JPS622166B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an electromagnetic powder brake that is equipped with a heat dissipation means to increase the allowable slip efficiency and reduce the axial dimension.

(Prior Art) Conventionally, in an electromagnetic powder brake, as shown in the longitudinal cross-sectional view of FIG. The magnetic powder 6 between the cylinder 4 and the fixed rotor 5 solidifies, and the magnetic coupling force connects the cylinder 4 and the fixed rotor 5 to transmit torque from the cylinder 4 to the fixed rotor 5. do.

In addition, due to its operating characteristics, electromagnetic powder brakes are often used for continuous slip applications such as tension control and buffer control, and therefore, those with a high allowable slip efficiency and high heat dissipation capacity are required due to their thermal usage limits when using continuous slip applications. required. However, the first
In the electromagnetic powder brake configured as shown in the figure, the operating part between the cylinder 4 and the fixed rotor 5, which are magnetically connected by magnetic powder 6, is located inside the brake, and therefore the heat generated in the operating part during continuous slip use is Until it reaches the outer shell of the electromagnetic powder brake, it is mainly dissipated into the outside air via the fixed rotor 5 → fixed rotor boss 7, and the outside air via the cylinder 4 → yoke 1 → input side bracket 8 or fixed side bracket 9. There are paths through which heat is dissipated, but the heat transfer distance is long in both cases, and air with low heat transfer coefficient is interposed in the middle, so the heat dissipation effect becomes small, the temperature rise becomes excessive, and the allowable slip efficiency is reduced. The drawback was that it had to be kept low.

(Object of the Invention) The present invention provides a rotating body in which magnetic powder, which is magnetized and fixed by magnetic flux generated by energization of a coil, is rotated by an externally input torque, and the magnetic powder is transferred from the rotating body to the A magnetic coupling device for performing slip operation by magnetically coupling the fixed body to which the torque is transmitted through powder, the fixed body having a heat dissipation tube for dissipating slip heat generated during slip operation. Further, the rotating body is an annular rotating body having a T-shaped cross section and a magnetic shield in the center of the T-shaped cross section, and the magnetic powder is applied to the inner and outer circumferential surfaces of the annular rotating body. By providing a magnetic coupling device in which a plurality of actuating parts are magnetically coupled together, and the fixed body facing the inner periphery of the annular rotating body is divided into parts, slip heat generated during continuous slip use can be avoided. The objective is to quickly dissipate heat, increase the allowable slip efficiency, and reduce the external size.

(Configuration of the Invention) The configuration of the present invention will be explained with reference to the longitudinal cross-sectional view of FIG. A rotating body 2 that contains magnetic powder 22 that is magnetized and solidified by magnetic flux generated by energization of a coil 21, and rotates by externally input torque.
3 forms a magnetic flux path 24 together with the rotating body 23 and the magnetic powder 22, and the rotating body 2
A magnetic coupling device comprising a fixed body 25 to which torque is transmitted from the rotating body 23 and a heat dissipation pipe 26 for dissipating slip heat generated by continuous slip when torque is transmitted from the rotating body 23 to the fixed body 25. The rotating body 23 is an annular rotating body having a T-shaped cross-section and a magnetic shield 27 in the center of the T-shaped cross-section, and magnetic powder 22 is provided on the inner and outer circumferential surfaces of the annular rotating body. A plurality of actuating parts 28 connected by
The magnetic coupling device is characterized in that a fixed body 25 facing the inner periphery of the annular rotating body is formed in sections.

(Embodiment of the Invention) The configuration of an embodiment of the present invention will be explained with reference to the vertical cross-sectional view of FIG. A predetermined current is applied to the coils 33 formed in the yokes 31 and 32 to generate magnetic flux to form a magnetic flux path 34, and to magnetize and solidify the magnetic powder 35 provided in the middle of the magnetic flux path 34. Therefore, the rotating body 38 rotates with external torque input from the input shaft 36, has a T-shaped cross-section, and is equipped with a disk 37 having a magnetic shielding function in the center of the T-shaped cross-section. It is magnetically connected to the magnetic pole 39 and the yokes 31 and 32, and transmits the external torque to the internal magnetic pole 39 and the yokes 31 and 32 to perform slip operation.

The magnetic path of the annular rotor 38 having a T-shaped cross section is divided into two parts by the disk 37, and the two divided magnetic path parts are designated as 38A and 38B, respectively, and magnetic powder is applied to the inner and outer circumferential surfaces of the magnetic path parts 38A and 38B. Actuating part 4 magnetically coupled by body 35
1, 42, 43, and 44, and further divides the internal magnetic pole 39 in contact with the inner circumferential surface actuating portions 41 and 42 into two, and arranges them laterally symmetrically as 39A and 39B, respectively, and the divided internal magnetic poles 39A and 39B To,
A plurality of cylindrical heat pipes 45 having their central axes in the direction of the input axis are arranged, and the other ends of the cylindrical heat pipes 45 are passed through the left and right brackets 47 and 48 that constitute the space 46 of the magnetic powder 35 to the outside. make it protrude, and attach a heat dissipation fin 49 to the protrusion,
Further, radial fans 50 that rotate together with the input shaft 36 and dissipate the heat radiated from the heat dissipation fins 49 to the atmosphere are provided on both left and right sides, and the blade portions 51 of the radial fans 50 are placed outside the circumference of the heat pipe heat dissipation fins 49. By providing a plurality of outside air inlet ports 52 on the inner circumferential portion of the radial fan 50, the connection actuating portions 41, 42, 4
3, 44 and magnetic pole parts 31, 32, 38A, 38
The slip heat generated in B, 39A, and 39B is directly radiated to the atmosphere from the fins 49 through the heat pipe 45, and outside air is introduced from the inner circumferential side of the heat pipe 45 by rotation of the radial fan 50.
Outside air is caused to flow in a radial direction from the axial direction of the heat pipe 45 as indicated by an arrow 53.

Other components include a magnetic shear ring 54 that prevents short-circuiting of the magnetic paths of the yokes 31 and 32, sealing materials 55 and 56 that prevent the magnetic powder 35 from leaking to the outside, and bearings 57 and 58.

(Operation of this embodiment) Next, the operation of this embodiment will be explained. Connection operating parts 41, 42, 43, 4 shown in FIG.
4 and magnetic pole parts 31, 32, 38A, 38B, 39
The slip heat generated in A and 39B is radiated directly to the atmosphere from the fins 49 via the heat pipe 45, and by the rotation of the radial fan 50, outside air is introduced from the outside air inlet 52 as shown by the arrow 53, and the air is radially released. By circulating outside air through the shaft, heat dissipation is promoted by both the radiant heat dissipation effect and the convection heat dissipation effect, which has the effect of increasing the allowable slip efficiency.

Next, in general, the coupling torque T in the operating part of an electromagnetic powder brake is expressed as follows: where k is a constant, Φ is the magnetic flux density, D is the diameter of the operating part, and L is the width of the operating part.
= k・Φ・D ²・L.

On the other hand, since the electromagnetic powder brake as shown in Fig. 1 in the prior art has two operating parts, if the width of each operating part is l, the coupling torque is T1 =
2k・Φ・D ²・l. -(1) In this embodiment, there are four actuating parts as described above, so the width of each actuating part is assumed to be ll, which is the same as the actuating part width l in the electromagnetic powder brake shown in Fig. 1, i.e.
Let ll=l, and let the working part diameters of the inner and outer circumferences of the rotating body 38 of the present invention be d1 and d2, respectively, (d1+d2)/
2 = D, that is, when the value of D is the same as the diameter of the operating part in the electromagnetic powder brake shown in Figure 1, the coupling torque T2 is T2 = 4k・Φ・D ²・ll−(2), and (d1 + d2 )/2=T2 while maintaining the relationship of D
If the relationship = T1 is established, ll = l/2 from equations (1) and (2). This has the effect that when there are four actuating parts, the axial dimension can be made smaller under the above conditions compared to an electromagnetic powder brake which has two actuating parts.

(Effects of the Invention) The present invention provides a rotating body in which magnetic powder, which is magnetized and solidified by magnetic flux generated by energization of a coil, is rotated by an externally input torque, and the magnetic powder is transferred from the rotating body to the magnetic powder. A magnetic coupling device for performing slip operation by magnetically coupling the fixed body to which the torque is transmitted through powder, the fixed body having a heat dissipation tube for dissipating slip heat generated during slip operation. Further, the rotating body is an annular rotating body having a T-shaped cross section and a magnetic shield in the center of the T-shaped cross section, and the magnetic powder is applied to the inner and outer circumferential surfaces of the annular rotating body. By providing a plurality of actuating parts that are magnetically connected to each other, and by forming the fixed body that faces the inner periphery of the annular rotating body in sections, the slip heat generated during continuous slip use can be quickly dissipated. , increase the allowable slip rate,
It also has the effect of reducing the external size.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional view of a conventional electromagnetic powder brake, Fig. 2 is a longitudinal sectional view showing the structure of the present invention, and Fig. 3 is a longitudinal sectional view of a conventional electromagnetic powder brake.
The figure is a longitudinal sectional view of one embodiment of the present invention. 21... Coil, 22... Magnetic powder, 23... Rotating body, 24... Magnetic flux path, 25... Fixed body, 26... Heat dissipation tube, 27... Magnetic shield, 28... Actuating part.

Claims (1)

[Scope of Claims] 1. A rotating body containing magnetic powder that is magnetized and solidified by magnetic flux generated by energization of a coil and rotated by externally input torque; Forms a magnetic flux path with the powder,
A magnetic coupling device comprising a fixed body to which torque is transmitted from the rotating body through magnetic coupling with the magnetized solidified magnetic powder, the rotating body having a symmetrical T-shaped cross section. The annular rotating body is formed into a circular ring shape and has a magnetic shield in the center thereof, and a plurality of actuating parts are provided on the inner and outer circumferential surfaces of the circular rotating body, and the actuating parts are connected by the magnetic powder, and The fixed body facing the inner periphery of the annular rotating body is divided into left-right symmetrical parts, and each fixed body has a heat dissipation device for evenly dissipating the slip heat generated when the torque is transmitted. The tubes are installed so as to communicate with the atmosphere from the slip heat generating part, and each heat dissipation tube is provided with heat dissipation fins at the part where it comes into contact with the atmosphere. A magnetic coupling device characterized by symmetrically provided radial fans for forcibly exhausting the air into the atmosphere.