Hollow dual-encoder joint motor

Abstract

The application relates to the technical field of electric machines, and particularly discloses a hollow double-encoder joint motor, which comprises a shell, an electric machine, a speed reducer and a driving module and the like. The shell is fixed with an electric machine stator, a speed reducer and a driving module. The rotor of the electric machine is fixedly connected with the input shaft of the speed reducer. The driving module comprises a driving plate, a magnetic encoder, a circular magnet, an annular magnet and a double-Hall encoder plate. The rotor of the electric machine is connected with the circular magnet through a gear set, and the axis of the circular magnet is opposite to the center point of the magnetic encoder of the driving module. The output shaft of the speed reducer is fixedly connected with the annular magnet. The double-Hall encoder plate is provided with two Hall sensors which are distributed on the circumference and opposite to the annular magnet. The rotor of the electric machine is a hollow shaft, the output shaft of the speed reducer is a hollow shaft, and the driving module is a hollow structure. The hollow double-encoder joint motor can realize accurate angle detection at low cost through the magnetic encoder, the Hall sensor and the like.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a hollow dual encoder joint motor. Background Technology

[0002] With the rapid development of industrial robots, collaborative robots, and precision automation equipment, the joint drive unit, as a core actuator, faces increasingly higher requirements in terms of structural compactness, angle detection accuracy, cable management convenience, and cost-effectiveness. Currently, the mainstream technical solution for robot joint drive systems has formed a basic architecture of "motor + reducer + encoder" to achieve power transmission and precise positioning control.

[0003] The existing technology has the following drawbacks: Insufficient cable-passing capability and low reliability: Existing joint motors cannot pass cables, or only achieve hollowing of a single component such as the motor / reducer, without forming an overall through-hole hollow channel, which cannot meet the requirements for synchronous cable, air pipe and other media to pass through; external cable layout is easily affected by friction and entanglement, resulting in a high cable breakage rate, reducing the reliability of equipment operation, and limiting the movement flexibility and range of motion of robot joints.

[0004] The angle detection accuracy and zero-point positioning issues are prominent: the single encoder solution relies on the transmission ratio to calculate the output angle, and the detection accuracy is greatly affected by the reducer error, and the mechanical zero point is easily lost when the power is off; in the dual encoder solution, the high-precision optical encoder is too expensive and is not suitable for low-cost scenarios, while the low-cost Hall encoder solution is prone to detection deviation due to the unstable fixing of the ring magnet and insufficient bearing limit accuracy, and cannot balance accuracy and economy.

[0005] Poor ease of assembly and maintenance: The ring magnet is fixed by mechanical connection methods such as screws. Disassembly and assembly require the removal of multiple related parts, resulting in low assembly efficiency and high maintenance costs. Summary of the Invention

[0006] The present invention aims to solve the above-mentioned problems. To this end, the present invention provides a hollow dual encoder joint motor.

[0007] This invention provides a hollow dual-encoder joint motor, the technical solution of which is as follows: It includes a housing, a motor, a reducer, and a drive module. The stator of the motor, the reducer, and the drive module are fixed on the housing. The stator of the motor is fixedly connected to the input shaft of the reducer. The drive module includes a drive board, a magnetic encoder, a circular magnet, an annular magnet, and a dual Hall encoder board. The rotor of the motor is connected to the circular magnet via a gear set. The axis of the circular magnet is aligned with the center point of the magnetic encoder. The output shaft of the reducer is fixedly connected to the annular magnet. The dual Hall encoder board has two Hall sensors distributed circumferentially and aligned with the annular magnet. The rotor of the motor is a hollow shaft, the output shaft of the reducer is a hollow shaft, the drive module has a hollow structure, and the magnetic encoder is fixed on the drive board.

[0008] Furthermore, the gear set includes gear A and gear B that mesh with each other. Gear A is fixedly connected to the rotor of the motor and is coaxial with the rotor of the motor. Gear B is fixedly connected to the circular magnet and is coaxial with the circular magnet.

[0009] Furthermore, the tooth ratio of gear A and gear B is 1:1.

[0010] Furthermore, the two Hall sensors are arranged at 90° around the circumference.

[0011] Furthermore, the formula for calculating the rotation angle of the annular magnet detected by the dual Hall encoder board is as follows: in, The angle of rotation of the ring magnet. A The amplitude of a leading-phase sine wave signal. B The amplitude of a phase-lagging sinusoidal signal. The value of the leading sine wave signal. b This represents the value of a sinusoidal signal with phase lag.

[0012] Furthermore, the reducer output shaft serves as the joint output end, and the formula for calculating the angle of the joint output end is as follows: in, For the joint output angle, This is the rotation angle of the ring magnet read at the mechanical zero point. The rotation angle of the ring magnet was read at the moment of power-on. This refers to the rotation angle of the motor during operation. This refers to the reduction ratio of the speed reducer.

[0013] The above-described one or more technical solutions in the embodiments of the present invention have at least one of the following technical effects: 1. The present invention forms an all-round hollow structure, which facilitates the installation and management of wires: the motor rotor, reducer output shaft, drive module and rear cover are all provided with through holes and form an overall hollow channel, allowing wires to be installed, realizing the hidden arrangement of robot cables, reducing the risk of wear caused by exposed cables, and improving the overall structural neatness and operational reliability of the robot.

[0014] 2. This invention achieves a low-cost, precise detection solution using dual encoders: Through a dual detection structure of a magnetic encoder and a Hall sensor, the magnetic encoder can detect the motor rotation angle in real time, providing precise signals for motor servo control; the Hall sensor is specifically designed to detect the angle of the reducer output shaft, accurately identifying the mechanical zero point of the joint motor output each time it is powered on, avoiding the problem of zero point loss; and the combination of magnetic encoder and Hall sensor is more cost-effective than high-precision optical encoder solutions, balancing accuracy and economy.

[0015] 3. This invention ensures the synchronization and accuracy of angle detection and transmission: the gear set adopts a 1:1 reduction ratio and is coaxial with the motor rotor and the circular magnet respectively, which can ensure that the circular magnet rotates synchronously with the motor rotor, enabling the magnetic encoder to accurately capture the real-time angle of the motor and provide reliable data support for servo control.

[0016] 4. This invention optimizes structural positioning and stability, and improves detection accuracy: The reducer output shaft is fixedly connected to the ring magnet, reducing the coaxiality deviation and shaking when the ring magnet rotates, ensuring that the Hall sensor is always facing the ring magnet, avoiding detection errors caused by the offset of the ring magnet, and ensuring the accuracy of the Hall sensor in detecting the angle of the reducer output shaft.

[0017] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 This is a cross-sectional schematic diagram provided by the present invention.

[0020] Figure 2 This is a front view of the dual Hall encoder board provided by the present invention.

[0021] Figure 3 This is a front view of the driver board provided by the present invention.

[0022] Figure 4 This is a schematic diagram of the gear set provided by the present invention.

[0023] Figure 5 This invention provides <180° and < A schematic diagram showing the angle of rotation of the ring magnet relative to the zero position at the beginning of power-on.

[0024] Figure 6 This invention provides A schematic diagram showing the angle of rotation of the ring magnet relative to the zero position at the beginning of power-on.

[0025] Figure 7 This invention provides A schematic diagram showing the angle of rotation of the ring magnet relative to the zero position at the beginning of power-on.

[0026] Figure 8 This invention provides A schematic diagram showing the angle of rotation of the ring magnet relative to the zero position at the beginning of power-on.

[0027] Figure 9 This invention provides A schematic diagram showing the angle of rotation of the ring magnet relative to the zero position at the beginning of power-on.

[0028] Figure 10 This invention provides A schematic diagram showing the angle of rotation of the ring magnet relative to the zero position at the beginning of power-on.

[0029] Figure label: 1. Housing; 2. Stator; 3. Rotor; 4. Output shaft; 5. Drive module; 6. Ring magnet; 7. Magnetic encoder; 8. Drive board; 9. Circular magnet; 10. Dual Hall encoder board; 11. Hall sensor; 12. Gear A; 13. Gear B. Detailed Implementation

[0030] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The following embodiments are used to illustrate this invention but should not be used to limit the scope of this invention.

[0031] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0032] The following is combined Figures 1 to 10 The present invention will be further described in detail below, including a hollow dual encoder joint motor: In this embodiment, as Figures 1 to 4 As shown, a hollow dual encoder joint motor is provided, including: housing 1, motor, reducer and drive module 5.

[0033] The stator 2 of the motor, the reducer, and the drive module 5 are fixed on the housing 1. The stator 2 of the motor is fixedly connected to the input shaft of the reducer.

[0034] The drive module 5 includes a drive board 8, a magnetic encoder 7, a circular magnet 9, a ring magnet 6, and a dual Hall encoder board 10. For example... Figure 3 As shown, the magnetic encoder 7 is fixed to the drive board 8. The drive board 8 is connected to the motor via wires.

[0035] like Figure 4 As shown, the rotor 3 of the motor is connected to the circular magnet 9 via a gear set. The gear set includes meshing gears A12 and B13, with a tooth ratio of 1:1. Gear A12 is fixedly connected to the rotor 3 of the motor and is coaxial with it; gear B13 is fixedly connected to the circular magnet 9 and is coaxial with it. The circular magnet 9 is radially magnetized. The axis of the circular magnet 9 is aligned with the center point of the magnetic encoder 7. Gear A12 rotates synchronously with the motor rotor 3, driving gear B13 and the circular magnet 9 to rotate, and the magnetic encoder 7 detects the motor rotation angle. The drive module 5 is used for servo control of the motor.

[0036] The reducer output shaft 4 is fixedly connected to the annular magnet 6. The annular magnet 6 is radially magnetized, meaning its north and south poles are located on two opposite semicircles. Figure 2As shown, the dual Hall encoder board 10 is equipped with two Hall sensors 11 that are distributed at 90° on the circumference and face the annular magnet 6. The annular magnet 6 rotates synchronously with the reducer output shaft 4. The two Hall encoders detect the angle of the reducer output shaft 4 and are used to detect the angle position of the joint motor output end at the beginning of each power-on, so as not to lose its mechanical zero point.

[0037] The back cover (not shown in the figure) covers the drive module 5 and is fixedly connected to the housing 1 by screws. The drive module 5 is located in the cavity formed by the back cover and the housing 1.

[0038] The motor rotor 3 is a hollow shaft, the reducer output shaft 4 is a hollow shaft, the drive module 5 has a hollow structure, meaning the drive plate 8 and the dual Hall encoder plate 10 have through holes in their middle sections, and the rear cover is also a hollow structure, meaning the rear cover also has through holes in its middle section. The motor rotor 3, reducer output shaft 4, drive module 5, and rear cover all have through holes and form an integral hollow channel, allowing wires to pass through. In this embodiment, the motor is a hollow shaft motor, and the reducer is a hollow shaft reducer.

[0039] The driver board 8 is equipped with necessary supporting components such as a microcontroller and communication interface to realize motor servo control and to work with the magnetic encoder 7. The dual Hall encoder board 10 is equipped with necessary supporting components such as a microcontroller and communication interface to work with the dual Hall encoder board 10. The connection methods between the supporting components, as well as the connection methods between the supporting components and the motor, magnetic encoder 7, and dual Hall encoder board 10, are existing technologies and will not be described in detail here.

[0040] The principle of angle detection using a dual Hall effect sensor: Since the annular magnet 6 is radially magnetized, the magnetic field strength of its ring is sinusoidally distributed. Two Hall sensors detect the changing magnetic field during the rotation of the annular magnet 6 and output two sinusoidal voltage signals with a 90° phase difference. The dual Hall sensors transmit the two sinusoidal voltage signals to the microcontroller on the drive module 5 via wires.

[0041] Let the amplitude of the leading sinusoidal signal be A, and the amplitude of the lagging sinusoidal signal be B. At a certain moment, the rotation angle of the ring magnet is... The value of the leading sine wave signal is The value of the phase-lagging sinusoidal signal is b. Then... Seek value .

[0042] Running the above algorithm in the microcontroller on driver module 5 will yield the rotation angle of the ring magnet 6 at a given moment. To ensure that the rotation angle of the ring magnet 6 remains within 0-360 degrees, the above formula can be revised as follows: .

[0043] Joint output end angle calculation method: Let the angle at the output end of the joint be... Typically, the output angle range of an integrated joint is defined as -180°. <180°. The following describes a method for calculating the output angle of an integrated joint that combines the rotation angle of the ring magnet, the rotation angle of the motor, and the reduction ratio.

[0044] Let the reduction ratio of the reducer be... The rotation angle of the ring magnet read when setting the mechanical zero point is: , The rotation angle of the annular magnet used to indicate the mechanical zero point position of the joint output end is [value missing]. The rotation angle of the annular magnet read at the beginning of power-on is [value missing]. (Power on at a random location), the motor rotates at the following angle during operation: At the beginning of power-on =0°.

[0045] Joint output angle The calculation approach is as follows: First, calculate the angle of rotation of the ring magnet 6 relative to the zero position at the beginning of power-on. In addition, the angle corresponding to the motor rotation at the output end during operation The following is divided into... <180° and Introduction to two cases with a maximum angle of ≥180°.

[0046] when When <180°: when ,like Figure 5 As shown, at this time, the ring magnet 6 rotates clockwise by a certain angle relative to the zero point position. The angle is negative. .

[0047] when ,like Figure 6 As shown, at this time, the ring magnet 6 rotates counterclockwise by a certain angle relative to the zero point position. The angle is positive. .

[0048] when ,like Figure 7 As shown, at this time, the ring magnet 6 rotates clockwise by a certain angle relative to the zero point position. The angle is negative. .

[0049] when When ≥180°: when ,like Figure 8 As shown, at this time, the ring magnet 6 rotates counterclockwise by a certain angle relative to the zero point position. The angle is positive. .

[0050] when ,like Figure 9 As shown, at this time, the ring magnet 6 rotates clockwise by a certain angle relative to the zero point position. The angle is negative. .

[0051] when ,like Figure 10 As shown, at this time, the ring magnet 6 rotates counterclockwise by a certain angle relative to the zero point position. The angle is positive. .

[0052] During operation, the motor rotates at the angle corresponding to the output end. for .

[0053] In summary, the formula for calculating the joint output angle is: .

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A hollow dual-encoder joint motor, characterized in that, include: The device comprises a housing, a motor, a reducer, and a drive module. The housing houses the stator of the motor, the reducer, and the drive module. The rotor of the motor is fixedly connected to the input shaft of the reducer. The drive module includes a drive board, a magnetic encoder, a circular magnet, a ring magnet, and a dual Hall encoder board. The rotor of the motor is connected to the circular magnet via a gear set. The axis of the circular magnet is aligned with the center point of the magnetic encoder. The output shaft of the reducer is fixedly connected to the ring magnet. The dual Hall encoder board has two Hall sensors distributed circumferentially and aligned with the ring magnet. The rotor shaft of the motor is a hollow shaft, the output shaft of the reducer is a hollow shaft, the drive module has a hollow structure, and the magnetic encoder is fixed to the drive board. A magnetic encoder detects the rotation angle of the motor; the annular magnet rotates synchronously with the output shaft of the reducer, and a dual Hall encoder board detects the rotation angle of the annular magnet; the motor rotor, reducer output shaft, drive module, and rear cover are all provided with through holes and form an integral hollow channel, allowing wires to pass through; the motor is a hollow shaft motor, and the reducer is a hollow shaft reducer; The reducer output shaft serves as the joint output end, and the formula for calculating the angle of the joint output end is as follows: in, For the joint output angle, This is the rotation angle of the ring magnet read at the mechanical zero point. The rotation angle of the ring magnet was read at the moment of power-on. This refers to the rotation angle of the motor during operation. This refers to the reduction ratio of the speed reducer.

2. The hollow dual encoder joint motor as described in claim 1, characterized in that, The gear set includes gear A and gear B that mesh with each other. Gear A is fixedly connected to the rotor of the motor and is coaxial with the rotor of the motor. Gear B is fixedly connected to the circular magnet and is coaxial with the circular magnet.

3. A hollow dual encoder joint motor as described in claim 2, characterized in that, The ratio of the number of teeth of gear A to gear B is 1:

1.

4. A hollow dual encoder joint motor as described in claim 1, characterized in that, The two Hall sensors are arranged at 90° on the circumference.

5. A hollow dual encoder joint motor as described in claim 1, characterized in that, The formula for calculating the rotation angle of the annular magnet detected by the dual Hall encoder board is as follows: in, The angle of rotation of the ring magnet. A The amplitude of a leading-phase sine wave signal. B The amplitude of a sinusoidal signal with phase lag. The value of the leading-phase sine wave signal. b This represents the value of a sinusoidal signal with phase lag.

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