JP2011004559A - Electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a motor with a brush, which securely stops displacement of a protector sleeve under a high vibration environment.SOLUTION: In the electric motor 1, a stator 2 is provided with: a cylindrical yoke 4, a plurality of permanent magnets 3 fixed to the inner peripheral face of the yoke 4 by adhesive; a cylindrical protector sleeve 40 facing the inner peripheral face of each permanent magnet 3; and disk-like stopper rings 50 and 51 facing ends of the protector sleeve 40. The stopper rings 50 and 51 regulate displacement of the protector sleeve 40 in a rotation axis direction of the rotor 9 by making the ends of the protector sleeve 40 abut each other.

Description

  The present invention relates to an electric motor in which a plurality of permanent magnets are bonded and fixed to the inner peripheral surface of a cylindrical yoke.

  As this type of electric motor, Patent Document 1 discloses a motor provided with a cylindrical protector sleeve (3) facing the inner peripheral surface of each permanent magnet (2) as shown in FIG.

  When the inner peripheral surface of each permanent magnet (2) is covered with the protector sleeve (3) and the permanent magnet (2) is cracked or the like, the protector sleeve (3) causes the fragments of the permanent magnet to collide with the rotor. It is prevented.

  The cylindrical protector sleeve (3) is bonded and fixed to the inner peripheral surface of each permanent magnet (2).

JP-A-9-56090

  However, in this type of electric motor, when the electric motor is used in a high vibration environment, the adhesive fixing portion of the protector sleeve (3) to the permanent magnet (2) peels off, and the protector sleeve (2) There was a possibility that displacement occurred.

  The present invention has been made in view of the above-described problems, and an object thereof is to provide an electric motor in which the protector sleeve is surely prevented from being displaced under a high vibration environment.

  The present invention is an electric motor in which a rotor rotates inside a stator, and the stator includes a cylindrical yoke, a plurality of permanent magnets fixed to the inner peripheral surface of the yoke by an adhesive, and the permanent magnets. A cylindrical protector sleeve that faces the inner peripheral surface of the protector and a disc-shaped stopper ring that faces the end of the protector sleeve, and the stopper ring comes into contact with the end of the protector sleeve to contact the end of the protector sleeve. Displacement is regulated in the direction of the rotation axis of the rotor.

  According to the present invention, since the displacement of the protector sleeve in the motor rotation axis direction is restricted by the stopper ring, the protector sleeve is prevented from being displaced even if the adhesive fixing portion to the permanent magnet is peeled off in the high vibration environment. This improves the reliability of the electric motor.

Sectional drawing of the electric motor which shows embodiment of this invention. The front view of a stator similarly. Sectional drawing of a stator similarly. Sectional drawing of the electric motor which shows a prior art example.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a longitudinal sectional view of a brushed electric motor 1 provided as a rotating electrical machine.

  The electric motor 1 includes a cylindrical stator 2 and a rotor 9 that rotates inside the stator 2.

  The electric motor 1 having four magnetic poles includes a cylindrical yoke 4 and four permanent magnets 3 fixed to the inner periphery of the yoke 4 as the stator 2. Note that the number of magnetic poles of the electric motor 1 is not limited to this, and is increased or decreased according to the specification.

  As shown in FIG. 3, a plurality of screw holes 22 are opened at both ends of the yoke 4. The end cover 20 and the bracket 30 are respectively fastened to both ends of the yoke 4 via bolts (not shown) that are screwed into the screw holes 22. The yoke 4, the bracket 30, and the end cover 20 define a rotor chamber 16 that houses the rotor 9.

  O-rings 23 and 24 are interposed in the opening portions at both ends of the yoke 4 so that the space between the bracket 30 and the end cover 20 is sealed.

  The rotor 9 includes a shaft 12 serving as a rotation axis thereof, a commutator 10 attached to the shaft 12, and a winding 13 through which current flows through the commutator 10.

  The shaft 12 of the rotor 9 is rotatably supported by ball bearings 7 and 8. The ball bearing 7 is interposed in the bracket 30. The ball bearing 8 is interposed in the end cover 20.

  Four brushes 11 are interposed in the end cover 20. Each brush 11 is in sliding contact with the outer periphery of the commutator 10 provided in the rotor 9. In the electric motor 1, electricity supplied from a power source (not shown) through the brush 11 and the commutator 10 flows through the winding 13 of the rotor 9, so that the magnetic force generated in the rotor 9 rotates relative to the magnetic force of the permanent magnet 3. Working in the direction, the rotor 9 is driven to rotate.

  FIG. 2A is a front view of the stator 2. The permanent magnet 3 has a cross-sectional shape curved in an arc along the inner peripheral surface of the annular yoke 4.

  The outer peripheral surface of the permanent magnet 3 is bonded and fixed to the inner peripheral surface of the yoke 4 via an adhesive 5.

  The stator 2 includes a cylindrical protector sleeve 40 that faces the inner peripheral surface of each permanent magnet 3.

  The protector sleeve 40 is formed of a thin plate having a thickness of about 0.2 mm, for example, and a nonmagnetic material such as an aluminum material or stainless steel material or a weak magnetic material is used as the material thereof.

  The protector sleeve 40 has its inner peripheral surface bonded and fixed to the outer peripheral surface of the permanent magnet 3 via the adhesive 5.

  When the permanent magnet 3 is cracked or the like, the protector sleeve 40 prevents the fragments of the permanent magnet 3 from colliding with the rotor 9.

  The stator 2 includes a pair of stopper rings 50 and 51 that face opposite ends of the protector sleeve 40.

  The stopper rings 50 and 51 are formed in a disc shape and have the same shape. The stopper rings 50 and 51 are formed of a thin plate of about 0.2 mm, for example, and a nonmagnetic material or a weak magnetic material such as an aluminum material or stainless steel material is used as the material thereof.

  FIG. 2B is a front view of the stator 2 showing a state in which the stopper rings 50 and 51 are assembled. The ends of the protector sleeve 40 face each other in the middle of the disc-shaped stopper rings 50 and 51.

  The stopper rings 50 and 51 prevent displacement by restricting the displacement of the protector sleeve 40 in the motor rotation axis direction by bringing both ends of the protector sleeve 40 into contact with each other.

  FIG. 3 is a cross-sectional view of the stator 2 showing a state in which the protector sleeve 40 and the stopper rings 50 and 51 are assembled.

  The yoke 4 is formed with an inlay portion 25 for fitting the bracket 30 at one end thereof and an accommodating portion 26 in which the O-ring 23 is interposed. As shown in FIG. 1, the stopper ring 50 is fitted to the inlay portion 25 together with the bracket 30, and is sandwiched between the end surface of the bracket 30 and the end surface of the permanent magnet 3.

  The yoke 4 is formed with an inlay portion 27 for fitting the end cover 20 at the other end and a housing portion 28 in which the O-ring 24 is interposed. As shown in FIG. 1, the stopper ring 51 is fitted to the spigot 27 together with the end cover 20, and is sandwiched between the end surface of the end cover 20 and the end surface of the permanent magnet 3.

  Each permanent magnet 3 is sandwiched between the bracket 30 and the end cover 20 via stopper rings 50 and 51. As a result, the displacement of each permanent magnet 3 in the motor rotation axis direction is restricted, so that even if the adhesive fixing portion with respect to the yoke 4 is peeled off in the high vibration environment, the displacement of each permanent magnet 3 is prevented. Done.

  As shown in FIG. 2A, the adhesive 5 is applied to the outer peripheral surface of the permanent magnet 3 or the inner peripheral surface of the yoke 4, and between the end of the adjacent permanent magnet 3 and the protector sleeve 40. Is also filled.

  At the time of manufacturing the electric motor 1, the step of filling the adhesive 5 is performed according to the following procedure.

  In a state where the permanent magnets 3, the protector sleeve 40, and one stopper ring 51 are assembled to the yoke 4, the yoke 4 is arranged to extend in the vertical direction with the stopper ring 51 facing downward.

  The adhesive 5 is filled between the yoke 4, each permanent magnet 3, and the protector sleeve 40. At this time, since the lower opening between the yoke 4 and the protector sleeve 40 is closed by the lower stopper ring 51, the liquid adhesive 5 does not flow over the stopper ring 51.

  The stopper ring 50 is mounted on the yoke 4, the permanent magnets 3, and the upper end of the protector sleeve 40.

  Thus, the yoke 4, the permanent magnets 3, the protector sleeve 40, and the stopper rings 50 and 51 are fixed via the adhesive 5, thereby forming an assembly of the stator 2 in which these are unitized.

  In the electric motor 1, the assemblies constituting the stator 2, the rotor 9, the end cover 20, and the bracket 30 are assembled in a predetermined procedure.

  As described above, in the present embodiment, the rotor 9 is the electric motor 1 that rotates inside the stator 2, and the stator 2 is fixed to the cylindrical yoke 4 and the inner peripheral surface of the yoke 4 with an adhesive. A plurality of permanent magnets 3, a cylindrical protector sleeve 40 facing the inner peripheral surface of each permanent magnet 3, and disk-shaped stopper rings 50, 51 facing the end of the protector sleeve 40. The stopper rings 50 and 51 are configured to restrict the displacement of the protector sleeve 40 in the direction of the rotation axis of the rotor 9 by contacting the end of the protector sleeve 40.

  Based on the above configuration, the protector sleeve 40 is restricted in displacement in the motor rotation axis direction by the stopper rings 50 and 51. Therefore, even if the adhesive fixing part to the permanent magnet 3 peels off the electric motor 1 in a high vibration environment, The protector sleeve 40 is prevented from being displaced, and the reliability of the electric motor 1 can be improved.

  In the present embodiment, a bracket 30 that rotatably supports the rotor 9 is provided, and the yoke 4 has an inlay portion 25 into which the bracket 30 is fitted, and a stopper ring 50 is interposed in the inlay portion 25 to provide a stopper. The ring 50 is sandwiched between the yoke 4 and the bracket 30.

  Based on the above configuration, the stopper ring 50 can be easily fixed to the yoke 4 via the bracket 30, and the cost of the product can be suppressed.

  In the present embodiment, a brush 11 that is in sliding contact with the commutator 10 of the rotor 9 and an end cover 20 that supports the brush 11 are provided, and the yoke 4 has an inlay portion 27 into which the end cover 20 is fitted, A stopper ring 51 is interposed in the inlay portion 27 so that the stopper ring 51 is sandwiched between the yoke 4 and the end cover 20.

  Based on the above configuration, the stopper ring 51 can be easily fixed to the yoke 4 via the bracket 30, and the cost of the product can be suppressed.

  The present invention is not limited to a motor, and can also be applied to a rotating electrical machine such as a generator that generates an electromotive force in a stator by the magnetic force of a rotating rotor.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

DESCRIPTION OF SYMBOLS 1 Motor 2 Stator 3 Permanent magnet 4 Yoke 5 Adhesive 7 Ball bearing 8 Ball bearing 9 Rotor 10 Commutator 11 Brush 12 Shaft 13 Winding 20 End cover 25 Inlay part 27 Inlay part 30 Bracket 40 Protector sleeve 50 Stopper ring 51 Stopper ring

Claims (3)

An electric motor whose rotor rotates inside the stator,
The stator is
A cylindrical yoke,
A plurality of permanent magnets fixed to the inner peripheral surface of the yoke by an adhesive;
A cylindrical protector sleeve facing the inner peripheral surface of each permanent magnet;
A disc-shaped stopper ring facing the end of the protector sleeve,
The electric motor according to claim 1, wherein the stopper ring restricts displacement of the protector sleeve with respect to a rotation axis direction of the rotor by contacting an end portion of the protector sleeve. A bracket for rotatably supporting the rotor;
The yoke has an inlay portion for fitting the bracket,
The stopper ring is interposed in this inlay part,
The electric motor according to claim 1, wherein the stopper ring is sandwiched between the yoke and the bracket. A brush in sliding contact with the commutator of the rotor;
With an end cover that supports this brush,
The yoke has an inlay portion into which the end cover is fitted,
The stopper ring is interposed in this inlay part,
The electric motor according to claim 1, wherein the stopper ring is sandwiched between the yoke and the end cover.

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