CN107492965B

CN107492965B - Insulating rotor and motor

Info

Publication number: CN107492965B
Application number: CN201710811269.1A
Authority: CN
Inventors: 甘峰; 李虎; 迟闯
Original assignee: Guangdong Welling Motor Manufacturing Co Ltd
Current assignee: Guangdong Welling Motor Manufacturing Co Ltd
Priority date: 2017-09-11
Filing date: 2017-09-11
Publication date: 2020-06-30
Anticipated expiration: 2037-09-11
Also published as: CN107492965A

Abstract

The invention relates to the field of motor structures, and discloses an insulating rotor and a motor, wherein the insulating rotor comprises a rotor core (4) and a rotor rotating shaft (1), a central hole (42) is formed in the rotor core (4), an insulating connecting piece (3) which is attached to the outer wall of the rotor rotating shaft (1) in an insulating mode is filled between the inner hole wall of the central hole (42) and the rotor rotating shaft (1), and a reinforcing connecting piece (2) which is fixed to the rotor rotating shaft (1) is arranged on the inner side of the insulating connecting piece (3).

Description

Insulating rotor and motor

Technical Field

The invention relates to a rotor structure of a brushless motor, in particular to an insulating rotor and a motor with the insulating rotor.

Background

The use of high-efficiency brushless motors in the field of air conditioners instead of induction motors is an inevitable requirement for the development of energy conservation trends in recent years. In this type of motor, the permanent magnet structure is fixed to the outer peripheral surface of the rotor core as needed. In use, the rotor core rotates along with the rotating shaft which is connected with the center of the rotor core through the shaft, induced electromotive force is generated on the surface of the rotor core, and the rotor core, the permanent magnet and the rotating shaft form an equipotential body due to the installation relation.

In order to make rotary support for the rotating shaft, bearings are arranged at two ends of the rotating shaft, and an equipotential body is also formed by interference fit of the inner ring of the bearing and the rotating shaft; the bearing outer ring is in contact with a bearing chamber on the motor. Due to the above-mentioned mounting relationship, a potential difference exists between the inner and outer races of the bearing. When the motor works (especially when the working environment is dry), the potential difference enables the inner ring and the outer ring of the bearing to relatively rotate to discharge on the surface of the rolling body, the rolling body is subjected to electrostatic corrosion along with the continuous discharging process, and finally abnormal noise exists in the motor running process and the bearing is scrapped in advance.

In the prior art, a means for preventing electrostatic corrosion of a bearing, such as an insulating rotor structure disclosed in application publication No. CN106787313A, includes a permanent magnet, an outer rotor yoke, and an inner rotor core, and PBT plastic is filled between the outer rotor yoke and the inner rotor core. In the mode disclosed in the patent, the rotor core is equivalently divided into two layers (namely, the inner rotor core and the outer rotor magnetic yoke in the patent), and an insulating material (namely, filled PBT plastic) is filled between the two layers of rotor cores, so that the inner rotor core and the outer rotor magnetic yoke are insulated, the rotating shaft is prevented from forming an equipotential body by contacting the rotor core, and the inner ring of the bearing is electrified.

However, the rotor core is subjected to radial and axial forces during operation, which requires the inner layer of the laminated rotor core to have a certain thickness to meet the strength requirement, and the thickness of the plastic-filled portion for insulation is greatly limited in consideration of the simplicity of manufacturing.

Therefore, although the method of dividing the rotor core into the inner and outer races and filling the insulating material can reduce the increase in electromotive force of the bearing inner race, the thickness of the insulating material is such that the electromotive force of the bearing inner race is inevitably still not present, and a large shaft voltage is still present between the bearing inner and outer races.

Disclosure of Invention

The present invention has been made to overcome the above problems occurring in the prior art, and an object of the present invention is to provide an insulated rotor and a motor, which can effectively reduce motor noise caused by electrical corrosion of bearings.

In order to achieve the above object, an aspect of the present invention provides an insulated rotor, including a rotor core and a rotor shaft, where the rotor core is formed with a central hole, an insulated connecting member that is attached to an outer wall of the rotor shaft in an insulated manner is filled between an inner hole wall of the central hole and the rotor shaft, and a reinforcing connecting member that is fixed to the rotor shaft is disposed inside the insulated connecting member.

Preferably, the reinforcing connector includes a connecting portion connected to the rotor shaft in an interference fit manner, and a joint portion bent from the connecting portion in a direction deviating from an axial direction of the rotor shaft and embedded in the insulating connector.

Preferably, the end of the engagement portion remote from the connection portion has a return bend.

Preferably, the joint part is formed with a plurality of through holes which are evenly distributed along the circumferential direction.

Preferably, the reinforcing connecting member is a metal integral molding member.

Preferably, the insulating rotor includes two reinforcing connecting members arranged at intervals and symmetrical to each other in an axial direction of the rotor rotating shaft.

Preferably, a plurality of bulges and/or depressions used for increasing the attaching area of the insulating connecting piece and the inner hole wall of the central hole are uniformly arranged on the inner hole wall of the central hole at intervals along the circumferential direction.

Preferably, a plurality of limiting protrusions are arranged on the peripheral wall of the rotor core along the circumferential direction, and magnetic tiles are bonded between the limiting protrusions.

Preferably, the rotor core comprises a plurality of silicon steel sheets stacked in a pressing mode, and the insulating connecting piece is provided with limiting parts abutted to two ends of the silicon steel sheets in the stacking direction.

A second aspect of the invention provides an electrical machine having an insulated rotor as described above.

Through above-mentioned technical scheme, on insulating connecting piece was connected rotor core insulation to the rotor pivot rather than the enhancement connecting piece that the inboard set up jointly, because insulating connecting piece direct contact rotor pivot, the joint strength between rotor core and the rotor pivot was realized by enhancement connecting piece, and insulating nature is then guaranteed by insulating connecting piece. After the inner layer of the rotor core is omitted, the thickness adjusting range of the insulating connecting piece in the radial direction is enlarged, and the insulativity of the rotor rotating shaft between the rotor cores is improved.

Drawings

Fig. 1 is an assembly structural view of an insulating rotor;

FIG. 2 is an exploded view of the insulated rotor in an axial direction;

fig. 3 is a structural view of a single silicon steel sheet stacked to form a rotor core;

fig. 4 is a structural view of the reinforcing connector.

Description of the reference numerals

1-a rotor shaft; 2-reinforcing the connecting piece; 20-a connecting part; 21-a joint; 22-a return bend; 23-through holes; 3-an insulating connector; 30-a clamping part; 31-a limiting part; 4-a rotor core; 40-dishing; 41-limiting protrusions; 42-a central hole; 5-magnetic shoe.

Detailed Description

As shown in fig. 1 to 4, the present invention first provides an insulated rotor including a rotor core 4, a rotor shaft 1, and magnetic shoes 5 adhesively fixed to an outer circumferential wall of the rotor core 4. Wherein: the rotor core 4 is formed with a center hole 42, the rotor shaft 1 passes through the center hole 42, and an insulating connector 3 is filled between the inner hole wall of the center hole 42 and the outer wall of the rotor shaft 1, the insulating connector 3 is attached to the outer wall of the rotor shaft 1 in an insulating manner, so that the rotor core 4 and the rotor shaft 1 are separated in an insulating manner, and the rotor core 4 and the rotor shaft 1 are prevented from forming an equipotential body. One side of laminating to 1 outer wall of rotor shaft of insulating connecting piece 3 is provided with and will connects

rotor core

4 and 3 axial of insulating connecting piece and the fixed stiffened connection piece 2 to rotor shaft 1 of circumference.

Specifically, as shown in fig. 1 and 2, the insulating connector 3 is integrally a single injection-molded piece made of an insulating material such as plastic, and includes a clamping portion 30 for engaging with an inner hole wall of the central hole 42, and stopper portions 31 located at both ends of the clamping portion 30 in the axial direction. In the present invention, the rotor core 4 is preferably a plurality of silicon steel sheets (shown in fig. 3) laminated in the axial direction, a through hole is formed in the center of each silicon steel sheet, and after all the silicon steel sheets are laminated, all the through holes together form the central hole 42. The inner hole wall of each through hole of each silicon steel sheet is attached to the outer peripheral wall of the clamping portion 30, and the limiting portions 31 are pressed against the silicon steel sheets at the two ends in the laminating direction to keep the laminating relation of all the silicon steel sheets, so that the rotor core 4 is formed. In addition, in order to form the limiting relationship, the radial dimension of the limiting portion 31 is larger than that of the through hole, so that the rotor core 4 and the rotor shaft 1 can be better insulated and separated.

The specific structure of the reinforcing connecting member 2 is shown in fig. 4, and it includes a connecting portion 20 connected to the rotor shaft 1 in an interference fit manner, and an engaging portion 21 bent from the connecting portion 20 in a direction deviating from the axis direction of the rotor shaft 1, and the end of the engaging portion 21 away from the connecting portion 20 has a bent back portion 22.

The rotor core 4 rotates under the action of the current and the magnetic field, and outputs the rotation motion through the rotor rotating shaft 1. In the present invention, since the rotor core does not directly contact the rotor rotating shaft 1, but the insulating connection member 3 contacts the rotor core 4 and the rotor rotating shaft 1, respectively, the motion of the rotor rotating shaft 1 needs to be transmitted through the insulating connection member 3. Therefore, it can be understood that the purpose of the reinforcing connecting member 2 is to ensure that the two connection strengths meet the use requirements of the insulating rotor: first, the strength of connection with the insulating connector 3 itself; secondly, the connection strength between the connection part 20 and the rotor rotating shaft 1 is high. Therefore, the reinforcing connector 2 is preferably formed by a metal integral molding, and the joint portion 21 and the bent back portion 22 are provided for enhancing the connection strength between the reinforcing connector 2 itself and the insulating connector 3, and therefore, the shapes of the two are not limited to the illustrated structure, and may be any special-shaped structure capable of achieving the above purpose.

The engaging portion 21 is further provided with through holes 23 uniformly distributed in the circumferential direction. Adopt insulating connecting piece 3 and strengthening the connecting piece 2 to replace current rotor core inlayer and add insulating plastic envelope, except can increasing insulating effect, its on the other hand's beneficial effect embodies that insulating rotor's whole quality is lighter, and inertia is littleer, and when the motor at insulating rotor place received external drive, insulating rotor's that has less inertia response sensitivity was higher than the great rotor structure of inertia under the same condition. As mentioned above, in order to enhance the connection strength between the insulating connection member 3 and the rotor shaft 1, the reinforcing connection member 2 made of metal is disposed inside the insulating connection member 3, which will inevitably increase the mass of the insulating rotor (it can be understood that the density of metal is generally higher than that of insulating rubber material), and therefore, the through holes 23 can further reduce the influence of the introduction of the metal material on the inertia moment of the insulating rotor. And all the through holes 23 are uniformly arranged along the circumferential direction, so that the center of mass of the insulating rotor is positioned on the straight line of the rotating shaft of the insulating rotor, and the rotation is more stable. The through-hole 23 can also further enhance the connection strength between the reinforcing connector 2 and the insulating connector 3.

Preferably, two reinforcing connecting pieces 2 which are arranged at intervals and are symmetrical to each other are embedded in the insulating connecting piece 3 along the axial direction of the rotor rotating shaft 1. Especially when the reinforcing connecting members 2 adopt the structure having the bent-back portions 22 as shown in fig. 4, the symmetry here means that the bending directions of the bent-back portions 22 on the two reinforcing connecting members 2 are away from each other to prevent the two-way play of the insulating connecting members 3 in the axial direction of the rotor shaft 1, and the axial positioning is more reliable.

A plurality of protrusions and/or depressions are uniformly spaced in the circumferential direction on the inner hole wall of the center hole 42 to increase the contact area of the rotor core 4 with the insulating connector 3. While a uniform arrangement of depressions 40 is shown in fig. 3, it should be understood that the present invention is not limited to the depressions shown, or a single raised structure, or a combination of both structures, as long as the structure is sufficient for the purpose of increasing the contact area.

A plurality of limiting protrusions 41 are arranged on the peripheral wall of the rotor core 4 along the circumferential direction, and the magnetic shoe 5 is fixed between the adjacent limiting protrusions 41 according to the requirement of the motor installed on the insulating rotor.

The following steps of the insulating rotor of the present invention are given to further explain the above structure:

step one, forming interference fit between the connecting parts 20 of the two reinforcing connecting pieces 2 and the rotor rotating shaft 1 to form axial and circumferential positioning between the two reinforcing connecting pieces;

step two, placing the rotor iron core 4 according to a correct position relation, and forming an insulating connecting piece 3 between the inner hole wall of the central hole 42 and the outer wall of the rotor rotating shaft 1 in an injection molding mode;

and step three, adhering and fixing the magnetic shoe 5 to the outer wall of the rotor iron core 4.

In addition, the invention also provides a motor, wherein a rotor part in the motor adopts the insulated rotor.

The preferred embodiments of the present invention have been described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, numerous simple modifications can be made to the technical solution of the invention, including combinations of the specific features in any suitable way, and the invention will not be further described in relation to the various possible combinations in order to avoid unnecessary repetition. Such simple modifications and combinations should be considered within the scope of the present disclosure as well.

Claims

1. An insulated rotor comprises a rotor core (4) and a rotor rotating shaft (1), and is characterized in that a central hole (42) is formed in the rotor core (4), an insulated connecting piece (3) which is attached to the outer wall of the rotor rotating shaft (1) in an insulated mode is filled between the inner hole wall of the central hole (42) and the rotor rotating shaft (1), and a reinforcing connecting piece (2) which is fixed to the rotor rotating shaft (1) is arranged on the inner side of the insulated connecting piece (3);

the reinforcing connecting piece (2) comprises a connecting part (20) connected to the rotor rotating shaft (1) in an interference fit mode, and a joint part (21) bent from the connecting part (20) to the direction deviating from the axis direction of the rotor rotating shaft (1) and embedded into the insulating connecting piece (3).

2. An insulating rotor according to claim 1, characterised in that the end of the engagement portion (21) remote from the connection portion (20) has a return bend (22).

3. The insulated rotor of claim 1, wherein the engaging portion (21) is formed with a plurality of through holes (23) uniformly distributed in a circumferential direction.

4. An insulated rotor according to claim 1, characterised in that the reinforcing connecting piece (2) is a metal one-piece moulding.

5. The insulating rotor according to claim 1, characterized in that it comprises two reinforcing connectors (2) arranged at intervals and symmetrical to each other in the axial direction of the rotor shaft (1).

6. The insulating rotor of claim 1, characterized in that the inner bore wall of the central bore (42) is provided with a plurality of protrusions and/or depressions at even intervals in the circumferential direction for increasing the fitting area of the insulating connector (3) with the inner bore wall of the central bore (42).

7. The insulated rotor according to claim 1, characterized in that a plurality of limiting protrusions (41) are arranged on the outer circumferential wall of the rotor core (4) along the circumferential direction, and magnetic tiles (5) are bonded between adjacent limiting protrusions (41).

8. The insulated rotor according to any one of claims 1 to 7, wherein the rotor core (4) comprises a plurality of silicon steel sheets stacked in layers, and the insulated connecting member (3) has a position-limiting portion (31) abutting against both ends of the silicon steel sheets in the stacking direction.

9. An electrical machine having an insulated rotor according to any one of claims 1 to 8.