Motor reducer integrated rotating device with axial magnetic field lightweight rotor

Abstract

The present invention discloses an integrated rotating device for a motor reducer with an axial magnetic field lightweight rotor, comprising an integrated drive unit, a support arm and a working arm, wherein the integrated drive unit is arranged in a rotating device formed by the movable connection between the support arm and the working arm. The rotor portion of the axial magnetic field motor of the present invention is completely embedded in the harmonic reducer, thereby greatly shortening the axial dimension of the rotating device; secondly, the rotor adopts a yokeless design, separating the rotor yoke into a stationary yoke, thereby greatly reducing the mechanical time constant of the rotating device; finally, the stationary yoke is fixed in a block embedded bracket, shortening the axial dimension of the stationary yoke, making it possible for the motor rotor to be completely embedded in the harmonic reducer. The space inside the casing of the present invention is compact, and the output torque per unit volume far exceeds that of conventional products.

Description

Technical Field

[0001] The invention belongs to the field of electric transmission, and in particular relates to a motor reducer integrated rotating device with an axial magnetic field lightweight rotor. Background Art

[0002] The motor-reducer integrated rotating device is widely used in the fields of humanoid robots, industrial robots, high-end equipment, etc. At present, the common technology is to integrate the conventional radial magnetic field servo motor with the reducer. The servo motor runs at high speed and inputs the high-speed and low-torque mechanical power into the reducer. The reducer plays the role of reducing the speed and increasing the torque. The disadvantage of the existing technology is that the axial length of the conventional motor and reducer integrated body is too long, which is not suitable for flat space applications, such as automobile wheels and flat platforms.

[0003] Axial magnetic field motors and harmonic reducers are structural forms with low length-to-diameter ratios (length-to-diameter ratios) in the field of motors and reducers. Harmonic reducers can provide a large reduction ratio in a flat space, so they are very suitable for integrated rotating devices used in flat spaces. However, the rotor part of a conventional axial magnetic field motor has a large inertia, of which the yoke of the rotor part occupies a large proportion, and as the diameter of the motor increases, this proportion increases rapidly. The excessive proportion of the yoke's rotational inertia causes a sharp increase in the axial magnetic field motor's rotor rotational inertia, so it cannot meet the requirements of fast start and stop and high dynamic response, and is therefore not suitable as a servo motor. Summary of the invention

[0004] The purpose of the present invention is to propose an integrated rotating device of a motor reducer with an axial magnetic field lightweight rotor to solve the two problems of the above-mentioned prior art.

[0005] The technical solution to achieve the purpose of the present invention is: an integrated rotating device of a motor reducer with an axial magnetic field lightweight rotor, comprising an integrated drive unit, a support arm and a working arm, wherein the integrated drive unit is arranged inside a rotating device formed by the active connection between the support arm and the working arm, wherein the integrated drive unit comprises an axial magnetic field motor without a flange end cover and a hollow harmonic reducer, wherein the axial magnetic field motor comprises a rotor part, a stator part, a transmission shaft and a bearing, wherein the rotor part of the axial magnetic field motor comprises a cavity extending into the hollow harmonic reducer, wherein the harmonic reducer comprises a steel wheel, a flexible wheel and a wave generator, wherein the wave generator is driven to rotate at a high speed by the transmission shaft, and the elliptical cam in the wave generator rotates in the flexible wheel to deform the flexible wheel, so that the gear teeth of the steel wheel and the flexible wheel continuously change their original working states in the four movements of meshing in, meshing out and disengaging, thereby generating staggered tooth movement, thereby realizing the motion transmission from the wave generator to the flexible wheel.

[0006] Preferably, the rotor part adopts a yoke separation structure, including a permanent magnet rotor and a stationary yoke, wherein the permanent magnet rotor includes a spoke-shaped fixed bracket and axially magnetized magnets, the magnets are embedded in the rotor bracket at equal intervals, and the magnetization directions of adjacent magnets are opposite. The rotor bracket is fixed to the motor transmission shaft and rotates at high speed with the motor transmission shaft. The stationary yoke includes a stationary yoke bracket and a yoke, wherein the yoke is embedded in the stationary yoke bracket, and the stationary yoke bracket is fixed in the inner cavity of the harmonic reducer.

[0007] Preferably, the stationary yoke bracket and the magnetic yoke are both made of magnetic conductive material.

[0008] Preferably, an air gap is left between the stationary yoke and the permanent magnet rotor.

[0009] Preferably, the interior of the flexible spline is a hollow cavity, which is used as the inner cavity of the harmonic reducer, the wave generator is located in the flexible spline, and the flexible spline is located in the steel wheel.

[0010] Preferably, the rotor part is connected to the transmission shaft, the stator part is connected to the casing, an air gap is provided between the rotor part and the stator part, and the bearing is provided on the transmission shaft.

[0011] Preferably, the stator part of the axial magnetic field motor includes a stator core and a winding, the winding is embedded in the stator slot on the side of the stator core facing the permanent magnet rotor, the stator core is fixed to the casing by being embedded in the groove in the casing, the casing is fixed to the casing of the harmonic reducer by screws, and the harmonic reducer casing is fixed to the steel wheel with screws and is in a stationary state.

[0012] Preferably, the outer diameter of the motor winding end is larger than the stator core.

[0013] Preferably, the axial magnetic field motor rotor is connected to the wave generator of the harmonic reducer through a transmission shaft through a key transmission, and rotates together at high speed.

[0014] Compared with the prior art, the present invention has the following significant advantages: the rotor of the axial magnetic field motor in the present invention is completely embedded in the harmonic reducer, thus greatly shortening the axial dimension of the rotating device; secondly, the rotor adopts a yokeless design, separating the rotor yoke into a stationary yoke, thus greatly reducing the mechanical time constant of the rotating device; finally, the stationary yoke is fixed by a block embedded bracket, shortening the axial dimension of the stationary yoke, making it possible for the motor rotor to be completely embedded in the harmonic reducer. The space inside the casing of the present invention is compact, and the output torque per unit volume far exceeds that of conventional products. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of the motor reducer integrated rotating device of the axial magnetic field lightweight rotor of the present invention.

[0016] Figure 2It is a schematic diagram of the structure of the axial magnetic field lightweight rotor motor of the present invention.

[0017] Figure 3 It is a schematic diagram of the rotor structure of the axial magnetic field lightweight rotor motor of the present invention.

[0018] Figure 4 It is a schematic diagram of the no-load magnetic field distribution of the axial magnetic field lightweight rotor motor of the present invention. DETAILED DESCRIPTION

[0019] The present invention will be further described below in conjunction with the accompanying drawings.

[0020] like Figure 1 As shown, an integrated rotating device for a motor reducer with an axial magnetic field lightweight rotor comprises an integrated drive unit (1), a support arm (3) and a working arm (4); the integrated drive unit (1) is arranged inside a rotating device formed by a movable connection between the support arm (3) and the working arm (4); the integrated drive unit (1) comprises an axial magnetic field motor without a flange end cover and a hollow harmonic reducer (2); the harmonic reducer (2) comprises a steel wheel (21), a flexible wheel (22) and a wave generator (23); the flexible wheel (22) has a cavity inside, which is used as the inner cavity of the harmonic reducer (2); the wave generator (23) is located inside the flexible wheel (22); and the flexible wheel (22) is located inside the steel wheel (21).

[0021] like Figure 2 As shown, in a further embodiment, the axial magnetic field motor comprises a rotor part, a stator part, a transmission shaft (16) and a bearing (17); the relative position relationship thereof is as follows: Figure 1 As shown, the rotor part is connected to the transmission shaft (16), the stator part is connected to the housing (11), and there is an air gap of 1 mm between the rotor part and the stator part. The composition and connection relationship of each part are described in detail below. The bearing (17) is arranged on the transmission shaft (16).

[0022] In a further embodiment, Figure 3The figure shows a schematic diagram of the rotor structure of the axial magnetic field lightweight rotor motor of the present invention, wherein the rotor part adopts a yoke separation structure, including a permanent magnet rotor (14) and a stationary yoke (15), wherein the permanent magnet rotor (14) includes a spoke-shaped fixed bracket (141) and axially magnetized magnetic steel (142), the magnetic steel (142) is embedded in the rotor bracket (141) at equal intervals, and the magnetization directions of adjacent magnetic steels (142) are opposite, and the rotor bracket (141) is fixed to the motor transmission shaft (16) and rotates at high speed with the motor transmission shaft (16). This structure makes the permanent magnet rotor (14) lightweight, that is, has a very small moment of inertia, thereby meeting the requirements of high dynamic response of the servo motor and greatly reducing the mechanical time constant of the rotating device. The permanent magnet rotor (14) and the stationary yoke (15) extend into the cavity of the harmonic reducer.

[0023] In a further embodiment, Figure 1 and Figure 2 As shown, the stationary yoke (15) is composed of a stationary yoke bracket (151) and a magnetic yoke (152), wherein the magnetic yoke (152) is embedded in the stationary yoke bracket (151), and the stationary yoke bracket (151) is fixed in the inner cavity of the harmonic reducer (2), that is, connected to the harmonic reducer flexible wheel (22) by means of tensioning, glue, etc., and rotates at a low speed together with the harmonic reducer flexible wheel (22). In this structure, the magnetic circuit of the rotor is divided, which means that the permanent magnet rotor (14) itself cannot form a closed magnetic circuit independently. Therefore, the stationary yoke (15) needs to be arranged close to the permanent magnet rotor (14) to close the magnetic circuit.

[0024] In a specific embodiment, the stationary yoke bracket (151) and the magnetic yoke (152) are both made of magnetic conductive materials. For example, the stationary yoke bracket (151) uses electrical pure iron, and the magnetic yoke (152) uses radially laminated silicon steel sheets. The inner and outer diameters of the magnetic yoke (152) are consistent with the magnetic steel (142), which can greatly reduce the eddy current loss of the stationary yoke (15). In addition, only a 1 mm air gap is left between the stationary yoke (15) and the permanent magnet rotor (14) to minimize the magnetic resistance of the closed magnetic circuit.

[0025] In a further embodiment, Figure 2 As shown, the stator part of the axial magnetic field motor comprises a stator core (12) and a winding (13), wherein the winding (13) is embedded in a stator slot on a side of the stator core (12) facing the permanent magnet rotor (14). Figure 1 As shown, the stator core (12) is fixed to the housing (11) by being embedded in a groove in the housing (11), and the housing (11) is fixed to the housing of the harmonic reducer (2) by screws. The housing of the harmonic reducer and the steel wheel (21) are fixed by screws and are in a stationary state; the outer diameter of the end of the motor winding (13) is larger than that of the stator core (12) and is located in the cavity of the motor housing (11).

[0026] In a further embodiment, in order to reduce the eddy current loss of the stator core (12), the stator core (12) is manufactured by winding silicon steel sheets around the axial direction of the motor.

[0027] In a further embodiment, the axial magnetic field motor rotor is connected to the wave generator (23) of the harmonic reducer via a transmission shaft (16) through a key transmission, and rotates together at high speed.

[0028] The wave generator (23) is driven to rotate at high speed by the transmission shaft (16), and the elliptical cam in the wave generator (23) rotates in the flexible wheel (22), causing the flexible wheel to deform, so that the gear teeth of the steel wheel (21) and the flexible wheel (22) continuously change their original working states in the four movements of meshing, meshing, meshing out and disengaging, thereby generating staggered tooth movement, thereby realizing the motion transmission from the wave generator (23) to the flexible wheel (22).

[0029] In a further embodiment, a schematic diagram of the no-load magnetic field distribution of the axial magnetic field lightweight rotor motor of the present invention is obtained by finite element analysis software, as shown in FIG. Figure 4 It can be observed that the magnetic flux density of the stator core (12) and the stationary yoke (15) is not obviously saturated when no-load, and the closed magnetic circuit formed can be intuitively seen from the magnetic flux density distribution.

[0030] The present invention controls the current of the motor winding (13) so that the permanent magnet rotor (14) generates torque, and the transmission shaft (16) drives the wave generator (23) of the harmonic reducer (2) to rotate at high speed, thereby causing the flexible wheel (22) to rotate at low speed, thereby transmitting power from the permanent magnet rotor (14) to the flexible wheel (22). The driving of the rotating device can be achieved by only fixing the housing (11) and the flexible wheel (22) to the support arm (3) and the working arm (4) respectively.

[0031] The present invention first combines an axial magnetic field motor with a harmonic reducer, embeds the motor rotor part into the cavity of the harmonic reducer, and shortens the axial size of the integrated unit;

[0032] Secondly, by separating the excitation part and the yoke part of the axial magnetic field motor rotor, the rotor's rotational inertia is greatly reduced, thereby meeting the high dynamic response requirements of the servo motor.

[0033] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention.

Claims

1. An integrated rotating device for a motor reducer with an axial magnetic field lightweight rotor, characterized in that: The invention comprises an integrated drive unit (1), a support arm (3) and a working arm (4), wherein the integrated drive unit (1) is arranged inside a rotating device formed by the movable connection between the support arm (3) and the working arm (4), wherein the integrated drive unit (1) comprises an axial magnetic field motor without a flange end cover and a hollow harmonic reducer (2), wherein the axial magnetic field motor comprises a rotor part, a stator part, a transmission shaft (16) and a bearing (17), wherein the rotor part of the axial magnetic field motor extends into a cavity of the hollow harmonic reducer (2), wherein the harmonic reducer (2) comprises a steel wheel (21), a flexible wheel (22) and a wave generator (23), wherein the wave generator (23) is driven to rotate at a high speed through the transmission shaft (16), wherein an elliptical cam in the wave generator (23) rotates in the flexible wheel (22) to deform the flexible wheel, thereby causing the gear teeth of the steel wheel (21) and the flexible wheel (22) to mesh, engage, mesh out and disengage. The four kinds of motion continuously change their original working states, generate staggered tooth motion, and realize motion transmission from the wave generator (23) to the flexible wheel (22). The rotor part adopts a yoke separation structure, including a permanent magnet rotor (14) and a stationary yoke (15), wherein the permanent magnet rotor (14) includes a spoke-shaped fixed bracket and axially magnetized magnetic steel (142), the magnetic steel (142) is embedded in the rotor bracket (141) at equal intervals, and the magnetization directions of adjacent magnetic steels (142) are opposite. The rotor bracket (141) is fixed to the motor transmission shaft (16) and rotates at high speed with the motor transmission shaft (16). The stationary yoke (15) includes a stationary yoke bracket (151) and a magnetic yoke (152), wherein the magnetic yoke (152) is embedded in the stationary yoke bracket (151), and the stationary yoke bracket (151) is fixed in the inner cavity of the harmonic reducer (2); an air gap is left between the stationary yoke (15) and the permanent magnet rotor (14).

2. The motor reducer integrated rotating device with axial magnetic field lightweight rotor according to claim 1 is characterized in that: The stationary yoke bracket (151) and the magnetic yoke (152) are both made of magnetic conductive material.

3. The motor reducer integrated rotating device with axial magnetic field lightweight rotor according to claim 1 is characterized in that: The interior of the flexible wheel (22) is a hollow cavity used as the inner cavity of the harmonic reducer (2); the wave generator (23) is located in the flexible wheel (22); and the flexible wheel (22) is located in the steel wheel (21).

4. The motor reducer integrated rotating device with axial magnetic field lightweight rotor according to claim 1, characterized in that: The rotor part is connected to the transmission shaft (16), the stator part is connected to the casing (11), an air gap is provided between the rotor part and the stator part, and the bearing (17) is arranged on the transmission shaft (16).

5. The motor reducer integrated rotating device with axial magnetic field lightweight rotor according to claim 1, characterized in that: The stator part of the axial magnetic field motor comprises a stator core (12) and a winding (13), wherein the winding (13) is embedded in a stator slot on a side of the stator core (12) facing the permanent magnet rotor (14), and the stator core (12) is fixed to the casing (11) by being embedded in a groove in the casing (11), and the casing (11) is fixed to the casing of the harmonic reducer (2) by screws, and the casing of the harmonic reducer is fixed to the steel wheel (21) by screws and is in a stationary state.

6. The motor reducer integrated rotating device with axial magnetic field lightweight rotor according to claim 1, characterized in that: The outer diameter of the end of the winding (13) is larger than that of the stator core (12).

7. The motor reducer integrated rotating device with axial magnetic field lightweight rotor according to claim 1, characterized in that: The axial magnetic field motor rotor is connected to the wave generator (23) of the harmonic reducer through a transmission shaft (16) through a key transmission, and rotates together at a high speed.

Images