Motor rotor shaft and assembling device thereof

Abstract

The utility model discloses a motor rotor shaft and an assembling device thereof, and belongs to the technical field of unmanned aerial vehicle motors. The motor rotor shaft is applied to an unmanned aerial vehicle motor and comprises a shaft knurling section and a shaft matching section, the diameter of the shaft knurling section is larger than that of the shaft matching section, a tool withdrawal groove and a taper face are arranged at the connecting position between the shaft knurling section and the shaft matching section, and the motor rotor shaft is used for being assembled and connected with a shaft hole matching section on a rotor. According to the motor rotor shaft and the assembling device thereof provided by the embodiment of the invention, the swing abnormity of the rotor can be reduced, the abnormal scrapping is reduced, the cost is saved, and the production yield is improved.

Description

Technical Field

[0001] The present application belongs to the technical field of UAV motors, and in particular, relates to a motor rotor shaft and an assembly device thereof. Background Art

[0002] The rotor of the motor is a rotating part, and its stability determines the motor's yield rate. Among them, the assembly of the rotor shaft is one of the main factors that determine whether the rotor swings. The rotor shaft is generally divided into two sections, one is the shaft fitting section, and the other is the shaft knurling section. Generally, the shaft knurling section must resist torsion and must be pressed in through interference fit, so its diameter must be larger than the shaft fitting section. The difference in diameter between the two sections will cause a step at the connection. This step will cause the shaft hole fitting section to scratch during the shaft press-fitting process, resulting in abnormal deformation of the rotor shaft assembly. Utility Model Content

[0003] The present application provides a motor rotor shaft and an assembly device thereof, which are used to solve the above-mentioned technical problems, so as to reduce the rotor swing amplitude and improve the production yield rate.

[0004] In order to achieve the above application purpose, the technical solution adopted in this application is as follows:

[0005] A first aspect of an embodiment of the present application provides a motor rotor shaft, which is applied to a drone motor. The motor rotor shaft includes a shaft knurling section and a shaft mating section. The diameter of the shaft knurling section is larger than the diameter of the shaft mating section. A back cutter groove and a tapered surface are provided at the connection portion between the shaft knurling section and the shaft mating section. The motor rotor shaft is used to be assembled and connected with the shaft hole mating section on the rotor.

[0006] In some embodiments, the shaft knurling section is connected with the shaft hole matching section by interference fit, and the shaft matching section is connected with the shaft hole matching section by transition fit.

[0007] In some embodiments, the diameter of the motor rotor shaft is 3-20 mm.

[0008] In some embodiments, the shaft-hole fitting section is an aluminum part.

[0009] In some embodiments, the taper of the tapered surface is 20°.

[0010] A second aspect of the embodiment of the present application provides an assembly device for a motor rotor shaft as described in the first aspect, comprising:

[0011] A heating device is used to heat the shaft hole fitting section, the shaft hole fitting section and the shaft fitting section are transitionally fitted before heating, and the shaft hole fitting section and the shaft fitting section are clearance fitted after heating;

[0012] Auxiliary pressing tooling, the auxiliary pressing tooling is provided with a vertical shaft segment guide surface and a horizontal contact support surface, the shaft segment guide surface is used to guide the shaft matching segment, and the contact support surface is used to support the shaft press-fitting surface on the rotor;

[0013] A press is used to press the knurled section of the shaft into the matching section of the shaft hole.

[0014] In some embodiments, the heating device includes: a heating rod, a temperature sensor, a temperature feedback module and a temperature control module;

[0015] The temperature sensor is used to detect the temperature of the heating rod and transmit it to the temperature feedback module;

[0016] The temperature control module is used to control the temperature of the heating rod according to the temperature received by the temperature feedback module.

[0017] Compared with the prior art, the beneficial effects of the embodiments of the present application are:

[0018] A motor rotor shaft and its assembly device provided in an embodiment of the present application can reduce abnormal rotor swing, reduce abnormal scrapping, save costs, and improve production yield. Specifically, a back-cut groove and a tapered surface are provided at the connection portion between the shaft knurling section and the shaft mating section, which can alleviate the step difference between the shaft knurling section and the shaft mating section and effectively remove burrs. The tolerance of the rotor's shaft hole and the shaft mating section is designed to be a transition fit. Before assembling the shaft mating section, first heat the shaft hole mating section so that the shaft hole mating section is heated and expanded to a clearance fit, so that the shaft mating section can be smoothly installed into the rotor shaft hole and pressed to the back-cut groove. The auxiliary shaft pressing tool is installed on the shaft pressing surface of the rotor, and the shaft segment guide surface cooperates with the shaft mating section to position it, and finally it is completely pressed in by a press, and the tooling is removed to complete the shaft assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 A schematic diagram of the structure of a motor rotor shaft provided in an embodiment of the present application is shown;

[0021] Figure 2 A partial enlarged view of the motor rotor shaft provided in an embodiment of the present application is shown;

[0022] Figure 3 A schematic diagram of the structure of a rotor provided in an embodiment of the present application is shown;

[0023] Figure 4 A schematic diagram of the structure of the auxiliary pressing tooling provided in an embodiment of the present application is shown;

[0024] Figure 5 and Figure 6 A schematic diagram of auxiliary assembly of the auxiliary pressing tool provided in an embodiment of the present application is shown;

[0025] Figure 7 The figure shows a schematic diagram of the assembly of the motor rotor shaft and the rotor provided in the embodiment of the present application;

[0026] Figure 8 A schematic diagram of the structure of a heating device provided in an embodiment of the present application is shown;

[0027] Fig. 9 Another structural schematic diagram of the heating device provided in an embodiment of the present application is shown.

[0028] Illustration Description:

[0029] 11. shaft knurling section; 12. shaft matching section; 111. taper surface; 121. tool relief groove;

[0030] 21. rotor; 22. shaft hole matching section; 23. magnet; 24. rotor upper shaft press-fitting surface;

[0031] 31. Auxiliary pressing tooling; 32. Shaft segment guide surface; 33. Contact support surface;

[0032] 41. Heating rod; 42. Temperature sensor; 43. Temperature feedback module; 44. Temperature control module; 45. Switching power supply; 46. Air switch; 47. Protection board. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0034] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0035] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0036] The related art provides a motor rotor shaft, including a shaft knurling section and a shaft mating section, wherein a back-cut groove is provided at the connection portion between the shaft knurling section and the shaft mating section. Due to the inconsistency in the diameters of the shaft knurling section and the shaft mating section, the heights of the two sides of the back-cut groove are inconsistent, thereby forming a step with an inconsistent height difference with the bottom of the groove. As a result, the shaft hole mating section is scratched during the shaft press-fitting process, resulting in abnormal deformation of the rotor shaft assembly.

[0037] In view of this, an embodiment of the present application provides a motor rotor shaft and an assembly device and method thereof, which can solve the above-mentioned technical problems, reduce the rotor swing amplitude, and improve the production yield by optimizing the structure and assembly technology of the motor rotor shaft.

[0038] In order to illustrate the technical solution described in this application, a specific embodiment is provided below for illustration.

[0039] See also Figures 1 to 9 As shown, the embodiments of the present application provide a motor rotor shaft, an assembly device for a motor rotor shaft, and an assembly method based on the assembly device, which can be applied to drone motors.

[0040] The motor rotor shaft includes a shaft knurling section 11 and a shaft fitting section 12. The diameter of the shaft knurling section 11 is larger than the diameter of the shaft fitting section 12. The connection portion between the shaft knurling section 11 and the shaft fitting section 12 is provided with a backing groove 121 and a tapered surface 111. The motor rotor shaft is used to be assembled and connected with the shaft hole fitting section 22 on the rotor 21.

[0041] In some embodiments, the shaft knurling section 11 is connected to the shaft hole fitting section 22 by interference fit, and the shaft fitting section 12 is connected to the shaft hole fitting section 22 by transition fit.

[0042] In some embodiments, the diameter of the motor rotor shaft is 3-20 mm.

[0043] In some embodiments, the shaft hole fitting section 22 is an aluminum member.

[0044] In some embodiments, the taper of the tapered surface 111 is 20°. Optionally, the taper can be determined according to the length of the shaft fitting section 12 and the length of the shaft knurling section 11.

[0045] In some embodiments, the assembly device of the motor rotor shaft includes: a heating device, an auxiliary pressing tool 31, and a press.

[0046] The heating device is used to heat the shaft hole fitting section 22. Before heating, the shaft hole fitting section 22 and the shaft fitting section 12 are transitionally fitted. After heating, the shaft hole fitting section 22 and the shaft fitting section 12 are clearance fitted.

[0047] The auxiliary shaft pressing tool 31 is provided with a vertical shaft segment guiding surface 32 and a horizontal contact support surface 33 . The shaft segment guiding surface 32 is used to guide the shaft matching segment 12 , and the contact support surface 33 is used to support the shaft pressing surface 24 on the rotor.

[0048] The press is used to press the shaft knurling section 11 into the shaft hole matching section 22. Optionally, the press is a servo press.

[0049] In some embodiments, the expansion amount of the shaft hole fitting section 22 after heating is calculated as follows: S=D*a*(Kmax-Kmin)*10^-6.

[0050] Among them, S is the size after heating expansion, D is the size of the shaft hole, a is the linear expansion coefficient of the material, Kmax is the temperature after heating, and Kmin is the ambient temperature.

[0051] It should be noted that the rotor shaft hole tolerance is designed by this calculation formula so that the shaft hole matching section 22 can be installed into the shaft knurling section 11 after heating.

[0052] For example: shaft size 8+0.002^-0.003; shaft hole matching section 22 is aluminum, heated to 100℃, linear expansion coefficient a is 23.38, ambient temperature is 20℃, by calculation S=0.0149632. The tolerance of shaft hole matching section 22 is designed to meet the clearance fit after heating. Considering that there will be some heat loss during the heating to assembly process, that is, a certain clearance margin is given, the tolerance of shaft hole matching section 22 is designed to be 8.0^-0.01, which meets the minimum clearance after heating of 0.003. At this time, the heating assembly can meet the positioning accuracy requirements and a very small clearance.

[0053] In some embodiments, the heating device includes: a heating rod 41 , a temperature sensor 42 , a temperature feedback module 43 and a temperature control module 44 .

[0054] The temperature sensor 42 is used to detect the temperature of the heating rod 41 and transmit the temperature to the temperature feedback module 43 .

[0055] The temperature control module 44 is used to control the temperature of the heating rod 41 according to the temperature received by the temperature feedback module 43 .

[0056] Optionally, the heating device further includes: a switching power supply 45, an air switch 46 and a protection plate 47, wherein the switching power supply 45 is used to provide electrical energy, the air switch 46 is used for overvoltage and overcurrent protection, and the protection plate 47 is used to prevent contact burns.

[0057] In some embodiments, an assembly method implemented by an assembly device based on a motor rotor shaft includes:

[0058] S110, heating the shaft hole matching section 22 on the rotor 21 by using a heating device; wherein the magnet 23 on the rotor 21 is a neodymium iron boron magnet, the shaft hole matching section 22 is an aluminum part, the heating temperature is less than 120°C, the shaft hole matching section 22 and the shaft matching section 12 are transitionally matched before heating, and the shaft hole matching section 22 and the shaft matching section 12 are clearance matched after heating. The characteristic of the neodymium iron boron magnet is that the temperature resistance does not exceed 120°C.

[0059] S120, inserting the motor rotor shaft into the shaft hole matching section 22 under clearance fit until the position of the undercut groove 121;

[0060] S130, using the auxiliary pressing tool 31 to guide the shaft matching section 12 of the motor rotor shaft;

[0061] S140, using a servo press to press the shaft knurling section 11 into the shaft hole matching section 22 to complete the assembly. In this process, the conical surface 111 is used to guide the shaft knurling section 11.

[0062] It should be noted that in the field of UAV motor technology, since the diameter of the motor rotor shaft is small and the temperature resistance of the magnet 23 of the rotor 21 is usually not more than 120°C, aluminum with a larger thermal expansion coefficient is selected as the shaft hole matching section 22, the heating temperature is controlled to be less than 120°C, and the ambient temperature is a transition fit (shaft matching section 12 and shaft hole matching section 22), so as to achieve assembly, reduce the swing amplitude of the rotor 21, and improve the production yield rate.

[0063] In summary, the motor rotor shaft and its assembly device and method provided in the embodiments of the present application can reduce abnormal swing of the rotor 21, reduce abnormal scrapping, save costs, and improve production yield.

[0064] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A motor rotor shaft, It is characterized in that Applied to drone motors, the motor rotor shaft includes a shaft knurling section and a shaft fitting section, the diameter of the shaft knurling section is larger than the diameter of the shaft fitting section, a connection portion between the shaft knurling section and the shaft fitting section is provided with a back cut groove and a tapered surface, and the motor rotor shaft is used for assembly and connection with the shaft hole fitting section on the rotor.

2. The motor rotor shaft according to claim 1, It is characterized in that The shaft knurling section is connected to the shaft hole matching section by interference fit, and the shaft matching section is connected to the shaft hole matching section by transition fit.

3. The motor rotor shaft according to claim 1, It is characterized in that The diameter of the motor rotor shaft is 3-20 mm.

4. The motor rotor shaft according to claim 1, It is characterized in that The shaft hole matching section is an aluminum part.

5. The motor rotor shaft according to claim 1, It is characterized in that The taper of the tapered surface is 20°.

6. An assembly device for a motor rotor shaft according to any one of claims 1 to 5, It is characterized in that include: A heating device is used to heat the shaft hole fitting section, wherein the shaft hole fitting section and the shaft fitting section are transitionally fitted before heating, and the shaft hole fitting section and the shaft fitting section are clearance fitted after heating; An auxiliary shaft pressing tool, wherein the auxiliary shaft pressing tool is provided with a vertical shaft segment guiding surface and a horizontal contact support surface, wherein the shaft segment guiding surface is used to guide the shaft matching segment, and the contact support surface is used to support the shaft pressing surface on the rotor; A press is used to press the shaft knurling section into the shaft hole matching section.

7. The motor rotor shaft assembly device according to claim 6, It is characterized in that The heating device comprises: a heating rod, a temperature sensor, a temperature feedback module and a temperature control module; The temperature sensor is used to detect the temperature of the heating rod and transmit it to the temperature feedback module; The temperature control module is used to control the temperature of the heating rod according to the temperature received by the temperature feedback module.

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