JPS6344979B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in an electromagnetic brake device that automatically compensates for wear of brake plates.

A conventional device of this type will be explained with reference to FIGS. 1 and 2. In the figure, reference numeral 1 denotes a motor shaft, which becomes a rotary shaft to be braked when the motor is stopped.
1a is a spline formed on the opposite end of the motor shaft 1, 2 is a bracket that rotatably supports the motor shaft 1 via a bearing 3, and 4 is a bracket 2.
A brake box 5 has one end fixed to the outside of the brake box, and 5 is a brake disk whose inner circumference is fitted to a spline 1a so as to be freely movable in the axial direction, and brake linings 5a and 5b are correspondingly arranged on both sides of the outer circumference. The brake lining 5a is attached to the fixed part 2 on one side of the bracket 2.
It is opposite to a. 6 is movable in the axial direction, but becomes unrotatable when its outer periphery engages with the inner periphery of the brake box 4, and 7 is a friction plate whose one side 6a faces the brake lining 5b; It is a brake disk fitted to a spline 1a so as to be freely movable in the axial direction, and brake linings 7a and 7b are correspondingly arranged on both sides near the outer periphery, and the brake lining 7a faces the other side 6b of the friction plate 6. be. 8 is movable in the axial direction, but when the outer periphery engages with the inner periphery of the brake box 4, it becomes unrotatable, and one side 8a is attached to the brake lining 7.
A pressure plate 9 faces b, a nut 9 is fixed to the inner periphery of the reaction plate 8 by welding, and 10 is movable in the axial direction, but when the outer periphery engages with the inner periphery of the brake box 4, A movable iron core 11 that cannot rotate and has one side facing the other side of the pressure plate 8 is disposed on the other side of the movable iron core 10, and is energized and deenergized in response to the operation and stop of the electric motor. A ring-shaped electromagnet,
When energized, the movable iron core 10 is moved by suction to release the pressed state between the pressure plate 8 and the brake lining 7b, which will be described later. 12 is a cylindrical claw support member disposed concentrically around the inner circumference of the electromagnet 11; 13;
14 is a ratchet wheel support member rotatably supported on the inner periphery of the pawl support member 12; 14 is a ratchet wheel fixed to the outer periphery of the movable iron core 10 side end of the ratchet support member 13 so as to rotate together; 15 is a nut. A screw member screwed into 9, 1
6 is a movable iron core 10 arranged concentrically with the screw member 15.
is rotatably penetrated through the screw member 1, and one end is connected to the screw member 1.
5, the other end is a shaft that loosely fits into the center through hole 12a of the claw support member 12, and the other end has a slit 16.
It has a. 17 is a ratchet support member 13
radially through and supported, and the slit 1
This is a pin that is inserted into the shaft 6a and is used to transmit the rotational force of the ratchet support member 13 to the shaft 16. Reference numeral 18 indicates a shaft supported by the claw support member 12, and reference numeral 19 indicates a claw rotatably supported by the shaft 18. When the electromagnet 11 attracts and moves the movable core 10 by a predetermined amount, a torsion spring, which will be described later, is activated in response. The pawl resists the spring force and engages with the ratchet wheel 14 to rotate the ratchet wheel 14 by a predetermined amount.
It is designed to move a predetermined amount to the side.
20 is a torsion spring supported by the shaft 18;
The movable iron core 10 is always urged to be in pressure contact with the movable iron core 10. A rotation control spring 21 is disposed such that one end is in pressure contact with one end of the ratchet support member 13 and the other end is in pressure contact with the spring receiver 22, and controls the rotation of the ratchet wheel 14 via the ratchet support member 13; 23 is the claw support member 12
and a bolt that fixes the spring receiver 22 to the outer end of the electromagnet; 24 is a brake spring that presses the pressure plate 8 against the brake lining 7b via the movable iron core 10 and the screw member 15 when the electromagnet 11 is deenergized; 25;
is the cover. In addition, Fig. 2 shows − of Fig. 1.
FIG. 3 is a cross-sectional view of a cross section taken along the line in the direction of the arrow.

In this structure, when the electric motor is energized, the electromagnet 11 is energized and the movable iron core 10 is attracted, and the pressure between the pressure plate 8 and the brake lining 7b is released.
The electric motor rotates without any braking torque acting on it.

Next, when the electric motor is turned off, the electromagnet 11 is simultaneously deenergized, and the pressure plate 8 is moved against the brake lining 7b by the action of the brake spring 24.
and press the brake lining 5a to the fixed part 2a.
Since the friction plates 6 are brought into pressure contact with the brake linings 5b and 7a, in this state, braking torque acts on the motor shaft 1, which is the body to be braked. Moreover, when the claw 19 rotates the ratchet wheel 14 when the electromagnet 11 attracts the movable iron core 10, the pressure plate 8 moves toward the brake disc 7 due to the rotation, so that the brake linings 5a, 5b, 7a, 7
b wear is automatically compensated. Further, since one end of the ratchet support member 13 is pressed against one end of the spring 21 to prevent free rotation, the rotation of the ratchet wheel 14 is restricted only when the pawl 19 is engaged. However, since the screw member 15 is disposed on the inner periphery of the ring-shaped electromagnet, the structure is complicated and the number of parts is large, so disassembly and assembly are complicated and expensive. This invention was made in view of the above-mentioned conventional circumstances, and was made with the purpose of providing an electromagnetic brake device that is simple in structure, has a small number of parts, is easy to disassemble and assemble, and is inexpensive. An embodiment of the present invention will be described below with reference to FIGS. 3 and 4. In the figure, reference numeral 26 denotes a bottomed cylindrical screw member whose outer periphery is screwed into the inner periphery of the pressure plate 8, and whose open end fits into the end of the motor shaft 1 by a small amount. 27 is a ratchet wheel disposed adjacent to the outside of the bottom of the screw member 26; 28 is the screw member 2;
6 and the ratchet wheel 27, and a hexagonal column part 28a that rotates the screw member 26 and the ratchet wheel 27 integrally, and a head part 28b that faces the movable iron core 10. The connecting member 29 is a stopper fixed to the other side of the pressure plate 8, and the connecting member 29 is a stopper fixed to the other side of the pressure plate 8.
It allows normal rotation, but prevents reverse rotation. 30 is a brake spring disposed on the inner circumference of the electromagnet 11, and when the electromagnet 11 is deenergized, the movable iron core 10
This is for bringing the pressure plate 8 into pressure contact with the brake lining 7b via the connecting member 28, ratchet wheel 27, and screw member 26. 31 is detachably attached to the end of the motor shaft 1 with a bolt 32, and the electromagnet 11
is an engaging member that engages so that its tip comes into pressure contact with the inner surface of the bottom of the screw member 26 when the electric motor is deenergized, and when the electric motor is started, the screw member 26 is moved in the normal rotation direction of the ratchet wheel 27 ( The pressure plate 8 is rotated in the direction in which the pressure plate 8 moves toward the brake disc 7. Note that explanations of other symbols are the same as those of FIGS. 1 and 2, and will therefore be omitted. Also,
FIG. 4 is a cross-sectional view taken along the line - in FIG. 3, viewed in the direction of the arrow.

In this structure, when the electric motor is energized, the electromagnet 11 is energized and the movable iron core 10 is attracted, and the press contact between the pressure plate 8 and the brake lining 7b is released. The electric motor rotates without any brake torque acting on it. Next, when the electric motor is turned off, the electromagnet 11 is deenergized at the same time, and the brake spring 30 is connected to the movable iron core 10, the connecting member 28, and the ratchet wheel 27.
The pressure plate 8 is pressed against the brake lining 7b through the screw member 26, the brake lining 5a is connected to the fixed part 2a, and the friction plate 6 is connected to the brake lining 5.
b and 7a, so in this state a brake torque acts on the motor shaft 1, which is the body to be braked. Furthermore, at the same time as the electric motor starts up, that is, starts operating, the screw member 26, which had been in pressure contact with the engaging member 31, is rotated due to the frictional resistance with the engaging member 31, thereby causing the pressure plate 8 to move around the brake circle. Since it moves toward the plate 7 side, wear of the brake linings 5a, 5b, 7a, and 7b is automatically corrected, so there is almost no reduction in braking torque. Furthermore, since the stopper 29 prevents the ratchet wheel 27 from reversing, the wear of the brake linings 5a, 5b, 7a, and 7b can be reliably corrected.

In this invention, as described above, a screw member that is screwed onto the inner periphery of a pressure plate that is movable in the axial direction but cannot be rotated is pressed into contact with the engagement member fixed to the tip of the rotary shaft to be braked when the electromagnet is deenergized. When the rotary shaft to be braked starts rotating, the screw member is rotated by the frictional resistance of the pressure contact portion, and the pressure plate is appropriately moved toward the brake plate, so that the brake lining of the brake plate is rotated. This has the effect of providing an electromagnetic brake device that can automatically correct wear, has a simple structure, has a small number of parts, is easy to disassemble and assemble, and is inexpensive.

[Brief explanation of the drawing]

Figures 1 and 2 show a conventional electromagnetic brake device, with Figure 1 being a longitudinal sectional view and Figure 2
FIG. 3 is a cross-sectional view taken along the - line in the figure, viewed in the direction of the arrow. 3 and 4 show an embodiment of the present invention; FIG. 3 is a longitudinal cross-sectional view, and FIG. 4 is a cross-sectional view taken along the line - in FIG. 3, viewed in the direction of the arrow. . In the figure, 1 is a rotary shaft to be braked, 4 is a brake box, 5 is a brake disc, 5a, 5b are brake linings, 6 is a friction plate, 7 is a brake disc, 7a, 7b is a brake lining, 8 is a pressure plate, 10 is a movable iron core, 11 is an electromagnet, 22 is a spring receiver, 26 is a screw member, 27 is a ratchet, 28 is a connecting member, 28a is a hexagonal column, 29 is a stopper, 3
0 is a brake spring, and 31 is an engagement member. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Scope of Claims] 1. An inner peripheral portion is fitted to the outer periphery of a rotary shaft to be braked so that the rotary shaft can freely move in the axial direction, and rotates integrally with the rotary shaft, and an outer peripheral edge on one side A brake disc whose vicinity faces the fixed part, a pressure plate whose one side faces the other side of the brake disc and which is movable in the axial direction but cannot rotate, and a screw screwed into the inner peripheral part of the pressure plate. a member, a ratchet wheel that rotates integrally with the screw member, a stopper that engages with the pawl portion of the ratchet wheel to allow the ratchet wheel to rotate in the forward direction and prevent reverse rotation, and a stopper that is disposed on the other side of the pressure plate. a movable iron core, an electromagnet that attracts and moves the movable iron core when energized, a brake spring that presses the pressure plate against the other side of the brake disc via the movable iron core and the screw member when the electromagnet is deenergized; One end is fixed to the shaft end of the rotary body to be braked, and the other end is pressed against the axial end of the screw member when the electromagnet is deenergized, and due to the frictional resistance of the press-contact part, the shaft of the rotary body to be braked is An electromagnetic brake device comprising an engaging member that rotates the screw member when rotation starts. 2. Claim No. 2, characterized in that the screw member is a bottomed cylindrical body that is open on the brake disc side, and that the open end thereof is always fitted to the outer periphery of the rotary shaft to be braked. The electromagnetic brake device according to item 1.