JP2008256218A - Deenergization operation type friction brake - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce backlash in a rotation direction of a deenergization operation type friction brake. <P>SOLUTION: The deenergization operation type friction brake comprises: a hub 12 with rectangular cross section fixed to an outer circumference of a rotational shaft 1; a coil 11; a coil spring; a field core 8; a brake disc 63; and an armature 5. The friction brake further comprises an anisotropic member stuffed in an engagement part where the hub 12 is engaged with a rectangular hole of the brake disc 63. In this case, the anisotropic member is constituted by embedding, in an elastic member, a reinforcement member with continuous or discontinuous constitution in the rotation direction of the rotational shaft, or various deformation thereof may be employed. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an improvement in a non-excitation actuated friction brake, and in particular, reduces a hitting sound caused by a backlash in a rotating direction caused by a spline engagement between a hub and a disk of a non-excited actuating friction brake, particularly in the case of forward and reverse rotation methods. Related to improvements.

FIG. 6 is a longitudinal sectional view of a conventional non-excitation actuated friction brake, and the structure will be described with reference to this figure.
For example, the hub 2 is fixed to the rotating shaft 1 of the motor with a key 2a or the like, and both friction surfaces 4, 4 'of the disk 3 engaged with the hub 2 by the spline S are in contact with the armature 5 and the plate 6, respectively. .
The armature 5 is guided by a guide spacer 7 also serving as a lock nut and moves to both sides in the axial direction.
On the other hand, in the plate 6, the countersunk hole 6a is normally engaged with three equally-divided angles in the circumferential direction, and is drawn to the field core 8 by a countersunk head bolt (not shown). The amount of movement of the armature 5 is determined by hitting the head 9a of the arm 9, and is fixed at that position.
Further, the plate 6 is attached to a fixed body such as a motor main body by bolts or the like, and the field core 8 is provided with three coil springs 10 and coils 11 which are usually equally divided in the circumferential direction, and 8a , 8b are an outer diameter side magnetic pole and an inner diameter side magnetic pole of the field core 8, respectively.

The operation will be described. When the coil 11 is not energized, the armature 5 is pushed by the coil spring 10, and the disk 3 is pressed against the plate 6 and sandwiched. Due to the frictional force of the friction surface 4 'on the opposite side, the rotation of the disk 3 and hence the rotary shaft 1 is braked and stopped.
When the coil 11 is energized, the armature 5 is attracted to the magnetic poles 8a and 8b against the force of the coil spring 10, and the disk 3 becomes free, so the rotating shaft 1 rotates freely.

JP 06-257629 A

  The above non-excited operation type friction brake has a small number of parts and is compact and has excellent braking characteristics. However, it is a striking sound caused by a backlash in the rotational direction caused by the spline engagement between the hub and the brake disc, particularly in the normal and reverse rotation type. It is a problem imposed on the present invention to reduce backlash in some cases.

In the present invention, the above problem is solved by forming the cross section of the hub into a specific shape and integrating the hub and the brake disc with an anisotropic member.
Specifically, as described in claim 1, a non-excitation operation type friction brake according to the present invention includes a hub having a square cross section fixed to the outer periphery of a rotating shaft, a coil and a coil spring, A field core disposed at the end opposite to the hub in the axial direction and a guide spacer, and fixed to the tip of a bolt screwed radially outward from the coil and coil spring of the field core. A plate integrated with the field core, a brake disk located on the outer periphery of the hub and having a square hole in which the square cross section of the hub is enlarged, and a engagement between the hub and the square hole. When the anisotropic member packed in the joint portion and the brake disk and the field core are arranged in the middle in the axial direction and the coil is excited, the field resists the coil spring. An armature that is attracted to-core, characterized in that it comprises a.

  In this case, as described in claim 2, the anisotropic member may include a reinforcing material having a configuration continuous in the rotation direction of the rotation shaft in the elastic body.

  Alternatively, according to a third aspect of the present invention, the anisotropic member may include a reinforcing material having a discontinuous configuration in the rotation direction of the rotation shaft in the elastic body.

  Note that, as described in claim 4, the anisotropic member is anisotropic by adjusting a ratio t / w of a radial thickness (t) to an axial width (w) to 1 or less. It is desirable to use an elastic body having

  Further, as described in claim 5, the hub and the square hole of the brake disc are formed so that spaces are formed at the four corners when these are engaged, and the spaces formed at the four corners of the engaging portion are elastic. It is desirable to arrange an anisotropic member composed of a body.

As described above, in the non-excited operation type friction brake according to the present invention, the backlash can be reduced to zero by integrating the hub and the disk with the anisotropic member.
Further, in the second aspect of the present invention, since there is an anisotropic member including a continuous reinforcing material in the elastic body in the engaging portion of the hub and the brake disk as described above, The backlash in the circumferential direction is zero.
According to the third aspect of the present invention, since there is an anisotropic member including a discontinuous reinforcing material in the elastic body at the engaging portion of the hub and the brake disk, the circumferential direction The backlash is zero.
According to the fourth aspect of the present invention, the anisotropic member provided at the engaging portion between the hub and the brake disc is adjusted to have a thickness and width ratio so as to have an appropriate anisotropy. Therefore, the backlash in the circumferential direction is zero.
Further, according to the fifth aspect of the present invention, since there are anisotropic members such as rubber and plastic in the spaces formed at the four corners where the hub and the brake disk are engaged, the circumferential backlash is zero.

First, a half longitudinal sectional view of a basic structure of a non-excitation operation type friction brake described in claim 1 of the present application will be described with reference to FIG. Parts corresponding to those in FIG. 6 of the conventional example are denoted by the same reference numerals as those in FIG.
As shown in FIG. 1, an anisotropic member 63a is fixed to the outer periphery of the hub 12 fixed to the rotating shaft 1, and a brake disk 63 is fixed to the outer periphery of the anisotropic member 63a.
Further, the field core 8 is disposed at the end portion on the opposite side of the hub 12 in the axial direction.
The field core 8 is provided with a coil 11 and a coil spring (not shown).
The coil spring is not shown because FIG. 1 is a vertical sectional view of the upper half of the body, but is disposed in a corresponding portion of the coil spring 10 in the case of the conventional example of FIG.

The plate 6 passes through the guide spacer 7 and is fixed to the head 11 (a tip) 9 a of the bolt 9 screwed radially outward from the coil 11 of the field core 8 and the coil spring, and integrated with the field core 8. To be configured.
The armature 5 is guided by a guide spacer 7 that also serves as a lock nut and moves to both sides in the axial direction. When the coil 11 is not excited, the armature 5 is separated from the field core 8 as shown in the figure, but when the coil 11 is excited, the armature 5 is attracted to the field core 8 against the coil spring. .
The anisotropic member 63 a is fixed to the outer periphery of the hub 12, and the brake disc 63 is disposed at an intermediate position in the axial direction between the field core 8 and the plate 6. The above is the basic configuration of the present invention.
First embodiment:

In the present invention, in the above basic configuration, there is a structural feature in that the cross section of the hub is formed in a specific shape and engaged with the brake disc. Next, this specific configuration will be described.
First, as a first embodiment of the present invention, a front view of an engagement portion between a hub and a brake disk is shown in FIG.
As shown in FIG. 2, an anisotropic member 74 is packed between the engaging portions of the hub 72 having a square cross section and the brake disc 73 having the square hole 73a.
The anisotropic member 74 is made of an elastic material such as rubber or plastic, and a reinforcing material 74a such as a thin plate is continuous in the rotational direction of the rotary shaft 1 in the anisotropic member 74 as shown in FIG. It is included in the configuration.
In the case of the first embodiment, as described above, the anisotropic member 74 in which the reinforcing member 74a configured continuously is included in the elastic body at the engaging portion of the hub 72 and the brake disc 73. Therefore, the circumferential backlash is zero.
Second embodiment:

FIG. 3 is a front view of an engagement portion between a hub and a brake disk showing a second embodiment of the present application.
In the second embodiment of the present application, in place of the anisotropic member 74 shown in FIG. 2, as shown in FIG. 3, the anisotropy included in the reinforcing material 75a discontinuously configured in the rotational direction is included. It is characterized in that the member 75 is used.
Also in the case of the second embodiment, since there is an anisotropic member 75 in which the reinforcing material 75a configured discontinuously is included in the elastic body at the engaging portion of the hub 72 and the brake disk 73, The circumferential backlash is zero.
Third embodiment:

FIG. 4 shows a half cross-sectional view as a third embodiment of the present invention.
The configuration is the same as that of the first embodiment shown in FIG. 1, but the anisotropic member 84 is an elastic body such as rubber or plastic having no reinforcing material, and has a radial thickness t and an axial direction. The ratio t / w of the width w is adjusted to be 1 or less, for example, to provide anisotropy.
Also in the case of the third embodiment, the anisotropic member 84 provided at the engaging portion of the hub 2 and the brake disk 83 is provided with appropriate anisotropy by adjusting the ratio of the thickness and width. Therefore, the backlash in the circumferential direction is zero.
Fourth embodiment:

FIG. 5 shows a front view of an engagement portion between a hub and a brake disk as a fourth embodiment. An anisotropic member 94 made of an elastic material such as rubber or plastic is disposed in spaces formed at the four corners where the hub 92 having a square cross section and the brake disc 93 having the square hole 93a are engaged.
Also in the case of the fourth embodiment, since there are anisotropic members 94 made of an elastic body such as rubber or plastic in the spaces formed at the four corners where the hub 92 and the brake disc 93 are engaged, The backlash is zero.

1 is a half longitudinal sectional view showing a basic structure of each embodiment of a non-excitation operation type friction brake according to the present invention. It is a front view of the engaging part of the hub and brake disc which shows the 1st Embodiment of this invention. It is a front view of the engaging part of the hub and brake disc which shows the 2nd Embodiment of this invention. It is a half body longitudinal cross-sectional view which shows the 3rd Embodiment of this invention. It is a front view of the engaging part of the hub and brake disc which shows the 4th Embodiment of this invention. It is a longitudinal cross-sectional view of the conventional non-excitation operation type friction brake.

Explanation of symbols

1: Rotating shaft 5: Armature 6: Plate 7: Guide spacer 8: Field core 9: Bolt 9a: Bolt head (tip)
11: Coils 2, 12, 72, 92: Hubs 3, 63, 73, 83, 93: Brake discs 73a, 93a: Square holes 63a, 74, 75, 84, 94: Anisotropic members 74a, 75a: Reinforcing materials t: thickness w: width

Claims (5)

A hub having a square cross section fixed to the outer periphery of the rotating shaft;
A field core having a coil and a coil spring and disposed at the end opposite to the hub in the axial direction;
A plate that penetrates the guide spacer, is fixed to the tip of a bolt that is screwed radially outward from the coil and the coil spring of the field core, and is integrated with the field core;
A brake disc having a square hole located on the outer periphery of the hub and enlarging the square cross section of the hub;
An anisotropic member packed in an engaging portion in which the hub and the square hole are engaged;
Arranged in the axial direction between the brake disc and the field core, and when the coil is excited, an armature that is attracted to the field core against the coil spring;
A non-excitation actuated friction brake characterized by comprising: The non-excitation actuated friction brake according to claim 1, wherein the anisotropic member includes a reinforcing material having a configuration that is continuous in a rotation direction of a rotation shaft in an elastic body. 2. The non-excitation actuated friction brake according to claim 1, wherein the anisotropic member includes a reinforcing material having a discontinuous configuration in a rotation direction of a rotating shaft in an elastic body. The anisotropic member is an elastic body having anisotropy by adjusting a ratio t / w between a radial thickness (t) and an axial width (w) to 1 or less. The non-excitation actuated friction brake according to claim 1. The hub and the square hole of the brake disc are formed so that spaces are created at the four corners when they are engaged,
The non-excitation actuated friction brake according to claim 1, wherein an anisotropic member made of an elastic body is disposed in spaces generated at four corners of the engaging portion.

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