JPH0321189Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention uses the motor gap formed between the rotor and the stator as the bearing clearance of a hydrostatic bearing or a hydrodynamic bearing, and injects pressure fluid into the bearing clearance. The present invention relates to a motor that is supplied with a rotor to rotatably support the rotor.

[Conventional technology]

As the conventional technology of the above motor, for example,
There is one shown in Japanese Patent No. 59-213254. The configuration of this motor will be explained with reference to FIG.
A bearing clearance 5 is formed between the rotor 2 provided on the spindle 1 and the stator 4 supported on the inner surface of the housing 3, and pressure is applied to the bearing clearance 5 from the fluid passage 6 provided in the housing 3 and the stator 4. The rotor 2 is rotatably supported by supplying fluid.

As mentioned above, in a motor in which a hydrostatic bearing is provided between the rotor 2 and the stator 4, the hydrostatic bearing on one side of the spindle is different from a motor in which both ends of the spindle are supported by a hydrostatic bearing. can be omitted, the length of the spindle in the axial direction can be shortened, and the rotor 2 can be omitted.
Since the gap between the stator 4 and the stator 4 is small, there is an advantage that the efficiency of the motor can be improved.

[Problem that the invention attempts to solve]

However, in the above-mentioned motor, the bearing clearance of the hydrostatic bearing is extremely small, ranging from several microns to several tens of microns. There is a drawback.

Generally, in order to improve the rotation accuracy of the spindle in a motor, the distance between the rotor and stator is 0.2
A clearance on the order of mm is required, while a bearing clearance on the order of tens of microns is required between the rotor and stator to fully demonstrate its function as a hydrostatic bearing. For this reason, in a motor that forms a bearing clearance between the rotor and stator as a hydrostatic bearing, it is necessary to sacrifice either the rotational accuracy of the spindle or the bearing accuracy; A motor that satisfies these requirements does not yet exist.

Therefore, the technical object of this invention is to provide a motor that can solve the above-mentioned conventional drawbacks and satisfy both the rotation accuracy of the spindle and the accuracy of the bearings.

[Means for solving problems]

In order to solve the above problems, this invention forms a non-magnetic film on either the outer diameter surface of the rotor or the inner diameter surface of the stator, and this non-magnetic film does not affect the rotation accuracy of the spindle. A thrust plate is provided at the end located inside the housing of the spindle that supports the rotor, and a static pressure thrust plate is provided on both sides of the thrust plate to ensure the motor air gap and the bearing clearance of the hydrostatic bearing or the hydrodynamic bearing. A bearing clearance was formed, and pressure fluid was supplied to this hydrostatic thrust bearing clearance to receive the thrust load of the spindle.

〔Example〕

Hereinafter, embodiments of this invention will be described based on the accompanying drawings.

As shown in FIGS. 1 and 2, a non-magnetic film 7 is provided on the outer diameter surface of the rotor 2 provided on the spindle 1, and the outer diameter surface of the non-magnetic film 7 and the stator 4
A bearing clearance 5 is formed between the inner diameter surfaces of the bearing. This bearing clearance 5 is approximately 10μm to 30μm,
Its dimensions are appropriately determined depending on the conditions of use.

The non-magnetic film may be provided on the inner diameter surface of the stator 4, as shown in FIG.

In the nonmagnetic film 7 shown in FIG. 2, a fiber layer 8 is formed by winding long fibers such as carbon fibers around the outer peripheral surface of the rotor 2, and this fiber layer 8 is fixed to the rotor 2. When fixing the fiber layer 8, there are two methods: impregnating the fiber layer 8 with a thermosetting resin such as epoxy resin and curing it by heating; A wrapping tape made of polyester film, etc. is wrapped around the surface and primary curing is performed at a temperature of about 100℃ to 120℃.After the wrapping tape is peeled off, a wrapping tape of
A method of secondary curing at about 0.degree. C. or the like can be adopted. 9 shown in FIG. 2 indicates a cured resin layer.

Alternatively, a nonmagnetic film may be formed by thermally spraying ceramic onto the shaft.

The non-magnetic film 7' shown in FIG. 3 is made of a non-magnetic sleeve 1 made of ceramic or tetrafluoroethylene resin.
0, and the sleeve 10 is adhered to the inner diameter surface of the stator 4.

The thickness of such nonmagnetic films 7, 7' is approximately 0.1 mm to 0.2 mm. Furthermore, when the stator 4 provided with the fluid passage 6 is provided with the non-magnetic film 7',
A small hole 1 communicating with the fluid passage 6 in the non-magnetic film 7'
Provide a large number of 1s.

Therefore, when the non-magnetic film 7 is provided on the rotor 2 having a fluid passage, small holes communicating with the fluid passage are provided in the non-magnetic film.

Now, when high pressure fluid such as air is supplied to the fluid passage 6 formed in the housing 3 and the stator 4,
Since this high-pressure fluid flows out into the bearing gap 5 formed between the rotor 2 and the stator 4, it can support the radial load of the rotor 2.

As shown in FIG. 1, a thrust plate 12 is provided at the end of the spindle 1, and thrust bearing gaps 13 are formed on both sides of the thrust plate 12, so that the high pressure fluid supplied to the fluid passage 6 can be It is also supplied to the thrust bearing clearance 13. For this reason,
The thrust load is supported by the pressure fluid supplied to the thrust bearing clearance 13, the rotational resistance of the spindle 1 is small, and the spindle 1 can be rotated at an extremely high speed.

〔effect〕

As described above, according to this invention, since a non-magnetic film is provided on either the outer diameter surface of the rotor or the inner diameter surface of the stator, by appropriately setting the thickness of the non-magnetic film, Proper motor clearance can be secured between the rotor and stator,
Unbalance of magnetic attraction force can be reduced. In addition, by forming the above-mentioned non-magnetic film, it is possible to create an optimal bearing clearance between the rotor and stator for a hydrostatic bearing or a hydrodynamic bearing, and the function of the hydrostatic bearing or hydrodynamic bearing can be fully maintained. can be demonstrated.

In addition, a thrust plate is provided at the end located inside the spindle housing, and pressure fluid is supplied to the hydrostatic thrust bearing clearance formed on both sides of the thrust plate to receive the thrust load of the spindle. Since the rotational resistance of the spindle is small, the spindle can be rotated at an extremely high speed, and the rotation accuracy can be further improved.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing one embodiment of the motor according to the invention, FIG. 2 is a partially cutaway perspective view showing the rotor of the above, and FIG. 3 is a cross-sectional view of the stator showing another embodiment of the same. It is. 2... Rotor, 4... Stator, 5... Bearing clearance, 7, 7'... Non-magnetic film, 12... Thrust plate, 13... Thrust bearing clearance.

Claims (1)

[Scope of utility model registration request] In a motor in which a motor gap between a rotor provided on a spindle and a stator supported by a housing is a static pressure radial bearing gap, a non-magnetic film is provided on either the outer diameter surface of the rotor or the inner diameter surface of the stator. 1. A motor characterized in that a thrust plate is provided at an end of the spindle located within the housing, and a hydrostatic thrust bearing clearance is formed on both sides of the thrust plate to which pressure fluid is supplied.