JPS5913385Y2 - Permanent magnet actuated electromagnetic brake - Google Patents

Description

[Detailed description of the invention] This invention relates to a permanent magnet actuated electromagnetic brake that applies braking to a braked object by the attractive force of a permanent magnet and releases the braking by excitation of an electromagnetic coil, and aims to obtain good operating characteristics. It is an object of the present invention to provide a brake of this type which is small in size and highly reliable, and has a large heat dissipation in the permanent magnet part.

The present invention will be described in detail below with regard to the illustrated embodiments.

In the drawing, 1 is a hub fitted to a braked shaft 2, and 3 is a spline adapter fitted to spline teeth provided on the outer periphery of the hub 1, making it movable in the axial direction.

Numerals 4 and 5 are retaining rings that restrict movement of the spline adapter 3 in the axial direction beyond a certain limit, and are fitted into grooves provided on the outer periphery of the hub 1.

6 is an annular armature fixed to the spline adapter 3, and a permanent magnet 7 is attached to the inner side surface thereof.

The permanent magnet 7 has an annular plate shape or a sector shape, and the outer peripheral edge is magnetized to the north pole, and the inner peripheral edge is magnetized to the south pole.

Reference numeral 8 denotes an annular yoke having a U-shaped cross section and is attached to the wall 9 of the machine to be braked via a connecting flange 10 on the back side.

Note that each end face of the opening of the yoke 8 faces each magnetic pole portion of the permanent magnet 7, respectively.

11 is an electromagnetic coil housed within the yoke 8.

12 is a power supply connection terminal for the electromagnetic coil 11, and 13 is a brake lining provided on the yoke 8 side and facing the permanent magnet 7.

The embodiment of the present invention is constructed as described above, and when no current is supplied to the electromagnetic coil 11, the effect of the permanent magnet 7 creates a gap between this magnetic pole part and the part of the yoke 8 that faces the other magnetic pole parts. Because of the magnetic attraction force, the spherical magnet 7 is drawn toward the yoke 8 together with the armature 6, and is brought into pressure contact with the brake lining 13.

Therefore, when no power is being supplied to the electromagnetic coil 11, braking is applied to the braked shaft 1 via the armature 6, spline adapter 3, and hub 1.

Next, a current is supplied to the electromagnetic coil 11 so that the portion of the yoke 8 facing each magnetic pole of the permanent magnet 7 has a polarity that is the same as the polarity of the opposing magnetic pole portion of the permanent magnet. By selectively energizing the direction, a magnetic repulsion force is generated between the opposing magnetic poles of the permanent magnet and the yoke, and as a result, the permanent magnet 7, and therefore the armature 6 equipped with it, moves away from the brake lining 13 and is exposed to the yoke. The braking force on the braking shaft 1 is released.

The brake according to the present invention is a non-excitation type brake that uses a permanent magnet to constantly perform braking action and releases braking by excitation by an electromagnetic coil, and is different from a normal non-excitation type brake that performs braking by a spring action. In contrast, in the case of a magnet, it can be made into a disk shape or a sector shape, and the axial dimension of the brake can be reduced to make it compact, and the brake can be released using the repulsive force of the magnetic poles. Since the contact parts are separated by the magnet, the brake release action can be accelerated.Furthermore, since the permanent magnet is attached to the rotating part, the frictional heat generated during the braking action is dissipated into the atmosphere through the convection heat dissipation effect generated by the rotation. As a result, it is possible to reduce the temperature rise of the magnet portion, minimize the demagnetization effect due to the temperature rise of the magnet, and stabilize the performance.

[Brief explanation of the drawing]

The drawing shows an embodiment of the present invention, and is a front view showing a cross section of the upper half. 1... Braked shaft, 6... Armature, 7... Permanent magnet, 8... Yoke, 11... Electromagnetic coil.

Claims (1)

[Scope of utility model registration request] A permanent magnet is fixed to one side of the armature that is dynamically connected to the braked side, and the inner and outer edges of each layer have different polarities.
A yoke having a U-shaped cross section is provided such that the end face of the opening faces each of the magnetic poles of the permanent magnet, and the opening end of the yoke is connected to the opening of the permanent magnet opposite to the yoke. A permanent magnet actuated electromagnetic brake characterized by having an electromagnetic coil magnetized to the same polarity as the magnetic pole.