JPH09331654A - Holding brake for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a holding brake for motor which makes a lower noise while satisfying the requirement for reduction in size. SOLUTION: Friction plates 4 which do not rotate relatively with rotor hubs 2 in the circumferential direction of the rotor hubs 2 but can move toward a shaft center are set on outer surfaces of the rotor hubs 2 fastened to an outer surface of a rotary shaft of a motor through interlocking sections 3. Outer plates 5 are counterposed on one face of the friction plates 4 and are fastened to a fastened system. Meanwhile, inner plates 6 are counterposed on the other face of the friction plates 4 so that they can move in the axis direction of the rotary shaft. Electromagnets 7 for attracting the inner plates are so located on the fastened system as to face the inner plates 6. And, springs 8 are installed which separate the inner plates 6 from the electromagnets 7 when the electromagnets 7 are not excited. Ring-shaped plate springs 11 are located in the circumferential direction over the rotor hubs 2 and the friction boards 4. The plate springs 11 are installed at equal intervals in the circumferential direction and are fastened to the rotor hub 2 and the friction board 4 located on the opposite side.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor holding brake for fixing a rotating shaft of a motor such as a servo motor so as not to rotate.

[0002]

2. Description of the Related Art FIGS. 4 and 5 show the structure of a conventional holding brake for a motor of this type. This motor holding brake includes a rotor hub 2 fixed to the outer circumference of a rotating shaft 1 of a motor, and an outer circumference of the rotor hub 2 which does not rotate relative to the rotor hub in the circumferential direction but in the axial direction thereof. A friction plate 4 that is movably fitted through a meshing portion 3, and an outer plate 5 that is arranged facing one surface side of the friction plate 4 and is fixed to a fixed system such as a motor case, An inner plate 6 made of a magnetic material that is arranged opposite to the other surface of the friction plate 4 and is movable in the axial direction of the rotary shaft 1, and a fixed system such as a motor case that is arranged opposite to the inner plate 6. Electromagnet 7 that is fixed and magnetized when necessary to attract the inner plate 6
And a spring 8 for urging the inner plate 6 away from the electromagnet 7 when the electromagnet 7 is not excited.
The inner plate 6 is pressed against the friction plate 4 by the urging force of the inner plate 6 and the inner plate 6 and the outer plate 5.
The rotary shaft 1 is sandwiched by and fixed so as not to rotate.

In this example, the friction plate 4 is a metal cored bar 4
The structure is such that the friction material 4b is fixed to both sides of the outer peripheral side of a. The meshing portion 3 includes a plurality of outward teeth 3a provided on the outer circumference of the rotor hub 2 in the shape of external gears, and a plurality of internal teeth 3b provided on the inner circumference of the mandrel 4a in the shape of internal gears. It has a structure that meshes with. In this case, the thickness of the rotor hub 2 is formed to be thicker than the thickness of the mandrel 4a, and the friction plate 4 is movable in the axial direction of the rotary shaft 1 while being engaged with the rotor hub 2 at the engagement portion 3. . The electromagnet 7 is
A core 7a made of a magnetic material, which is fixed to a fixed system such as a motor case, and the core 7a is magnetized when necessary.
And an electromagnetic coil 7b that attracts the inner plate 6. The spring 8 is 2 in the circumferential direction of the core 7a.
It is fitted and supported in each of the recesses provided at equal intervals or more. The outer plate 5 and the core 7a are
Although not shown in detail, the inner plate 6 is slidably penetrated from the outer plate 5 side and connected by a connecting screw 9 screwed to the core 7a so that the mutual intervals are constant. As shown in the figure, the inner plate 6 is movable in the axial direction of the rotary shaft 1 within the range of the gap G.

In such a motor holding brake, the electromagnet 7 is magnetized when the motor is rotating, and the inner plate 6 is adsorbed to the core 7a against the pressure of the spring 8, so that the friction plate 4 is It rotates freely as the rotary shaft 1 rotates. In such a state, when the rotation of the motor is stopped and the electromagnet 7 is demagnetized at the same time, the inner plate 6 is pressed against the friction plate 4 by the pressure of the spring 8, and the friction plate 4 is separated from the inner plate 6 and the outer plate 5. The rotary shaft 1 is clamped by and fixed so as not to rotate.

[0005]

However, in the motor holding brake having such a structure, since the rotor hub 2 and the friction plate 4 are meshed with each other at the meshing portion 3 formed by the teeth 3a and 3b, the teeth 3a and the teeth 3a are not meshed. Due to the existence of a gap called backlash between 3b, there is a problem that noise is generated due to vibration from the motor during rotation and during stop.

In order to reduce the noise caused by the vibration from the motor, as shown in FIGS. 5 and 6, the leaf spring 10 is supported by one of the teeth 3a so that the leaf spring 10 is engaged with the teeth 3a and 3b. Although it has been proposed to interpose 10, the above-mentioned structure has a problem in that when the vibration of the motor itself is large, it is not possible to reduce the blush noise in the rotation axis direction.

As a means for reducing the noise of the holding brake, it has been considered that the meshing portion 3 between the rotor hub 2 and the friction plate 4 is omitted and the rotor hub 2 and the friction plate 4 are connected at their side faces by a leaf spring. There is.

However, in the structure in which the rotor hub 2 and the friction plate 4 are connected to each other only by the leaf spring on the side surface thereof in this manner, when a large torque is received from the motor side, a leaf spring having high strength is required, and such a leaf spring is required. The spring is less likely to bend in the direction of the rotation axis, and in order to attract the friction plate 4 against the force of the leaf spring, it is necessary to increase the input of the electromagnet 7, and the heat generation of the coil of the electromagnet 7 increases. There is a problem that ends up. If it is attempted to reduce the heat generation of the coil of the electromagnet 7, the brake size becomes large and it becomes impossible to satisfy the demand for downsizing.

An object of the present invention is to provide a holding brake for a motor which can reduce noise while satisfying the demand for downsizing.

Another object of the present invention is to provide a motor holding brake capable of operating a leaf spring which is a noise reducing means in a circumferentially balanced manner.

Another object of the present invention is to provide a holding brake for a motor, which is capable of reducing noise while achieving further miniaturization.

[0012]

SUMMARY OF THE INVENTION According to the present invention, there is provided a rotor hub fixed to the outer circumference of a rotary shaft of a motor, and an axial center of the rotor hub which does not rotate relative to the rotor hub in the circumferential direction thereof. The friction plate movably fitted in the direction through the meshing portion, the outer plate fixed to the fixed system facing one surface side of the friction plate, and the other of the friction plates. An inner plate that is arranged to face the surface of the inner plate and is movable in the axial direction of the rotating shaft, and an electromagnet that is arranged to face the inner plate and is fixed to a fixed system and magnetized when necessary to attract the inner plate.
A spring for urging the inner plate away from the electromagnet when the electromagnet is not excited, and when the rotation of the motor is stopped, the inner plate is pressed against the friction plate by the spring urging to move the friction plate. A holding brake for a motor which is sandwiched between the inner plate and the outer plate and fixed so as to prevent the rotation shaft from rotating is improved.

In the holding brake for a motor according to the first aspect of the present invention, a leaf spring is arranged so as to straddle the rotor hub and the friction plate, and one end side of the leaf spring is fixed to the rotor hub and the other end side is the friction plate. It is characterized by being fixed.

In this way, the meshing portion is provided between the rotor hub and the friction plate, and the plate spring is arranged on the side surface of the rotor hub and the friction plate so as to straddle the rotor hub and the friction plate. When fixed to, since the force in the rotational direction can be received by the meshing portion, the strength of the leaf spring can be weakened as compared with the case where only the leaf spring is used, and therefore the leaf spring is easily bent in the rotation axis direction, The input of the electromagnet that adsorbs the friction plate can be reduced against the force of the leaf spring, the problem of heat generation of the coil of the electromagnet can be solved, and noise reduction is achieved while satisfying the demand for downsizing. be able to.

According to another aspect of the motor holding brake of the present invention, the leaf spring extends annularly along the circumferential direction of the rotor hub and the friction plate, and the leaf spring extends in the circumferential direction. It is characterized in that it is fixed to the mating rotor hub and the friction plate at equal intervals.

As described above, the leaf springs are arranged in a ring shape along the circumferential direction of the rotor hub and the friction plate, and the leaf springs are arranged at equal intervals in the circumferential direction. If they are respectively fixed to and, the leaf spring, which is a noise reducing means, can be operated in a balanced manner in the circumferential direction, and rotation of the friction plate is not hindered.

In the holding brake for a motor according to a third aspect of the invention, the fixing position of the leaf spring with respect to the rotor hub and the fixing position with respect to the friction plate are provided so as to be displaced in the circumferential direction.

When the fixed position of the leaf spring with respect to the rotor hub and the fixed position with respect to the friction plate are displaced in the circumferential direction in this way, the length of the leaf spring existing between these fixed positions becomes long, and therefore the holding Even if the brake is downsized, it is easy to make the elasticity of the leaf spring weak in the axial direction of the rotating shaft and strong in the rotating direction. Therefore, even if the input of the electromagnet is small, the friction plate can be easily attracted. You can Therefore, noise reduction can be achieved while achieving further miniaturization.

According to another aspect of the motor holding brake of the present invention, spacers are respectively interposed between the leaf spring and the mating member at a fixed position of the leaf spring with respect to the rotor hub and the friction plate. To do.

When spacers are respectively interposed between the leaf spring and the mating member at the fixing position of the leaf spring with respect to the rotor hub and the friction plate, the length between the fixing positions of the leaf spring becomes long. Therefore, even if the holding brake is downsized, it is easy to make the elasticity of the leaf spring weak in the axial direction of the rotating shaft and strong in the rotating direction, and therefore the friction plate can be easily made even if the input of the electromagnet is small. Can be adsorbed.
Therefore, noise reduction can be achieved while achieving further miniaturization.

[0021]

1 to 3 show one example of an embodiment of a holding brake for a motor according to the present invention. Parts corresponding to those in FIGS. 4 and 5 described above are denoted by the same reference numerals.

In the motor holding brake of this example,
On the outer plate 5 side, a leaf spring 11 made of stainless steel and having a thickness of, for example, about 0.4 mm is disposed across the rotor hub 2 and the friction plate 4. The leaf spring 11 has an annular structure that straddles the rotor hub 2 and the friction plate 4 and exists along the circumferential direction thereof. The leaf springs 11 are fixed to the mating rotor hub 2 and the friction plate 4 with fixing screws 12 and 13 at equal intervals (120 ° intervals in this example) in the circumferential direction. In this example, in particular, the fixed position of the leaf spring 11 with respect to the rotor hub 2 and the fixed position with respect to the friction plate 4 are provided at positions shifted by 60 ° in the circumferential direction. Further, the fixing screw 1 for the rotor hub 2 and the friction plate 4 of the leaf spring 11 is fixed.
At the fixed positions of 2 and 13, spacers 14 and 15 are respectively interposed between the leaf spring 11 and the mating member. Fixing screws 12 and 13 are leaf springs 1 to prevent rotation.
They are bonded to each other with an adhesive 16. A key groove 17 is provided on the inner periphery of a boss portion 2a of the rotor hub 2 which is provided for fitting the rotating shaft 1 in the center of the rotor hub 2, and the boss portion 2a is provided with a key groove 17 Screw holes 18 into which fixing screws for fixing to the rotating shaft 1 (not shown) are screwed are provided at positions of 45 ° to the left and right.

Other configurations are similar to those in FIGS. 4 and 5 described above.

Thus, the meshing portion 3 is provided between the rotor hub 2 and the friction plate 4, and the leaf spring 11 is arranged on the side surface of the rotor hub 2 and the friction plate 4 so as to straddle the rotor hub 2 and the friction plate 4. When 11 is fixed to the rotor hub 2 and the friction plate 4,
Since the meshing portion 3 can receive the force in the rotating direction,
The strength of the leaf spring 11 can be weakened as compared with the case where only the leaf spring 11 is used. Therefore, the leaf spring 11 is easily bent in the rotation axis direction, and the friction plate 4 is attracted against the force of the leaf spring 11. The input of the electromagnet 7 can be reduced, the problem of heat generation of the coil 7b of the electromagnet 7 can be solved, and noise reduction can be achieved while satisfying the demand for downsizing.

Further, the leaf springs 11 are structured so as to straddle the rotor hub 2 and the friction plate 4 so as to be annularly present along the circumferential direction thereof, and the leaf springs 11 are arranged at equal intervals in the circumferential direction on the mating rotor hub. By fixing them to the friction plate 4 and the friction plate 4, respectively, the leaf spring 11 as the noise reducing means can be operated in a well-balanced manner in the circumferential direction, and the rotation of the friction plate 4 is not hindered.

When the fixing position of the leaf spring 11 with respect to the rotor hub 2 and the fixing position with respect to the friction plate 4 are displaced in the circumferential direction, the fixing screws 12, 1 at these fixing positions are located.
The length L of the leaf spring 11 existing between the three becomes long, so that even if the holding brake is downsized, the elasticity of the leaf spring 11 is weak in the axial direction of the rotating shaft 1 and strong in the rotating direction. Therefore, even if the input of the electromagnet 7 is small, the friction plate 4 can be easily attracted. Therefore, noise reduction can be achieved while achieving further miniaturization.

Further, at the fixing position of the leaf spring 11 with respect to the rotor hub 2 and the friction plate 4, the leaf spring 11 and the mating member 2,
If the spacers 14 and 15 are interposed between the springs 4 and 4, respectively, the length between the fixing positions of the leaf springs 11 becomes long. Therefore, even if the holding brake is downsized, the elasticity of the leaf springs 11 can be maintained. It is easy to weaken in the axial direction and strong in the rotating direction, so that the friction plate 4 can be easily attracted even if the input of the electromagnet 7 is small. Therefore, noise reduction can be achieved while achieving further miniaturization.

As in this example, the rotor hub 2 of the leaf spring 11 is
Between the fixed position with respect to the friction plate 4 and the fixed position with respect to the friction plate 4 in the circumferential direction, and at the fixed position with respect to the rotor hub 2 and the friction plate 4 of the plate spring 11 between the plate spring 11 and the mating members 2, 4. By interposing the spacers 14 and 15, respectively, the leaf spring 11 is more easily bent in the rotation axis direction, and the input of the electromagnet 7 that attracts the friction plate 4 against the force of the leaf spring 11 can be made smaller. , The electromagnet 7
The problem of heat generation of the coil 7b can be solved more easily, and the noise reduction can be achieved while further satisfying the demand for downsizing.

In the above example, (a) the fixed position of the leaf spring 10 with respect to the rotor hub 2 and the fixed position with respect to the friction plate 4 are displaced in the circumferential direction, and (b) the rotor hub 2 and the friction plate 4 of the leaf spring 10 are displaced from each other. The leaf spring 10 in a fixed position with respect to
Although the spacers 14 and 15 are respectively interposed between and the mating member, only one of these (a) and (b) can be adopted.

[0030]

In the motor holding brake according to the first aspect of the present invention, the leaf spring is disposed so as to straddle the rotor hub and the friction plate, and the leaf spring has one end fixed to the rotor hub.
Since the other end is fixed to the friction plate, the leaf spring connects the rotor hub and the friction plate to the circumferential direction of the rotary shaft and also to the axial direction of the rotary shaft. The leaf spring can reduce both the vibration of the friction plate in the rotation direction of the rotary shaft and the vibration of the friction shaft in the axial direction.

In the motor holding brake according to a second aspect of the present invention, the leaf spring has a structure in which the leaf spring straddles the rotor hub and the friction plate and is annularly present along the circumferential direction of the rotor hub and the friction plate. Since the rotor hub and the friction plate on the mating side are fixed at equal intervals, the leaf spring, which is a noise reducing means, can be operated in a well-balanced manner in the circumferential direction, and there is an advantage that the rotation of the friction plate is not hindered. is there.

In the holding brake for a motor according to claim 3, since the fixed position of the leaf spring with respect to the rotor hub and the fixed position with respect to the friction plate are displaced in the circumferential direction, the leaf spring existing between these fixed positions. Therefore, even if the holding brake is downsized, the elasticity of the leaf spring can be weakened in the axial direction of the rotating shaft and can be strengthened in the rotating direction, and even if the input of the electromagnet is small. The friction plate can be easily adsorbed. Therefore, according to the present invention, noise reduction can be achieved while maintaining downsizing.

In the motor holding brake of the fourth aspect, since the spacers are respectively interposed between the leaf spring and the mating member at the fixed position of the leaf spring with respect to the rotor hub and the friction plate, the leaf spring is provided. Since the length between the fixed positions of the springs becomes longer, the elasticity of the leaf spring can be weakened in the axial direction of the rotating shaft and strengthened in the rotating direction even when the holding brake is downsized, and the input of the electromagnet can be increased. Even if it is small, the friction plate can be easily adsorbed. Therefore, according to the present invention, noise reduction can be achieved while maintaining downsizing.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view showing an example of an embodiment of a motor holding brake according to the present invention.

FIG. 2 is an enlarged view of a main part of the motor holding brake shown in FIG.

FIG. 3 is a right side view showing a motor holding brake shown in FIG. 1 with a part thereof omitted.

FIG. 4 is a vertical cross-sectional view of a conventional motor holding brake.

5 is a right side view of the motor holding brake shown in FIG. 4. FIG.

6 is a view as seen in the direction of arrow A in FIG. 5;

[Explanation of symbols]

 1 Motor Rotating Shaft 2 Rotor Hub 3 Engagement Parts 3a, 3b Teeth 4 Friction Plate 4a Mandrel 4b Friction Material 5 Outer Plate 6 Inner Plate 7 Electromagnet 7a Core 7b Electromagnetic Coil 8 Spring 9 Connecting Screw 10 Leaf Spring 11 Leaf Spring 12, 13 Fixing screw 14,15 Spacer 16 Adhesive 17 Key groove 18 Screw hole

Claims (4)

[Claims] 1. A rotor hub fixed to the outer circumference of a rotary shaft of a motor, and meshed with the outer circumference of the rotor hub so as not to rotate relative to the rotor hub in the circumferential direction but to be movable in the axial direction thereof. A friction plate fitted through the section,
An outer plate that is arranged to face one surface side of the friction plate and is fixed to a fixed system, and an inner plate that is arranged to face the other surface side of the friction plate and is movable in the axial direction of the rotation shaft. And an electromagnet that is disposed opposite to the inner plate and is fixed to a fixed system and is magnetized when necessary to attract the inner plate, and that separates the inner plate from the electromagnet when the electromagnet is not excited. A spring for urging the inner plate against the friction plate by the urging of the spring when the rotation of the motor is stopped, and the friction plate is sandwiched between the inner plate and the outer plate to rotate. In a holding brake for a motor that fixes a shaft so as not to rotate, a leaf spring straddling the rotor hub and the friction plate. And a leaf spring having one end fixed to the rotor hub and the other end fixed to the friction plate. 2. The leaf spring is present in a ring shape across the rotor hub and the friction plate along the circumferential direction of the rotor hub and the friction plate, and the leaf spring is provided at equal intervals in the circumferential direction on the opposite side. The holding brake for a motor according to claim 1, wherein the holding brake is fixed to a rotor hub and the friction plate, respectively. 3. The motor holding brake according to claim 2, wherein a fixing position of the leaf spring with respect to the rotor hub and a fixing position of the friction plate are displaced from each other in a circumferential direction. 4. A spacer is interposed between the leaf spring and a mating member at a fixed position of the leaf spring with respect to the rotor hub and the friction plate, respectively. Holding brake for the motor described in.