Small high-integration deepwater motor with built-in magnetic encoder

Abstract

The invention discloses a small-sized high-integration deepwater motor with a built-in magnetic encoder, which is characterized in that a motor stator and rotor assembly is connected with a motor rotating shaft in a motor shell, a motor rear end cover is mounted on the motor shell through shape limiting, and an encoder static part is connected with the motor rear end cover; an encoder rotor of the magnetic encoder is installed on a motor rotating shaft in the axial direction, the inner diameter of the encoder rotor is in tolerance fit with the motor rotating shaft, a harmonic reducer is connected to the front side of a motor shell, a motor output shaft is connected to the harmonic reducer, a slender rotating shaft is connected with the motor output shaft, and an output shaft magnetic ring is fixed to one end of the slender rotating shaft. The thin and long rotating shaft penetrates through the hollow motor rotating shaft to transmit an output end signal to an output end Hall element of a motor controller center, the structure is simplified, the waterproof performance is improved by adopting multiple sealing, and high-precision control in a deep water environment is realized while the reliability is ensured.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater robot motors, and in particular to a small-sized highly integrated deep-water motor with a built-in magnetic encoder. Background Art

[0002] Nowadays, human ocean development activities, deep-water production and scientific research activities are increasing, and it is particularly important to provide power drive for many deep-water equipment. Due to its special application scenarios and size limitations, underwater detection robots require their motors to have a high degree of integration and to maintain high-performance operation in the harsh deep-sea environment. The traditional mechanical end face seals used in common waterproof motors are prone to aging under high-pressure and corrosive conditions in the deep sea, and the sealing effect and service life will be greatly weakened. In addition, most motors are equipped with two Hall sensors to control the angle data of the internal shaft and the output end respectively. Before using them under underwater conditions, the external Hall needs to be potted, which wastes the structural space and brings certain difficulties to later maintenance. Summary of the invention

[0003] In response to the above technical problems, the present invention provides a small highly integrated motor with a built-in magnetic encoder, which directly integrates traditional control circuits, encoders, Hall sensors and other components into the motor, streamlines the structure, and uses multiple seals to improve waterproof performance.

[0004] The technical solution adopted by the present invention is a small-sized highly integrated deep-water motor with a built-in magnetic encoder. The motor stator and rotor assembly are connected to the motor shaft in the motor housing, the rear end cover of the motor is installed with the motor housing through shape limiting, the encoder static part is connected with the rear end cover of the motor, and the encoder rotor of the magnetic encoder is installed on the motor shaft from the axial direction. The inner diameter of the encoder rotor is matched with the tolerance of the motor shaft. The harmonic reducer is connected to the front side of the motor housing, the motor output shaft is connected to the harmonic reducer, the slender shaft is connected to the motor output shaft, the output shaft magnetic ring is fixed to one end of the slender shaft, and the slender shaft passes through the hollow motor shaft to transmit the output end signal to the output end Hall element in the center of the motor controller. The motor as a whole is connected to the external power supply through a watertight connector.

[0005] Preferably, the magnetic encoder adopts an ultra-thin and compact hollow structure.

[0006] Preferably, the motor output shaft adopts two radial seals, and the motor housing and the end cover adopt axial seals.

[0007] Preferably, the rear end cover of the motor is lightweight. Compared with the prior art, the advantages and positive effects of the present invention are: 1. Optimizing the internal structure of the motor. Taking the stator and rotor assembly in the motor housing as the reference, the layout of important components such as the harmonic reducer, motor controller, and magnetic encoder is completed to improve the internal space utilization of the motor. The output signal is fed back to the Hall element of the controller via a slender shaft connected to the motor output shaft. There is no need to lead out an external Hall. The entire motor is connected to the external power supply through only a watertight cable, which improves the waterproof performance of the motor and greatly improves the integration. 2. Design multiple sealing structures. Two radial dynamic seals are used at the output end of the motor, and axial static seals are used between the motor housing and the front and rear end covers to improve the watertight performance of the motor. A strict waterproof test system is established to ensure that the motor has sufficient waterproof capabilities in practical applications. 3. Dynamic balancing and vibration reduction designs are introduced into small motors to reduce vibration and noise, and improve the reliability and service life of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a schematic diagram of the internal structure of the small-sized highly integrated deep-water motor of the present invention.

[0009] Figure 2 It is an enlarged schematic diagram of the magnetic encoder structure applied to the small-sized highly integrated deep-water motor of the present invention.

[0010] Figure 3 It is a schematic diagram of the overall structure of the small-sized highly integrated deep-water motor of the present invention.

[0011] Markings in the figure: 1. Motor housing; 2. Motor shaft; 3. Harmonic reducer; 4. Motor output shaft; 5. Motor front cover; 6. Radial dynamic seal; 7. Motor stator and rotor assembly; 8. Magnetic encoder; 9. Controller protection cover; 10. Output shaft magnetic ring; 11. Motor controller; 12. Output end Hall element; 13. Motor rear cover; 14. End face seal; 15. Slender shaft; 16. Watertight connector; 17. Encoder static part; 18. Encoder stator shield; 19. Encoder rotor; 20. Rotor magnetic ring; 21. Airtight test plug. DETAILED DESCRIPTION

[0012] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0013] In order to solve the above technical problems, the present invention provides a small, highly integrated deep-water motor with a built-in magnetic encoder. An ultra-thin absolute encoder is used to replace the more complex external Hall sensor structure. Multiple high-precision Hall sensors are integrated inside the encoder to measure the magnetic field changes of the rotor magnetic ring, which has certain advantages in application scenarios with high output accuracy requirements and tight space.

[0014] like Figures 1 to 3 As shown, the technical solution is as follows: the motor includes a motor housing 1, a motor front cover 5, a motor rear cover 13, a controller protection cover 9, a motor output shaft 4, etc., and the motor internally includes a motor stator and rotor assembly 7, a motor shaft 2, a slender shaft 15, a motor controller 11, a harmonic reducer 3, a magnetic encoder 8, a sealing ring, an output shaft magnetic ring 10, etc.; First, the motor stator and the motor housing 1, the rotor and the motor shaft 2 are respectively pressed and fixed. After the motor rear end cover 13 is installed, the static part of the magnetic encoder 8 is connected to it by screws. The rotor of the magnetic encoder 8 is installed on the motor shaft 2, the motor output shaft 4 is connected to the harmonic reducer 3, and the slender shaft 15 is connected to the motor output shaft 4 by threading, passing through the hollow motor shaft 2 to transmit the output end signal to the output end Hall element 12 located at the rear end controller of the motor. The required components are highly integrated in the small motor, and the motor housing 1 and the motor front end cover 5 and the motor output shaft 4 are sealed with standard O-rings, which can withstand the water pressure of 100 meters deep and achieve excellent waterproof and anti-corrosion effects. The airtight test plug 21 is connected to the controller protection cover 9 by its own screw, which is convenient for the overall sealing after the waterproof motor water pressure test. The magnetic encoder 8 is installed inside the motor. The magnetic encoder 8 selected by the motor adopts an ultra-thin and tight hollow structure, and uses magnetic shielding technology to provide higher measurement accuracy, directly obtain the parameters of the motor shaft 2, and ensure the high-precision output of the motor. The encoder stator shield 18 is welded to the encoder static part 17 and fixed to the motor rear end cover 13 by screws to keep it stationary. The encoder rotor 19 is installed on the motor shaft 2 in the axial direction and tightened by three top screws on the radial outside. The encoder stator shield 18 can shield the electromagnetic interference propagated in the motor, and the magnetic field strength of the rotor magnetic ring 20 is generally much higher than the external magnetic field. The combination of the two can stably resist external interference. Two radial seals are used at the output end of the motor, and axial seals are used between the motor housing 1 and the end cover. By designing two radial seals at the output shaft end, the O-ring and its corresponding sealing groove are selected with standard structural parameters and tolerances. During assembly, the O-ring and its corresponding sealing groove are evenly coated with sealing silicone grease, so that the sealing ring is not easily damaged when the motor shaft 2 rotates, which is convenient for installation and disassembly, making the motor dynamic seal more reliable.

[0015] An output shaft magnetic ring 10 is provided at one end of the slender shaft 15. The magnetic ring obtains the state of the output shaft and senses the Hall element 12 at the output end of the motor rear end controller center to achieve feedback and control. The motor rear end cover 13 is lightweight. The motor rear end cover 13 is embedded inside the motor to avoid contact with seawater, and an aluminum alloy material with a lower density is selected to reduce the total weight.

[0016] The advantages of the present invention are as follows: 1. Optimize the internal structure of the motor. Based on the stator and rotor assembly in the motor housing, the layout of important components such as the harmonic reducer, motor controller, and magnetic encoder is completed to improve the utilization rate of the internal space of the motor. The output signal is fed back to the Hall element of the controller via a slender shaft connected to the motor output shaft. There is no need to lead out an external Hall. The motor as a whole is only connected to the external power supply through a watertight cable, which improves the waterproof performance of the motor and greatly improves the integration. 2. Design multiple sealing structures. Two radial dynamic seals are used at the output end of the motor, and axial static seals are used between the motor housing and the front and rear end covers to improve the watertight performance of the motor. A strict waterproof test system is established to ensure that the motor has sufficient waterproof capabilities in practical applications. 3. Dynamic balancing and vibration reduction design are introduced into small motors. A certain length of simulated spring structure is added to the slender shaft to reduce the rigidity of the shaft and compensate for the movement of the bearing inside the motor. The weight of each part is calculated and reasonably distributed many times, which reduces vibration and noise and improves the reliability and service life of the motor.

[0017] The present invention designs a small highly integrated motor with a built-in magnetic encoder, and uses an ultra-thin absolute encoder to replace the more complex external Hall sensor structure. The encoder integrates multiple high-precision Hall sensors inside, and is driven by magnetoelectric technology to measure the magnetic field changes of the rotor magnetic ring. It has certain advantages in application scenarios with high output accuracy requirements and tight space. In addition, the structure also directly integrates traditional motor control circuits, encoders, Hall sensors and other components into the motor, streamlines the structure, and uses multiple seals to improve waterproof performance, achieving high-precision control in deep water environments while ensuring reliability.

[0018] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. A small, highly integrated deepwater motor with a built-in magnetic encoder, characterized in that: In a motor housing (1), a motor stator and rotor assembly (7) is connected to a motor shaft (2), a motor rear end cover (13) is mounted to the motor housing (1) by shape limiting, an encoder static part (17) is connected to the motor rear end cover (13), an encoder rotor (19) of a magnetic encoder (8) is mounted on the motor shaft (2) from an axial direction, an inner diameter of the encoder rotor (19) is tolerance matched with the motor shaft (2), a harmonic reducer (3) is connected to the front side of the motor housing (1), a motor output shaft (4) is connected to the harmonic reducer (3), a slender shaft (15) is connected to the motor output shaft (4), an output shaft magnetic ring (10) is fixed to one end of the slender shaft (15), the slender shaft (15) passes through the hollow motor shaft (2) to transmit an output end signal to an output end Hall element (12) at the center of a motor controller (11), and the motor as a whole is connected to an external power supply via a watertight connector (16).

2. A small-sized highly integrated deep-water motor with a built-in magnetic encoder according to claim 1, characterized in that: The magnetic encoder (8) adopts an ultra-thin and compact hollow structure.

3. The small-sized highly integrated deep-water motor with a built-in magnetic encoder according to claim 1 is characterized in that: The motor output shaft (4) adopts two radial seals, and the motor housing (1) and the end cover adopt an axial seal.

4. The small-sized highly integrated deep-water motor with a built-in magnetic encoder according to claim 1 is characterized in that: The rear end cover (13) of the motor is lightweight.

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