JP2001309621A - Rotor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotor of a low cost comprising an imbalance-correction means capable of reducing in size and weight and securing the strength. SOLUTION: A rotating shaft 20 of the rotor 10 consists of a basic rotating shaft 22 fitted with a core 50 mounting a winding 52 and an eccentric shaft 24 that is decentered from the center of the basic rotating shaft 22, and the eccentric shaft 24 comprises a counter-balance section 24c that positions at the side opposing to the eccentric direction and cancels the eccentric weight of the eccentric shaft 24 that extends to the side of the basic rotating shaft 22. The basic rotating shaft 22 is formed from a cylindrical member 22a that houses the counter-balance section 24c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotor as a component of a motor, and more particularly to a reduction in the weight of a rotating shaft of a rotor having an eccentric shaft.

[0002]

2. Description of the Related Art Many of the rotating shafts of a motor rotor used in a pump for generating hydraulic pressure by reciprocating an opposing piston are eccentric from an axial center of a basic rotating shaft having a core on which a winding is mounted. Eccentric shaft. That is,
A ball bearing is fixed to the eccentric shaft, the piston is brought into contact with the ball bearing, and the eccentric shaft is rotated to reciprocate the piston to generate hydraulic pressure.

[0003] Therefore, since these rotors have the eccentric shaft, they have an excessive rotational unbalance weight based on the eccentric shaft. Conventionally, in order to correct this rotational imbalance, a large amount of resin putty has been stuck to the end face of the core on the anti-eccentric shaft side, or a counterbalanced heavy object has been attached to the end face of the core on the anti-eccentric shaft side. In addition, a hole is formed on the eccentric shaft side of the core.

However, with a large amount of putty, there is little cost merit due to the material cost and the sticking cost. In this counterbalance, since it is arranged outside the rotor,
This is contrary to the demand for miniaturization of current motors.

Further, since a radial load is applied to the eccentric shaft from the piston, the rotating shaft is required to have a corresponding strength. However, in recent years, there has been a strong demand for motors to be lighter in weight in order to deal with environmental problems of automobiles. For this reason, at present, a high-grade magnet with a high residual magnetic flux density is adopted as the field magnet, or
The core of the magnetic circuit is made of a material having a high magnetic permeability. However, these countermeasures involve an increase in cost and are not preferable.

Looking at the weight structure of the motor, most of its weight is composed of a field magnet made of ceramics, a yoke made of steel that fixes the magnet and constituting a magnetic circuit, a core made of steel, and a steel made of steel. It can be seen that it is occupied by the rotation axis and the like. The light weight of the yoke requires high grade materials like the core described above, which raises the cost.In addition, since the yoke is generally manufactured by drawing, a highly permeable material whose drawability is maintained is required. It is difficult at present because of the small number. The remaining rotating shaft is considered to be the only component that can satisfy weight reduction and cost by replacing it with resin material because it does not constitute a magnetic circuit, but in the case of a rotating shaft with an eccentric shaft as described above Cannot be replaced simply because it requires a certain amount of strength.

[0007]

SUMMARY OF THE INVENTION Accordingly, the present invention solves the above-mentioned problems, and is an inexpensive, compact, lightweight, and secure antenna. It is an object of the present invention to provide a rotor provided with balance correcting means.

[0008]

According to a first aspect of the present invention, there is provided a rotating device comprising a basic rotating shaft housed in a motor and an eccentric shaft eccentric in a radial direction from the basic rotating shaft and exposed to the outside of the motor. In a rotor having a shaft, the eccentric shaft includes a counterbalance portion positioned on a side facing the eccentric direction and extending to the basic rotation shaft side to cancel the eccentric weight of the eccentric shaft. The gist is that it is formed of a cylindrical member that accommodates the balance portion.

According to a second aspect of the present invention, in the rotor according to the first aspect, the eccentric shaft is fitted inside an outer diameter side of the cylindrical member and inside a portion to which an output side bearing is fixed. The gist of the present invention is to provide a cylindrical fitting portion.

[0010] The invention described in claim 3 is the first and second inventions.
The gist of the present invention is that the inside of the cylindrical member is filled with a resin material.

[0011]

According to the first aspect of the present invention, in the rotor, the eccentric shaft is located on a side opposite to the eccentric direction and counterbalances the eccentric weight of the eccentric shaft extending toward the basic rotation shaft. And the basic rotation shaft is formed of a cylindrical member that houses the counterbalance portion. Therefore, since the counterbalance portion is accommodated inside the cylindrical member, the rotational imbalance of the rotary shaft based on the eccentric shaft is corrected without being exposed on the outer surface of the rotor. As a result, the rotor can be downsized, and the motor can be downsized. Further, since the counterbalance is formed on the eccentric shaft, there is no need to attach putty or the like, and the imbalance can be corrected at low cost.

Further, as described above, the eccentric shaft receives a radial load from the piston of the pump, and as a result,
During the rotation, a bending stress is generated. The bending stress is large on the eccentric shaft side and small on the basic rotation shaft side, and is larger on the outer diameter side of the rotation shaft. Therefore, in the present invention, in the basic rotating shaft having a small stress, the outer shell portion having a large stress among them is formed of a cylindrical member, so that the rotating shaft does not affect the magnetic amount and has sufficient strength. Sagging, lightweight.

According to the second aspect of the present invention, the eccentric shaft is a cylindrical fitting portion which is fitted inside a portion on the outer diameter side of the cylindrical member where the output side bearing is fixed. It has. Therefore, in the bearing fixing portion where the bending moment based on the reaction force from the piston of the pump is maximized, the inside of the cylindrical member is reinforced by the fitting portion. Even when the load is large, it can be sufficiently used.

According to the third aspect of the present invention, the inside of the cylindrical member is filled with a resin material. Accordingly, the strength of the rotating shaft is improved, and the cylindrical member is integrated with the resin material having a different elastic modulus, so that generation of vibration and sound can be suppressed.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIGS. As shown in FIG. 1 which is a front view of the rotor 10 of the rotor 10 of the present invention,
Ball bearing 30, commutator 40, which will be described later,
A steel cylindrical member 22a, which fixes the core 50 and the ball bearing 60 and is housed inside the motor (specifically, inside a case (not shown) constituting the motor), and a resin filled therein. 22b (for example, polyamide resin, polyphenylene sulfide resin), a basic rotating shaft 22 and a steel eccentric shaft 24 which is an output shaft exposed to the outside of the motor at a position eccentric from the axis of the basic rotating shaft 22 by 1 mm. Rotary shaft 20 consisting of
An output-side ball bearing 30 fixed to the basic rotation shaft 22, the commutator 40 also fixed to the basic rotation shaft 22 and distributing current from a brush (not shown) to a winding 52 described later; The core 50 is fixed to the rotating shaft 22 and has the winding 52 wound thereon, and the ball bearing 60 on the opposite side to the output is also fixed to the basic rotating shaft 22.

Here, the eccentric shaft 24 is, as shown in FIG.
A cylindrical eccentric portion 24a eccentrically arranged by 1 mm from the axis 2; a cylindrical fitting portion 24b which fits and press-fits an inner diameter portion of the cylindrical member 22a of the basic rotary shaft 22; The eccentric shaft portion 24a to be accommodated
A cross section D for canceling the eccentric weight of the eccentric shaft portion 24a which is located on the side facing the eccentric direction and extends toward the basic rotation shaft 22.
And a character-shaped counter balance portion 24c. The fitting portion 24b is arranged so as to be located on the outer diameter side of the cylindrical member 22a and inside the portion where the ball bearing 30 on the output side is fixed. Further, the counterbalance portion is not limited to the D-shaped cross section of this example, and may be any of a cylindrical shape, a columnar shape, a conical shape, and the like as long as the counterbalance portion is located on a side facing the eccentric direction of the eccentric shaft portion 24a.

The cylindrical member 22a and the eccentric shaft 24
And the resin 22 filled in the cylindrical member 22a
b is integrated by outsert molding. still,
The resin 22a has a cylindrical shape, and the cylindrical member 2
It may be integrated by press-fitting into the inside of 2a.

According to the above construction, the rotating shaft 20 of the rotor 10 is configured to strike the eccentric weight of the eccentric shaft 24 which is located on the side where the eccentric shaft 24 faces the eccentric direction and extends toward the basic rotating shaft 22. The basic rotating shaft 22 is formed of a cylindrical member 22a that accommodates the counterbalance portion 24c. Therefore, since the counterbalance portion 24c is housed inside the cylindrical member 22a, the rotational imbalance of the rotary shaft 20 based on the eccentric shaft 24 is corrected without being exposed on the outer surface of the rotor 10. As a result, downsizing of the rotor 10 and thus downsizing of the motor become possible.
Further, since the counterbalance 24c is formed on the eccentric shaft 24, there is no need to attach putty or the like, and the imbalance can be corrected at low cost.

As described above, the eccentric shaft 24 is
A radial load is applied from the piston of the pump, and as a result, a bending stress is generated during the rotation. The bending stress is large on the eccentric shaft 24 side and small on the basic rotation shaft 22 side, and is larger on the outer diameter side of the rotation shaft 20. Therefore, in the present embodiment, in the basic rotating shaft 22 having a small stress, the outer shell portion having a large stress among them is formed by the cylindrical member 22a, so that the rotating shaft 20 does not affect the magnetic quantity, Is sufficiently maintained and the weight is reduced.

The eccentric shaft 24 is connected to the cylindrical member 2.
2a, a cylindrical fitting portion 24 fitted inside a portion to which the output side ball bearing 30 is fixed.
b. Therefore, in the fixed portion of the ball bearing 30 where the bending moment based on the reaction force from the piston of the pump is maximized, the inside of the cylindrical member 22a is reinforced by the fitting portion 24b, so that the piston load is increased. Even in such a case, it can be sufficiently used.

The inside of the cylindrical member 22a is filled with a resin 22b. Accordingly, the strength of the rotating shaft 20 is improved, and the cylindrical member 22a is integrated with the resin 22b having a different elastic modulus, so that generation of vibration and sound can be suppressed.

[0022]

As described in detail above, according to the present invention,
The counter balance portion 24c is provided on the cylindrical member 22a.
, The rotational imbalance of the rotary shaft 20 based on the eccentric shaft 24 is corrected without being exposed to the outer surface of the rotor 10, and the rotor 10 can be downsized. Further, since the counterbalance 24c is formed on the eccentric shaft 24, there is no need to attach putty or the like, and the imbalance can be corrected at low cost. Further, in the basic rotating shaft 22 having a small stress, the outer shell portion having a large stress among them is formed by the cylindrical member 22a, so that the rotating shaft 20 does not affect the magnetic quantity and the strength is sufficiently maintained. , Light weight. The eccentric shaft 24
Is provided with a cylindrical fitting portion 24b fitted inside the portion to which the bearing 30 is fixed, so that it can sufficiently withstand use even when the piston load is large. Further, since the inside of the cylindrical member 22a is filled with the resin 22b, the strength of the rotating shaft 20 is improved, and
The generation of vibration and sound can be suppressed.

[Brief description of the drawings]

FIG. 1 is a front view of a rotor 10 according to the present invention.

FIG. 2 is an axial sectional view of a rotating shaft 20 according to the present invention.

3 is a view of the eccentric shaft 24 according to FIG.

[Explanation of symbols]

10 ... rotor, 20 ... rotating shaft, 22 ... basic rotating shaft,
22a: cylindrical member, 22b: resin, 24: eccentric shaft, 2
4a: Eccentric shaft part, 24b: Fitting part, 24c: Counterbalance part, 30, 60: Ball bearing, 4
0: Commutator, 50: Core, 52: Winding

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H607 AA04 AA12 BB01 BB04 BB14 CC01 DD03 DD18 EE57 FF06 GG08 5H615 AA01 BB01 BB04 BB14 PP02 PP24 SS19 SS44 SS54 TT37 TT39

Claims (3)

[Claims] 1. A rotor having a rotating shaft consisting of a basic rotating shaft housed inside a motor and an eccentric shaft eccentric radially from the basic rotating shaft and exposed to the outside of the motor, wherein the eccentric shaft has an eccentric direction. A counterbalance portion for canceling the eccentric weight of the eccentric shaft extending on the side of the basic rotation shaft which is located on the side opposite to the base rotation shaft, and the basic rotation shaft is formed of a cylindrical member accommodating the counterbalance portion. A rotor characterized by the above. 2. The eccentric shaft according to claim 1, wherein the eccentric shaft has a columnar fitting portion which is fitted inside a portion on the outer diameter side of the cylindrical member to which an output bearing is fixed. The rotor according to claim 1. 3. The rotor according to claim 1, wherein the inside of the cylindrical member is filled with a resin material.