Underwater motor with pressure compensation function

Abstract

The invention discloses an underwater motor with a pressure compensation function, which comprises a stator, a driving end cover, a non-driving end cover, a rotor, a bearing, a rotary transformer, a watertight connector, a rotary dynamic seal, insulating oil and a flexible compensation assembly, and is characterized in that the flexible compensation assembly is arranged outside the non-driving end cover; the flexible compensation assembly is of a structural form composed of a spring, a rear cover and a flexible pipe, one end of the flexible pipe is connected with the non-driving end cover, the rear cover is connected with the non-driving end cover through the spring in the flexible pipe, the other end of the flexible pipe is plugged by the rear cover, a displacement sensor is installed on the rear cover, and an inner cavity of the whole motor is filled with insulating oil. The pressure compensation function is achieved through the flexible compensation assembly, connection with an independent pressure compensation device through a hydraulic pipe and a sensor signal cable is not needed additionally, and the complexity of the system is reduced.

Description

Technical Field

[0001] This invention belongs to the field of underwater motor technology, specifically relating to an underwater motor with pressure compensation function. Background Technology

[0002] Electric propulsion systems and deep-sea submersible pumps are important components of unmanned underwater equipment, and underwater motors are the driving components of these systems. Since the pressure in the underwater environment is directly proportional to the depth, motors operating underwater, especially in deep water, must solve the problems of sealing and pressure resistance.

[0003] Currently, underwater motors are generally sealed using two methods: potting and oil-filled compensation. The potting method involves encapsulating the coil windings with potting compound and then welding a shielding sleeve to the casing to seal the stator windings. The potting structure and the shielding sleeve jointly withstand the water pressure, while the motor rotor is immersed in seawater and supported by water-lubricated bearings. While the potting structure is simple and compact, its pressure-bearing capacity is limited; it faces the risk of structural failure under water pressure at depths of several hundred meters, making it unsuitable for deep-sea environments.

[0004] The oil-filled compensation method involves filling the motor with oil and maintaining the oil pressure at a level comparable to the external water pressure through a pressure compensation device. This greatly alleviates the pressure stress on the motor's sealing structure and, in principle, eliminates depth limitations. However, current oil-filled compensation underwater motors require an additional pressure compensator. The outer contour of the pressure compensator is difficult to design in accordance with the motor's shape, resulting in a significant waste of valuable internal space in underwater unmanned equipment. Hydraulic pipelines and other accessories also increase the system's complexity.

[0005] Chinese patent application number 200510045851.9, filed on February 5, 2005, discloses an underwater brushless DC oil-filled motor structure. It utilizes a spring and piston integrated at the tail end of the brushless DC motor to achieve pressure compensation. However, it still has the following drawbacks: The design uses a single spring to press the piston to maintain the oil pressure slightly higher than the external water pressure. However, when the radial dimension of the motor increases, the piston is prone to jamming, making it unsuitable for large motors. In addition, the spring is directly exposed to seawater, and there is a conflict between the strength, toughness, and corrosion resistance of the spring material, making it difficult to meet the requirements for long-term reliable operation of underwater motors. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the above-mentioned technologies and to propose an underwater motor with pressure compensation function, which has the characteristics of simple and compact structure and high reliability.

[0007] The technical solution adopted by this invention patent to solve its technical problem is: an underwater motor with pressure compensation function, including a stator, a rotor, a rotary transformer, a watertight connector, a rotary dynamic seal, and insulating oil. The stator is the overall frame structure of the underwater motor, which is in direct contact with seawater. It has coil windings on the inside and drive end caps and non-drive end caps installed at both ends. The rotary dynamic seal is installed on the drive end cap to realize the dynamic seal at the rotor shaft extension end of the motor. The rotor is driven to rotate by the magnetic field of the stator and is supported by two bearings at the drive end and the non-drive end. The watertight connector leads out the coil windings and sensor wires inside the motor and connects them to the controller through a watertight cable. A flexible compensation component is provided outside the non-drive end cover. The flexible compensation component is a structure composed of a spring, a rear cover, and a flexible tube. One end of the flexible tube is connected to the non-drive end cover, and the rear cover is connected to the non-drive end cover through the spring inside the flexible tube. The other end of the flexible tube is sealed by the rear cover. A displacement sensor is installed on the rear cover to measure the distance from the rear cover to the non-drive end cover. The remaining compensation capacity is calculated and used to indicate the motor's subsequent working capacity. The flexible compensation component is assembled with the stator as a whole through the non-drive end cover. The insulating oil fills the entire internal cavity of the motor. The pressure compensation function of the motor is realized by the volume change caused by the deformation of the flexible compensation component.

[0008] The underwater motor with pressure compensation function has a flexible tube that is a rubber bladder or a corrugated tube.

[0009] The underwater motor with pressure compensation function has multiple springs arranged in a circumferential direction, which are in a stretched state during operation and are immersed in insulating oil in the working environment.

[0010] The underwater motor with pressure compensation function has static sealing rings between the stator and the drive end cover and the non-drive end cover, and static sealing rings are also placed between the rotary dynamic seal and the drive end cover and the rotor.

[0011] The underwater motor with pressure compensation function has a rotary transformer whose rotor part is installed on the non-shaft extension end of the rotor, and the rotary transformer stator part is installed on the non-drive end cover, which can measure the motor speed.

[0012] The insulating oil of the underwater motor with pressure compensation function can be hydraulic oil, transformer oil, benzyl silicone oil, etc.

[0013] Compared with the prior art, the present invention has the following advantages.

[0014] 1. Compact structure and low system complexity: The flexible compensation component is located at the non-drive end of the motor and integrated with the motor as a whole, making full use of the motor's radial dimension and adding only a small amount of axial dimension, resulting in a compact structure and high space utilization. The underwater motor directly uses the flexible compensation component to achieve pressure compensation, eliminating the need for additional hydraulic pipes and sensor signal cables to connect to a separate pressure compensation device, thus reducing system complexity.

[0015] 2. Low failure rate and high reliability: Multiple springs are arranged in the circumferential direction between the flexible compensation component and the non-drive end cap, which effectively avoids jamming failure that causes the compensation function to fail. The springs are immersed in insulating oil and do not need to consider corrosion resistance. High-strength and high-toughness materials can be used to achieve longer service life and higher reliability.

[0016] Because of the above technical solution, when the motor is working in an underwater environment, the external water pressure acts on the flexible compensation component to cause deformation, so that the internal insulating oil pressure of the motor is basically the same as the external water pressure, which greatly relieves the pressure on the motor stator and releases the working depth limit of the underwater motor; at the same time, the rear cover is also subjected to the spring tension, so the final insulating oil pressure will be slightly higher than the external water pressure. Even if there is leakage in the rotating dynamic seal, the leakage direction is only oil towards water, and there is no risk of water ingress and short circuit in the stator. Attached Figure Description

[0017] Figure 1 This is a half-sectional view of the structure of the present invention; Figure 2 This is a partial cross-sectional view of the flexible compensation component of the present invention.

[0018] The labels for each figure are as follows: 1—Stator, 2—Drive end cover, 3—Non-drive end cover, 4—Rotor, 5—Bearing, 6—Rotary transformer, 7—Watertight connector, 8—Rotary dynamic seal, 9—Insulating oil, 10—Flexible compensation component, 11—Spring, 12—Static seal ring, 13—Rear cover, 14—Flexible tube, 15—Displacement sensor. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0020] like Figure 1 As shown, the present invention patent is an underwater motor with pressure compensation function, including stator 1, drive end cover 2, non-drive end cover 3, rotor 4, bearing 5, rotary transformer 6, watertight connector 7, rotary dynamic seal 8, insulating oil 9 and flexible compensation component 10.

[0021] The stator 1 is an overall frame structure of an underwater motor, which is in direct contact with seawater. It has coil windings on the inside and drive end cover 2 and non-drive end cover 3 are installed at both ends respectively. The rotary dynamic seal 8 is installed on the drive end cover 2 to achieve dynamic sealing at the motor rotor shaft extension end.

[0022] The rotor 4 is driven to rotate by the magnetic field of the stator 1 and is supported by two bearings 5 ​​at the driving end and the non-driving end. The watertight connector 7 leads out the coil windings and sensor wires inside the motor and connects them to the controller through a watertight cable.

[0023] A flexible compensation component 10 is provided outside the non-drive end cover 3. The flexible compensation component 10 is a structure composed of a spring 11, a rear cover 13, and a flexible tube 14. The flexible tube 14 is a rubber bladder or corrugated tube with openings at both ends. One end of the flexible tube 14 is connected to the non-drive end cover 3, and the rear cover 13 is connected to the non-drive end cover 3 through the spring 11 inside the flexible tube 14. The other end of the flexible tube 14 is sealed by the rear cover 13. A displacement sensor 15 is installed on the rear cover 13 to measure the distance from the rear cover 13 to the non-drive end cover 3. The remaining compensation capacity is calculated and used to indicate the subsequent working capacity of the motor. The flexible compensation component 10 is assembled with the stator 1 as a whole through the non-drive end cover 3. The insulating oil 9 can be hydraulic oil, transformer oil, benzyl silicone oil, etc., filling the entire internal cavity of the motor. The pressure compensation function of the motor is realized by the volume change generated by the deformation of the flexible compensation component 10.

[0024] Multiple springs 11 are arranged circumferentially and work in groups. They are in a stretched state during operation and are immersed in insulating oil 9. Static sealing rings 12 are placed between the stator 1 and the drive end cover 2 and the non-drive end cover 3. Static sealing rings 12 are also placed between the rotary dynamic seal 8 and the drive end cover 2 and the rotor 4. The rotor portion of the rotary transformer 6 is mounted on the non-shaft extension end of the rotor 4, and the stator portion of the rotary transformer 6 is mounted on the non-drive end cover 3, allowing for the measurement of motor speed.

[0025] The above description is merely a preferred embodiment of the present invention. The orientations or positional relationships shown are only for the convenience of describing the present invention and simplifying the description. Terms such as "setting," "installing," "connecting," and "fixing" should be interpreted broadly. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An underwater motor with pressure compensation function, comprising a stator (1), a rotor (4), a rotary transformer (6), a watertight connector (7), a rotary dynamic seal (8), and insulating oil (9), wherein the stator (1) has coil windings, and a drive end cover (2) and a non-drive end cover (3) are respectively installed at both ends; the rotary dynamic seal (8) is installed on the drive end cover (2); and the rotor (4) is supported by two bearings (5) at the drive end and the non-drive end; characterized in that: A flexible compensation component (10) is provided outside the non-driving end cover (3). The flexible compensation component (10) consists of a spring (11), a rear cover (13) and a flexible tube (14). The flexible tube (14) is connected to the non-driving end cover (3). The rear cover (13) is connected to the non-driving end cover (3) through the spring (11) inside the flexible tube (14). The end of the flexible tube (14) is sealed by the rear cover (13). A displacement sensor (15) is installed on the rear cover (13). The flexible compensation component (10) and the stator (1) are assembled as a whole. The insulating oil (9) fills the entire internal cavity of the motor. The pressure compensation of the motor is achieved by the volume change generated by the deformation of the flexible compensation component (10).

2. The underwater motor with pressure compensation function according to claim 1, characterized in that, The flexible tube (14) is a rubber bladder or a corrugated tube.

3. The underwater motor with pressure compensation function according to claim 1, characterized in that, The springs (11) are multiple in number, work in groups, and are immersed in insulating oil (9).

4. An underwater motor with pressure compensation function according to claim 1, 2, or 3, characterized in that, There is a static sealing ring (12) between the stator (1) and the drive end cover (2) and the non-drive end cover (3), and there is a static sealing ring (12) between the rotary dynamic seal (8) and the drive end cover (2) and the rotor (4).

5. An underwater motor with pressure compensation function according to claim 4, characterized in that, The rotor portion of the rotary transformer (6) is mounted on the non-shaft extension end of the rotor (4), and the stator portion of the rotary transformer (6) is mounted on the non-drive end cover (3).

6. An underwater motor with pressure compensation function according to claim 5, characterized in that, The insulating oil (9) is hydraulic oil, transformer oil, or benzyl silicone oil.

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