JPS6235534B2 - - 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 is fixed, 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.

Furthermore, 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 efficiency 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 the 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 and the temperature rise becomes excessive, so the allowable slip efficiency The disadvantage 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 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 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 radiating outer shell for dissipating slip heat generated during slip operation. A plate is provided, and 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 provided on the inner and outer peripheral surfaces of the annular rotating body. By providing a magnetic coupling device in which a plurality of actuating parts are magnetically coupled by a plurality of actuators, and the fixed body facing the inner periphery of the annular rotating body is divided into parts, it is possible to prevent the occurrence of slippage when using a continuous slip. The objective is to quickly dissipate slip 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
3, and a heat dissipating outer shell plate 26 for dissipating slip heat generated by continuous slip when torque is transmitted from the rotating body 23 to the fixed body 25. In the coupling device, the actuating portion 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 is applied to the inner and outer circumferential surfaces of the annular rotating body. The magnetic coupling device is characterized in that a plurality of actuating parts 28 are provided which are connected by a body 22, and 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 rotating body 38 having a T-shaped cross-section is divided into two by the disk 37, and the two divided magnetic path portions are designated as 38A and 38B, respectively, and the inner and outer circumferential surfaces of the magnetic path portions 38A and 38B are magnetically attached. Actuating section 4 magnetically connected by powder 35
1, 42, 43, and 44 are provided, and furthermore, the internal magnetic pole 39 in contact with the inner circumferential surface actuating portions 41 and 42 is divided into two parts as 39A and 39B, which are arranged symmetrically on the left and right sides.

The left and right brackets 46 and 47, whose inner surfaces are in contact with the internal magnetic poles 39A and 39B to form the cavity 45 of the magnetic powder 35, and whose outer surfaces are in direct contact with the outside air, are made of materials with thermal conductivity, for example. In addition, the left and right brackets 4 are made of aluminum with good quality.
Radial heat dissipation fins 48 made of aluminum made of the same material as the bracket are placed in the parts 6 and 47 in contact with the outside air.
, actuating parts 41, 42, 43, 44 and magnetic pole parts 31, 32, 38A, 38b, 39A, 39
Remove the slip heat generated in B from the left and right brackets 4.
6, 47 to radially radiate heat from the heat radiation fins 48 to the outside air.

As other components, a magnetic shield ring 4 is used to prevent the magnetic flux paths of the yokes 31 and 32 from being short-circuited.
9. There are sealing materials 50 and 51 for preventing the magnetic powder 35 from leaking to the outside, and bearings 52 and 53 for the rotating shaft 36.

(Operation of this embodiment) Next, the operation of this embodiment will be explained. A magnetically coupled actuating part 41 shown in FIG.
42, 43, 44 and magnetic pole parts 31, 32, 38
A, 38B, 39A, 39B promotes the radiant heat dissipation effect by radiating the slip heat generated in the left and right brackets 46, 47 directly from the heat dissipation fins 48 to the atmosphere in a radial manner.
This has the effect of increasing the allowable slip efficiency.

Next, in general, the coupling torque T in the actuating part of an electromagnetic powder brake is as follows: where k is a constant, φ is the magnetic flux density, D is the diameter of the actuating part, and L is the width of the actuating part, T=k・φ・D ² - Indicated by 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 T1 is:
It is shown by the following formula.

T1=2k・φ・D ²・l ...(1) In this embodiment, since there are four actuating parts as mentioned above, the width of each actuating part is ll, and the first
The width l of the actuating part in the electromagnetic powder brake shown in the figure is the same, that is, ll = l, and the diameters of the actuating part on the inner and outer peripheries of the rotating body 38 of the present invention are d1 and d2, respectively.
Assuming that d1+d2/2=D, that is, the value of D is the same as the diameter of the operating part in the electromagnetic powder brake shown in Fig. 1, the coupling torque T2 is T2=4k・φ・D ²・ll ……(2 ), and while maintaining the relationship d1+d2/2=D, T2
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.

Furthermore, when the slip efficiency is Q, the slip torque is T, and the slip rotation speed is n, then Q=k×
There is a relationship of T×n (k: constant). Therefore, by using the T-shaped rotating body, when the operating part width ll=l, T2≒2×T1, so Q at T2 is doubled. Therefore, arranging the internal fixing body in parts and connecting them directly to the heat sinks 46 and 47 without intervening a gap is highly effective in increasing the allowable slip efficiency. By employing a symmetrical T-shaped rotating body, thermal deformation is made uniform, changes in the operating gap are small, and stable performance can be maintained.

(Effects of the Invention) The present invention provides a rotating body in which magnetic powder, which is magnetized and solidified by the magnetic velocity generated by energization of a coil, is rotated by a torque input from the outside, and from the rotating body to the A magnetic coupling device for performing a slip operation by magnetically coupling the fixed body to which the torque is transmitted through magnetic powder, the fixed body having a heat dissipating external device for dissipating the slip heat generated during the slip operation. A shell plate is provided, and 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 by the body, and by dividing the fixed body facing the inner periphery of the annular rotating body, the slip heat generated during continuous slip use can be quickly removed. It has the effect of dissipating heat, increasing the allowable slip efficiency, and 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, 2
6... Heat dissipation outer shell plate, 27... Magnetic shield, 28
...Operating 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. In addition to being formed into a circular ring-shaped rotating body with a magnetic shield in the center, there are four actuation points connected to the inner and outer peripheral surfaces of the left and right sides of the circular rotating body by the magnetic powder. Further, the fixed body facing the left and right inner peripheries of the annular rotating body is divided into left-right symmetrical parts, and the central part of the fixed body facing the left and right outer peripheries of the annular rotating body is provided with a magnetic shield. and the annular rotating body is connected to a rotating shaft so that the inner circumferential side magnetic powder storage portions do not communicate with each other, and the inner poles of the fixed body are connected to each other within the annular rotating body. A magnetic path is formed by arranging it to face the circumferential surface, and each of the symmetrically divided fixed bodies has a conductor for dissipating the slip heat generated when the torque is transmitted to the atmosphere evenly on the left and right sides. 1. A magnetic coupling device characterized in that a heat path and a heat dissipating outer shell plate are provided, and the heat dissipating outer shell plate is formed with fins for radially dissipating the slip heat.