Motor rotor assembly, motor, industrial robot

Abstract

The application provides a motor rotor assembly, a motor and an industrial robot. The motor rotor assembly comprises a rotating shaft and a first rotor core, the first rotor core is provided with a first magnetic steel, the rotating shaft is provided with a containing cavity, the motor rotor assembly further comprises a magnetic flux adjusting device, the magnetic flux adjusting device comprises a connecting sliding block connected with the first rotor core and an adjusting assembly in the containing cavity, and the adjusting assembly can drive the connecting sliding block to move so as to drive the first rotor core to move linearly and reciprocally along the axial direction of the rotating shaft. The adjusting assembly of the magnetic flux adjusting device is arranged in the containing cavity in the rotating shaft, so that the magnetic flux adjusting device can occupy as little motor space as possible, the motor structure is more compact, and the overall size of the motor can be smaller, which is especially suitable for the working condition that the motor installation space is limited.

Description

Technical Field

[0001] This invention belongs to the field of motor design technology, specifically relating to a motor rotor assembly, a motor, and an industrial robot. Background Technology

[0002] Servo motors are high-precision motors widely used in industrial automation, robotics, and precision positioning. Traditional servo motors have limited speed range at high speeds due to magnetic flux saturation and voltage limitations. Field weakening speed control of servo motors is mainly achieved by controlling the motor's magnetic field strength. Through field weakening control of the driver, the motor's speed range can be effectively widened, especially in the high-speed region, enabling the motor to operate stably over a wider speed range.

[0003] Currently, traditional servo motors typically have a fixed magnetic field strength. When magnetic field weakening is required, the servo driver usually applies a continuous magnetic field weakening current to weaken the air gap magnetic field. At this time, the permanent magnet is prone to irreversible demagnetization.

[0004] Patent CN115459476A discloses a permanent magnet synchronous motor and a field weakening speed control method. It uses four moving blocks to drive the stator core towards the center of the shaft hole, changing the air gap between the stator core and the permanent magnet, thus achieving speed regulation. Patent CN104811014A discloses a permanent magnet asynchronous speed control device. It uses a linear motion platform to allow the inner rotor to move axially relative to the permanent magnet in the outer rotor assembly. Speed ​​regulation is achieved by changing the axial magnetic flux area, or by ensuring complete coupling between the inner and outer rotor permanent magnets, thereby controlling the motor's speed. However, these prior art field weakening speed control methods have complex structures and occupy a large volume, making them unsuitable for smaller servo motors. Summary of the Invention

[0005] Therefore, the present invention provides a motor rotor assembly, a motor, and an industrial robot, which can overcome the technical problems of complex and bulky field-weakening speed regulation structures in related technologies, which are not conducive to the compact design of motor structures.

[0006] To address the aforementioned problems, the present invention provides a motor rotor assembly, including a rotating shaft and a first rotor core. The first rotor core has a first magnet. The rotating shaft has a receiving cavity. The motor rotor assembly further includes a magnetic flux adjustment device, which includes a connecting slider connected to the first rotor core and an adjustment component located in the receiving cavity. The adjustment component can drive the connecting slider to move so as to drive the first rotor core to reciprocate linearly along the axial direction of the rotating shaft.

[0007] In some embodiments, the first rotor core includes an inner core and an outer core fitted radially outward from the inner core. A first magnet is disposed on the outer peripheral wall of the outer core. The inner core is fixedly fitted onto the rotating shaft. The connecting slider is connected to the outer core to drive the outer core to reciprocate linearly along the axial direction of the rotating shaft.

[0008] In some embodiments, the accommodating cavity is a blind hole extending from the shaft extension end face to the non-shaft extension end face of the shaft. The adjusting assembly includes a threaded connecting rod and a slider mounting seat. The threaded connecting rod has a threaded head, a threaded shaft section, and a mating shaft section between the threaded head and the threaded shaft section. The slider mounting seat is fitted onto the mating shaft section with clearance. The threaded shaft section is threaded to the bottom wall of the blind hole, and the threaded engagement length is adjustable. The side wall of the blind hole has a through hole extending radially outward to the shaft. The connecting slider is fixedly connected to the slider mounting seat via the through hole, and the axial length of the through hole is greater than the axial length of the connecting slider.

[0009] In some embodiments, a connecting groove is formed on the outer circumferential wall of the slider mounting base, and the connecting slider is embedded in the connecting groove; and / or, the diameter of the mating shaft section is smaller than the diameter of the threaded shaft section so that the slider mounting base can be axially limited and fitted onto the mating shaft section.

[0010] In some embodiments, the inner core and the outer core each have an outer cylindrical surface and an inner cylindrical surface that are arranged opposite to each other. An axial protrusion is provided on one of the outer cylindrical surface and the inner cylindrical surface, and an axial groove is provided on the other. The axial protrusion and the axial groove are axially slidingly engaged.

[0011] In some embodiments, the axial protrusion is located on the inner cylindrical surface of the outer iron core; and / or, the axial protrusion and the axial groove are respectively provided with multiple sets of circumferentially evenly spaced around the rotating shaft.

[0012] In some embodiments, the axial groove includes a first axial groove, one axial end of which has a radial through hole. The radial through hole extends radially through the inner core to the area where the through hole is located. The axial protrusion that is slidably connected with the first axial groove is the first axial protrusion, and the first axial protrusion is fixedly connected to the connecting slider.

[0013] In some embodiments, the area corresponding to the position of the first axial protrusion and the through hole has an axial limiting boss, the axial limiting boss is located in the radial through hole, and the first axial protrusion is connected to the connecting slider via the axial limiting boss.

[0014] In some embodiments, the stack height of the inner core is greater than the stack height of the outer core.

[0015] In some embodiments, the motor rotor assembly further includes a second rotor core, which is fitted onto the shaft. A second magnet is provided on the outer peripheral wall of the second rotor core, and the second magnet and the first magnet form a skew pole on the axial projection of the shaft.

[0016] In some embodiments, the angle between the second magnet and the first magnet on the axial projection of the rotating shaft is 3°±0.2°; or, the first end face of the second rotor core is in contact with the first end face of the inner core of the first rotor core, and the total stack height of the second rotor core and the inner core is greater than the total stack height of the stator core of the motor stator that matches the motor rotor.

[0017] The present invention also provides an electric motor, including the above-described motor rotor assembly.

[0018] The present invention also provides an industrial robot, including a servo motor, wherein the servo motor is the motor described above.

[0019] The motor rotor assembly, motor, and industrial robot provided by this invention have the following beneficial effects:

[0020] The flux adjustment device has its adjustment components housed within a cavity inside the rotating shaft. This minimizes the space occupied by the device within the motor, resulting in a more compact motor structure and a smaller overall size, which is particularly suitable for applications with limited installation space. The flux adjustment device, through its adjustment components, drives the connecting slider to move, thereby causing the first rotor core to reciprocate linearly along the axial direction of the rotating shaft. This adjusts the axial relative position of the first magnet and the stator core, thus regulating the motor's magnetic field strength. This effectively widens the motor's speed range, achieving field weakening speed control, reducing back electromotive force, and enabling stable operation even at high speeds. This expanded speed range allows for more complex operating environments. Furthermore, field weakening control enables the motor to operate more efficiently under various conditions, especially at high speeds and high loads. It should be emphasized that the axial position of the first magnet on the first rotor core in this application can be adjusted, which can broaden the maximum speed of the corresponding motor from a physical structure perspective. Compared with the existing technology of electronic field weakening speed regulation through a controller, the mechanical field weakening speed regulation in this application can increase the maximum speed of the corresponding motor. Attached Figure Description

[0021] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. The drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the structure of the motor rotor assembly in an embodiment of the present invention;

[0023] Figure 2 yes Figure 1 A three-dimensional structural diagram of the first rotor core in the circuit;

[0024] Figure 3 yes Figure 1 A three-dimensional structural diagram of the first rotor core from another perspective;

[0025] Figure 4 yes Figure 2 A three-dimensional structural diagram of the inner iron core;

[0026] Figure 5 yes Figure 2 A three-dimensional structural diagram of the outer iron core;

[0027] Figure 6 yes Figure 1 A three-dimensional structural diagram of the assembled rotating shaft and magnetic flux adjustment device;

[0028] Figure 7 This is a three-dimensional structural diagram of the first rotor core and the shaft assembled in this invention;

[0029] Figure 8 This is a schematic diagram showing the connection state between the outer iron core and the connecting slider in this invention;

[0030] Figure 9 yes Figure 8 A schematic diagram of the structure after the pivot is hidden;

[0031] Figure 10 yes Figure 6 A front view of the magnetic flux adjustment device in the image;

[0032] Figure 11 yes Figure 10 The left view;

[0033] Figure 12 yes Figure 10 Longitudinal sectional view of the slider connector in the middle;

[0034] Figure 13 yes Figure 10 Side view of the threaded connecting rod in the middle;

[0035] Figure 14 yes Figure 1 Axial projection view of the motor rotor assembly in the image;

[0036] Figure 15 yes Figure 1 A schematic diagram of the structure of a lamination in the second rotor core;

[0037] Figure 16 yes Figure 1 A schematic diagram of another type of lamination in the second rotor core;

[0038] Figure 17 This is a schematic diagram of the internal structure of the motor according to an embodiment of the present invention.

[0039] The attached figures are labeled as follows:

[0040] 1. Rotating shaft; 11. Through hole; 2. First rotor core; 21. Inner core; 211. Axial groove; 2111. Radial through hole; 22. Outer core; 221. Axial protrusion; 2211. Axial limiting boss; 23. First magnet; 3. Magnetic flux adjustment device; 31. Connecting slider; 32. Threaded connecting rod; 321. Mating shaft section; 322. Threaded shaft section; 323. Thread head; 33. Slider mounting seat; 331. Connecting groove; 4. Second rotor core; 41. Second magnet; 42. Balance hole; 43. Balance putty; 5. Radial protrusion; 6. Magnetic circuit optimization hole; 100. Stator core; 101. Encoder. Detailed Implementation

[0041] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0042] In the description of this invention, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is generally based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this invention and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this invention; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0043] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90° or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0044] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0045] See Figures 1 to 17 As shown, according to an embodiment of the present invention, a motor rotor assembly is provided, including a rotating shaft 1 and a first rotor core 2 (specifically formed by stacking silicon steel sheets). The first rotor core 2 has a first magnet 23 (specifically a permanent magnet). The rotating shaft 1 has a receiving cavity (not shown in the figure, but indicated by reference). The motor rotor assembly also includes a magnetic flux adjustment device 3. The magnetic flux adjustment device 3 includes a connecting slider 31 connected to the first rotor core 2 and an adjustment component (not indicated in the figure) located in the receiving cavity. The adjustment component can drive the connecting slider 31 to move so as to drive the first rotor core 2 to reciprocate linearly along the axial direction of the rotating shaft 1.

[0046] In this technical solution, the adjustment component of the magnetic flux adjustment device 3 is housed within a cavity inside the rotating shaft 1. This allows the magnetic flux adjustment device 3 to occupy as little space as possible in the motor, resulting in a more compact motor structure and a smaller overall motor size. This is particularly suitable for applications where motor installation space is limited. It is understood that the magnetic flux adjustment device 3 of this invention drives the connecting slider 31 to move via its adjustment component, thereby causing the first rotor core 2 to reciprocate linearly along the axial direction of the rotating shaft 1. This adjusts the axial relative position of the first magnet 23 and the stator core 100, thereby regulating the magnetic field strength of the motor. This effectively widens the motor's speed range, achieving the purpose of field weakening speed regulation, reducing back electromotive force, and enabling the motor to operate stably at high speeds. This broadens the motor's speed range to cope with more complex operating environments. It is understood that through field weakening control, the motor can achieve more efficient operation under different operating conditions, especially under high speed and high load conditions. It should be emphasized that the axial position of the first magnet 23 on the first rotor core 2 in this application can be adjusted, which can broaden the maximum speed of the corresponding motor from a physical structure perspective. Compared with the existing technology of electronic field weakening speed regulation through a controller, the mechanical field weakening speed regulation in this application can increase the maximum speed of the corresponding motor.

[0047] In some embodiments, the first rotor core 2 includes an inner core 21 and an outer core 22 fitted radially outside the inner core 21. A first magnet 23 is disposed on the outer peripheral wall of the outer core 22. The inner core 21 is fixedly fitted (e.g., with an interference fit) onto the rotating shaft 1. The connecting slider 31 is connected to the outer core 22 so as to drive the outer core 22 to move linearly back and forth along the axial direction of the rotating shaft 1. It is understood that the aforementioned outer core 22 and inner core 21 should remain relatively stationary in their circumferential direction, that is, they rotate synchronously.

[0048] In this technical solution, the first rotor core 2 is designed as a combination structure consisting of an inner core 21 and an outer core 22 nested together. The relative axial position of the first magnet 23 and the stator core 100 can be adjusted by controlling the axial reciprocating linear motion of the outer core 22, which is equipped with the first magnet 23, relative to the inner core 21. The change in mass is smaller than the overall axial movement of the first rotor core 2, making it easier to adjust and control. At the same time, the load on the rotating shaft 1 does not change too much due to the adjustment of the axial position of the outer core 22.

[0049] In some embodiments, the accommodating cavity is a blind hole (not shown in the figure) extending from the shaft extension end face of the rotating shaft 1 to the non-shaft extension end face of the rotating shaft 1. The bottom position of the blind hole (i.e., the depth of the blind hole) should meet the adjustment requirements of the axial position of the first magnet 23. The adjustment assembly includes a threaded connecting rod 32 and a slider mounting seat 33. The threaded connecting rod 32 has a threaded head 323, a threaded shaft section 322, and a mating shaft section 321 located between the threaded head 323 and the threaded shaft section 322. The slider mounting seat 33 is fitted onto the mating shaft section 321 with clearance, that is, the slider mounting seat 33 is located between the bottom wall of the blind hole and the threaded head 323. The threaded shaft section 322 is threadedly connected to the bottom wall of the blind hole and threaded. The mating length is adjustable, meaning the length of the threaded hole on the bottom wall of the aforementioned blind hole should be large enough to ensure that the threaded shaft segment 322 and its threaded mating length can be adjusted within a required range. The side wall of the blind hole has a through hole 11 extending radially outward to the rotating shaft 1. The connecting slider 31 is fixedly connected to the slider mounting base 33 via the through hole 11, and the axial length of the through hole 11 (i.e., the length of the through hole 11 in the axial direction of the rotating shaft 1) is greater than the axial length of the connecting slider 31. It can be understood that the difference between the axial length of the aforementioned through hole 11 and the axial length of the connecting slider 31 is also the axial movement range of the connecting slider 31, which is also the linear movement range of the outer iron core 22 along the axial direction of the rotating shaft 1.

[0050] In this technical solution, the adjustment component includes a threaded connecting rod 32 and a slider mounting seat 33 fitted onto it with a clearance. The axial position of the slider mounting seat 33 is adjusted by changing the threaded engagement length between the threaded connecting rod 32 and the bottom wall of the blind hole, thereby adjusting the axial position of the connecting slider 31 and the outer iron core 22. The structure is very simple and does not occupy any external space of the motor, making it particularly compact. When mechanical field weakening speed regulation is required, only the aforementioned screw head 323 needs to be turned to change the threaded engagement length between the threaded connecting rod 32 and the rotating shaft 1, making operation simple and convenient.

[0051] In order to ensure the reliability of the connection between the connecting slider 31 and the slider mounting base 33, in some embodiments, a connecting groove 331 is formed on the outer circumferential wall of the slider mounting base 33, and the connecting slider 31 is embedded in the connecting groove 331. Specifically, the connection between the two can be achieved by interference fit and / or bonding.

[0052] The diameter of the mating shaft section 321 is smaller than the diameter of the threaded shaft section 233 so that the slider mounting base 33 can be axially limited and fitted onto the mating shaft section 321, ensuring the accuracy of the axial position adjustment of the connected slider 31. In this case, the aforementioned slider mounting base 33 can be a split structure that surrounds the aforementioned mating shaft section 321 to meet the assembly process requirements under the condition of diameter difference between the two. Specifically, the slider mounting base 33 is formed by assembling two semi-circular structures, and the two semi-circular structures can be reliably connected by methods such as bonding, welding, or bolting.

[0053] In some embodiments, the inner core 21 and the outer core 22 each have an outer cylindrical surface (not labeled) and an inner cylindrical surface (not labeled) arranged opposite to each other. An axial protrusion 221 is provided on one of the outer cylindrical surface and an axial groove 211 is provided on the other. The axial protrusion 221 and the axial groove 211 are axially slidingly engaged. In some embodiments, the axial protrusion 221 and the axial groove 211 are correspondingly provided with multiple sets of evenly spaced circumferentially spaced around the rotating shaft 1, for example... Figure 2 As shown, the aforementioned axial protrusions 221 and axial grooves 211 are respectively provided in four sets.

[0054] In this technical solution, the axial protrusion 221 and the axial groove 211 can slide together axially and limit the circumferential movement of the inner iron core 21 and the outer iron core 22 to prevent relative circumferential rotation between them.

[0055] In one specific embodiment, the axial protrusion 221 is located on the inner cylindrical surface of the outer iron core 22.

[0056] In some embodiments, the axial groove 211 includes a first axial groove (not indicated in the figure), one axial end of the first axial groove has a radial through hole 2111, the radial through hole 2111 extends radially along the inner iron core 21 to the area where the through hole 11 is located, the axial protrusion 221 that is slidably connected with the first axial groove is the first axial protrusion, the first axial protrusion is fixedly connected to the connecting slider 31, for example, the first axial protrusion is interference-fitted onto or bonded to the radial outer end face of the connecting slider 31.

[0057] In this technical solution, by setting a radial through hole 2111 at one end of the first axial groove, which is located in the area of ​​the through hole 11, the first axial protrusion can be fixedly connected to the connecting slider 31 through the through hole, which can reduce the axial length of the first rotor core 2 and help to increase the rotational speed of the shaft 1.

[0058] See also Figure 4 and Figure 5As shown, the area corresponding to the position of the first axial protrusion and the through hole 11 has an axial limiting boss 2211. The axial limiting boss 2211 is located within the radial through hole 2111, and the first axial protrusion is connected to the connecting slider 31 via the axial limiting boss 2211. Figure 5 As shown, the aforementioned axial limiting boss 2211 protrudes inward along the radial direction of the outer iron core 22. In one specific embodiment, two axial limiting bosses 2211 are provided, mirror-image of each other about the center line of the rotating shaft 1. Correspondingly, two radial through holes 2111 are also provided. It is understood that, in order to ensure the relative axial displacement of the outer iron core 22 and the inner iron core 21, the axial depth of the aforementioned radial through holes 2111 should match the axial displacement range of the outer iron core 22. The aforementioned connecting slider 31 should be made of a non-magnetic material (e.g., copper or aluminum).

[0059] In some embodiments, the stack height of the inner core 21 is greater than the stack height of the outer core 22 in order to reduce the eddy current loss of the first rotor core 2. It is understood that the portion where the stack height of the inner core 21 is greater than that of the outer core 22 is also the portion where the outer core 2 can move axially.

[0060] See details Figure 14 As shown, in some embodiments, the motor rotor assembly further includes a second rotor core 4, which is fitted onto the rotating shaft 1. A second magnet 41 is provided on the outer peripheral wall of the second rotor core 4. The second magnet 41 and the first magnet 23 form a skew pole on the axial projection of the rotating shaft 1. In a specific embodiment, the skew pole angle formed by the second magnet 41 and the first magnet 23 on the axial projection of the rotating shaft 1 is 3°±0.2°, so as to reduce the cogging torque of the servo motor.

[0061] The aforementioned first magnet 23 and second magnet 41 are specifically surface-mounted onto the corresponding outer circumferential wall of the iron core by adhesive bonding. In some specific embodiments, to ensure the reliability of the magnet connection, corresponding magnet slots are provided on the corresponding outer circumferential wall of the iron core. Taking the surface-mounting of the second magnet 41 on the outer circumferential wall of the second rotor iron core 4 as an example, see [link to relevant documentation]. Figure 15 Multiple radial protrusions 5 are provided on the outer circumferential wall of the second rotor core 4. The multiple radial protrusions 5 are evenly spaced around the rotating shaft 1 and extend along the axial direction of the rotating shaft 1 to both ends of the second rotor core 4. The aforementioned magnetic groove is formed between two adjacent radial protrusions 5, and the second magnet 41 is glued into each magnetic groove. The connection relationship and connection structure between the first magnet 23 and the outer core 22 are similar to the connection relationship and connection structure between the second rotor core 4 and the second magnet 41, and will not be described in detail here.

[0062] See also Figure 15 and Figure 16 As shown, the second rotor core 4 consists of multiple Figure 15 The first lamination and multiple laminations shown Figure 16 The second lamination shown is stacked together. Multiple magnetic circuit optimization holes 6 are provided on the first lamination and the second lamination respectively. The second lamination is different from the first lamination in that it also has multiple balance holes 42. The dynamic balance of the rotor assembly can be adjusted by filling the required balance holes 42 (such as the pentagon shown in the figure) with an appropriate mass of balance putty 43.

[0063] The first end face of the second rotor core 4 is in contact with the first end face of the inner core 21 of the first rotor core 2, and the total stack height of the second rotor core 4 and the inner core 21 is greater than the total stack height of the stator core 100 of the motor stator that matches the motor rotor. In order to increase the motor inertia, traditional servo motors add inertia disks before and after the rotor core. However, in this invention, the total stack height of the second rotor core 4 and the inner core 21 is greater than the total stack height of the stator core 100, which can achieve the purpose of increasing the motor inertia, eliminating the costly inertia disk, increasing power density, and reducing material usage.

[0064] In a preferred embodiment, the stack height of the outer iron core 22 is slightly greater than the axial length of the first magnet 23. For example, in a specific embodiment, the stack height of the outer iron core 22 is slightly greater than the axial length of the first magnet 23 by 0.4 mm, so as to prevent glue from overflowing onto the surface of the outer iron core 22 when the first magnet 23 is bonded in the corresponding magnet groove.

[0065] According to an embodiment of the present invention, an electric motor is also provided, including the above-described motor rotor assembly.

[0066] According to an embodiment of the present invention, an industrial robot is also provided, including a servo motor, wherein the servo motor is the motor described above.

[0067] It will be readily understood by those skilled in the art that, without conflict, the advantageous technical features of the above-mentioned methods can be freely combined and superimposed.

[0068] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention. The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the protection scope of the present invention.

Claims

1. A motor rotor assembly, characterized in that, The motor rotor assembly includes a rotating shaft (1) and a first rotor core (2), the first rotor core (2) having a first magnet (23), the rotating shaft (1) having a receiving cavity, and the motor rotor assembly also includes a magnetic flux adjustment device (3), the magnetic flux adjustment device (3) including a connecting slider (31) connected to the first rotor core (2) and an adjustment component located in the receiving cavity, the adjustment component being able to drive the connecting slider (31) to move so as to drive the first rotor core (2) to move linearly back and forth along the axial direction of the rotating shaft (1); The first rotor core (2) includes an inner core (21) and an outer core (22) fitted on the radially outer side of the inner core (21). A first magnet (23) is disposed on the outer peripheral wall of the outer core (22). The inner core (21) is fixedly fitted on the rotating shaft (1). The connecting slider (31) is connected to the outer core (22) so as to drive the outer core (22) to move linearly back and forth along the axial direction of the rotating shaft (1). The inner core (21) and the outer core (22) have an outer cylindrical surface and an inner cylindrical surface respectively arranged opposite to each other. An axial protrusion (221) is provided on one of the outer cylindrical surface and the inner cylindrical surface, and an axial groove (211) is provided on the other. The axial protrusion (221) and the axial groove (211) are axially slidingly engaged.

2. The motor rotor assembly according to claim 1, characterized in that, The accommodating cavity is a blind hole extending from the shaft extension end face of the rotating shaft (1) to the non-shaft extension end face of the rotating shaft (1). The adjusting assembly includes a threaded connecting rod (32) and a slider mounting seat (33). The threaded connecting rod (32) has a threaded head (323), a threaded shaft section (322), and a mating shaft section (321) between the threaded head (323) and the threaded shaft section (322). The slider mounting seat (33) is fitted onto the mating shaft section (321) with clearance. The threaded shaft section (322) is threaded to the bottom wall of the blind hole and the threaded mating length is adjustable. The side wall of the blind hole has a through hole (11) extending to the radially outer side of the rotating shaft (1). The connecting slider (31) is fixedly connected to the slider mounting seat (33) via the through hole (11), and the axial length of the through hole (11) is greater than the axial length of the connecting slider (31).

3. The motor rotor assembly according to claim 2, characterized in that, A connecting groove (331) is formed on the outer circumferential wall of the slider mounting base (33), and the connecting slider (31) is fitted into the connecting groove (331); and / or, the diameter of the mating shaft section (321) is smaller than the diameter of the threaded shaft section (322) so that the slider mounting base (33) can be axially limited and fitted onto the mating shaft section (321).

4. The motor rotor assembly according to claim 2, characterized in that, The axial protrusion (221) is located on the inner cylindrical surface of the outer iron core (22); and / or, the axial protrusion (221) and the axial groove (211) are respectively provided with multiple sets of circumferentially evenly spaced around the rotating shaft (1).

5. The motor rotor assembly according to claim 4, characterized in that, The axial groove (211) includes a first axial groove, one axial end of which has a radial through hole (2111). The radial through hole (2111) extends radially through the inner core (21) to the area where the through hole (11) is located. The axial protrusion (221) that is slidably connected with the first axial groove is the first axial protrusion. The first axial protrusion is fixedly connected to the connecting slider (31).

6. The motor rotor assembly according to claim 5, characterized in that, The area corresponding to the position of the first axial protrusion and the through hole (11) has an axial limiting boss (2211), the axial limiting boss (2211) is located in the radial through hole (2111), and the first axial protrusion is connected to the connecting slider (31) via the axial limiting boss (2211).

7. The motor rotor assembly according to claim 1, characterized in that, The stacking height of the inner iron core (21) is greater than the stacking height of the outer iron core (22).

8. The motor rotor assembly according to claim 1, characterized in that, It also includes a second rotor core (4), which is fitted onto the rotating shaft (1). A second magnet (41) is provided on the outer peripheral wall of the second rotor core (4). The second magnet (41) and the first magnet (23) form a slanted pole on the axial projection of the rotating shaft (1).

9. The motor rotor assembly according to claim 8, characterized in that, The angle between the second magnet (41) and the first magnet (23) on the axial projection of the rotating shaft (1) is 3°±0.2°; or, the first end face of the second rotor core (4) is in contact with the first end face of the inner core (21) of the first rotor core (2), and the total stack height of the second rotor core (4) and the inner core (21) is greater than the total stack height of the stator core (100) of the motor stator that matches the motor rotor.

10. An electric motor, characterized in that, Includes the motor rotor assembly according to any one of claims 1 to 9.

11. An industrial robot, comprising a servo motor, characterized in that, The servo motor is the motor described in claim 10.

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