No. 9 (1994), they are configured to face each other with a gap 7 of 0.1 mm or less. Numeral 8 denotes a paper feeding rubber roller which is connected to the second rotating base 4 and is driven to rotate by a hysteresis torque generated between the first connecting main body 5 and the second connecting main body 6.

[0003]

In the conventional torque limiter, the first connection main body 5 is made of Nd-Fe-B resin magnet NP-8L (manufactured by Daido Special Metal Co., Ltd .: energy product (BH) max8). .5 to 10 (MGOe)), and the second connecting subject is a Fe-Cr-Co alloy K
M-3H (Mitsubishi Steel Corporation: Energy product (BH)
max1.5 (MGOe)). With this configuration, it is difficult to generate a torque. For example, in order to obtain the torque (0.53 kgfcm) required for the paper feed roller, the gap 7 must be 0.1 m.
m. For this reason, high accuracy is required for the component parts, and the cost increases.

The first rotating base 3 and the second rotating base 4 are coaxially supported by sliding surfaces 9a and 9b therebetween, but a radial gap 10 between the sliding surfaces 9a and 9b is provided. ,
If the gap 11 is non-uniform, the gap 7 is as small as 0.1 mm or less, which has a large effect, and the gap 7 at both ends becomes large. The unevenness of the gap 7 is caused by the first connection main body 5 and the second connection main body 5.
This causes imbalance of the suction force at both ends of the connecting main body 6 and unevenness of the sliding resistance on the sliding surfaces 9a and 9b, so that the torque transmitted to the second rotating base 4 fluctuates greatly, Predetermined torque performance cannot be obtained.

If the suction force imbalance at both ends of the gap 7 is large, an excessive load is applied to the sliding surfaces 9a and 9b, the sliding resistance increases, and wear occurs. The uniformity increases, the imbalance of the suction force increases, and the torque fluctuation increases. Eventually, the first connection main body 5 and the second connection main body 6 come into contact with each other, or the adhesion of the first connection main body 5 comes off. Problems occur.

[0006] The above problems can be solved by increasing the gap 7, but a large torque limiter is required to obtain a predetermined transmission torque, which increases the cost and increases the cost.
A large mounting space is required, which causes an increase in the size of the device.

The present invention has been made to solve the above problems, and has as its object to obtain an inexpensive torque limiter which is small in size, can maintain a stable transmission torque for a long period of time, and has a low cost.

[0008]

A torque limiter according to the present invention comprises a first connecting body coaxially mounted on a drive shaft and a second connecting body rotatably supported coaxially with the first connecting body. A torque having a connecting main body, and one of the two connecting main bodies is formed of a cylindrical permanent magnet that is multipolarly magnetized in the circumferential direction, and the other is formed of a cylindrical hysteresis material. In the limiter, the first connection main body is formed of a polar anisotropic Nd—Fe—B rare earth magnet having an energy product (BH) max of 25 (MGOe) or more.

Further, the second connecting body is formed of a semi-hard magnetic material having an energy product (BH) max of 1.7 (MGOe) or more.

[0010] The gap between the first connecting main body and the second connecting main body is formed to be 0.3 mm or more.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings showing the embodiments. Embodiment 1 FIG. FIG. 1 is a longitudinal sectional view showing a torque limiter according to Embodiment 1 of the present invention. In the figure, 1
Is a torque limiter, 2 is a drive shaft that is rotationally driven by a drive device (not shown), 3 is a rotor-like first rotating base attached to the drive shaft 2, and is made of an oil-impregnated sintered aluminum material or the like. A first connection main body 12 formed of a polar anisotropic Nd—Fe—B rare earth magnet in a cylindrical shape and multipolarly magnetized in the circumferential direction is adhered to the outer peripheral surface thereof. Reference numeral 4 denotes a second rotating base made of a polypropylene resin or the like, which is composed of a bottomed cylindrical member 4a and a lid 4b that covers the opening end thereof, and has a shaft rotatable coaxially with the first rotating base 3. A cylindrical second member made of a semi-hard magnetic material (hysteresis material) which is supported on the inner peripheral surface of the bottomed cylindrical member 4a and faces the first connection main body 12 via the gap 7 is provided.
Are connected by press-fitting. The cylindrical first connection main body 12 is a polar anisotropic Nd- having an energy product (BH) max of 25 (MGCo) or more.
It is composed of a Fe-B rare earth magnet and is multipolarly magnetized to 12 or more poles in the circumferential direction.

FIG. 2 shows the conventional example and the first embodiment.
9 shows specifications of a torque limiter according to a second embodiment described later, and a calculated value and an actually measured value of a transmission torque when the permanent magnet is almost 100% magnetized. In the figure, "hysteresis material" is the second connection main body, "permanent magnet" is the first connection main body, and "operating width" is the axial dimension of the permanent magnet and the hysteresis material facing each other. The hysteresis material is formed to have a length that is 0.5 to 2.0 longer in order to effectively use. "Number of poles" is the number of magnetized poles in the circumferential direction of the permanent magnet.

In FIG. 2, patterns (1) to (4) show data of the first embodiment.
This is a value calculated using an ASIC calculation program.
Comparing the calculated value and the actually measured value of the transmission torque of the conventional example shown in FIG. 6 with the pattern of the first embodiment, the calculation results are very close to each other. It is considered expensive.

In the configuration of the first embodiment, when the dimensions of the first connection main body 12 and the second connection main body 6 are changed to have the same size as the conventional device as a pattern, the calculated value is 0.724 kgfcm. And the transmission torque is greatly increased. Further, as disclosed in Japanese Patent Application Laid-Open No. 6-235449, in order to generate a transmission torque of 0.532 to 0.543 Kgfcm required as a torque limiter for a paper feed roller without changing the axial dimension, As shown in the pattern, the outer diameter can be reduced by about 23%, and when the outer diameter is the same, the operating width (dimension in the axial direction) can be reduced by about 26% as shown in the pattern.

As described above, according to the first embodiment, if the transmission torque is the same, the size of the torque limiter can be reduced, and the material cost can be reduced as the size is reduced, so that the cost can be reduced. .

Embodiment 2 FIG. 3 is a diagram showing a torque limiter according to a second embodiment of the present invention. The same reference numerals as those in FIG. 1 denote the same or corresponding parts. In the figure, reference numeral 13 denotes a second connecting entity, which is a conventional KM-3H.
Energy product (B) larger than (Mitsubishi Steel Corporation)
H) KM-6H from which max is obtained (Mitsubishi Steel Corporation: energy product (BH) max 1.7 to 2 (MGO
e)) or YHJ32-14 (manufactured by Hitachi Metals, Ltd .: energy product (BH) max 1.7 (MGOe) or more). The pattern in FIG. 2 shows the calculated value of the transmission torque when each component of the second embodiment is configured to have the same dimensions as the conventional example. The transmission torque is about 2.7 times that of the conventional example. Is obtained.

FIG. 4 shows a conventional example, in which the gap between the pattern of the first embodiment and the pattern of the second embodiment in which the dimensions of the first and second connecting bodies are the same as that of the conventional example is enlarged. FIG. 7 is a diagram showing a change in the calculated value of the transmission torque in the case where the transmission torque is changed, in which the solid line indicates the conventional example, the broken line indicates the transmission torque according to the first embodiment, and the one-dot chain line indicates the transmission torque according to the second embodiment. As can be seen from FIG. 4, the size of the gap for obtaining a transmission torque of 0.53 kgfcm is 0.9 mm in the first embodiment and 1.33 mm in the second embodiment.

FIG. 5 shows the first and second embodiments.
In the above, when the size of the gap 7 was set to 0.3 mm and the external dimensions were reduced, the size was 0.532 to 0.543 Kgfc.
The figure shows the calculation results of the dimensions of each component member that can obtain the transmission torque of m, and the pattern and the pattern show the case of the first embodiment and the pattern and the case of the second embodiment. As can be seen from FIG. 5, in the pattern in which the operation width (dimension in the axial direction) is the same as that of the conventional example, the outer diameter dimension is 1 mm.
The size can be reduced by 6% and the pattern can be reduced by 22%. Further, in the pattern having the same outer diameter, the operation width (dimension in the axial direction) can be reduced by 26%, and in the pattern, the size can be reduced by 62%.

Thus, the size of the gap 7 is set to 0.3 mm
Therefore, even if unevenness occurs in the radial gap between the sliding surfaces 9a and 9b, the influence on the unbalance of the suction force at both ends of the first connection main body and the second connection main body is small. The influence on the sliding resistance of the moving surfaces 9a and 9b is small, and the transmission torque can be stably maintained for a long period of time.

In each of the above embodiments, the first connection main body is made of a permanent magnet, and the second connection main body is made of a hysteresis material. However, the first connection main body is made of a hysteresis material. The connection main body of 2 may be constituted by a permanent magnet,
Similar effects can be obtained.

[0021]

Since the present invention is configured as described above, it has the following effects.

The first connecting entity is defined as an energy product (BH)
polar anisotropic Nd—Fe with a max of 25 (MGOe) or more
Since the magnet is constituted by the -B rare earth magnet, the transmission torque is greatly increased, the size can be reduced, and the cost can be reduced.

Further, since the second connecting body is formed of a semi-hard magnetic material having an energy product (BH) max of 1.7 (MGOe) or more, the transmission torque further increases.
Further, the size can be reduced and the cost can be reduced.

Further, since the gap between the first connection main body and the second connection main body is formed to be 0.3 mm or more, there is an effect that a long-life torque limiter having no change in transmission torque for a long period of time can be obtained. .

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a torque limiter according to Embodiment 1 of the present invention.

FIG. 2 shows a conventional example, and first and second embodiments.
FIG. 4 is a diagram showing specifications of a torque limiter, and a calculated value and an actually measured value of a transmission torque.

FIG. 3 is a longitudinal sectional view of a torque limiter according to Embodiment 2 of the present invention.

FIG. 4 is a diagram showing calculated values of transmission torque to gaps in the conventional example and the first and second embodiments.

FIG. 5 is a graph showing a relationship between a gap value of 0.3 mm and a gap value of 0.3 mm;
FIG. 13 is a diagram showing a calculation result of dimensions of each component of the first and second embodiments capable of obtaining a transmission torque of 53 kgfcm.

FIG. 6 is a longitudinal sectional view of a conventional torque limiter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Torque limiter, 2 drive shaft, 3rd rotating base, 4th rotating base, 6, 13 2nd connection main body,
7 gap, 12 first connecting entity.

Claims (3)

[Claims] A first connecting body coaxially attached to a drive shaft; and a second connecting body rotatably supported coaxially with the first connecting body. One of the torque limiters is configured with a cylindrical permanent magnet that is multipolar magnetized in the circumferential direction, and the other is configured with a cylindrical hysteresis material, wherein the first connection main body is A torque limiter comprising an Nd-Fe-B rare earth magnet having an energy product (BH) max of 25 (MGOe) or more and having a polar anisotropy. 2. The torque limiter according to claim 1, wherein the second connection main body is formed of a semi-hard magnetic material having an energy product (BH) max of 1.7 (MGOe) or more. . 3. The torque limiter according to claim 1, wherein a gap between the first connection main body and the second connection main body is formed to be 0.3 mm or more.