JP2002349613A - Magnetic particle type transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make infiltration of magnetic particles into a seal and a bearing part difficult, even if the magnetic particles are stirred. SOLUTION: In a device in which the magnetic particles 9 are sealed between stators 1, 2 and a rotor 8, the infiltration of the magnetic particles 9 to the inside is prevented by providing a stepped part 8d to the rotor 8, and at the same time, the stepped parts 1b, 2b also to the stators 1, 2 so as to face the stepped part 8d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic particle type transmission device in which a limit of a transmission torque between a pair of connecting bodies is determined by a magnetic particle type coupling force.

[0002]

2. Description of the Related Art FIG. 4 is a partially sectional side view showing a conventional magnetic particle type transmission device. In the figure, 21 and 22 are annular stators made of a magnetic material,
It is fixed to a mechanical part not shown. Reference numeral 23 denotes a rotating shaft, which is rotatably supported by bearings 24, 25 built in the stators 21, 22. 26 is the stator 2l, 2
2 is a built-in coil, and 27 is a stator 2l, 2
2 is a ring made of a non-magnetic material fixed inside.
The flow of the magnetic flux φ generated from the coil 26 is regulated. Reference numeral 28 denotes a rotor which is disposed so as to face the side surfaces 21a and 22a of the stators 21 and 22 and is fixed to the rotating shaft 23. The side surface 28a serving as an operating surface of the rotor 28
And the side surfaces 2la, 2 serving as operating surfaces of the stators 21, 22
Magnetic particles 29 are sealed between 2a.

Reference numeral 30 denotes a retaining ring for fixing the bearings 24 and 25, and reference numerals 31 and 32 denote seals for preventing the magnetic particles 29 from entering the bearings 24 and 25. The holes 28b provided in the rotor 28 are provided for facilitating the magnetic particles 29 to enter the upper and lower operation surfaces of the rotor 28, and are arranged at several locations around the entire circumference. Also, 2
Reference numeral 3a denotes an annular groove provided on the rotating shaft 23 for preventing the magnetic particles 29 from getting over the seals 31, 32 and entering the bearings 24, 25.

Next, the operation will be described. When a voltage is applied from a power source (not shown) to the coil 26, a magnetic flux φ is generated in a magnetic path indicated by a dotted line, and the magnetic flux 29
Are the side surfaces 21a and 22a of the stators 21 and 22 and the rotor 2
8 between the side surfaces 28a, as if they were connected in a chain-like manner.
The braking force acts on the magnetic particles 29 to stop a load (not shown), or the magnetic particles 29 and the rotor 28 perform an operation of continuing braking while slipping, and there is an advantage that continuous slip control can be performed.

[0005]

Since the conventional magnetic particle transmission device is constructed as described above, when the voltage to the coil 26 is removed while the rotating shaft 23 is kept vertical, the magnetic flux φ When the rotating shaft 23 idles in this state, the magnetic particles 29 are stirred inside. And
The agitated magnetic particles 29 reach the rotating shaft 23, and, in some cases, get over the seal 31 to form the bearings 24, 25.
Up to that point. This is because when the magnetic particles 29 are in a free state, they tend to fall down due to gravity.
This is because the magnetic particles 29 tend to accumulate on the operation surface 21a which is the side surface of the stator 21. And especially the seal 31
On the side, it was remarkably observed that the magnetic particles 29 reached the bearing 24.

Thus, the magnetic particles 2 reaching the bearing 24
No. 9 has a problem that it penetrates into the inside of the bearing 24 and hinders rotation, and in the worst case, does not rotate, thereby impairing the function as a transmission device.
As a countermeasure for this, it is conceivable to increase the thickness of the seal 31 or the like, but there is a problem that the dimension in the axial direction increases. Furthermore, as another measure, the seal 3
There are methods such as applying pressure to the contact surface between the shaft 1 and the rotating shaft 23, or making the sealing structure of the bearing 24 itself a contact type, but in any case, the idling torque when the rotating shaft 23 is idling becomes large. However, there is a problem that the control range of the transmission device is restricted.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and at the same time obtains a structure for preventing magnetic particles from reaching a bearing at a low cost, and has high performance and performance.
It is an object of the present invention to provide a highly reliable magnetic particle transmission device having a size comparable to that of the current size.

[0008]

According to a first aspect of the present invention, there is provided a magnetic particle transmission device having a ring shape, a stator having a side surface serving as an operation surface on an inner periphery, and a stator built in the stator. A coil, a rotor arranged on the inner periphery of the stator via a gap, a rotor fixed to the rotor, and the stator is a rotating shaft provided via a bearing, and magnetic particles inserted into the gap. And a step is provided on the rotor, and a step is also provided on the stator at a position facing the step.

According to a second aspect of the present invention, there is provided a magnetic particle transmission device in which a seal is provided on the inner peripheral side of the step.

According to a third aspect of the present invention, there is provided a magnetic particle transmission device having an annular shape, a stator having an inner peripheral side surface serving as an operating surface, a coil built in the stator, and a stator. A rotor provided on the inner periphery of the rotor via a gap, a rotor fixed to the rotor, and the stator comprising a rotating shaft disposed via a bearing and magnetic particles inserted into the gap. In this configuration, one of the side surface of the rotor and the side surface of the stator facing the side surface is provided with a convex portion, and the other side surface is provided with a concave portion.

According to a fourth aspect of the present invention, there is provided a magnetic particle transmission device wherein a seal is provided on an inner peripheral side of the convex portion and the concave portion.

According to a fifth aspect of the present invention, in the magnetic particle transmission device, the rotor is formed in a disk shape.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a partial cross-sectional side view showing a magnetic particle transmission device according to Embodiment 1 of the present invention. In the drawing, reference numerals 1 and 2 denote stators formed in a ring shape and made of a magnetic material. Fixed to the part. Reference numeral 3 denotes a rotating shaft, which is rotatably supported by bearings 4 and 5 built in the stators 1 and 2. Reference numeral 6 denotes a coil built in the stators 1 and 2, and reference numeral 7 denotes a ring made of a non-magnetic material similarly fixed in the stators 1 and 2, which restricts the flow of the magnetic flux φ generated from the coil 6. It is. Reference numeral 8 denotes a rotor arranged to face the side surfaces 1a and 2a of the stators 1 and 2 and fixed to the rotating shaft 3.
Magnetic particles 9 are sealed between the side surfaces 8a and 8b serving as operating surfaces of the rotor 8 and the side surfaces la and 2a serving as operating surfaces of the stators 1 and 2.

Reference numeral 10 denotes a retaining ring for fixing the bearings 4 and 5, and reference numerals 11 and 12 denote seals for preventing the magnetic particles 9 from entering the bearings 4 and 5. The holes 8c provided in the rotor 8 are provided in order to make it easier for the magnetic particles 9 to enter the upper and lower operation surfaces of the rotor 8, and are arranged at several locations around the entire circumference. Reference numeral 3a denotes an annular groove provided on the rotating shaft 3, and the magnetic particles 9
In order to prevent the vehicle from getting over the bearings 4 and 5.

In this embodiment, the rotor 8 is further provided with a stepped portion 8d, and is located at a position facing the stepped portion 8d.
2b. In the step, the height of the side surface 1c of the stator 1 is set to be higher than the height of the side surface 8a of the rotor 8. The steps 1b, 2b, 8d are formed in an annular shape so as to correspond to the shape of the rotor 8.

Next, the operation will be described. According to the magnetic particle transmission device configured as described above, when a voltage is applied to the coil 6 from a power source (not shown), a magnetic flux φ is generated in a magnetic path indicated by a dotted line, and the magnetic particles 9
Stator 1, 2 and side surface 1a, 2a, 8a, 8b of rotor 8
As if they were connected like a chain, a braking force acts on the rotating shaft 3 that has been rotating so far, and a load (not shown) is stopped, or the magnetic particles 9 and the rotor 8
Is to continue receiving braking force while slipping.

Then, with the rotation axis 3 kept vertical,
When the voltage to the coil 6 is removed, the magnetic flux φ disappears, and the rotating shaft 3 idles. Then, the magnetic particles 9 are agitated inside, and the agitated magnetic particles 9 try to reach the rotating shaft 3, but the stepped portion 1 b provided on the stator 1 blocks the intrusion into the inside. Become. This is because the magnetic particles 9 fall down due to gravity. That is, the magnetic particles 9
Accumulates on the side surfaces 1a and 8b, which are the surfaces of the stator 1 and the rotor 8, however, at this time, if there are steps 1b and 8d, the entry of the magnetic particles 9 is stopped at these portions and the seals 11 and 1
2 and the bearings 4 and 5 are hardly reached, and a stable rotation function can be continued.

In FIG. 1, the rotor 8 and the stator 2 are also provided with a step. However, due to gravity, the seal 12 on the bearing 5 side is provided with a magnetic particle. Since it is considered that the step 9 does not easily penetrate, a step may not be provided in this portion. The step may be formed in a planar shape and a step may be provided only on one side. In addition, the stators 11 and 12 are
Since the seal 11 is provided on the inner peripheral side of the step portion 1b provided in the device, it is not necessary to increase the width of the entire device. Further, since the rotor 8 has a disk shape, the step 8d can be manufactured by press working, which does not increase the manufacturing cost. Further, in the structure shown in FIG. 1, the description has been given of the substantially vertical mounting in which the output side of the rotating shaft 3 is on the upper side.

Embodiment 2 FIG. FIG. 2 is a partially sectional side view showing a magnetic particle transmission device according to Embodiment 2 of the present invention. In the drawing, reference numerals 1 and 2 denote a stator, 8 denotes a rotor,
It has side surfaces 1a, 2a, 8a, and 8b serving as respective operation surfaces. Protruding protrusions 8e are provided on both side surfaces 8a and 8b of the rotor 8, and the stators 1 and 2 have recesses 1c and 2c is provided. The convex portion 8e and the concave portions 1c, 2c are formed in an annular shape.

According to this embodiment, the stator 1 is driven by gravity.
When the voltage is removed, the magnetic particles 9 between the side surface 1a of the rotor 8 and the side surface 8a of the rotor 8 are agitated in the same manner as in the related art, but the intrusion is stopped by the protrusion 8e provided on the rotor 8, and Since the stator 1 has the concave portion 1c, the magnetic particles 9 do not reach the bearings 4 and 5, as in the first embodiment, so that a highly reliable product can be provided. In addition,
In FIG. 2, the protrusions 8 are provided on both side surfaces 8a and 8b of the rotor 8.
e, the recesses 1c, 2c are provided in the stators 1, 2, but only the side surface 8a and the stator 1 side are provided.
Protrusions and recesses may be provided, and the side surface 8b and the side surface 2a may be formed to be planar.

Embodiment 3 FIG. 3 is a partially sectional side view showing a magnetic particle transmission device according to Embodiment 3 of the present invention. In the drawing, reference numerals 1 and 2 denote a stator, 8 denotes a rotor,
It has 1a, 2a, 8a, and 8b as the respective operation surfaces. A protrusion 1d is provided on the side surface 1a of the stator 1, and a concave portion 8f is provided on the side surface 8a of the rotor 8 at a position facing the protrusion 1d. Further, a protrusion 8e is provided on the side surface 8b of the rotor 8, and
A concave portion 2c is provided on the side surface 2a of the stator 2 at a position facing the convex portion 8e. In addition, the convex portion 1
d, 8e and recesses 2c, 8f are formed in an annular shape.

In the above configuration, an example is shown in which the convex portion 8e is provided on the side surface 8b and the concave portion 2c is provided on the side surface 2a, but the convex portion is provided on the side surface 2a and the concave portion is provided on the side surface 8b. You may. Further, the side surface 2a and the side surface 8b may be formed in a flat shape without providing a convex portion and a concave portion.

According to this embodiment, the stator 1 is driven by gravity.
Particles 9 between the side surface 1a of the rotor and the side surface 8a of the rotor
Is agitated in the same manner as before when the voltage is removed, but the stator 1
As described in the first embodiment, the magnetic particles 9 do not reach the bearings 4, 5 and the like, so that a highly reliable product can be provided. Become.

As described above, according to the magnetic particle transmission device of the present invention, the annular convex portion or concave portion is provided on the side surface serving as the operating surface. Even when the child 8 rotates and becomes idle and the magnetic particles 9 are agitated and scattered, these projections or depressions become weirs and do not reach the seals 11 and 12 side. Therefore, a stable function can be obtained even when used in a vertical type with the rotating shaft 3 being vertical.

The present invention can be used not only in the case of vertical use but also in the case of horizontal mounting with the rotating shaft 3 being horizontal. Further, since the rotor 8 has a disk shape,
Even if the magnetic particles 9 try to move down due to gravity, the stable slip characteristics can be obtained because the operating surface is up and down. Furthermore, although the case where it is used as a braking device has been described above, it goes without saying that the same effect can be obtained even if the stators 1 and 2 are rotated and used as a connecting device.

[0026]

According to the magnetic particle transmission device according to the first aspect of the present invention, a stator having an annular shape and having a side surface serving as an operating surface on the inner periphery, and a coil built in the stator are provided. , A rotor provided on the inner periphery of the stator through a gap,
The rotor is fixed to the stator, and the stator is composed of a rotating shaft provided via a bearing and magnetic particles inserted into the air gap. Since the step is provided at the position facing the step and the stator is also provided with the step, the magnetic particles are less likely to reach the bearing, and a stable rotation function can be continued.

According to the magnetic particle transmission device of the second aspect of the present invention, since the seal is provided on the inner peripheral side of the step portion,
The entire device can be made compact.

According to the magnetic particle transmission device of the third aspect of the present invention, a stator having an annular shape and having a side surface serving as an operating surface on an inner periphery, a coil built in the stator, A rotor provided on the inner periphery of the child via an air gap,
The rotor is fixed to the stator, and the stator is composed of a rotating shaft provided via a bearing and magnetic particles inserted into the gap, and faces the rotor side surface and the side surface. Among the side surfaces of the stator, a convex portion is provided on one side surface and a concave portion is provided on the other side surface, so that magnetic particles hardly reach the bearing portion, and a stable rotation function can be continued. .

According to the magnetic particle transmission device of the fourth aspect of the present invention, since the seal is provided on the inner peripheral side of the convex portion and the concave portion, the entire device can be made compact.

According to the magnetic particle transmission device of the present invention, the rotor is formed in a disk shape.
It can be easily manufactured by pressing.

[Brief description of the drawings]

FIG. 1 is a partial cross-sectional side view showing a magnetic particle transmission device according to a first embodiment of the present invention.

FIG. 2 is a partial sectional side view showing a magnetic particle transmission device according to a second embodiment of the present invention.

FIG. 3 is a partial cross-sectional side view showing a magnetic particle transmission device according to Embodiment 3 of the present invention.

FIG. 4 is a partially sectional side view showing a conventional magnetic particle transmission device.

[Explanation of symbols]

1, 2 Stator, 1b, 2b, 8d Step, 1d, 8
e convex part, 1c, 2c, 8f concave part, 3 rotation axis, 4,
5 bearings, 6 coils, 8 rotors, 9 magnetic particles.

Claims (5)

[Claims] An annular stator having a side surface serving as an operating surface on an inner periphery, a coil built in the stator, a rotor provided on the inner periphery of the stator via a gap, and In a transmission device fixed to a rotor and provided with a rotating shaft disposed via a bearing and the stator, and magnetic particles inserted into the gap, a step portion is provided on the rotor, and A magnetic particle-type transmission device, which is located at a position facing the stepped portion, wherein the stator also has a stepped portion. 2. The magnetic particle transmission device according to claim 1, wherein a seal is provided on an inner peripheral side of the step portion. 3. An annular stator having a side surface serving as an operation surface on an inner periphery, a coil built in the stator, a rotor provided on the inner periphery of the stator via a gap, and In a transmission device fixed to a rotor and provided with a rotating shaft disposed via a bearing and the stator, and magnetic particles inserted into the gap, the transmission device has a side surface of the rotor and a surface facing the side surface. A magnetic particle transmission device characterized in that, among the side surfaces of the stator, a convex portion is provided on one side surface and a concave portion is provided on the other side surface. 4. The magnetic particle transmission device according to claim 3, wherein a seal is provided on the inner peripheral side of the convex portion and the concave portion. 5. The magnetic particle transmission device according to claim 1, wherein the rotor has a disk shape.