EP4609148A1

EP4609148A1 - Encoder assembly and method for assembling the encoder assembly

Info

Publication number: EP4609148A1
Application number: EP22967600.2A
Authority: EP
Inventors: Ling Ling ZOU; Rui Chen; Zi Yan YU
Original assignee: Siemens AG; Siemens Corp
Current assignee: Siemens AG; Siemens Corp
Priority date: 2022-12-08
Filing date: 2022-12-08
Publication date: 2025-09-03
Also published as: WO2024119443A1; CN119998631A

Abstract

An encoder assembly (l) and a method for assembling the encoder assembly (l). The encoder assembly (l) includes: an encoder housing (13) and an encoder cover (14); the encoder housing (13) includes a first flange structure, the first flange structure includes a first mounting face (131) on the side facing the encoder cover (14), the encoder cover (14) includes a second mounting face (141) on the side facing the encoder housing (13); the first mounting face (131) and the second mounting face (141) is capable of contacting each other and being connected together through first connectors; the first flange structure further includes an annular positioning boss (132) on the side far from the encoder cover (14), when the encoder assembly (l) is assembled on a motor (2), the annular positioning boss (132) is matched with a shaft hole (221) on a rear endshield (22) of the motor (2) to achieve radial positioning; the encoder cover (14) further includes a second flange structure, and the second flange structure comprises a third mounting face (142) on the side facing the rear endshield (22), when the encoder assembly (l) is assembled on the motor (2), the third mounting face (142) is capable of contacting with the fourth mounting face (222) on the rear endshield (22) and being connected together through second connectors to achieve axial positioning of the encoder assembly (l). The technical solutions of the present application can reduce production and maintenance costs.

Description

ENCODER ASSEMBLY AND METHOD FOR ASSEMBLING THE ENCODER ASSEMBLY

FIELD

The present application relates to mechanical technologies, and more particularly, to an encoder assembly for a motor and a method for assembling the encoder assembly.

BACKGROUND

At present, the commonly used encoder assembly on the motor includes an encoder main body and a bearing system. Figure 1A and figure 1B are schematic diagrams showing a conditional encoder assembly and an assembly structure thereof when assembled with a motor. As shown in Figure 1A and figure 1B, the encoder assembly 1 may include a code disc 11, a printed circuit board (PCB) 12, an encoder housing 13, an encoder cover 14, etc. After the code disc 11 and the PCB 12 are installed in the encoder housing 13 and before they are installed onto the motor, the PCB 12 is exposed, and the code disc 11 is also exposed with some small slots.
When the encoder assembly 1 is installed on the motor 2, the encoder assembly 1 is connected with a motor shaft 21 through a coupling 3. The encoder housing 13 is fixed on a motor rear endshield 22 by screws, and a radial position and an axial position of the encoder housing 13 is determined by a fit between a flange structure of the encoder housing 13 and a first end surface with a first shaft-hole of the motor rear endshield 22. In order to reduce the temperature rise of the PCB 12, special heat dissipation glue is filled on the PCB 12, and then the encoder cover 14 is installed. The encoder cover 14 is positioned in the radial direction and axial direction through a fit between a flange structure of the encoder cover 14 and a second end surface with a second shaft-hole on the motor rear endshield 22 to achieve the fixation with the motor rear endshield 22. The encoder cover 14 will press the heat dissipation glue to make it completely stick the encoder cover 14 and the encoder PCB 12. After a certain period of time, the heat dissipation glue is solidified.
In addition, those skilled in the art are also working to find other encoder assembly implementation solutions.
SUMMARY
According to embodiments of the present application, an encoder assembly and a method for assembling the encoder assembly are provided to reduce production and maintenance costs.
The encoder assembly provided by embodiments of the present application includes: an encoder housing and an encoder cover; the encoder housing includes a first flange structure, the first flange structure includes a first mounting face on the side facing the encoder cover; the encoder cover includes a second mounting face on the side facing the encoder housing; the first mounting face and the second mounting face is capable of contacting each other and being connected together through first connectors; the first flange structure further includes an annular positioning boss on the side far from the encoder cover, when the encoder assembly is assembled on a motor, the annular positioning boss is matched with a shaft hole on a rear endshield of the motor to achieve radial positioning; the encoder cover further includes a second flange structure, and the second flange structure comprises a third mounting face on the side facing the rear endshield, when the encoder assembly is assembled on the motor, the third mounting face is capable of contacting with the fourth mounting face on the rear endshield and being connected together through second connectors to achieve axial positioning of the encoder assembly.
The method for assembling the encoder assembly provided by embodiments of the present application includes: assembling the PCB into the encoder housing; connecting the first mounting face of the encoder housing and the second mounting face of the encoder cover together; for assembled encoder assembly, matching the annular positioning table of the encoder housing with the shaft hole of the rear endshield of the motor to achieve the radial positioning of the encoder assembly on the motor; contacting and connecting the third mounting face on the encoder cover with the fourth mounting face of the rear endshield of the motor to achieve the axial positioning and installation of the encoder assembly on the motor.
It can be seen from the above technical solutions that in the embodiment of the application, the encoder assembly is integrated by directly assembling encoder housing and encoder cover together. Therefore, the PCB and the encoder disk can be packaged in the encoder assembly in a clean room. Therefore, when the encoder assembly is installed on the motor, it can be completed in the general workshop, so as to get rid of the restrictions on production line layout and greatly reduce production investment.
By directly assembling the encoder housing and the encoder cover together, the encoder assembly is integrated. Therefore, the PCB and the encoder disk can be packaged in the encoder assembly in a clean room. At this time, when the encoder assembly is installed on the motor, the assembly step can be completed in a general workshop, which can get rid of the restrictions on the layout of the production line and greatly reduce the production investment.
In addition, for maintenance, the encoder assembly can be taken down as a whole by removing the connectors between the encoder cover and the rear endshield. There is no need to worry about the damage of the heat dissipation material or the pollution of the encoder assembly, thus efficient maintenance is achieved and the maintenance costs are reduced.
Further, by directly assembling the encoder housing and the encoder cover, the gap between encoder components can be reduced, thereby improving the heat dissipation efficiency of the encoder body and the encoder bearing, and improving the reliability and life of the encoder assembly.
Finally, by separating the axial positioning from the radial positioning, the accumulated error can be reduced, and the concentricity between encoder assembly and motor shaft can be improved, thus the operation reliability of encoder assembly is further improved.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present application, reference should be made to the Detailed Description below, in conjunction with the following drawings in which like reference numerals refer to corresponding parts throughout the figures.
Figure 1A and figure 1B are schematic diagrams illustrating a conditional encoder assembly and an assembly structure thereof when assembled with a motor.
Figure 2 is a structure diagram illustrating an encoder assembly and an assembly structure of the encoder assembly and the motor according to an embodiment of the application.
Figure 3 is a flow diagram illustrating a method for assembling the encoder assembly according to an embodiment of the application.
The reference numerals are as follows:

Reference numeral	Object
1	encoder assembly
11	code disc
12	PCB
13	encoder housing
131	first mounting face
132	annular positioning boss
14	encoder cover
141	second mounting face
142	third mounting face
2	motor
21	motor shaft
22	rear endshield
221	shaft hole
222	fourth mounting face
3	coupling
4	screw
5	heat dissipation material
301～305	processes

DETAILED DESCRIPTION

In embodiment of the application, the following problems exist in the structure of existing encoder assembly:
1) Because there are exposed parts in encoder assembly 1, when encoder assembly 1 is to be assembled on motor 2, a very clean assembly environment is required. In actual production, this assembly step is carried out in a special clean room. If there are three types of motors using this encoder assembly at the same time, three clean rooms or a large clean room should be built, and each motor production line should be surrounded by this clean room, thus the space layout of the production line is greatly limited.
2) For subsequent maintenance services, no matter which part of the motor is being repaired, the encoder cover 14 is generally removed, which will expose the encoder PCB12, etc., thus pollution may be caused to the encoder assembly.
3) When the encoder cover 14 is disassembled during maintenance, the cured heat dissipation glue will be immediately disconnected, and its effect will be weakened and it cannot be reused. Therefore, the maintenance engineer needs to clean up the damaged glue, and then reapplies new heat dissipation glue. However, since this heat dissipation glue is AB component, it cannot be stored as a mixture, and then on-site mixing and coating will be very time-consuming and material consuming, thus the maintenance costs are high.
4) The encoder housing 13 and the encoder cover 14 are respectively fixed on the rear endshield 22 of the motor 2. Due to the accumulation of dimension chains, the fitting clearance between other parts of the encoder and a hole of the encoder cover is uneven. In order to prevent mutual interference, the clearance can only be increased in design, which is not conducive to the heat dissipation of the encoder bearing.
For this reason, in embodiments of the application, it is considered to directly assemble the encoder housing 13 and the encoder cover 14 together to make the encoder assembly as a whole, so that the tolerance chain between the two components is shortened, and there is no uneven problem of gap between other parts of the encoder and the encoder cover, so that the gap can be very small (for example, less than 0.2mm) , thus more heat from the encoder bearing can be transferred to the encoder cover 14 and dissipated by the fan, thus the temperature rise of the encoder bearing can be improved. Before assembling the two parts together, heat dissipation materials can be set on the PCB12. During assembly, the encoder cover 14 presses the heat dissipation materials to fully fill the space between the PCB12 and the encoder cover 14. Since the two components are assembled as a whole, they can be disassembled as a whole during maintenance, so as not to damage the heat dissipation materials. In this embodiment, the heat dissipation material 5 may be fluid or elastic. For example, it can be a fluid heat dissipation material, such as heat dissipation adhesive, or an elastic heat dissipation material, such as a heat sink.
Further, it is considered that after the two components are assembled as a whole, if the radial and axial positioning with the rear endshield 22 is still achieved through the flange structure of the encoder cover 14, the dimension chain between the encoder housing 13 and the rear endshield 22 may become very long, thus the cumulative tolerance will be increased. Especially in the radial direction, the encoder assembly 1 may not be concentric with the motor shaft 21, thus the performance of the encoder will be affected. Therefore, in this embodiment, it is considered to achieve the radial positioning between the encoder housing 13 and the rear endshield 22 of the motor 2, and achieve the axial positioning between the encoder cover 14 and the rear endshield 22 of the motor 2, that is, the positioning in both directions is separated, so as to reduce the cumulative tolerance of radial positioning and improve the coaxiality between the encoder assembly 1 and the motor shaft 21.
Reference will now be made in detail to examples, which are illustrated in the accompanying drawings. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present application. Also, the figures are illustrations of an example, in which assemblies shown in the figures are not necessarily essential for implementing the present application. In other instances, well-known assemblies, components, and circuits have not been described in detail so as not to unnecessarily obscure aspects of the examples.
Figure 2 is a structure diagram illustrating an encoder assembly and an assembly structure of the encoder assembly and the motor according to an embodiment of the application. As shown in figure 2, in this embodiment, the encoder assembly 1 includes: a code disc 11, a PCB12, an encoder housing 13, an encoder cover 14, etc.
The encoder housing 13 includes a first flange structure, the first flange structure includes a first mounting face 131 on the side facing the encoder cover 14, and the encoder cover 14 includes a second mounting face 141 on the side facing the encoder housing 13. After the code disc 11, PCB12 and other components are assembled into the encoder housing 13, the first mounting face 131 and the second mounting face 141 can contact each other and be connected together through first connectors. In this embodiment, the first connectors may be screws 4. Accordingly, a through hole can be set on either of the first mounting face 131 and the second mounting face 141, and a threaded hole can be set on the other. In this embodiment, a through hole is set on the first mounting face131, and a threaded hole is set on the second mounting face 141. In practical application, the positions of the through hole and the threaded hole can be determined according to actual needs. In addition, in other embodiments, the connectors can also be other structural members, such as clips or locking members, which will not be listed here. In this embodiment, before the encoder housing 13 and the encoder cover 14 are assembled together, heat dissipation material 5 can be set on the PCB12. During assembly, the encoder cover 14 presses the heat dissipation material 5 to make the heat dissipation material 5 fully fill the space between the PCB12 and the encoder cover 14.
In addition, the first flange structure of the encoder housing 13 includes an annular positioning boss 132 on the side far from the encoder cover 14. When the encoder assembly 1 is assembled on the motor 2, the annular positioning boss 132 is matched with a shaft hole 221 on the rear endshield 22 of the motor 2 to achieve the radial positioning. In this embodiment, the first flange structure and the rear endshield 22 have a set gap in the axial direction, so that axial positioning is no longer achieved.
The encoder cover 14 includes a second flange structure, and the second flange structure includes a third mounting face 142 on the side facing the rear endshield 22. When the encoder assembly 1 is assembled on the motor 2, the third mounting face 142 can contact with the fourth mounting face 222 on the rear endshield 22 of the motor 2 and can be connected together through second connectors to achieve axial positioning of the encoder assembly 1. In this embodiment, the second connectors can be screws (not shown in the figure 2) . In addition, in other embodiments, the second connectors can also be other structural members, such as clips or locking members, which will not be listed here. In this embodiment, there is a set gap in the radial direction between the second flange structure and the rear endshield 22, so that the radial positioning is no longer achieved.
Figure 3 is a flow diagram illustrating a method for assembling the encoder assembly according to an embodiment of the application. As shown in figure 3, the method can include the following processes:
At block 301, the PCB 12 is assembled into the encoder housing 13.
At block 302, heat dissipation material is set on the PCB 12.
At block 303, the first mounting face 131 of the encoder housing 13 and the second mounting face 141 of the encoder cover 14 are connected together. At this time, the encoder cover 14 presses the heat dissipation material so that the heat dissipation material can fully fill the space between the PCB 12 and the encoder cover 14.
At block 304, for assembled encoder assembly, the annular positioning table 132 of the encoder housing 13 is matched with the shaft hole 221 of the rear endshield 22 of the motor 2 to achieve the radial positioning of the encoder assembly 1 on the motor 2.
At block 305, the third mounting face 142 on the encoder cover 14 is contacted and connected with the fourth mounting face 222 of the rear endshield 22 of the motor 2 to achieve the axial positioning and installation of the encoder assembly 1 on the motor 2.
It can be seen that in the embodiment of the application, the encoder assembly 1 is integrated by directly assembling encoder housing 13 and encoder cover 14 together. Therefore, the PCB12 and the encoder disk 11 can be packaged in the encoder assembly 1 in a clean room. At this time, when the encoder assembly 1 is installed on the motor 2, it can be completed in the general workshop, so as to get rid of the restrictions on production line layout and greatly reduce production investment.
By directly assembling the encoder housing 13 and the encoder cover 14 together, the encoder assembly 1 is integrated. Therefore, the PCB12 and the encoder disk 11 can be packaged in the encoder assembly 1 in a clean room. At this time, when the encoder assembly 1 is installed on the motor 2, the assembly step can be completed in a general workshop, which can get rid of the restrictions on the layout of the production line and greatly reduce the production investment.
In addition, for maintenance, the encoder assembly 1 can be taken down as a whole by removing the connectors between the encoder cover 14 and the rear endshield 22. There is no need to worry about the damage of the heat dissipation material or the pollution of the encoder assembly 1, thus efficient maintenance is achieved and the maintenance costs are reduced.
Further, by directly assembling the encoder housing 13 and the encoder cover 14, the gap between encoder components can be reduced, thereby improving the heat dissipation efficiency of the encoder body and the encoder bearing, and improving the reliability and life of the encoder assembly 1.
Finally, by separating the axial positioning from the radial positioning, the accumulated error can be reduced, and the concentricity between encoder assembly 1 and motor shaft 21 can be improved, thus the operation reliability of encoder assembly 1 is further improved.
The foregoing description, for purpose of explanation, has been described with reference to specific examples. However, the illustrative discussions above are not intended to be exhaustive or to limit the present application to the precise forms disclosed. Many modifications and variations are possible in view of the above teachings. The examples were chosen and described in order to best explain the principles of the present application and its practical applications, to thereby enable others skilled in the art to best utilize the present application and various examples with various modifications as are suited to the particular use contemplated.

Claims

A encoder assembly, comprising: an encoder housing (13) and an encoder cover (14) ; characterized in that,

the encoder housing (13) comprises a first flange structure, the first flange structure comprises a first mounting face (131) on the side facing the encoder cover (14) ;

the encoder cover (14) comprises a second mounting face (141) on the side facing the encoder housing (13) ;

the first mounting face (131) and the second mounting face (141) is capable of contacting each other and being connected together through first connectors;

the first flange structure further comprises an annular positioning boss (132) on the side far from the encoder cover (14) , when the encoder assembly is assembled on a motor (2) , the annular positioning boss (132) is matched with a shaft hole (221) on a rear endshield (22) of the motor (2) to achieve radial positioning;

the encoder cover (14) further comprises a second flange structure, and the second flange structure comprises a third mounting face (142) on the side facing the rear endshield (22) , when the encoder assembly is assembled on the motor (2) , the third mounting face (142) is capable of contacting with the fourth mounting face (222) on the rear endshield (22) and being connected together through second connectors to achieve axial positioning of the encoder assembly.
The encoder assembly according to claim 1, characterized in that,

the first connectors are screws, clips or locking members; the second connectors are screws, clips or locking members.
The encoder assembly according to claim 1, further comprising: a PCB (12) , characterized in that,

after the PCB (12) is assembled into the encoder housing (13) , heat dissipation material (5) is set on the PCB (12) , when the first mounting face (131) and the second mounting face (141) is connected together, the encoder cover (14) presses the heat dissipation material (5) to make the heat dissipation material (5) fully fill the space between the PCB (12) and the encoder cover (14) .
A method for assembling the encoder assembly according to any one of claims 1 to 3, characterized in that, comprising:

assembling the PCB (12) into the encoder housing (13) ;

connecting the first mounting face (131) of the encoder housing (13) and the second mounting face (141) of the encoder cover (14) together;

for assembled encoder assembly, matching the annular positioning table (132) of the encoder housing (13) with the shaft hole (221) of the rear endshield (22) of the motor (2) to achieve the radial positioning of the encoder assembly on the motor (2) ;

contacting and connecting the third mounting face (142) on the encoder cover (14) with the fourth mounting face (222) of the rear endshield (22) of the motor (2) to achieve the axial positioning and installation of the encoder assembly on the motor (2) .
The method for assembling the encoder assembly according to claim 4, characterized in that,

before connecting the first mounting face (131) of the encoder housing (13) and the second mounting face (141) of the encoder cover (14) together, further comprising: setting heat dissipation material (5) on the PCB (12) ;

when connecting the first mounting face (131) of the encoder housing (13) and the second mounting face (141) of the encoder cover (14) together, pressing, by the encoder cover (14) , the heat dissipation material (5) to make the heat dissipation material (5) fully fill the space between the PCB (12) and the encoder cover (14) .