JPH0227219Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a magnetic particle type electromagnetic coupling device.

[Prior art]

FIG. 1 is a sectional view of a conventional magnetic particle type electromagnetic coupling device. A drive member 1 is a first connecting body connected to a drive source (not shown), and is made of a magnetic material and has a cylindrical first connecting part 1b with a connecting surface 1a located on the inner periphery. . 2 is a shaft connected to the load side (not shown), 3 is the shaft 2
This is the driven member which is the second connecting body fixed to. This drib member 3 is made of a magnetic material, and has a cylindrical second connecting portion 3b having a connecting surface 3a facing the connecting surface 1a of the first connecting portion 1b with a single radial annular gap g interposed therebetween. have 4 is the second
It is an annular non-magnetic member that magnetically divides the connecting portion 3b into two, and is fixed to connect the second connecting portion 3b that has been divided into two. 5 is a magnetic particle arranged in a single annular gap g, and 6 and 7 are labyrinths fixed to both sides of the driven member 3, which catch the magnetic particles 5 that have fallen out of the annular gap g and Prevent the leakage to the outside.
A cover 8 is fixed to the opening side of the drive member 1, and has a labyrinth function that cooperates with the labyrinth 7 to prevent the magnetic particles 5 that have fallen from the annular gap g from flowing out. A bearing 9 is installed between the drive member 1 and the shaft 2, and is positioned by snap springs 10 and 11. Reference numeral 12 denotes a stator made of a magnetic material disposed on the inner peripheral side of the second connecting portion 3b, and is an annular stator that faces the radially inner peripheral surface of the second connecting portion 3b divided into two with a gap in between. magnetic pole 1
It has 2a. This stator 12 is prevented from rotating by a rotation preventing member (not shown). 13
is an excitation coil wound annularly around the stator 12,
14 is a bearing installed between the shaft 2 and the stator 12, and includes snap springs 15, 16,
17.

Next, the operation will be explained. When the drive member 1 is being rotated by the drive source, the excitation coil 13
When an excitation current is applied to , a magnetic flux Φ is generated between the stator 12 - one magnetic pole 12 a - one second connecting part 3 b - magnetic particles 5 - first connecting part 1 as shown by the dotted line in the figure.
b-magnetic particles 5-other second connecting portion 3b-other magnetic pole 12a-stator 12. As a result, the magnetic particles 5 between the first and second connecting portions 1b and 3b are magnetized. The magnetized magnetic particles 5 are connected in a chain to form a first connecting portion 1b and a second connecting portion 3.
In order to interconnect the drive member 1 and the driven member 3, torque is transmitted from the drive member 1 to the driven member 3, and the driven member 3 rotates. On the contrary, the excitation coil 13
When the energization is stopped, the magnetic flux disappears, and the magnetic particles 5
The connection between the first and second connecting portions 1b and 3b is separated, and torque transmission from the drive member 1 to the driven member 3 is stopped.

The conventional device is as described above, but at the same time, frictional heat is generated between the first and second connecting portions 1b and 3b during the connecting operation, and at the same time, heat is generated due to exciting coil loss by energizing the exciting coil 13. do. For this reason, a seizure phenomenon of the magnetic particles 5 occurred between the magnetic particles 5 and between the magnetic particles 5 and the first and second connecting portions 1b and 3b. As a result, a malfunction occurs between the first and second connecting parts 1b and 3b,
This was reducing the reliability of the device.

[Summary of the idea]

This idea was made to eliminate the above-mentioned drawbacks of conventional devices. By providing cooling fins on the outer periphery of the connecting body that is in direct contact with the outside air, it improves the heat dissipation effect and prevents the burning of magnetic particles. The purpose of this invention is to provide a highly reliable electromagnetic coupling device by preventing

[Example of idea]

An embodiment of this invention will be described below with reference to FIG. In FIG. 2, 20 is a drive member as a first connecting body connected to a drive source (not shown), which includes a non-magnetic member 20b provided with first cooling fins 20a on the outer periphery, and a non-magnetic member 20b on the inner periphery. The first connecting portion 20d is made of a magnetic material and has a connecting surface 20c around the periphery. 21 is a shaft connected to the load side (not shown), 22 is a driven member as a second connecting body fixed to the shaft 21 by a rivet 23,
An annular gap is formed in the connecting surface 20c of the first connecting portion 20d.
It has a cylindrical second connecting portion 22b made of a magnetic material and having connecting surfaces 22a facing each other via g ₁ . 22c is a non-magnetic member that magnetically divides the second connecting portion 22b into two, and is fixed to connect the two divided second connecting portions 22b. 24
is a magnetic particle disposed in the annular gap _g1 , and 25 is a ball bearing, which has the function of mutually rotatably supporting the shaft 21 and the drive member 20 and keeping the size of the annular gap _g1 constant. . This bearing 25 is a snap spring 2
6, 27 and a space collar 28. 29 and 30 are stators composed of two magnetic materials almost symmetrically on the left and right, and a second stator divided into two parts;
A gap g ₂ is provided on the radial inner circumferential surface of the connecting portion 22b.
It has annular magnetic poles 29a and 30a that face each other via. Reference numeral 31 denotes an excitation coil which is wound around and held between the stators 29 and 30, and together with the stators 29 and 30 constitutes a magnetizing device for the magnetic particles 24. Reference numeral 32 denotes a fixed member made of a non-magnetic material, on the outside of which third cooling fins 32a are formed.
Dissipates heat of 9.30. Numeral 33 is a bolt that fixes the stators 29, 30 and the fixing member 32. 34 is a ball bearing,
It is fitted between the shaft 21, the stators 29, 30, and the fixing member 32, and supports the shaft 21, the stators 29, 30, and the fixing member 32 so as to mutually rotate, and also supports the stators 29, 30 and the fixing member 32. This facilitates radial alignment. Furthermore, this bearing 34 has a gap g ₂
It has the function of keeping the radial width constant. 35
is a plate fixed to the driven member 22,
Reference numeral 36 denotes a cover made of a non-magnetic material and provided with second cooling fins 36a on the outer periphery, and is fixed to the first connecting portion 20d with bolts 37 to form a first connecting body. . Labyrinths 38 and 39 are provided on the outer side surfaces of the driven member 22 and the plate 35 to prevent the magnetic particles 24 from flowing out. 40 is a terminal for feeding power to the excitation coil 31. 41 is a seal.

The operation of this device will be explained below. When the drive member 20 is rotated by a drive source (not shown), the excitation coil 31 is connected to the power supply terminal 4.
0, the magnetic flux Φ flows from the stator 29 to the magnetic pole 29a to one of the air gaps g ₂ as shown by the dotted line in the figure.
- One second connection part 22b - Magnetic particles 24 - First connection part 20d - Magnetic particles 24 - One second connection part 20d - One gap g ₂ - Magnetic pole 30a - Stator 30 is passed through. As a result, the magnetic particles 24 between the first and second connecting portions 20d and 22b are magnetized and connected in a chain, thereby forming the first and second connecting portions 20d and 22b.
22b are magnetically interconnected. As a result, torque is transmitted from the drive member 20 to the driven member 22, and rotational force from the drive source is transmitted to the load via the shaft 21. vice versa,
When the excitation coil 31 is de-energized, the magnetic flux disappears and the magnetic particles 24 connect the first and second connecting portions 2.
The connection between 0d and 22b is disconnected, and torque transmission is stopped.

The operation is as described above, and during the connection operation, the first
At the same time that frictional heat is generated between the second connecting portions 20d and 22b, heat is generated due to excitation coil loss by energizing the excitation coil 31. However, due to the cooling air (indicated by arrows A and B) generated by the centrifugal fan effect caused by the rotation of the first cooling fin 20a and the second cooling fin 36a of the first connecting body, The frictional heat is radiated, and the cooling air generated by the second cooling fin 36a indicated by the arrow B is directed to the stators 29, 30.
The third cooling fin 3 of the fixing member 32 fixed to
The heat dissipation effect of 2a is further enhanced, and the stators 29, 3
0 is being cooled. In other words, the above-mentioned heat is efficiently radiated by the synergistic effect of the cooling effect of the fins and the cooling air of the fan. For this reason, the magnetic particles 24
It is possible to prevent the lighting phenomenon and obtain a stable connection operation, and also to prevent the stators 29, 30, the exciting coil 31, and the bearings 25, 34 from overheating. Further, in this device, the stators 29, 30
Further, since the outer circumferential dimension of the bearing 34 is used for radial positioning of the fixing member 32, extra stamping processing is unnecessary and processing time is shortened.

[Effect of idea]

As described above, in this invention, the first and second cooling fins are provided on the outer periphery of the first connecting body connected to the drive source, and the frictional heat in the connecting part is absorbed by the centrifugal fan effect of the fins. In addition to dissipating heat, the cooling air generated by the fan effect of the second cooling fin enhances the heat dissipation effect of the third cooling fan provided on the stator, thereby preventing the seizure phenomenon of magnetic particles and creating a highly reliable electromagnetic coupling device. can be provided.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional electromagnetic coupling device, and FIG. 2 is a sectional view showing an electromagnetic coupling device according to an embodiment of the invention. In the figure, 20...first coupling body, 20c...coupling surface, 20d...first coupling portion, 20a, 32a,
36a... cooling fin, 22... second connection body,
22a...Connection surface, 22b...Second connection part, 2
9, 30... Stator, 31... Excitation coil, 3
2...Fixing member, 41...Seal.

Claims (1)

[Scope of utility model registration request] a first connecting body having a first connecting part made of a magnetic material; a second connecting body disposed radially inside the first connecting body and facing the first connecting part through a gap; a second connecting body having a connecting part;
The magnetic particles disposed in the gap, the magnetic flux flowing through the first and second connecting portions provided on the inner peripheral side of the second connecting body, and magnetizing the magnetic particles to a magnetizing device that magnetically connects the two connecting bodies, first and second cooling fins provided on the outer periphery of the first connecting body, and provided on an externally exposed part of a fixing part that fixes the magnetizing device. The third
An electromagnetic coupling device comprising a cooling fin, wherein the third cooling fin is positioned in a cooling air path created by rotation of the second cooling fin.