JPH0583455U - Rotating device - Google Patents

Abstract

(57) [Summary] [Object] To provide a rotating device that can be downsized in the radial direction without the presence of a rotor and a stator increasing the radial size and reducing the dynamic pressure generation capability. [Structure] The rotor 10 attached to the lower end surface of the shaft 7 of the rotating body 9 and the stator 6 attached to the bottom plate 3 of the support body 5 constitute a flat motor, and the stator 6 and the rotor 10 face each other in the axial direction. It is arranged to. Therefore, the presence of the stator 6 and the rotor 10 does not increase the radial dimension.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotating device used in, for example, a spindle unit and having a stator and a rotor.

[0002]

[Prior Art]

 Conventionally, as this type of rotating device, there is one shown in FIG. In this rotating device, a bottom flange portion 31 and a bottomed sleeve 32 constitute a support body 30, and a stator 33 is attached to the outer peripheral surface of the bottomed sleeve 32. A housing 36, which covers the bottomed sleeve 32, is fixed to the shaft end surface of a shaft 35 partially housed in the bottomed sleeve 32, and a rotor facing the stator 33 is provided on the inner peripheral surface of the housing 36. 37 is attached.

Further, a dynamic pressure groove 38 is formed on the outer peripheral surface of the shaft 35 facing the inner peripheral surface of the bottomed sleeve 32. Further, an annular permanent magnet 41 is fixed to a flange portion 40 formed at the opening end of the housing 36, and an annular permanent magnet 41 is attached to the bottom flange portion 31 of the support 30 so that the same poles as the permanent magnet 41 face each other. The permanent magnet 42 is fixed.

In the rotating device, the rotor 37, the housing 36, and the shaft 35 are integrally rotated by the rotating magnetic field generated by the stator 33, and the dynamic pressure groove 38 formed in the shaft 35 is provided with the bottomed bottom. Dynamic pressure is generated in the air between the sleeve 32 and the shaft 35 to support the shaft 35 in the radial direction with respect to the bottomed sleeve 32. The repulsive force of the permanent magnets 41 and 42 supports the shaft 35 and the housing 36 in the axial direction with respect to the bottomed sleeve 32.

[0005]

[Problems to be solved by the device]

 However, in the above-described conventional rotating device, the rotor 37 and the stator 33 are arranged so as to face each other in the radial direction, and therefore a dedicated radial space for the rotor 37 and the stator 33 is required. For this reason, it is necessary to reduce the diameter of the shaft 35 in order to realize compactness in the radial direction. The reduction in the diameter of the shaft 35 leads to a reduction in the dynamic pressure generation capability. Therefore, the conventional rotating device has a problem that it is difficult to reduce the diameter of the shaft 35 in a radial direction without reducing the dynamic pressure generating ability.

Therefore, an object of the present invention is to provide a rotating device that can be downsized in the radial direction without the presence of the rotor and the stator increasing the radial dimension and reducing the dynamic pressure generation capability. .

[0007]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the present invention comprises a support, a rotary body fitted to the support, and a flat motor, and the support and the rotary body are provided on at least one of the opposing circumferential surfaces. A dynamic pressure groove is formed, and the rotor and the stator of the flat motor are attached to the end surface of the rotary body and the end surface of the support body so as to face each other in the axial direction.

[0008]

[Action]

 Since the rotor and the stator of the flat motor are attached to the end surface of the rotating body and the end surface of the support so as to face each other in the axial direction, a radial space exclusively used by the rotor and the stator is required. Unlike the conventional example, the presence of the rotor and the stator does not increase the radial dimension. Therefore, according to the present invention, the size can be reduced in the radial direction as compared with the conventional example without lowering the dynamic pressure generation capability.

[0009]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows a first embodiment of the rotating device of the present invention. In this embodiment, a sleeve 2 having a bottom flange portion 1 and a bottom plate 3 that closes the bottom opening of the sleeve 2 constitute a support body 5, and a disk-shaped stator 6 is attached to the inner surface of the bottom plate 3. There is. A housing 8 that covers the sleeve 2 is fixed to the axially upper end of a shaft 7 that is partially housed in the sleeve 2, and the shaft 7 and the housing 8 form a rotating body 9. A disc-shaped rotor 10 facing the stator 6 is attached to the lower end surface of the shaft 7. The diameter of the stator 6 and the diameter of the rotor 10 are slightly smaller than the diameter of the shaft 7. The stator 6 and the rotor 10 form a flat motor.

A dynamic pressure groove 15 is formed on the outer peripheral surface of the shaft 7 facing the inner peripheral surface of the sleeve 2.

An annular permanent magnet 12 is fixed to a flange portion 11 formed at the open end of the housing 8, and the same pole as the permanent magnet 12 faces the bottom flange portion 1 of the sleeve 2. Thus, the annular permanent magnet 13 is fixed.

In the above structure, when the stator 6 attached to the support 5 generates a rotating magnetic field, the rotor 10, the shaft 7 and the housing 8 rotate integrally, and the dynamic pressure groove formed in the shaft 7 is rotated. A dynamic pressure 15 is generated in the air between the sleeve 2 and the shaft 7 to support the rotating body 9 in the radial direction with respect to the supporting body 5. Further, the rotating body 9 is supported in the axial direction with respect to the support body 5 by the repulsive force of the permanent magnets 12 and 13.

In the rotating device of the above embodiment, the stator 6 and the rotor 10 are arranged so as to face each other in the axial direction, the stator 6 and the rotor 10 constitute a flat motor, and the diameter of the stator 6 and the rotor Since the diameter of 10 is slightly smaller than the diameter of the shaft 7, the presence of the rotor 10 and the stator 6 does not increase the radial dimension of the rotating device. Therefore, according to this embodiment, as compared with the conventional example in which the rotor and the stator occupy the radial space exclusively, the diameter of the shaft 7 in which the dynamic pressure groove 15 is formed is not reduced, that is, the dynamic pressure generation capability. The size can be made smaller in the radial direction than the conventional example without reducing the

Next, a second embodiment is shown in FIG. In this embodiment, in place of the permanent magnets 12 and 13 of the first embodiment shown in FIG. 1, a protrusion 7A having a curved tip provided on the bottom surface of the shaft 7 allows the rotor 5 to rotate relative to the support 5. 9 is different from the first embodiment only in that the rotor 9 and the stator 6 are supported in the axial direction and the rotor 10 and the stator 6 are formed in an annular shape in order to provide the protrusion 7A.

Also in this embodiment, the stator 6 and the rotor 10 are arranged so as to face each other in the axial direction, the stator 6 and the rotor 10 constitute a flat motor, and the diameter of the stator 6 and the rotor 10 are equal to each other. Since the diameter is substantially the same as the diameter of the shaft 7, the presence of the rotor 10 and the stator 6 does not increase the radial dimension of the rotating device, as in the first embodiment. Therefore, according to this embodiment, as compared with the conventional example in which the rotor and the stator occupy the radial space exclusively, the size can be reduced in the radial direction without lowering the dynamic pressure generation capability.

In the first and second embodiments, the dynamic pressure groove is formed on the outer peripheral surface of the shaft 7, but the dynamic pressure groove may be formed on the inner peripheral surface of the sleeve 2.

[0018]

[Effect of the device]

 As is apparent from the above description, in the rotating device of the present invention, the rotor and the stator constituting the flat motor are axially opposed to each other on the end surface of the rotating body and the end surface of the support body fitted with the rotating body. They are attached to each other.

Therefore, according to the present invention, unlike the conventional example in which the radial space exclusively used by the rotor and the stator is required, the presence of the rotor and the stator can prevent the radial dimension from increasing. Therefore, it is possible to reduce the size in the radial direction more than the conventional example without reducing the dynamic pressure generation capability.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of a rotating device of the present invention.

FIG. 2 is a sectional view of a second embodiment of the present invention.

FIG. 3 is a sectional view of a conventional rotating device.

[Explanation of symbols]

1 Bottom Flange Part 2 Sleeve 3 Bottom Plate 5 Support 6 Stator 7 Shaft 8 Housing 9 Rotating Body 10 Rotor 11 Flange Part 12, 13 Permanent Magnet

Claims (1)

[Scope of utility model registration request] 1. A support body, a rotary body fitted to the support body, and a flat motor, wherein a dynamic pressure groove is formed on at least one of circumferential surfaces of the support body and the rotary body facing each other. A rotating device in which a rotor and a stator of the flat motor are attached to an end surface of the rotating body and an end surface of the supporting body so as to face each other in an axial direction.