JP2004156639A - Rotation transmitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reliable, compact/high torque limiter at low costs. <P>SOLUTION: A cylindrical hysteresis material 2 is firmly fixed on a housing case 1 as a first rotary shaft. A cylindrical permanent magnet 4 in which its outer raceway is faced with an inner periphery of a cylindrical magnetic plate is firmly fixed on a second rotary shaft 5. Rotary force3 for either of the respective rotary shafts is transmitted to the other rotary shaft by hysteresis torque generated between the hysteresis material 2 and the permanent magnet 4. Pressed contact torque is added in addition to the hysteresis torque such that washes 6 and 7, a coil spring 8, and a washer 9 are interposed between the housing case 1 and the second rotary shaft 5. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a rotation transmission device, for example, a rotation transmission device such as a torque limiter used in a paper feeding / separating device such as a copying machine, a printer, and a facsimile.
[0002]
[Prior art]
A torque limiter using a hysteresis torque is used for a paper feeding device such as a copying machine or a printer, a reel stand device of audio or video equipment, and the like.
[0003]
FIG. 5 is a longitudinal sectional view showing an example of such a conventional torque limiter. In FIG. 5, a cylindrical hysteresis material 2 is fixed to an inner peripheral surface of a housing case 1 serving as a first rotation shaft, and an opening at one end of the housing case 1 is sealed by a lid member 3. A cylindrical permanent magnet 4 is fixed to the second rotating shaft 5 by press fitting so as to face the inner peripheral surface of the hysteresis material 2. When a driving force is applied to the housing case 1 serving as the first rotating shaft, the driving force is transmitted to the second rotating shaft 5 on the driven side by a hysteresis torque between the hysteresis member 2 and the permanent magnet 4.
[0004]
Although the torque limiter that transmits the torque by such a hysteresis torque is excellent in reliability, the upper limit value is limited because the torque value generated from the magnetic properties of the permanent magnet 4 and the facing area is determined. Moreover, this torque limiter is disadvantageous in that it is expensive.
[0005]
JP-A-4-46222, JP-B-7-3082, and JP-A-4-224316 disclose, as an example of a compact, high-torque hysteresis torque limiter, a combination of a hysteresis torque and a friction torque. Japanese Unexamined Patent Publication No. Hei 6-235449 discloses a technique in which the distance and width between a permanent magnet and a semi-hard magnet are specified to be equal to or less than a certain value to realize a high torque.
[0006]
Japanese Utility Model Publication No. 5-43311 discloses a torque limiter using both a hysteresis torque and a planetary gear. Japanese Utility Model Publication No. 4-113338 discloses a torque limiter using both a hysteresis torque and a roller. ing. Japanese Patent Application Laid-Open No. 5-118344 discloses a torque limiter using both a hysteresis torque and a ball.
[0007]
Further, a torque limiter that generates a torque by a binding force of a coil spring is also an existing technology.
[0008]
[Patent Document 1]
JP-A-4-46222 (FIG. 1)
[0009]
[Patent Document 2]
Japanese Utility Model Publication No. 7-3082 (FIG. 1)
[0010]
[Patent Document 3]
JP-A-4-224316 (FIG. 1)
[0011]
[Patent Document 4]
Japanese Patent Application Laid-Open No. 6-235449 (FIG. 1)
[0012]
[Patent Document 5]
Japanese Utility Model Publication No. 5-43311 (FIG. 1)
[0013]
[Patent Document 6]
Japanese Utility Model Publication No. 4-113338 (FIG. 1)
[0014]
[Patent Document 7]
JP-A-5-118344 (FIG. 1)
[0015]
[Problems to be solved by the invention]
However, this type of torque limiter has a disadvantage in that the spring constant and the dimensional accuracy tend to vary due to its structure, so that the torque varies greatly and the reliability is poor. Therefore, there is a demand for a small, high-torque, and inexpensive torque limiter with high reliability. It is also expensive.
[0016]
Therefore, a main object of the present invention is to provide a small-sized, high-torque, and inexpensive torque limiter having excellent reliability.
[Means for Solving the Problems]
The invention according to claim 1 is a cylindrical magnetic plate fixed to the first rotating shaft, and a cylindrical magnetic plate fixed to the second rotating shaft, the outer peripheral surface of which faces the inner peripheral surface of the cylindrical magnetic plate. A rotation transmitting device for transmitting one of the first and second rotating shafts to the other by a hysteresis torque generated between the magnetic plate and the permanent magnet. An elastic member is provided between the rotation shaft and the second rotation shaft to generate a press-contact torque by an elastic force.
[0018]
By configuring the rotation transmitting device in this way, in addition to the hysteresis torque generated between the magnetic plate and the permanent magnet, the press-contact torque can be added through an elastic member, so that the reliability and the compactness are excellent.・ High torque and inexpensive torque limiter can be realized.
[0019]
In the invention according to claim 2, the first rotating shaft has an inner flange portion extending radially inward, the second rotating shaft has an outer flange portion extending radially outward, and the elastic member has an inner member. It is provided between the flange portion and the outer flange portion.
[0020]
This makes it possible to apply an elastic force in the axial direction between the inner flange portion and the outer flange portion to generate a press-contact torque.
[0021]
The invention according to claim 3 is characterized in that the elastic member is a spring that generates an elastic force directed in the axial direction.
[0022]
The torque value can be set arbitrarily by selecting a spring constant using such a spring.
[0023]
The invention according to claim 4 is characterized in that a washer is mounted between each of the inner flange portion, the spring and the outer flange portion, and thus the elastic force from the spring can be smoothly transmitted by the washer. .
[0024]
In the invention according to claim 5, the first rotating shaft includes a cylindrical housing member having a magnetic plate fixed to an inner peripheral surface thereof, and a lid member for sealing one end of the housing member. The part is a lid member.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a longitudinal sectional view of a torque limiter according to an embodiment of the present invention, and FIG. 2 is an exploded view of the same.
[0026]
In FIG. 1, a housing case 1 and a lid member 3 serving as a first rotating shaft are formed of a synthetic resin material. For example, a resin having a crystallinity of 38% or more is used as a thermoplastic / crystalline resin. If necessary, 5 to 30% by weight of a filler such as potassium titanate whisker, flaky hexaaluminate, fibrous calcium silicate, graphite or the like is mixed. Specific examples include polyphenylene sulfide resin (PPS), polypropylene resin (PP), polybutylene terephthalate resin (PBT), polyacetal resin (POM), polyethylene terephthalate resin (PET), and polycarbonate resin (PC).
[0027]
A cylindrical hysteresis material (Fe—Cr—Co-based magnetic material) 2 is fixed to the inner peripheral surface of the housing case 1. This cylindrical hysteresis material 2 is formed in a seamless pipe shape or a curl shape.
[0028]
When the second rotating shaft 5 involves high load and heat at high speed and high torque, a metal having low thermal conductivity such as an aluminum alloy, a stainless steel alloy, or a copper alloy is suitable, and heat is generated at low speed and low torque. When not accompanied, a sliding agent such as a polyacetal resin, a polyolefin resin, a polycarbonate resin, or a filler can be used.
[0029]
Electrodeposition coating is performed by dispersing a solid lubricant having excellent self-lubricating properties in a binder on friction surfaces 51 and 52 of a second rotating shaft 5 serving as a sliding portion with the housing case 1 serving as the first rotating shaft. Alternatively, a coating film of 8 μm to 25 μm is formed by spray coating. As a solid lubricant, molybdenum disulfide (MoS2) alone, a mixture of molybdenum disulfide and graphite, a mixture of molybdenum disulfide and fluororesin, a mixture of molybdenum disulfide, fluororesin and graphite , Tungsten disulfide (WS2), graphite fluoride, etc. have reliable slidability. In order to reduce the cost of forming a coating film of a solid lubricant, it is also effective to press-fit a resin sleeve-formed product mixed with a sliding agent to the sliding portion of the second rotating shaft 5.
[0030]
On the outer peripheral surface of the second rotating shaft 5, a cylindrical permanent magnet 4 whose outer peripheral surface is multipolarly magnetized is bonded and fixed at a position facing the hysteresis material 2. After compression molding or injection molding of the Nd-Fe-B-based bonded magnet, the permanent magnet 4 is heat-cured, and a resin coating is applied to the surface for rust prevention.
[0031]
An outer flange portion 53 extending radially outward is formed on the outer peripheral surface of the second rotary shaft 5, and one end surface of the permanent magnet 4 contacts the outer flange portion 53. Note that the lid member 3 forms an inner flange portion extending inward in the radial direction. Washers 6 and 7, a coil spring 8 and a washer 9 are mounted between the outer flange portion 53 and the lid member 3 as an inner flange portion to generate a pressing torque. The washers 6, 7, and 9 are made of stainless steel alloy or ultra-high-molecular polyethylene, polyamide resin, unsaturated polyester resin, or fluororesin, and are formed in a disk shape. The coil spring 8 as a spring member has a spring constant according to a set torque value for applying a press contact torque, and is provided between the washers 7 and 9.
[0032]
The thus configured torque limiter is assembled as described below. That is, as shown in FIG. 2, a coating film of a solid lubricant is formed on the sliding surface of the outer peripheral surface of the second rotating shaft 5 in advance, and the cylindrical permanent magnet 4 is adhered and fixed to the magnet rotor 10. Be prepared. A cylindrical hysteresis material 2 is press-fitted and fixed to the housing case 1 to serve as a first rotating shaft. The magnet rotor 10 is mounted in the housing case 1.
[0033]
Next, the washer 6 is mounted so as to contact the outer flange 53 of the magnet rotor 10, and the washer 7, the coil spring 8, and the washer 9 are sequentially mounted on the magnet rotor 10. Sliding grease is applied between the washers 6 and 7 to prevent seizure and abrasion. Friction surfaces 51 and 52 which are sliding parts between the housing case 1 and the rotary shaft 5 are also seized to prevent seizure and abrasion. The sliding grease is applied to the required minimum. Then, when the lid member 3 is fixed to the housing case 1, the washers 6, 7, the coil spring 8, and the washer 9 are fixed.
[0034]
In the torque limiter configured as described above, since the sliding grease is applied between the washers 6 and 7, the washer 6 rotates together with the second rotating shaft 5. Washer 9 rotates with housing case 1. As a result, in addition to the hysteresis torque generated between the hysteresis material 2 and the permanent magnet 4, a friction torque is generated between the washers 6 and 7 due to the press-contact stress of the coil spring 8, so that a high torque value can be obtained. . The set torque value can be easily set by changing the magnetizing voltage of the permanent magnet 4 and the spring constant of the coil spring 8.
[0035]
In the above embodiment, the coil spring 8 is used as the elastic member. However, the present invention is not limited to this, and a coiled wave spring may be used.
[0036]
FIG. 3 is a longitudinal sectional view of a torque limiter according to another embodiment of the present invention, and FIG. 5 is an exploded view of the same. In this embodiment, a curved disc spring 11 is mounted between the washers 6 and 9 in place of the coil spring 9 in the embodiment shown in FIGS. Sliding grease is applied between the washer 6, the curved spring 11, and the washer 9 curved spring 11, respectively. Also in this embodiment, in addition to the hysteresis torque generated between the hysteresis member 2 and the permanent magnet 4, a friction torque is generated between the washers 6 and 9 due to the pressure contact stress of the curved disc spring 11, so that a high torque value is obtained. Can be obtained. The set torque value can be easily set by changing the magnetizing voltage of the permanent magnet 4 and the spring constant of the curved disc spring 11.
[0037]
One embodiment of the present invention has been described with reference to the drawings, but the present invention is not limited to the illustrated embodiment. Various changes can be made to the illustrated embodiment within the same or equivalent scope as the present invention. For example, the elastic member is not limited to a spring, but may be a rubber member or a fluid having elasticity. The elastic force may generate not only a pressing torque in the axial direction but also a pressing torque in the radial direction.
[0038]
【The invention's effect】
As described above, according to the present invention, the cylindrical magnetic plate fixed to the first rotating shaft and the cylindrical magnetic plate fixed to the second rotating shaft, the outer peripheral surface of which faces the cylindrical inner peripheral surface In a rotation transmission device including a permanent magnet in a shape, in addition to a hysteresis torque generated between the magnetic plate and the permanent magnet, an elastic member is provided between the first rotation shaft and the second rotation shaft to perform pressure contact. Since the torque is added, a small, high-torque and inexpensive torque limiter with excellent reliability can be realized.
[0039]
In addition, the torque value can be increased by 30% compared to a torque limiter having only the hysteresis torque of the same shape and size without losing reliability such as durability, and the number of parts increases, but the volume of an expensive magnet decreases. , The cost could be reduced by 20%.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a torque limiter according to an embodiment of the present invention.
FIG. 2 is an exploded view of the torque limiter according to the embodiment of the present invention.
FIG. 3 is a longitudinal sectional view of a torque limiter according to another embodiment of the present invention.
FIG. 4 is an exploded view of a torque limiter according to another embodiment of the present invention.
FIG. 5 is a longitudinal sectional view showing an example of a conventional torque limiter.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 housing case, 2 hysteresis material, 3 lid member, 4 permanent magnet, 5 second rotating shaft, 6, 7, 9 washer, 8 coil spring, 10 magnet rotor, 11 curved disc spring, 51, 52 friction surface, 53 Outer flange part.

Claims (5)

A cylindrical magnetic plate fixed to the first rotating shaft; and a cylindrical permanent magnet fixed to the second rotating shaft and having an outer peripheral surface facing an inner peripheral surface of the cylindrical magnetic plate. A rotation transmitting device that transmits a rotational force of one of the first and second rotation shafts to the other by a hysteresis torque generated between the magnetic plate and the permanent magnet;
A rotation transmission device, wherein an elastic member that generates a press-contact torque by an elastic force is provided between the first rotation shaft and the second rotation shaft. The first rotation shaft has an inner flange portion extending radially inward,
The second rotation shaft has an outer flange portion extending radially outward,
The rotation transmitting device according to claim 1, wherein the elastic member is provided between the inner flange portion and the outer flange portion. The rotation transmitting device according to claim 2, wherein the elastic member is a spring that generates an elastic force directed in an axial direction. The rotation transmitting device according to claim 3, wherein a washer is mounted between each of the inner flange portion, the spring, and the outer flange portion. The first rotation axis is
A cylindrical housing member having the magnetic plate fixed to its inner peripheral surface,
A lid member for sealing one end side of the housing member,
The rotation transmitting device according to claim 2, wherein the inner flange portion is the lid member.

Images