CN108390499B

CN108390499B - Motor and blower

Info

Publication number: CN108390499B
Application number: CN201810095535.XA
Authority: CN
Inventors: 丸山洋平
Original assignee: Shinano Kenshi Co Ltd
Current assignee: Shinano Kenshi Co Ltd
Priority date: 2017-02-03
Filing date: 2018-01-31
Publication date: 2022-04-15
Anticipated expiration: 2038-01-31
Also published as: JP2018126034A; US20180223874A1; CN108390499A; JP6783679B2

Abstract

A vibration-proof structure is provided for a stator, a rotor, and a bearing which are assembled in a motor case, thereby preventing vibration of the motor from being transmitted to the motor case. A stator core (2a) is integrally assembled to the inner wall surface of a motor housing (1b) through an elastic member (3) in the radial direction, bearing housings (4a, 4b) are integrally assembled to a center hole surrounded by pole teeth (2e) from both ends in the axial direction of the stator core (2a), and the pole teeth (2e) are provided so as to protrude inward in the radial direction of the stator core (2 a).

Description

Motor and blower

Technical Field

The present invention relates to a motor for use in, for example, CPAP (Continuous Positive Airway pressure) or the like, and a blower including the motor.

Background

As components constituting the motor, there are a rotor, a stator, a bearing, a motor case, and the like. For example, in an inner rotor type motor, an outer diameter portion of a stator core of a stator is fixed to a motor case. The rotor is rotatably supported by the motor housing via a bearing member.

In the above-described motor structure, all of the vibration caused by the magnetic attraction force of the stator and the rotor and the vibration associated with the rotor and the bearing are transmitted to the motor case. Further, the vibration transmitted to the motor case becomes large as the rotation speed of the motor increases.

Therefore, the assembled motor is assembled with the product after taking vibration-proof measures such as surrounding or lifting the motor by elastic parts and the like. For example, a cylindrical cover made of an elastic body is attached to an outer peripheral portion of a ball bearing, and the ball bearing is fitted into a ball bearing housing provided with a through hole for suppressing a creep phenomenon of a bearing that axially supports a rotor. The inner peripheral surface of the cover is provided with a protrusion corresponding to the through hole. A technique has been proposed in which a cover is attached to an outer peripheral portion of a ball bearing housing by fitting a protrusion into a through hole, and an outer ring of the ball bearing is pressed by the protrusion to suppress rotation of the outer ring (see patent document 1).

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open No. 2003-250245

In the above-described motor, the vibration-proof measure is provided, and when the motor is surrounded by the elastic member, the outer diameters of the motor and the blower incorporating the motor become large, and when the motor is suspended by the elastic member, a space for vibration-proof is required, and therefore, the product shape becomes large.

In patent document 1, since a cover made of an elastic body is attached to an outer peripheral portion of the ball bearing housing, vibration between the rotor and the bearing is slightly attenuated, but vibration between the stator and the rotor is easily transmitted to the motor housing (bracket) and becomes noise.

Disclosure of Invention

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a motor in which vibration of the motor is hardly transmitted to a motor case by providing a vibration-proof structure for a stator, a rotor, and a bearing which are assembled in the motor case, and a blower including the motor and having a reduced noise.

In order to achieve the above object, the present invention includes the following configurations.

An electric motor, comprising: a motor housing; a stator in which a stator core is integrally assembled in the motor case; a bearing housing concentrically disposed in the center hole of the stator core, integrally assembled, and formed in a cylindrical shape; and a rotor rotatably supported by a bearing shaft inserted into the bearing housing, wherein the stator core is integrally assembled by interposing an elastic member in a radial direction between the stator core and the motor housing, the bearing housing is integrally assembled to a center hole surrounded by pole teeth protruding inward in a radial direction of the stator core from both axial ends of the stator core.

According to the above configuration, the stator core, the bearing, and the bearing housing are integrally fixed, and the elastic member is interposed and assembled between the stator core and the motor housing. Therefore, by providing a vibration-proof structure in the stator assembled in the motor case and the rotor rotatably supported by the stator, vibration of the motor is less likely to be transmitted to the motor case.

Preferably, the bearing housing is integrally assembled to a center hole surrounded by pole teeth from both ends of the stator core, and the pole teeth are protruded inward in a radial direction of the stator core. Thus, since the bearing housing is integrally assembled with the stator core, not the motor housing, it is difficult for the vibration to be directly transmitted from the bearing to the motor housing.

An elastic member may be interposed and assembled between the bearing housing and the bearing along the axial direction.

Thereby, the service life can be increased by applying a preload to the bearing rotating at a high speed.

Further, the elastic member may be a wave washer, a plate spring, a disc spring, a coil spring, or the like, but in CPAP using a small ball bearing rotating at high speed, since the deviation of the preload applied by compressing and sandwiching the coil spring from the natural length is smaller than that of a wave washer, it is preferable that the load can be stably applied in the axial direction.

In the blower, since the motor housing and the blower housing of the motor are integrally assembled to form the air blowing passage and the impeller is integrally assembled to the rotor shaft extended to the blower housing, vibration of the motor housing is hardly transmitted to the blower housing, and thus noise can be reduced.

The vibration-proof structure is provided in the stator assembled in the motor case and the rotor rotatably supported by the stator, so that the vibration of the motor is hardly transmitted to the motor case.

Further, it is possible to provide a blower in which vibration of the motor case is hard to occur and the vibration is hard to be transmitted to the blower case, and which can be made silent.

Drawings

Fig. 1 is a sectional view of the motor.

Fig. 2 is a sectional view of the blower.

Detailed Description

Hereinafter, an embodiment of a motor and a blower according to the present invention will be described with reference to the drawings. First, a schematic structure of the motor will be described with reference to fig. 1. The motor is a DC brushless motor, and in the present embodiment, an inner rotor type motor is used.

As shown in fig. 1, the motor housing 1 is assembled by combining a first motor housing 1a and a second motor housing 1b and screwing bolts, not shown, into

screw holes

1c and 1d communicating with each other. As the motor case 1, SUS (stainless steel), aluminum material, or the like is used.

The stator 2 is assembled in the motor case 1. The stator 2 includes: a stator core 2 a; an insulator 2b covering both end surfaces thereof; and a coil 2c around the pole tooth 2e, with a magnet wire wound through an insulator 2 b. The stator core 2a is a laminated core formed by laminating and caulking a plurality of electromagnetic steel sheets. The stator core 2a has a plurality of pole teeth 2e formed radially inward from an annular core support portion 2 d. The stator core 2a is integrally fixed to the inner wall surface of the second motor case 1b with the elastic member 3 interposed between the outer peripheral surfaces of the core support portions 2 d. As the elastic member 3, a rubber sheet, an elastomer resin, or the like is used.

This makes it possible to prevent the vibration between the stator 2 and the rotor 6 from being transmitted to the motor case 1.

A pair of bearing

housings

4a and 4b formed in a cylindrical shape is press-fitted or bonded to a center hole 2f surrounded by teeth 2e protruding radially inward of the stator core 2a from both ends. Since the bearing

housings

4a and 4b are made of a non-magnetic metal material (e.g., aluminum, non-magnetic stainless steel, etc.), and are pressed into the magnetic flux acting surfaces of the respective pole teeth 2e, the amount of pressing needs to be adjusted to a minimum amount. This is because, if the amount of press-fitting of the bearing

housings

4a and 4b into the stator core 2a is increased to inhibit the magnetic flux generated on the magnetic flux acting surface of the pole teeth 2e, eddy current may be generated and the performance of the motor may be degraded.

Bearings

5a and 5b (ball bearings) are inserted into the cylindrical holes of the

bearing housings

4a and 4b, respectively, and the inner and outer races are bonded and fixed.

The rotor shaft 7 of the rotor 6 is rotatably supported via

bearings

5a and 5b inserted into the

bearing housings

4a and 4 b. A wave washer 8a (elastic member) is interposed between the bearing housing 4a and the bearing 5 a. Thereby, the service life can be increased by applying a preload to the

bearings

5a and 5b rotating at a high speed.

Further, the wave washer 8a may be replaced with a plate spring, a disc spring, or the like, but in CPAP using a small ball bearing at high speed rotation, the deviation of the preload applied by compressing and sandwiching the coil spring 8b (see fig. 2) from the natural length is smaller than that of the wave washer 8a, and therefore, it is preferable that the load can be stably applied in the axial direction.

A rotor magnet 9 is concentrically assembled to the rotor shaft 7. The rotor shaft 7 is inserted into

bearings

5a and 5b assembled with the

bearing housings

4a and 4b, and the rotor magnet 9 is assembled in a manner to be opposed to the pole teeth 2e of the stator core 2 a.

Spacers

10a and 10b are provided between the rotor magnet 9 and the

bearings

5a and 5 b.

One end of the rotor shaft 7 extends outward from the first motor housing 1a and is an output side. A sensor magnet 11 and a balancer 12 are integrally assembled to the other end of the rotor shaft 7 on the second motor case 1b side. The sensor magnet 11 is a member for detecting the rotor magnetic pole position, and is magnetized in the same phase as the rotor magnet 9 in the circumferential direction. The balancer 12 is used as a support yoke of the sensor magnet 11 or as a counter balance correcting member of an impeller described later.

A motor substrate 13 is supported by the insulator 2b, and a motor drive circuit is provided on the motor substrate 13. Lead wires drawn out from the coils 2c are connected to the motor substrate 13. Further, a magnetic pole detection sensor 14 (hall IC or the like) is provided on the surface of the motor substrate 13 facing the sensor magnet 11. The magnetic pole position of the sensor magnet 11 is detected by the magnetic pole detection sensor 14, and the rotational position of the rotor magnet 9 is detected to switch the direction of energization to the coil 2 c.

As described above, the stator core 2a is integrally assembled to the inner wall surface of the second motor case 1b via the elastic member 3 in the radial direction, the rotor shaft 7 is integrally assembled to the bearing case 4a via the bearing 5a, and the rotor 6 is rotatably supported between the bearing 5a and the bearing case 4a via the wave washer 8a (elastic member) in the axial direction.

According to the above configuration, the stator core 2a, the bearing 5a, and the bearing housing 4a are integrally fixed, and the elastic member 3 is interposed and assembled between the stator core 2a and the second motor housing 1 b. Therefore, by providing a vibration-proof structure in the stator 2 assembled in the motor case 1 and the rotor 6 rotatably supported by the stator, it is possible to make it difficult for the vibration of the motor to be transmitted to the motor case 1.

Fig. 2 shows an example of the structure of the blower 15 including the same motor M as that of fig. 1. Since the internal structure of the motor M is the same as that of fig. 1, a description will be given centering on a different structure. The blower 15 is assumed to be a CPAP blower.

The motor M is housed in the motor case 16 (the first motor case 16a and the second motor case 16 b). In addition, the impeller 18 is housed in a blower chamber 20 enclosed by the first motor casing 16a and the blower casing 17. Curved concave grooves are formed on the outer peripheral sides of the motor casing 16 (the first motor casing 16a and the second motor casing 16b) and the blower casing 17, respectively, and the motor casing 16 and the blower casing 17 are combined to form an annular air blowing passage 19. A suction port 17a for sucking fluid in an axial direction is formed in a central portion of the blower housing 17, and the fluid is pressurized in a circumferential direction by the impeller 18, flows around the air blowing passage 19, and is discharged.

The stator core 2a is integrally assembled by interposing the elastic member 3 between the outer peripheral surface of the core support portion 2d and the inner wall surface of the second motor case 16b, and between both end surfaces of the second motor case 16b facing the first motor case 16 a. This makes it possible to prevent the vibration between the stator 2 and the rotor 6 from being transmitted to the motor case 16.

Further, a coil spring 8b (elastic member) is interposed between the bearing housing 4a and the bearing 5a in a state of being compressed from a natural length. This makes it possible to apply a stable preload (a small variation in the preload applied) to the

bearings

5a and 5b rotating at high speed, thereby increasing the life.

Therefore, by providing a vibration-proof structure in the stator 2 assembled in the motor case 16 and the rotor 6 rotatably supported by the stator 2, the vibration of the motor M is less likely to be transmitted to the motor case 16.

The impeller 18 is assembled to one end of the rotor shaft 7 extending outward from the first motor housing 16a and entering the blower chamber 20. Further, the sensor magnet 11 and the balancer 12 are integrally assembled to the other end of the rotor shaft 7 in the second motor case 16 b. The balancer 12 has functions as a support yoke of the sensor magnet 11 and as a counterweight of the impeller 18.

When the motor M is started, the impeller 18 of the blower 15 rotates, and the fluid sucked in the axial direction from the suction port 17a in the blower housing 17 flows around the air blowing passage 19 by the rotation of the impeller 18, is pressurized, and the compressed air is discharged through the discharge port, not shown. According to the above configuration, since the vibration of the motor casing 16 can be reduced, the vibration can be hardly transmitted to the blower casing 17, and the noise can be reduced.

In the above embodiment, the inner rotor type motor was described, but the present invention is also applicable to an outer rotor type motor as long as the stator core is integrally assembled to the outer wall surface of the motor housing (bearing housing) via the elastic member in the radial direction.

Claims

1. An electric motor, comprising:

a motor housing formed by combining a first motor housing and a second motor housing;

a stator having a stator core integrally assembled in the motor case;

a pair of bearing housings that are concentrically arranged and integrally assembled to the center hole of the stator core, and that are formed in a cylindrical shape; and

a rotor having a pair of bearing housings, wherein the inner ring of each bearing inserted into the bearing housing is bonded to the rotor shaft of the rotor, and the outer ring is bonded to the bearing housing, so that the rotor shaft of the rotor is rotatably supported,

it is characterized in that the preparation method is characterized in that,

the stator core is provided with a first elastic member interposed in a radial direction between an outer peripheral surface of a core support portion and an inner wall surface of the second motor housing, the outer peripheral surface of the core support portion is covered, and both end portions of the first elastic member extending in a rotor axis direction are bent along the core support portion and sandwiched between opposite end surfaces of the first motor housing and the second motor housing, a pair of bearing housings are integrally assembled from both axial ends of the stator core to a center hole surrounded by pole teeth protruding inward in a radial direction of the stator core, and a second elastic member is assembled in a rotor axis direction between the bearings assembled in one of the bearing housings.

2. The motor of claim 1,

the second elastic member is a coil spring, and the coil spring is interposed between the bearing housing and the bearing in a state of being compressed from a natural length.

3. A blower is characterized in that a blower body is provided with a blower body,

the motor according to claim 1 or 2, wherein a first groove having a semicircular cross section is continuously formed in a concave portion provided on an outer peripheral side of a first motor housing and an outer peripheral side of a blower housing covering the outer peripheral side of the first motor housing, a second groove having a semicircular cross section is continuously formed on an outer peripheral side of a second motor housing, the first groove and the second groove having concave portions facing each other are integrally assembled to form an annular air blowing passage, and the impeller is integrally assembled to a rotor shaft extended to the blower housing.