Motor system

Abstract

The invention relates to a motor system, the connection structure of an encoder and a motor has high concentricity and reliability, the motor system comprises the motor and the encoder, the encoder is arranged at the end of the main shaft of the motor, and the encoder shaft of the encoder is coaxially arranged with the main shaft of the motor and is connected with the main shaft of the motor in an anti-torsion manner. The motor main shaft is provided with an axial inner taper hole, the encoder shaft is provided with an outer conical surface, the outer conical surface is matched with the inner taper hole in shape, and the outer conical surface and the inner taper hole are in friction fit on a contact surface; the motor further comprises a pressing plate, the end of the motor spindle is sleeved with the pressing plate, the pressing plate is located on the outer side of the built-in nut, a first through hole is formed in the pressing plate, the hole diameter of the first through hole is smaller than the outer diameter of the built-in nut, and the pressing plate is provided with a second through hole. The encoder shaft penetrates through the first through hole and then is in threaded fit with the built-in nut.

Description

Technical Field

[0001] This invention relates to motor systems, and more particularly to motor systems with encoders. Background Technology

[0002] For motor systems with optical encoders, especially high-speed motor systems, the mechanical connection between the encoder and the motor shaft needs to achieve a high degree of concentricity to ensure stable and accurate signals and guarantee reliability.

[0003] One installation method in the prior art is as follows: Figure 1 As shown, the outer conical surface of the encoder shaft mates with the inner conical surface of the motor shaft to ensure concentricity; then, a screw passes through the center of the encoder and is screwed onto the motor shaft to fix the encoder to the motor shaft. However, some encoder models, in order to achieve a compact structure, do not have a center hole, making it impossible to pass a screw, and therefore the above fixing method cannot be achieved.

[0004] Another installation method in the prior art Figure 2 As shown, the encoder shaft's outer conical surface mates with the motor shaft's inner conical surface. An external thread at the end of the encoder shaft mates with the internal thread of the motor shaft, securing the encoder to the motor shaft. The encoder shaft also has a transversely arranged hole. During encoder installation, a pin-like tool is inserted into this hole, and rotating the pin causes the encoder shaft to rotate, thus locking the threads. Regardless of whether it's the encoder shaft or the motor shaft, there is a certain degree of misalignment between the conical surface fit and the threaded fit. If both are involved in the fit, it will lead to over-constraint, making the connection unreliable or misaligned.

[0005] Therefore, a motor system that eliminates over-constraint phenomena has become an urgent technical problem to be solved. Summary of the Invention

[0006] The purpose of this invention is to provide a motor system in which the connection structure between the encoder and the motor has high concentricity and reliability. This motor system includes a motor and an encoder. The encoder is disposed at the end of the motor spindle, and the encoder housing is fixed to the motor housing. The encoder shaft is coaxially arranged with the motor spindle and connected in a torsion-resistant manner. The motor spindle has an axial inner conical hole, and the encoder shaft has an outer conical surface. The outer conical surface matches the shape of the inner conical hole and forms a friction fit on the contact surface. An internal nut is provided in the opening of the inner conical hole, and the internal nut forms a form fit with the opening and is non-rotatable relative to the motor spindle. The motor also includes a pressure plate, which is sleeved on the end of the motor spindle, located outside the internal nut. The pressure plate has a first through hole, the diameter of which is smaller than the outer diameter of the internal nut. The encoder shaft passes through the first through hole and forms a threaded fit with the internal nut.

[0007] Preferably, the encoder shaft is provided with a first operating part, which is located at the root of the encoder shaft. The encoder shaft can be rotated by operating the first operating part with a tool. The first operating part has at least a pair of parallel and symmetrically arranged first operating planes.

[0008] More preferably, the first operating part is a hexagonal prism arranged along the axis of the encoder shaft.

[0009] Preferably, the opening is provided with two sliding grooves, and the built-in nut is provided with a slider corresponding to the sliding grooves.

[0010] Preferably, the pressure plate is interference-fitted onto the end of the motor spindle.

[0011] The present invention further aims to provide a motor system comprising a motor and an encoder, wherein the encoder is disposed at the end of the motor spindle, the encoder housing is fixed to the motor housing, the encoder shaft is coaxially disposed with the motor spindle and is torsionally connected, wherein the motor spindle has an axial inner conical hole, and the encoder shaft has an outer conical surface, the outer conical surface matching the shape of the inner conical hole and forming a friction fit on the contact surface; the motor further comprises a cap, the outer surface of the motor spindle has an external thread, the inner surface of the cap has an internal thread, the cap is threadedly engaged with the motor spindle, the bottom center of the cap has a second through hole, the encoder shaft passes through the second through hole and enters the inner conical hole, the encoder shaft also has a flange, the diameter of the flange being larger than the inner diameter of the second through hole, the cap applying axial pressure to the encoder shaft through the flange, thereby generating a clamping force on the contact surface between the outer conical surface and the inner conical hole.

[0012] Preferably, the cap is provided with a second operating part, which is located outside the side wall of the cap. By operating the second operating part with a tool, the cap can be rotated. The second operating part consists of a pair of parallel and symmetrically arranged second operating planes. Attached Figure Description

[0013] Figure 1 This is a partial structural diagram of an existing motor system;

[0014] Figure 2 This is a partial structural diagram of another existing motor system;

[0015] Figure 3 This is a partial structural schematic diagram of the motor system according to the first embodiment of the present invention;

[0016] Figure 4 This is a partial structural diagram of the motor spindle of the motor system in the first embodiment described above;

[0017] Figure 5 This is a schematic diagram of the encoder shaft structure of the motor system in the first embodiment described above;

[0018] Figure 6 This is a partial structural schematic diagram of a motor system according to a second embodiment of the present invention;

[0019] Figure 7 This is a schematic diagram of the screw cap structure of the second embodiment described above.

[0020] Label Explanation

[0021] 10 Electric motors

[0022] 11. Motor spindle

[0023] 111 Internal tapered hole

[0024] 112 Inner cone surface

[0025] 113 Opening

[0026] 114 Slide

[0027] 20 encoders

[0028] 21 Encoder shaft

[0029] 22. External conical surface

[0030] 23 First Operations Department

[0031] 24 First operating plane

[0032] 25 flange

[0033] 30 pressure plate

[0034] 301 First Through Hole

[0035] 31 Built-in nut

[0036] 311 Slider

[0037] 40 Screw cap

[0038] 401 Second Through Hole

[0039] 402 Second Operations Section

[0040] 403 Second Operating Plane Detailed Implementation

[0041] The specific embodiments of the present invention will be described below with reference to the accompanying drawings.

[0042] Figure 3 A partial structure of a motor system according to a first embodiment of the present invention is shown. The motor system includes a motor (not fully shown) and an encoder. The motor has an inner conical hole on its main shaft, the bottom radius of which is smaller than the opening radius. The encoder is mounted on one end of the motor's main shaft, and an outer housing of the encoder is fixed to the motor's housing. The encoder shaft extends into the inner conical hole, and the encoder shaft has an outer conical surface that matches the shape of the inner conical hole. At least one of the inner conical hole wall and the outer conical surface has a friction surface. When the encoder shaft and the main shaft are pressed together axially, a frictional force is generated on the contact surface between the inner conical hole and the outer conical surface to prevent mutual sliding.

[0043] like Figure 4 The spindle has two radial grooves at the opening of its inner conical hole. In this embodiment, the grooves are symmetrical about the center. Those skilled in the art can adjust the number of grooves or their positions according to product design requirements. An internal nut is located at the opening of the inner conical hole. The main body of the internal nut is annular with internal threads and coaxially disposed within the inner conical hole. Two radial sliders are located at both ends of the internal nut, corresponding to the grooves. The sliders are sized to match the grooves with a certain gap, allowing the internal nut to rotate slightly and translate slightly within the inner conical hole.

[0044] like Figure 5As shown, the encoder shaft is provided with a first operating part, an external thread, and an external conical surface sequentially from the root to the end. The external thread matches the internal thread of the built-in nut, and the external conical surface matches the internal conical surface of the internal conical hole. In this embodiment, the first operating part is a pair of centrally symmetrical and parallel planes. Using a wrench-like tool or a special tool, the encoder shaft can be rotated after being engaged with the first operating plane. Optionally, the first operating part can also be hexagonal prism-shaped, facilitating operation from different positions and angles using a wrench.

[0045] For example Figure 3 As shown, a pressure plate covers the opening of the inner conical hole. The pressure plate is fitted onto the end of the main shaft with an interference fit. The pressure plate has a first through hole, the diameter of which is smaller than the outer diameter of the internal thread and larger than the inner diameter of the internal straight thread. During installation, the encoder shaft passes through the first through hole from the outside to the inside and enters the inner conical hole. By operating the first operating plane with a tool, the encoder shaft rotates, thereby creating a threaded engagement between the external thread and the internal thread of the internal straight thread. As the encoder shaft is gradually tightened, the built-in nut abuts against the pressure plate, and the encoder shaft is axially pressed against the inner conical surface. The friction generated by the clamping force keeps the encoder shaft and the main shaft rotating synchronously, preventing circumferential slippage.

[0046] In this embodiment of the motor system, during installation, only the inner and outer conical surfaces provide alignment and a fixed connection. Because the internal thread has a certain clearance within the inner conical hole, it can adaptively displace according to actual conditions. Therefore, it only exerts axial force on the encoder shaft, avoiding over-constraint due to the combined action of two different fixing mechanisms. Consequently, the encoder and motor in this embodiment of the motor system achieve higher concentricity and a more reliable physical connection.

[0047] Figure 6 A second embodiment of the invention is shown, which differs from the first embodiment in that a screw cap replaces the connection structure of the built-in nut and pressure plate. An external thread is provided on the outer surface of the end of the spindle, and an internal thread is provided on the inner sidewall of the screw cap, thereby enabling a threaded engagement with the spindle.

[0048] like Figure 7 As shown, the bottom of the screw cap is provided with a second through hole, and the outside of the side wall is provided with a second operating part, which is a pair of symmetrical and parallel planes.

[0049] For example Figure 6As shown, the encoder shaft has a flange with a diameter larger than the diameter of the second through hole. The cap is fitted onto the root of the encoder shaft and is clamped between the encoder body and the flange with a gap. During installation, the encoder shaft is first inserted into the inner conical hole, and then the cap is rotated using a wrench, gradually tightening it inward along the main shaft direction. During tightening, the encoder shaft is also pressed axially inward into the inner conical hole. Because there are gaps between the cap and the encoder shaft in all dimensions, adaptive positional adjustments can be made during tightening, thus avoiding over-constraint. The cap only provides axial clamping force; concentricity and connection reliability rely entirely on the fit between the inner and outer conical surfaces.

[0050] Although the present invention has been described in detail through the above preferred embodiments, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above. Therefore, the scope of protection of the present invention should be defined by the appended claims. Furthermore, no reference numerals in the claims should be construed as limiting the scope of the claims. The word "comprising" does not exclude any means or steps not listed in other claims or the specification; words such as "first," "second," etc., are used only to indicate names and do not indicate any particular order. In this document, terms such as "parallel," "perpendicular," etc., are not strict mathematical and / or geometric limitations, but also include tolerances that are understandable to those skilled in the art and permissible in manufacturing or use.

Claims

1. A motor system comprising a motor and an encoder, the encoder being disposed at the end of the motor spindle, the encoder housing being fixed to the motor housing, and the encoder shaft being coaxially mounted with and torsionally connected to the motor spindle, wherein... The motor spindle is provided with an axial inner conical hole, and the encoder shaft is provided with an outer conical surface. The outer conical surface matches the shape of the inner conical hole and forms a friction fit on the contact surface. The feature is that the opening of the inner conical hole is provided with a built-in nut, the built-in nut and the opening are in a form fit, and it is not rotatable relative to the motor spindle. The motor also includes a pressure plate, the pressure plate is sleeved on the end of the motor spindle, located outside the built-in nut, the pressure plate is provided with a first through hole, the diameter of the first through hole is smaller than the outer diameter of the built-in nut, and the encoder shaft passes through the first through hole and forms a threaded fit with the built-in nut.

2. The motor system according to claim 1, wherein, The encoder shaft is provided with a first operating part, which is located at the root of the encoder shaft. The encoder shaft can be rotated by operating the first operating part with a tool.

3. The motor system according to claim 2, wherein, The first operating unit has at least one pair of parallel and symmetrically arranged first operating planes.

4. The motor system according to claim 3, wherein, The first operating part is a hexagonal prism arranged along the axis of the encoder shaft.

5. The motor system according to claim 1, wherein, The opening has two grooves, and the built-in nut has a slider corresponding to the groove.

6. The motor system according to claim 1, wherein, The pressure plate is interference-fitted onto the end of the motor spindle.

7. A motor system comprising a motor and an encoder, the encoder being disposed at the end of the motor spindle, the encoder housing being fixed to the motor housing, and the encoder shaft being coaxially mounted with and torsionally connected to the motor spindle, wherein... The motor spindle is provided with an axial inner conical hole, and the encoder shaft is provided with an outer conical surface. The outer conical surface matches the shape of the inner conical hole and forms a friction fit on the contact surface. The feature is that the motor further includes a cap, the outer surface of the motor spindle is provided with an external thread, the inner surface of the cap is provided with an internal thread, the cap is threadedly engaged with the motor spindle, the bottom center of the cap is provided with a second through hole, the encoder shaft passes through the second through hole and enters the inner conical hole, the encoder shaft is also provided with a flange, the diameter of the flange is larger than the inner diameter of the second through hole, the cap applies axial pressure to the encoder shaft through the flange, so that a clamping force is generated on the contact surface between the outer conical surface and the inner conical hole.

8. The motor system according to claim 7, wherein, The cap is provided with a second operating part, which is located outside the side wall of the cap. The cap can be rotated by operating the second operating part with a tool.

9. The motor system according to claim 8, wherein, The second operating part is a pair of parallel and symmetrically arranged second operating planes.

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