JP2001186739A - Stator for motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive stator for a motor which suppresses the occurrence and expansion of vibration and sound. SOLUTION: A stator 20 for a permanent magnet field motor 10, where the pistons in opposition installed in a pump 50 abut from diametrical direction on an eccentric shaft 35 at the tip of a rotary shaft 32, consists of a magnet 22 and a yoke 24 retaining that magnet 22 at its inside periphery, and the essential points are that the yoke 24 is made in the shape of a bottomed cylinder whose output side is open, and that a rib 24a2 extending in roughly parallel with the direction of reciprocation of the piston 52 is made at the bottom part 24a of that yoke 24.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor stator for a permanent magnet field motor used in a piston pump, and more particularly to a structure for reducing vibration in the stator.

[0002]

2. Description of the Related Art In general, a motor stator of a permanent magnet field motor used for a piston type pump includes a magnet and a yoke for fixing the magnet to an inner peripheral surface. The yoke is formed in a bottomed cylindrical shape having a bottom that is substantially perpendicular and flat in the axial direction of the motor, and in the center of the bottom,
A cylindrical bearing holding portion for holding the mounted bearing is provided so as to project from the lower portion toward the outside in the axial direction of the yoke.

[0003] Since the bottom has a flat shape and corresponds to the membrane of a drum, it is a problematic part in generating and expanding vibration or sound. Particularly, since the bearing holding portion is provided at the center thereof, when the motor is used in the piston type pump, a repetitive radial load is applied to the rotating shaft of the motor, so that the yoke on the non-output side is rotated. It receives a repetitive radial reaction force via a bearing on which the bearing holding portion is mounted, and generates vibration at the bottom.

[0004] For this reason, in some motors, the clearance between the rotating shaft and the bearing is reduced, or the clearance between the bearing outer diameter and the bearing holding portion is reduced, so that the reaction force causes the clearance between the bearing holding portion and the bearing. We respond by reducing the impact force.

[0005]

However, in the above measures, it is necessary to increase the precision of normally high-precision parts such as the rotating shaft, the bearing, and the bearing holder, so that an increase in cost is unavoidable.

Accordingly, the present invention provides a method for generating vibration or sound.
An object is to provide an inexpensive motor stator that suppresses expansion.

[0007]

According to a first aspect of the present invention, there is provided a motor stator for a permanent magnet field motor in which an opposed piston provided in a pump abuts an output shaft at a tip of a rotating shaft in a radial direction. Wherein the stator comprises a magnet and a yoke for holding the magnet on its inner peripheral surface, and the yoke is formed in a bottomed cylindrical shape having an open output side, and the yoke has a bottom portion. The gist is that a rib extending substantially parallel to the reciprocating direction of the piston is formed.

According to a second aspect of the present invention, in the motor stator according to the first aspect, a rib extending in an axial direction substantially perpendicular to a reciprocating direction of the piston is formed in the cylindrical portion of the yoke. The gist is that

The invention described in claim 3 is the first and second inventions.
In the motor stator according to the above, on the opening side of the yoke is formed a flat flange perpendicular to the motor axis direction that comes into contact with the pump, and the flange is provided on the pump with the piston interposed therebetween. The gist is that a bolt insertion hole for fixing the motor with a bolt is formed.

[0010]

According to the first aspect of the invention, the yoke of the stator is formed in a bottomed cylindrical shape having an open output side, and the bottom of the yoke is substantially parallel to the reciprocating direction of the piston. Is formed. Therefore, when a repeated radial load is applied to the rotating shaft of the motor,
The bearing holding portion of the yoke on the non-output side receives a repetitive radial reaction force via a mounted bearing, and the bottom portion generates bending vibration mainly in the direction of the piston. Since the bottom portion is formed substantially parallel to the reciprocating direction, the section modulus of the bottom portion with respect to the reaction force direction of the piston is increased, the bending is reduced, and the vibration or sound generated at the bottom portion is suppressed. According to the present invention,
No new parts are required, and there is no need to increase the precision of the parts, so that no cost increase occurs.

According to the second aspect of the invention, the cylindrical portion of the yoke is provided with a rib extending in an axial direction substantially perpendicular to the reciprocating direction of the piston. Therefore, as in the first aspect of the invention, the section modulus of the cylindrical portion with respect to the direction of the reaction force of the piston increases, and the vibration or sound generated in the cylindrical portion, and the vibration or sound generated by the cylindrical portion are amplified by the cylindrical portion. The generated vibration or sound is suppressed.

According to the third aspect of the present invention, a flat flange perpendicular to the axial direction of the motor that contacts the pump is formed on the opening side of the yoke, and the piston is mounted on the flange. A bolt insertion hole is formed between the pump and the pump to fix the motor with bolts. Accordingly, since the motor is fixed to the pump with the piston interposed therebetween, the deflection of the yoke in the direction of the reaction force of the piston is reduced, and the generation of vibration or noise is further suppressed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment embodying the present invention will be described below with reference to FIGS. FIG. 1 is a view showing a state in which a motor 10 including a stator 20 according to the present invention is mounted with bolts 70 on a pump 50 that generates hydraulic pressure by a piston 52 (see FIG. 2) provided facing the motor 10. 2 which is a partial cross-sectional view taken along the line AA in FIG.
, An eccentric shaft 34 as an output shaft eccentric with 1 mm at the tip, and a tip bearing 35 fixed to the eccentric shaft 34
Shaft 3 for reciprocating the piston 52 in contact with the left and right
Armature 30 including magnet 2, magnet 22, and magnet 2
Bearing 2 as a rear bearing for holding the rotating shaft 32 at the rear of the motor while holding the rotating shaft 32 on the inner peripheral surface.
The stator 2 comprising a yoke 24 holding the
And an end plate 40 for holding a ball bearing 44 as a front bearing for supporting the rotary shaft 32 at the front.

The yoke 24 has a bottom 24a which is open toward the output side and which is substantially perpendicular to the axial direction of the motor 10 and is flat, and a cylindrical portion 24b which is cylindrical. In the center of the bottom 24a, there is provided a bearing holding portion 24a1 in which the ball bearing 26 fixed to the rotating shaft 32 is loosely fitted.

The bottom portion 24a is provided with the bottom portion 24a.
At the center of a, a rib 24a2 that extends substantially parallel to the reciprocating direction of the piston 52 with the bearing holding portion 24a1 interposed therebetween and that is convex toward the inside of the motor is formed. Further, the cylindrical portion 24b of the yoke 24 extends in the axial direction substantially perpendicular to the reciprocating direction of the piston 52 as shown in FIG. Two convex ribs 24b2 are formed so as to oppose each other in the reciprocating direction of the piston 52.

In addition, a flat flange 24c is formed on the opening side of the yoke 24 so as to be in contact with the pump 50 and perpendicular to the motor axis direction. There are formed two bolt insertion holes 24d on the left and right sides for fixing the motor with bolts.

According to the configuration of the embodiment of the present invention described above, the yoke 24 of the stator 20 is formed in a bottomed cylindrical shape having an open output side, and the bottom 2 of the yoke 24 is formed.
4a is formed with a rib 24a2 extending substantially parallel to the reciprocating direction of the piston 52. Therefore, the motor 10
When a repetitive radial load is applied to the eccentric shaft 35, which is the tip of the rotary shaft 32, the bearing holding portion 24a1 of the yoke 24, which is on the non-output side, is mounted on the ball bearing 26.
The bottom portion 24a undergoes bending vibration mainly in the direction of the piston 52, while receiving a repetitive radial reaction force via
Since the ribs 24a2 are formed substantially parallel to the reciprocating direction of the piston 52, the section modulus of the bottom portion 24a in the direction of the reaction force of the piston 52 is increased, the bending is reduced, and the rib 24a2 is generated at the bottom portion 24a. Vibration or sound is suppressed. Further, according to the present invention, no new parts are required, and it is not necessary to increase the precision of the parts.

The cylindrical portion 24b of the yoke 24 has a rib 24b2 extending in an axial direction substantially perpendicular to the reciprocating direction of the piston 52. Therefore, the section modulus of the cylindrical portion 24b with respect to the direction of the reaction force of the piston 52 increases, and the vibration or sound generated in the cylindrical portion 24b, and the vibration or sound amplified in the cylindrical portion 24b and generated in the bottom portion 24a, Sound is suppressed.

Further, on the opening side of the yoke 24, there is formed a flat flange 24c which is perpendicular to the motor axis direction and is in contact with the pump 50. The flange 24c is provided with the piston 52 interposed therebetween. A bolt insertion hole 24d for fixing the motor 10 with a bolt 70 is formed in 50. Therefore, the motor 10 is fixed to the pump 50 with the piston 52 interposed therebetween.
2. The deflection of the yoke 24 in the reaction force direction 2 is reduced,
Generation of vibration or sound is further suppressed.

[0020]

As described in detail above, according to the present invention,
The yoke 24 of the stator 20 is formed in a cylindrical shape with a bottom opening on the output side, and a rib 24a2 extending substantially parallel to the reciprocating direction of the piston 52 is formed on the bottom 24a of the yoke 24. Therefore, the section modulus of the bottom portion 24a with respect to the direction of the reaction force of the piston 52 is increased, the deflection is reduced, and the vibration or sound generated at the bottom portion 24a is suppressed. Further, according to the present invention, no new parts are required, and it is not necessary to increase the precision of the parts. Further, the yoke 2
4 is formed with an axially extending rib 24b2 substantially perpendicular to the reciprocating direction of the piston 52, so that the section coefficient of the cylindrical portion 24b with respect to the reaction force direction of the piston 52 is large. The cylindrical portion 24
The vibration or sound generated at b, and the vibration or sound amplified at the bottom portion 24a and amplified by the cylindrical portion 24b are suppressed. In addition, the motor 10 is
Since the piston 52 is fixed with the piston 52 interposed therebetween, the deflection of the yoke 24 in the reaction force direction of the piston 52 is reduced, and the generation of vibration or sound is further suppressed.

[Brief description of the drawings]

FIG. 1 shows a motor stator 20 according to the present invention and a pump 5
FIG.

FIG. 2 is a partial sectional view taken along line AA of FIG.

FIG. 3 is a view as viewed in a direction B in FIG. 1;

[Description of References] 10 motor, 20 stator, 22 magnet, 24
... Yoke, 24a ... Bottom part, 24a1 ... Bearing holding part,
24a2, 24b2 ... rib, 24b ... cylindrical part, 24c
... Flange, 24d ... Insertion hole, 26, 44 ... Ball bearing, 30 ... Armature, 32 ... Rotating shaft, 34
... Eccentric shaft, 35 ... Tip bearing, 40 ... End plate, 50 ... Pump, 52 ... Piston, 70 ... Bolt

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) // F04B 53/00 F04B 39/00 106E 39/00 106 21/00 VF term (reference) 3H003 AA02 AB06 AC04 BA00 BB08 CA01 CA02 CB00 CE03 CE04 CF04 3H071 AA03 BB01 CC21 DD84 5H605 AA04 AA05 BB05 CC01 CC05 DD03 DD05 GG06 5H607 AA04 AA12 BB01 BB14 CC01 CC05 DD01 DD02 DD03 DD16 DD17 DD19 J05H07K08 J05 H07A07

Claims (3)

[Claims] 1. A motor stator for a permanent magnet field motor in which an opposing piston provided in a pump abuts an output shaft at a tip of a rotating shaft in a radial direction, the stator comprising a magnet and the magnet. The yoke is formed in a cylindrical shape with a bottom opening on the output side, and a rib extending substantially parallel to the reciprocating direction of the piston is provided at the bottom of the yoke. A motor stator characterized by being formed. 2. The motor stator according to claim 1, wherein a rib extending in an axial direction substantially perpendicular to a reciprocating direction of the piston is formed in the cylindrical portion of the yoke. 3. A flat flange, which is perpendicular to the motor axis direction and contacts the pump, is formed on the opening side of the yoke. 3. The motor stator according to claim 1, wherein a bolt insertion hole is formed to be fixed by using.