Electric machines, machine tools

Abstract

The application provides a motor and a machining device, wherein the motor comprises a motor rear end cover and an encoder end cover connected to the motor rear end cover, an encoder mounting space is formed between the motor rear end cover and the encoder end cover, the encoder end cover is connected with an encoder on the side facing the motor rear end cover, and the encoder is non-contact connected with the end of a motor rotating shaft close to the motor rear end cover through a magnetic coupling assembly. According to the application, the connection of the encoder and the encoder end cover can directly conduct the heat generated by the encoder to the encoder end cover and then to the external environment through the encoder end cover, effectively preventing the heat of the motor stator, the motor rotor and the motor rotating shaft from being directly conducted to the encoder to cause the temperature rise of the encoder, and effectively ensuring the heat dissipation performance of the encoder, and the signal precision of the encoder is improved.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of motor manufacturing, and particularly relates to a motor and a machining device. BACKGROUND

[0002] A motor is a common power source and is widely used, and usually includes various types, such as a stepper motor and a servo motor. The servo motor converts a voltage signal into torque and rotational speed to drive a control object, and is accurate in control speed and position accuracy, and is usually used as an important component in a servo system to realize power output. An encoder is a device that encodes, converts and transmits signals or data into a form that can be communicated, transmitted and stored. The encoder chip of the servo motor usually withstands a high temperature. The existing encoder is difficult to dissipate heat due to internal closure, and is prone to failure due to over-temperature in some cases due to the operation of the motor and the heat generated by the chip itself. In addition, the overall encoder needs to fix a leaf spring on a mounting surface during installation, and the operation may cause installation failure and affect the signal accuracy of the encoder and the service life of the leaf spring due to the influence of the overall assembly size of the motor. SUMMARY

[0003] Therefore, the present application provides a motor and a machining device, which can overcome the problem that the encoder is installed close to one side of the motor stator and rotor in the related art, causing high temperature and installation failure and affecting the signal accuracy of the encoder.

[0004] To solve the above problem, the present application provides a motor, which comprises a motor rear end cover and an encoder end cover connected to the motor rear end cover, an encoder installation space is formed between the encoder end cover and the motor rear end cover, an encoder is connected to one side of the encoder end cover facing the motor rear end cover, and the encoder is non-contact connected to one end of a motor rotating shaft close to the motor rear end cover through a magnetic shaft coupling assembly.

[0005] In some embodiments, the magnetic shaft coupling assembly comprises a first connecting piece fixedly connected with a code disc of the encoder, and a second connecting piece fixedly connected with the one end of the motor rotating shaft, at least two first magnetic rods are connected to the first connecting piece, at least two second magnetic rods are connected to the second connecting piece, the first magnetic rods and the second magnetic rods are staggered and overlapped in the circumferential direction of the motor rotating shaft, and the magnetic properties of at least the first magnetic rods and the second magnetic rods at the staggered and overlapped positions are the same.

[0006] In some embodiments, the first connecting member has a first connecting disc, and the at least two first magnetic rods are uniformly and spacedly connected to the first connecting disc along the circumference of the first connecting disc; the second connecting member has a second connecting disc, and the at least two second magnetic rods are uniformly and spacedly connected to the second connecting disc along the circumference of the second connecting disc; and the first magnetic rods and the second magnetic rods have the same pitch circle radius and the same number.

[0007] In some embodiments, the first connecting disc has at least two first mounting holes on one side thereof facing the second connecting disc, and one end of each of the first magnetic rods is correspondingly and tightly connected or bonded in each of the first mounting holes; and / or the second connecting disc has at least two second mounting holes on one side thereof facing the first connecting disc, and one end of each of the second magnetic rods is correspondingly and tightly connected or bonded in each of the second mounting holes.

[0008] In some embodiments, the first connecting member and the second connecting member are made of non-magnetic metal material.

[0009] In some embodiments, the first magnetic rods and the second magnetic rods are made of neodymium iron boron or ferrite.

[0010] In some embodiments, the encoder comprises an encoder shell, and a leaf spring is connected to the encoder shell, and the encoder is connected to the encoder end cover through the leaf spring.

[0011] In some embodiments, the motor rear end cover is provided with a stop structure on the side thereof facing the encoder end cover, and the encoder end cover is positioned and connected to the motor rear end cover through the stop structure.

[0012] The application also provides a machining device comprising the motor.

[0013] The motor and the machining device provided by the application have the following advantages: on the one hand, the connection of the encoder to the encoder end cover can directly conduct the heat generated by the encoder to the encoder end cover and then to the external environment through the encoder end cover; on the other hand, the non-contact connection between the encoder and the motor shaft through the magnetic coupling assembly can effectively prevent the heat of the motor stator, the motor rotor and the motor shaft from being directly conducted to the encoder to cause the temperature rise of the encoder, so that the encoder only partially bears the heat radiation and the heat dissipation performance of the encoder is effectively ensured; and on the other hand, the installation reference of the encoder is improved from the end face of the motor shaft to the encoder end cover, so that the assembly accumulation error is reduced and the installation precision of the encoder is improved, which can also improve the signal precision of the encoder. BRIEF DESCRIPTION OF DRAWINGS

[0014] Figure 1 Fig. 2 is a schematic view of an internal structure of an embodiment of the motor according to the present application;

[0015] Figure 2 Fig. 3 is a schematic view of a perspective structure of a magnetic coupling assembly in Fig. 2. Figure 1

[0016] The reference signs are as follows:

[0017] 101, motor rear end cover; 102, motor rotating shaft; 103, motor rotor; 104, motor stator; 105, motor housing; 106, bearing; 107, brake; 108, front end cover; 201, encoder end cover; 300, encoder; 301, leaf spring; 41, first connecting member; 411, first magnetic rod; 412, first connecting disc; 413, first connecting shaft; 42, second connecting member; 421, second magnetic rod. DETAILED DESCRIPTION

[0018] With reference to Fig. 1, Figures 1 to 2 According to the embodiment of the present application, a motor, especially a servo motor, is provided, which comprises a motor rear end cover 101 and an encoder end cover 201 connected to the motor rear end cover 101. An encoder installation space is formed between the encoder end cover 201 and the motor rear end cover 101. The encoder end cover 201 is connected with an encoder 300 on the side facing the motor rear end cover 101. The encoder 300 is non-contact connected with the motor rotating shaft 102 near the end of the motor rear end cover 101 through a magnetic coupling assembly. In this technical solution, on the one hand, the connection of the encoder 300 and the encoder end cover 201 can directly conduct the heat generated by the encoder 300 to the encoder end cover 201 and then to the external environment through the encoder end cover 201. On the other hand, the non-contact connection between the encoder 300 and the motor rotating shaft 102 through the magnetic coupling assembly effectively prevents the heat of the motor stator 104, the motor rotor 103 and the motor rotating shaft 102 from being directly conducted to the encoder 300, which causes the temperature rise of the encoder 300. The encoder 300 only partially bears the heat radiation, which reduces the heat transfer to the encoder 300 and effectively guarantees the heat dissipation performance of the encoder 300. On the other hand, the installation reference of the encoder 300 is improved from the end face of the motor rotating shaft 102 to the encoder end cover 201, which reduces the assembly accumulation error and further improves the installation accuracy of the encoder 300. This can also improve the encoder signal accuracy.

[0019] ​In some embodiments, the magnetic coupling assembly comprises a first connecting piece 41 fixedly connected with the code disc of the encoder 300, a second connecting piece 42 fixedly connected with one end of the motor rotating shaft 102, at least two first magnetic rods 411 connected on the first connecting piece 41, and at least two second magnetic rods 421 connected on the second connecting piece 42. The first magnetic rods 411 and the second magnetic rods 421 are staggered and overlapped in the circumferential direction of the motor rotating shaft 102, and the magnetic properties of at least the first magnetic rods 411 and the second magnetic rods 421 at the staggered and overlapped positions are the same. In this technical solution, the first connecting piece 41 and the second connecting piece 42 can be made to rotate synchronously by the staggered and overlapped magnetic rods in the circumferential direction of the motor rotating shaft 102, and the non-contact between the first connecting piece 41 and the second connecting piece 42 can be achieved, which can ensure the signal accuracy of the encoder 300 and completely eliminate the direct heat conduction caused by contact. More importantly, this kind of staggered and overlapped magnetic rod arrangement does not need to consider the spacing and magnetic force size limitation of two same-polarity magnetic rods, and with the relative rotation of the two, the spacing between the two can be adjusted to be sufficient to keep the two rotating synchronously and not contacting, regardless of the size of the magnetic force.

[0020] Specifically, the first connecting piece 41 has a first connecting disc 412, and the at least two first magnetic rods 411 are uniformly and spacedly connected to the first connecting disc 412 in the circumferential direction of the first connecting disc 412. The second connecting piece 42 has a second connecting disc, and the at least two second magnetic rods 421 are uniformly and spacedly connected to the second connecting disc in the circumferential direction of the second connecting disc. The setting pitch circle radii of the first magnetic rods 411 and the second magnetic rods 421 are equal, and the number of the first magnetic rods 411 and the second magnetic rods 421 is equal, which can realize the synchronism of the two connecting pieces during rotation.

[0021] In some embodiments, the side of the first connecting disc facing the second connecting disc has at least two first mounting holes, and one end of each first magnetic rod 411 is correspondingly and one-to-one fitted or bonded in each first mounting hole. The side of the second connecting disc facing the first connecting disc has at least two second mounting holes (not shown in the figure), and one end of each second magnetic rod 421 is correspondingly and one-to-one fitted or bonded in each second mounting hole. The aforementioned interference fit connection can be cold pressing connection, and when the magnetic rods are made of heat-resistant magnetic material, it can also be hot pressing connection. By embedding the corresponding magnetic rods in the corresponding mounting holes, the reliability of the connection can be ensured.

[0022] In some embodiments, the first connecting piece 41 and the second connecting piece 42 are made of non-magnetic metal materials such as stainless steel, so as to avoid the interference of the aforementioned first magnetic rods 411 and second magnetic rods 421 with the motor stator 104 and the motor rotor 103 and the encoder 300. The first magnetic rods 411 and the second magnetic rods 421 are made of neodymium iron boron or ferrite.

[0023] In some embodiments, the encoder 300 comprises an encoder shell, a leaf spring 301 is connected to the encoder shell, the encoder 300 is connected with the encoder end cover 201 through the leaf spring 301, the leaf spring 301 can be made of metal materials such as aluminum and copper, and the encoder 300 is reliably fixed through the leaf spring 301, which has a certain displacement compensation capability and can reduce the vibration of the encoder 300.

[0024] The motor rear end cover 101 is configured with a stop structure on the side surface facing the encoder end cover 201, and the encoder end cover 201 is positioned and connected with the motor rear end cover 101 through the stop structure, facilitating the assembly of the encoder end cover 201. It can be understood that the cross-sectional shape of the first magnetic rod 411 and the second magnetic rod 421 can be circular (i.e. cylindrical magnetic rod), rectangular, etc., which is not particularly limited in the present application.

[0025] The technical scheme of the present application converts the original leaf spring mounting hole of the encoder 300 from the motor rear end cover 101 to the encoder end cover 201, and the leaf spring 301 is connected with the encoder 300 and the encoder end cover 201 through screws, so that the rear cover of the encoder 300 (i.e. part of the shell) is attached to the encoder end cover 201. This way can reduce the heat generated by the motor stator 104, bearing 106 (rear bearing) and brake 107 (specifically its coil) during the operation of the motor, which is conducted from the motor rear end cover 101 to the leaf spring 301 and then to the inside of the encoder 300, effectively reducing the heating of the encoder 300. At the same time, the rear cover of the encoder 300 attached to the encoder end cover 201 can effectively improve the heat dissipation of the encoder itself, effectively conduct the heat generated by the chip inside the encoder 300 to the encoder end cover 201 and then dissipate to the air. By changing the installation reference of the leaf spring 301, the leaf spring is prevented from being significantly stretched or bent due to the assembly error of the motor stator 104 and the motor rotor 103 during the installation process of the encoder 300, thereby affecting the accuracy of the encoder signal and the service life of the leaf spring.

[0026] The assembly sequence of the motor related components of the present application is described as follows:

[0027] The plate spring 301 is connected with the encoder 300 by screws, the first connecting piece 41 is matched with the corresponding first magnetic bar 411 by cold pressing or gluing connection, then the first connecting shaft 413 of the first connecting piece 41 is assembled with the encoder 300 (the code disc inside) by screws; the assembly is locked on the encoder end cover by screws to form the encoder assembly. The second connecting piece 42, the second magnetic bar 421, and the second connecting piece 42 are connected with the motor rotating shaft 102 by the same assembly method, then the encoder end cover 201 is assembled with the motor rear end cover 101 by the stop structure, and the whole assembly is completed by screw locking. During the driving motor rotation, the motor rotating shaft 102 rotates, drives the second connecting piece 42 at the end of the rotating shaft to rotate, and the code disc inside the encoder 300 also rotates correspondingly by the principle of same polarity repulsion, so that the encoder 300 can record the motor rotation speed, position and other related information. The magnetic coupling assembly changes the heat transfer mode of the motor stator, front and rear bearings and the brake to the encoder body during the motor operation from the original contact conduction heat dissipation of the motor rotating shaft and the rear end cover to heat radiation transmission, greatly reduces the heating of the encoder chip, and is beneficial to the long-term stable work of the encoder.

[0028] According to the embodiments of the present application, a machining device is also provided, which comprises the above motor and the machining device such as a lathe, a machine tool and the like.

[0029] It is easy for those skilled in the art to understand that the above advantageous modes can be freely combined and superimposed without conflict.

[0030] The above is only the preferred embodiment of the present application, and is not used to limit the present application. Any modification, equivalent replacement and improvement within the spirit and principle of the present application should be included in the protection scope of the present application. The above is only the preferred embodiment of the present application, and it should be pointed out that, for ordinary skilled in the art, without departing from the technical principles of the present application, a number of improvements and modifications can be made, and these improvements and modifications should be regarded as the protection scope of the present application.

Claims

1. An electric machine characterized in that, The motor rear end cover (101) and the encoder end cover (201) connected to the motor rear end cover (101) form an encoder mounting space between them, and the encoder (300) is connected to one side of the encoder end cover (201) facing the motor rear end cover (101), and the encoder (300) is non-contact connected with one end of the motor shaft (102) close to the motor rear end cover (101) through a magnetic coupling assembly; the magnetic coupling assembly includes a first connecting piece (41) fixedly connected with a code disc of the encoder (300), and a second connecting piece (42) fixedly connected with the one end of the motor shaft (102), at least two first magnetic rods (411) are connected on the first connecting piece (41), and at least two second magnetic rods (421) are connected on the second connecting piece (42), the first magnetic rods (411) and the second magnetic rods (421) are staggered and overlapped in the circumferential direction of the motor shaft (102), and the magnetic properties of at least the first magnetic rods (411) and the second magnetic rods (421) at the staggered and overlapped positions are the same.

2. The electric machine of claim 1, wherein, The first connecting piece (41) has a first connecting disc (412), and the at least two first magnetic rods (411) are uniformly spaced and connected on the first connecting disc (412) in the circumferential direction of the first connecting disc (412); the second connecting piece (42) has a second connecting disc, and the at least two second magnetic rods (421) are uniformly spaced and connected on the second connecting disc in the circumferential direction of the second connecting disc; the setting pitch circle radii of the first magnetic rods (411) and the second magnetic rods (421) are equal, and the number of the first magnetic rods (411) and the second magnetic rods (421) is equal.

3. The electric machine of claim 2, wherein, At least two first mounting holes are formed on one side of the first connecting disc facing the second connecting disc, and one end of each of the first magnetic rods (411) is connected or bonded in each of the first mounting holes in a one-to-one correspondence by interference fit; and / or, at least two second mounting holes are formed on one side of the second connecting disc facing the first connecting disc, and one end of each of the second magnetic rods (421) is connected or bonded in each of the second mounting holes in a one-to-one correspondence by interference fit.

4. The electric machine of claim 1, wherein, The material of the first connecting piece (41) and the second connecting piece (42) is a non-magnetic metal material.

5. The electric machine of claim 1, wherein, The first magnetic rods (411) and the second magnetic rods (421) are made of neodymium iron boron or ferrite.

6. The electric machine of claim 1, wherein, The encoder (300) includes an encoder shell, and a leaf spring (301) is connected to the encoder shell, and the encoder (300) is connected to the encoder end cover (201) through the leaf spring (301).

7. The electric machine of claim 1, wherein, The motor rear end cover (101) is provided with a stop structure on the side surface facing the encoder end cover (201), and the encoder end cover (201) is positioned and connected to the motor rear end cover (101) through the stop structure.

8. A machine tool, characterized by The motor includes any one of claims 1-7.

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