CN110247517B

CN110247517B - Encoder and motor assembly

Info

Publication number: CN110247517B
Application number: CN201810195181.6A
Authority: CN
Inventors: 张利光; 邹玲玲; 王小勇; 王胜友
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2018-03-09
Filing date: 2018-03-09
Publication date: 2021-10-26
Anticipated expiration: 2038-03-09
Also published as: CN110247517A

Abstract

The invention provides an encoder, which is provided with a cylindrical shell, wherein the shell is provided with a circumferential surface, and a heat dissipation coating is coated on the circumferential surface. In addition, the invention also provides a motor component adopting the encoder. The design of the invention can effectively improve the heat dissipation efficiency of the encoder and prolong the service life.

Description

Encoder and motor assembly

Technical Field

The invention relates to the field of motors, in particular to an encoder with improved heat dissipation capacity and a motor assembly thereof.

Background

In the field of industrial motors, encoders are mounted on servo motors. When the servo motor operates at a high speed, the temperature of the encoder may be high. Excessive encoder temperature can damage the encoder or reduce the useful life of the encoder. Therefore, heat dissipation of the encoder is a technical issue of concern in the industry.

Disclosure of Invention

The present invention improves upon the encoder and related components of the motor assembly by applying heat sink and heat sink coatings to the appropriate locations to provide additional heat dissipation paths for the encoder disposed within the motor assembly.

According to one aspect of the present invention, an encoder is provided having a cylindrical housing with a circumferential surface coated with a heat sink coating. The heat dissipation material is beneficial to improving the overall heat dissipation efficiency of the encoder.

According to an embodiment, in the above encoder, the casing of the encoder further has a top portion connected to the circumferential surface, and the top portion is also coated with the heat dissipation coating. By coating a special heat dissipation material on a part opposite to the housing and correspondingly coating a heat absorption material on a corresponding part on the housing, the heat conduction from the encoder to the housing can be obviously improved, and the heat dissipation efficiency of the encoder is improved.

According to one embodiment, in the encoder described above, the heat-dissipating coating is a layer of dark paint or a thermally conductive silicone grease.

According to one embodiment, in the encoder, the black body emissivity of the heat-dissipating coating is between 0.9 epsilon and 0.94 epsilon, and radiates energy in an infrared wavelength band of 0.5-13.5 mu m.

According to another aspect of the present invention, there is provided a motor assembly including:

a motor;

an encoder disposed at one side of the motor and having a cylindrical housing having a circumferential surface;

a housing disposed opposite the encoder and having an annular inner wall opposite the circumferential surface of the housing,

wherein, the circumference is coated with a heat dissipation coating and/or the annular inner wall is coated with a heat absorption coating.

According to one embodiment, in the above-described motor assembly, the heat dissipation coating is a dark paint layer or a heat conductive silicone grease.

According to one embodiment, in the motor assembly described above, the blackbody emissivity of the heat-dissipating coating is between 0.9 epsilon and 0.94 epsilon and radiates energy in the infrared wavelength band of 0.5-13.5 mu m.

According to one embodiment, in the above-described motor assembly, the heat-absorbing coating has a conductivity greater than or equal to 45W/(m · K) at 70 ℃, and the black body emissivity of the heat-absorbing coating is between 0.9 epsilon and 0.94 epsilon. The black body thermal emissivity of the heat dissipation material and the heat absorption material is equivalent or even the same, so that the heat generated on the encoder can be efficiently conducted to the housing through thermal radiation, and the heat dissipation is facilitated.

According to an embodiment, in the above-described motor assembly, the housing further includes:

a first vane pack extending radially outwardly from the inner annular wall;

the spacing piece is connected with the annular inner wall and one side of the first blade group;

the extension section is arranged on the other side, opposite to the side connected with the annular inner wall, of the spacing piece; and

a second set of vanes extending radially outwardly from the extension. The special shape design of the housing increases the overall heat dissipation area of the housing.

According to one embodiment, in the motor assembly, the cover casing is in a truncated cone shape as a whole, a plurality of through holes are formed in the outer edge of the cone bottom of the cover casing, and the cover casing is fixed to one side of the motor by screws penetrating through the through holes.

According to an embodiment, in the above-mentioned motor assembly, further comprising:

and the fan is arranged at one end of the motor component and is opposite to the extension section of the housing and the second blade group.

According to an embodiment, in the above-mentioned motor assembly, the casing of the encoder further has a top portion connected to the circumferential surface, the top portion is also coated with the heat dissipation coating, and a portion of the spacer opposite to the top portion is coated with the heat absorption coating.

It is to be understood that both the foregoing general description and the following detailed description of the present invention are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention. In the drawings:

FIG. 1 illustrates a partial cross-sectional view of one embodiment of an encoder and housing in accordance with the present invention.

Figure 2 shows a cross-sectional view of one embodiment of a motor assembly according to the present invention.

Fig. 3a and 3b show a schematic view of an embodiment of the housing.

Description of reference numerals:

10 encoder

20 electric machine

30 end cap

40 case

50 Fan

101 outer casing

102 circumferential surface

103 top of

201 rotating shaft

401 annular inner wall

402 first vane set

403 spacing piece

404 extension segment

405 second set of blades

406 through hole

Detailed Description

Embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. Further, although the terms used in the present invention are selected from publicly known and used terms, some of the terms mentioned in the description of the present invention may be selected by the applicant at his or her discretion, the detailed meanings of which are described in relevant parts of the description herein. Furthermore, it is required that the present invention is understood, not simply by the actual terms used but by the meaning of each term lying within.

The basic principles and preferred embodiments of the present invention are discussed in more detail with reference to the accompanying drawings. Referring first to fig. 1 and 2, an encoder 10 according to the present invention is provided in a motor assembly, and a rotor (not shown) within the encoder 10 is connected to a rotating shaft 201 of a motor 20 and rotates along with the rotating shaft 201. The encoder 10 has a cylindrical housing 101. The housing 101 has a circumferential surface 102. Wherein the circumferential surface 102 is coated with a heat-dissipating coating. Generally, the heat of the encoder 10 is derived from the high-speed rotation of the rotating shaft 201 described above and the operating heat of the encoder 10 itself. Therefore, the heat dissipation material contributes to improvement of the heat dissipation efficiency of the entire encoder.

In addition, the housing 101 of the encoder 10 has a top portion 103 (e.g., the rightmost side of the housing in FIG. 1) that meets the circumferential surface 102. The top 103 may also be coated with a heat sink coating. As will be discussed in more detail below, the circumferential surface 102 and the top 103 of the housing 101 of the encoder 10 are locations that are housed in the housing 40 of the present invention, opposite the housing 40. Therefore, by applying a special heat-dissipating material to a portion opposite to the cover 40 and correspondingly applying a heat-absorbing material to a corresponding portion of the cover 40, heat conduction from the encoder 10 to the cover 40 can be significantly improved, and the heat-dissipating efficiency of the encoder 10 can be improved.

For example, the heat dissipation coating may be a dark paint layer or a heat conductive silicone grease. Further, the heat-dissipating coating preferably has a blackbody emissivity of 0.9 to 0.94 epsilon, for example, 0.92 epsilon, and is capable of radiating energy in an infrared wavelength band of 0.5 to 13.5 mu m.

In the motor assembly shown in fig. 2, one side of the motor 20 is provided with an end cap 30. In some embodiments, the end cap 30 may also be integrally formed with the housing of the motor 20 as part of the motor housing. The rotating shaft 201 of the motor 20 is connected to the rotor in the encoder 10 through the end cap 30. The cylindrical housing 101 of the encoder 10 is fixed to the end cap 30, for example, by screws, or the cylindrical housing 101 may be fixed to another stationary member (for example, the housing 40). When the motor 20 is running, the motor 20 will rotate the rotor inside the encoder 10, while the cylindrical housing 101 will remain relatively stationary. In addition, the motor assembly of the present invention also provides a cover 40 disposed opposite the encoder 10, such as in this embodiment the cover 40 is secured to the end cap 30. The casing 40 has an annular inner wall 401 opposite the circumferential surface 102 of the housing 101 of the encoder 10 as shown in figure 3 a. The annular inner wall 401 is adapted to receive the housing 101 of the encoder 10, as shown in FIG. 1.

In particular, according to the present invention, the circumferential surface 102 of the casing 101 of the encoder 10 is coated with a heat-dissipating coating, and/or the annular inner wall 401 of the casing 40 is coated with a heat-absorbing coating. For example, the heat-absorbing coating has a conductivity greater than or equal to 45W/(mK), for example up to 50W/(mK), at 70 ℃ and a black body emissivity of between 0.9 epsilon and 0.94 epsilon, for example 0.92 epsilon. The black body emissivity of the heat sink material and the heat sink material are comparable or even the same, so that the heat generated by the encoder 10 can be efficiently conducted to the housing 40 through thermal radiation, thereby facilitating heat dissipation.

Furthermore, applying a heat-dissipating coating on the surface of the housing 101 of the encoder 10 and/or applying a heat-absorbing coating on the annular inner wall 401 of the housing 40 may also reduce the difference between the outer diameter of the encoder and the inner diameter of the housing, i.e., the spacing between the housing of the encoder and the annular inner wall of the housing. A smaller spacing may further enhance the heat transfer effect between the two.

The housing 40 is discussed in detail below in conjunction with fig. 3a and 3 b. The special shape design of the casing 40 increases the overall heat dissipation area of the casing 40. In addition to the annular inner wall 401, the casing 40 comprises: a first set of blades 402, spacers 403, extension 404, and a second set of blades 405.

In the embodiment shown in fig. 3a and 3b, the casing 40 is generally in the shape of a truncated cone. The annular inner wall 401 for accommodating the encoder 10 is a conical bottom with a larger cross section area to provide a larger space for the heat dissipation blades of the first blade group 402, and the other side is a conical top. A plurality of through holes 406 are provided at the outer edge of the tapered bottom of the cover 40, and the cover 40 is fixed to the end cap 30 by means of screws passing through the plurality of through holes 406.

A first vane set 402 extends radially outwardly from the inner annular wall 401 to the outer edge of the conical bottom as described above. Since the sectional area of the conical bottom is large, the heat dissipating blades of the first blade group 402 can obtain a large heat dissipating surface area. The spacer 403 is connected to the annular inner wall 401 and one side of the first blade group 402. The portion of the spacer 403 opposite the top 103 of the encoder 10 may be coated with a heat absorbing coating and, correspondingly, the top 103 of the housing 101 of the encoder 10 may also be coated with a heat dissipating coating to increase the radiative heat transfer area between the encoder 10 and the casing 40.

Further, an extension 404 is provided on the other side of the spacer 403 opposite to the side connecting the annular inner wall 401. A second set of vanes 405 extends radially outward from the extension section 404. The surface area of each blade of the second blade group 405 is smaller than the blades in the first blade group 402 due to the constraint of the overall shape of the shroud 40, but the overall heat dissipation surface area of the second blade group 405 can be increased by increasing the number of blades in the second blade group 405.

According to the above structure, the heat generated at the encoder 10 can be conducted to the casing 101 and the housing 40 in turn. Then, the heat dissipation is assisted by the larger heat dissipation area formed by the first blade group 402, the spacer 403, the extension section 404 and the second blade group 405 on the casing 40, so that the heat dissipation efficiency is improved. In addition, as shown in fig. 2, a fan 50 may be further provided at the right side of the motor assembly, i.e., the side opposite to the extension 404 and the second blade group 405 of the casing 40, to help dissipate heat of the casing 40.

In conclusion, the encoder and the motor assembly can realize better heat dissipation effect through the combination of multiple heat dissipation designs, the working temperature of the encoder is obviously reduced, and the service life of the encoder is prolonged. In addition, the implementation of the technical scheme requires low cost and has high cost advantage.

It will be apparent to those skilled in the art that various modifications and variations can be made to the above-described exemplary embodiments of the present invention without departing from the spirit and scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Claims

1. An electric machine assembly, comprising:

a motor (20);

an encoder (10) provided on one side of the motor and having a cylindrical housing (101) having a circumferential surface (102);

a housing (40) disposed opposite the encoder and having an annular inner wall (401) opposite the circumferential surface of the housing,

wherein the circumferential surface is coated with a heat dissipation coating and/or the annular inner wall is coated with a heat absorption coating,

wherein the casing (40) further comprises:

a first set of blades (402) extending radially outwardly from the inner annular wall (401);

the spacing piece (403) is connected with the annular inner wall and one side of the first blade group;

an extension section (404) provided on the other side of the spacer opposite to the side connected to the annular inner wall; and

a second set of vanes (405) extending radially outwardly from the extension,

wherein the casing (101) of the encoder (10) is also provided with a top part (103) connected with the circumferential surface (102), the top part is also coated with the heat dissipation coating, and the part of the spacing sheet (403) opposite to the top part is coated with the heat absorption coating,

the radiation rate of the black body of the heat dissipation coating is between 0.9 epsilon and 0.94 epsilon, the radiation energy is carried out under the infrared wave long wave band of 0.5 to 13.5 mu m, the conductivity coefficient of the heat absorption coating at 70 ℃ is greater than or equal to 45W/(m.K), and the heat radiation rate of the black body of the heat absorption coating is between 0.9 epsilon and 0.94 epsilon.

2. The electric motor assembly of claim 1, wherein the heat dissipating coating is a dark paint layer or a thermally conductive silicone grease.

3. The motor assembly according to claim 1, wherein the cover (40) has a truncated conical shape as a whole, and a plurality of through holes (406) are provided at an outer edge of a conical bottom of the cover, and the cover is fixed to one side of the motor (20) by screws passing through the plurality of through holes.

4. The electric machine assembly of claim 1, further comprising:

a fan (50) disposed at one end of the motor assembly and opposite the extension (404) and the second set of blades (405) of the shroud (40).