JPS62152357A - Motor - Google Patents

Abstract

PURPOSE:To reduce the movement or vibration of a rotor section and improve corrosion-proof property and abrasion-proof property, by using a ceramics with a spiral groove formed in the sliding surface of the rotor. CONSTITUTION:A rotor 10 is organized with a dish-formed iron yoke 1 with a circular plane, a ring-formed permanent magnet2 fitted and fixed on the yoke 1, and a ceramic plate 100 fixed on the yoke 1 in the inner periphery of the permanent magnet 2. The permanent magnet 2 is magnetized at equal intervals with a plurality of magnetic poles in a ring shape. The surface of the ceramic plate 100 is finished into a smooth plane,and a spiral groove in one direction is formed, and a concave section 12 is formed on the central section. A coil 4 is fixed on a fixing plate 6 and is fixed by fixing plates 3, 6 through pressure welding from both surfaces, and a stator 101 is organized.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to an electric machine, and particularly to an electric machine that has a flat structure, a simplified structure, and does not require a drive shaft for transmitting rotational force. Regarding.

[Prior Art] No. 70 is a longitudinal sectional view of a brushless flat motor, which is an example of a conventional electric machine. The heath 21 and the board 22 for mounting the stator coil are connected by stake bolts 23, and the motor shaft 26, which is pivotally connected to bearings 24 and 25 fixed to the sheath 21 and the board 22, respectively, has a rotor magnet fixed thereto. 27 is fixed. The stator coil 28 is placed between the rotor 27 and the substrate 22.
is fixed to the substrate 22, and to the substrate 22 are fixed a tacho generator 33 that is generated by the rotor 27 and a Hall element 29 for controlling the rotation speed. The structure is the same for sheet coil motors whose motor coils are manufactured by photoetching, which makes the stator coils extremely thin.

[Problem that the invention seeks to solve]

In the electric machine as described above, the radial clearance between the bearings 24 and 25 is large, and the rotor 27 may vibrate. In particular, when ball bearings are used for the bearings 24 and 25, there is a risk of generating rolling vibrations, so tape recorders and V
This is a problem in TR.

Furthermore, without a shaft sealing means, radial bearings do not have excellent corrosion resistance, cannot withstand use underwater, and have insufficient durability even in environments where condensation occurs repeatedly.

In addition, rotational unevenness is a particular problem in motors used in electronic application products, and the variation in frictional resistance in the radial bearing portion is large, which can sometimes cause rotational unevenness.

Although it is often preferable for such an electric machine to be thin with a short axial length, the motor cannot be made thin unless the distance between the radial bearings 24 and 25 is shortened.

If the distance between the radial bearings is shortened, the bearing load relative to the radial load will increase, and the inclination of the motor shaft due to the bearing clearance will also increase.

By supporting the rotor with a spiral grooved thrust bearing made of ceramic, the present invention minimizes the wobbling and vibration of the rotor part, which has been a problem in the past, and has excellent corrosion resistance and wear resistance, and has no uneven rotation. The purpose is to provide an electric machine that can be used underwater.

[Means for solving problems]

The present invention provides an electric machine in which a stator is disposed facing an end surface of a rotor in the direction of a rotating shaft, in which a rotating side sliding surface is formed on the yoke end surface, and the stator surface facing the rotating side sliding surface is used as a bearing surface. A second aspect of the present invention is an electric machine characterized in that a ceramic material having spiral grooves formed on a smooth plane is used as a member constituting the rotating side sliding surface. , furthermore, it is an electric machine in which the blades are directly fixed to the rotor.

[For production]

When the yoke rotates, dynamic pressure of the fluid is generated between the sliding surface on the rotating side and the bearing surface on the stator side, which are formed with spiral grooves. Rotates due to dynamic resistance.

Furthermore, by directly fixing blades, impellers, etc. to this yoke, it is possible to operate a desired rotating body substantially without providing a drive shaft.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a general-purpose brushless flat motor to which one spiral grooved thrust bearing is applied.

The rotor 1O is composed of a dish-shaped iron yoke 1 with a circular plane, an annular permanent magnet 2 fitted and fixed to the yoke 1, and a ceramic plate 100 fixed to the yoke 1 on the inner circumference of the permanent magnet 2. . The permanent magnet 2 has a plurality of annular magnetic poles magnetized at equal intervals. The surface of the ceramic plate 100 is finished into a smooth plane, and is further machined with spiral grooves in one direction, but this plane has a mirror-like surface and the waviness is within 1 μm.

Further, the depth of the spiral groove is 3 to 50 μm.

In addition, a ceramic plate 1 on which spiral grooves are formed
A recess 12 is formed in the center of 00.

FIG. 2 is an enlarged longitudinal cross-sectional view of the main part of FIG. 1, and a stator-side bearing surface 8 is provided so as to face this rotation-side sliding surface 9. Reference numeral 4 denotes a stake coil, and the coils are arranged in a ring shape corresponding to the ring-shaped permanent magnet 2, so that a rotating magnetic field can be formed. 3 is a fixed plate that covers the surface of the stator side on which the bearing part 18 is formed, and is made of a ceramic plate;
.

Base intermetallic compounds (eg Cr: 30wt%, M
.

:20wt%, Si:4wt%, Co:balance), cemented carbide, or ferrite.

In Fig. 1, 6 is a fixing plate that fixes the coil 4, the coil 4 is fixed by pressure from both sides by the fixing plate 3.6, and 31 is a bolt that fixes the fixing plate 6.3 in a fixed position. Yes, 32 is Nando's. Further, 29 is a Hall element that detects the magnetism of the rotor fixed to the fixed plate 3.

Furthermore, referring to FIG. 2, the bearing surface 8 on the surface of the fixed plate 3 is finished with a smooth mirror surface, and its waviness is also within 1 μm. Also, like the rotating side sliding surface 9, the rotor A hemispherical recess 11 is formed in a portion facing the rotation center 13, and a small ceramic ball 7 is accommodated in the space formed by the two recesses 11 and 12. 14 is a bearing surface 8 on the surface of the rotor 10 and the stator.
A wide range of fluids such as air, water, and oil can be used. Particularly when operating in a vacuum, it is desirable to use oil with a low vapor pressure.

FIG. 3 is a front view of the rotating side sliding surface 9, in which a unidirectional spiral groove 15 is formed in a circular ceramic plate 100, and the center 16 of the ceramic plate is also machined to the same depth as the groove 15. has been done. Of course, the center 16 is a spiral'
The land portion 17 adjacent to a15 may be at the same height as a smooth plane, or may be machined deeper than the spiral groove 15. However, since starting torque is large in this type of electric machine, it is desirable to reduce the area of the land portion 17, which is a convex portion on the rotating side sliding surface 9.

In FIG. 3, arrow A is the direction in which the rotor 10 rotates, and since the rotating side sliding surface 9 also rotates together with the rotor 10, the fluid 14 is directed from the outer circumferential side to the center 1 by the spiral groove 15.
In the spiral 'a15 part, a large dynamic pressure is generated from the outer circumferential end toward the inner circumferential side, and furthermore, at the center 16, the pressure distribution is uniform. Note that the magnitude of the dynamic pressure generated here is such that the rotor 10 is
01, and the rotor 10 and stator 101 can rotate with extremely small sliding resistance via the fluid film.

The most protruding part of the rotating side sliding surface 9 is the land part 17, and the waviness on the entire surface thereof is within 1 μm. Furthermore, the protruding part on the bearing surface 8 side is this smooth bearing surface. The undulation on the entire surface is also 1μ
Since the amplitude of the rotor 10 in the rotational axis direction is extremely small, the gap between the permanent magnet 2 fixed to the rotor 10 and the fixed plate 3 can be maintained at an extremely small dimension.

Therefore, the magnetic field generated by the coil 4 is effectively
It is efficient because it is transmitted to If the fixing plate 6 on the back side of the coil 4 is to prevent leakage of magnetic flux, it may be made of iron. However, all materials interposed in the magnetic gap between the permanent magnets 2 and the coils 4 of the rotor should have good magnetic permeability.

Various coils can be used for the coil 4 of the stake 101. For example, it is possible to use a stack of sheet coils in which a spiral conductor coil is sandwiched between plastic insulating sheets, or a normal coil in which a conductor is wound around an iron core.

Also, known winding methods such as direct winding, shunt winding, and overlap winding can be applied.

Fig. 1 shows a so-called Hall motor that uses a Hall element to detect the position of the permanent magnet 2 of the rotor 10 and passes current through a coil that provides the best rotation. Can be used.

FIG. 4 is a front view of the fixing plate 3 seen from the surface, and shows that the fixing plate 3 is fixed at four places, and the Hall element 29 is fixed on the surface, and the bearing surface of the central part 8 is shown in FIG. protrudes in a convex manner, its surface is finished as a smooth mirror surface, and the waviness of the entire surface of the central bearing surface 8 is within 1 μm. The bearing surface 8 in the center is a bearing surface on the stator side, and has a recess 11 formed at a position facing the rotation center line 13 of the rotor 10, and has a recess 11 formed at a position facing the rotation center line 13 of the rotating side sliding shaft 9. The recess 12 formed on the recess 13 forms a space in which a hard ball 7, which can be present over both recesses 11, 12, is accommodated.

FIG. 5 is a longitudinal sectional view of an embodiment in which both ends can output.

A coil 4 made of stacked sheet coils is fixed from both sides by two ceramic fixing plates 3.
．． 3, the central bearing surface 8.8 is a smooth plane, and the tacho generator 33 is concave relative to the central bearing surface 8 so as not to be in fixed contact with the opposing surface of the rotor 10.

In FIG. 5, the position of the permanent magnet 2 attached to the lower rotor 10 is detected by the Hall element 29, and a predetermined coil 4 is energized by a control device (not shown) to rotate the lower rotor 10. Become. The magnetic flux generated by the coil 4 at this time also appears on the upper surface of the coil 4, so that the upper rotor 10 also rotates in the same way.

However, the opposing poles of the upper and lower rotors 10 are completely opposite, and as a result, the rotors 10 and 10 are attracted to each other.
0.10 is held in the stator.

Note that the small ball 7 corresponds to a type of radial bearing. With this small ball 7, the rotor 10.10 and the stator 1
01 from moving in the flat diameter direction, that is, in the radial direction, and also serves as a guide for positioning.

As the small balls, in addition to iron balls, stainless steel balls, and ceramic balls, various shapes such as cylinders, hundred cones, etc. can be used.

The member constituting the rotating side sliding surface 9 on which the spiral groove is formed must be made of ceramics. Then, the surface is made smooth by lapping, and a spiral groove-shaped resin mask is attached to the smooth surface. The resin where the grooves will be processed will flow out with water, and the areas that will not be processed will be protected by the resin before shot blasting. conduct. By performing shot blasting on the ceramic plane corresponding to the rotating side sliding surface to which the resin mask is attached, the unmasked areas can be processed to a substantially uniform depth in proportion to the shot time.

Note that the ceramic used for the sliding surface 9 is S i
Although there are C+ S i 3 N a + ^1203 and the like, β-3iC is particularly good because it has a low failure rate, has a secret structure, and has high strength.

FIG. 6 is a longitudinal sectional view showing a second embodiment of the present invention, in which blades 103 for blowing air are attached to the outer periphery of the rotor 10 of the electric machine shown in FIG. This allows an extremely flat type of blower to be constructed, and can be used as a ventilation fan, cooling fan, etc. Similarly, the present invention
It can also be used for liquid pumps, creating a magnet pump with a simple structure.

〔effect〕

The present invention is an electric machine in which a stator is disposed facing the end face of the rotor in the rotational axis direction, and uses ceramics with spiral grooves formed on the sliding surface of the rotor. 1. Small, lightweight, and long-life electric machine. Machines can be configured.

2. The thrust bearing has improved wear resistance and corrosion resistance, making maintenance easier.

3. It can be used in both liquid and gas environments, and even in slurry.

4. Sliding friction resistance in the thrust bearing part is 0.
001 or less, and the loss of power in the bearing is extremely small.

5. A flat motor can be created.

In addition, the second invention has the following effects: 6. Since the blades are directly attached to the rotor, if used for liquid pumps and gas pumps, it is possible to create an electric machine with an extremely simple structure. .

This has the effect of

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a partially enlarged view of FIG. 1, FIG. 3 is a partially enlarged view of FIG. 1, and FIG. 4 is a part of FIG. 1. An enlarged view, FIG. 5 is a vertical sectional view of another embodiment of the present invention, FIG. 6 is a longitudinal sectional view of the second embodiment of the invention, and FIG.
The figure is a conventional diagram. 1...Yoke, 2...Permanent magnet, 3...Fixing plate,
4...Coil, 6...Fixing plate, 7...Small ball, 8...
...Bearing surface, 9...Rotating side sliding surface, 10...Rotor, 11...Recess, 12...Recess, 13...Rotation center line, 14...Fluid, ]5. ...Spiral groove, 16
...Center, 17...Land part, 21...Base,
22... Board, 23... Stay bolt, 24...
Bearing, 25...Bearing, 26...Motor shaft, 29...
- Hall element, 31... Fixing bolt, 32... Nut, 33... Tacho generator, 100... Ceramic plate, 101... Stator. Patent Applicant: Ebara Research Institute, Inc. Ebara Corporation, Representative Patent Attorney: Tadashi Takagi Yukima Yakushi Nejiri
1) Takatsugu Part Figure 1 Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1. In an electric machine having a stator arranged opposite to an end face of a rotor in the direction of the rotation axis, a rotating side sliding surface is formed on the end face of the rotor, and a stator facing the rotating side sliding surface is provided. An electric machine characterized in that the surface of the electric machine is a bearing surface, and the rotating side sliding surface is made of ceramic having spiral grooves formed on a smooth plane. 2. The electric machine according to claim 1, wherein the member constituting the bearing surface is made of ceramics. 3. A recess is formed at a position on the axis of rotation of each of the rotating side sliding surface and the bearing surface, and the rotating side sliding surface and the bearing surface are placed in the space formed by the two opposing recesses. An electric machine according to claim 1 or 2, which accommodates a hard member supported so as to be rotatable relative to each other. 4. In an electric machine in which a stator is arranged facing the end face of the rotor in the rotational axis direction, a rotating side sliding surface is formed on the rotor end face, and the stator surface facing the rotating side sliding surface is used as a bearing surface. An electric machine characterized in that a ceramic member having a spiral groove formed in a smooth plane is used as a member constituting the rotating side sliding surface, and a blade is fixed to the rotor.