Self-locking high-reliability sealing underwater steering engine

Abstract

According to the self-locking type high-reliability sealing underwater steering engine, the front end of a motor shaft of a servo motor in a steering engine shell drives an RV speed reducer to rotate through a gear shaft so as to drive an output shaft to rotate, the output shaft and the steering engine shell are sealed through a dynamic sealing assembly, and other components are sealed in an inner cavity of the steering engine shell through the dynamic sealing assembly; the part of the output shaft arranged outside the steering engine shell is used for being connected with a driven object; the rear end of the motor shaft is connected with an angle measuring assembly and an electromagnetic brake assembly. A self-pressurization oil tank is arranged in the motor shell, and a filling assembly is arranged on the motor shell. An inner cavity of the steering engine shell is vacuumized and filled with lubricating oil with preset pressure through the filling assembly, the inner cavity of the steering engine shell is filled with the lubricating oil, the lubricating oil enters the self-pressurization oil tank, the self-pressurization oil tank compensates for oil volume changes caused by temperature changes, and the preset pressure is larger than the maximum water pressure of the working water depth of the working environment; the pressure sensor is installed in the inner cavity of the steering engine shell and used for detecting the pressure value so as to judge the sealing state of the steering engine.

Description

Technical Field

[0001] The present application relates to the technical field of underwater rotary output execution and actuators, and can be applied to underwater vehicle servos, underwater robot swing arm joints, and underwater vehicle retraction and deployment mechanisms, especially in underwater applications that require high-reliability sealing and large torque output and self-locking. Background Art

[0002] The underwater servo mainly outputs rotational motion and torque. Currently, the electromechanical solution is mainly adopted, that is, the motor drives the mechanical transmission mechanism. The underwater use environment places high demands on the sealing technology of the servo. The existing technology mainly adopts the method of internal oil filling and pressurization to ensure that the internal oil pressure of the servo is higher than the external water pressure. In the use environment immersed in lubricating oil, the locking torque of the traditional friction plate electromagnetic brake drops sharply, and as the viscosity of the oil increases, the friction plate cannot be effectively disengaged, and there is a risk of damage to the brake. Therefore, there is little research at home and abroad on the research of underwater servos with high reliability, ultra-large torque (above 15000Nm) and self-locking function.

[0003] The patent CN 108839787 of Shanghai Maritime University discloses a small-sized, high-torque underwater steering gear. The invention uses a brushless torque motor as the power source, drives the rudder shaft to rotate after passing through a harmonic reducer, and installs a rotary transformer at the rear end of the motor. It is connected to the output shaft through a transmission shaft passing through the harmonic reducer to detect the absolute angle of the rudder shaft. The steering gear is filled with hydraulic oil, and a small pressure compensation mechanism is provided inside the rudder shaft. The above design reduces the size of the steering gear. Although the steering gear scheme has a watertight design, it cannot achieve self-locking of the output shaft, which limits its scope of application.

[0004] Patent CN 116176822 of Shenyang Automation Institute of Chinese Academy of Sciences discloses an underwater steering gear device suitable for deep-sea bionic fish, which has a built-in pressure compensator to achieve pressure compensation in deep-water environment; dynamic seal, static seal and built-in pressure compensator can achieve maintenance-free full sealing; dynamic seal, static seal and watertight connector outlet mode are adopted to achieve the ability of steering gear to work in deep-water environment. Although this invention patent solves the sealing problem of steering gear in deep-sea environment, it is impossible to monitor the sealing status of the steering gear in real time, and the reliability and maintainability of long-life use need to be improved.

[0005] Hangzhou Shenhao Technology Co., Ltd.'s CN 118560656 patent discloses a self-locking jet spray gun swing arm mechanism suitable for underwater use and its underwater operation robot, which can achieve self-locking by adopting worm gear transmission, making installation and adjustment convenient, sealing stable, and operation strong. Although the patent achieves self-locking, the transmission efficiency of the worm gear structure is low, and the steering gear does not adopt an internal oil filling design, so the sealing reliability is low. Summary of the invention

[0006] The technical problem solved by the present invention is to provide a self-locking high-reliability sealed underwater steering gear, which solves the problems of low sealing reliability and inability to achieve both high torque and high efficiency transmission and self-locking function in existing underwater steering gears.

[0007] The technical solution of the present invention is: a self-locking high-reliability sealed underwater steering gear, including an output shaft, a dynamic seal assembly, an RV reducer, a servo motor, a watertight electrical connector, a self-pressurizing oil tank, an electromagnetic brake assembly, a filling assembly, an angle measurement assembly, a pressure sensor, and a steering gear housing;

[0008] The front end of the motor shaft of the servo motor in the steering gear housing drives the RV reducer to rotate through the gear shaft, thereby driving the output shaft to rotate. The output shaft and the steering gear housing are sealed by a dynamic sealing assembly, and other components are sealed in the inner cavity of the steering gear housing through the dynamic sealing assembly; the output shaft is placed outside the steering gear housing for connection with the driven object; the rear end of the motor shaft in the inner cavity of the steering gear housing is connected to the angle measurement assembly and the electromagnetic brake assembly, which are used to achieve the measurement of the motor rotation angle and the output steering angle and the self-locking of the steering gear; a self-pressurizing oil tank is arranged in the motor housing, and a filling assembly is arranged on the motor housing; the inner cavity of the steering gear housing is evacuated and filled with lubricating oil of a preset pressure through the filling assembly, the lubricating oil fills the inner cavity of the steering gear housing and enters the self-pressurizing oil tank, and the self-pressurizing oil tank compensates for the oil volume change caused by temperature change, and the preset pressure is greater than the maximum water pressure of the working water depth of the working environment; the pressure sensor is installed in the inner cavity of the steering gear housing to detect the pressure value, thereby judging the sealing state of the steering gear.

[0009] Preferably, the steering gear housing includes a reducer housing, a servo motor housing, a boost oil tank housing, and an electromagnetic brake housing in sequence; adjacent housings are connected and sealed by flanges, and the seal adopts a double-pass radial static seal.

[0010] Preferably, the electromagnetic brake assembly includes a wiring protection cover, a brake output shaft, a brake rotor support sleeve, an electromagnetic brake, a brake stator support seat, an adjustment gasket, a bearing, a back nut and a plurality of fasteners;

[0011] The electromagnetic brake consists of two parts, a rotor and a stator. The rotor is installed on the brake rotor support sleeve and is coaxially installed with the brake stator support seat through bearings and back nuts. The brake output shaft is connected to the servo motor motor shaft. The stator of the electromagnetic brake is fixedly connected to the brake stator support seat and the steering gear housing. The wires on the stator are led out to the watertight electrical connector on the steering gear housing through the wiring protection cover. When the electromagnetic brake is powered on, the rotor and stator are separated and unlocked under the action of electromagnetic force; when the power is off, the rotor and stator are attracted and locked under the action of permanent magnetic force.

[0012] Preferably, the locking torque is generated between the stator and the rotor through the engagement of the tooth structure.

[0013] Preferably, the self-pressurizing oil tank comprises a T-ring, an oil tank back nut, an oil tank piston, a small spring, a large spring, a piston wear ring, a spring support seat and an oil tank drain seal plug;

[0014] The oil tank is divided into an air chamber and an oil chamber by the oil tank piston, and dynamic sealing isolation of the air chamber and the oil chamber is achieved by a T-ring. The oil chamber is connected to the inner cavity of the steering gear housing; a spring support seat is arranged at the static end of the air chamber, and the maximum stroke of the oil tank piston is between the spring support seat and the oil tank piston rod. The large spring is sleeved outside the small spring and both are compression springs. The two springs are installed between the spring support seat and the oil tank piston. An oil drain seal is arranged at the tail of the oil tank, which is mainly used to release the lubricating oil accumulated in the air chamber after long-term use.

[0015] Preferably, when the oil chamber is in an oil-free state, the pre-pressure provided by the two springs is ≥ the maximum water pressure of the working water depth in the working environment.

[0016] Preferably, the preset pressure is the pressure generated by the spring compressed by the change in oil volume inside the steering gear corresponding to the middle value of the working environment temperature change range.

[0017] Preferably, the oil tank volume corresponding to the maximum compression stroke can be sufficient to compensate for the volume change of the oil in the underwater steering gear within the operating temperature range, and the steering gear operates at the highest temperature point when the spring is compressed to the maximum stroke.

[0018] Preferably, the dynamic seal assembly comprises a Glyd ring, a dynamic seal end cover, a wear-resistant ring, an O-ring, a pan-seal, and a pan-seal cover plate; the dynamic seal between the dynamic seal assembly and the output shaft is achieved by the Glyd ring and the pan-seal, the wear-resistant ring is used to support the output shaft and reduce the friction on the dynamic seal end cover during rotation, and the static seal between the dynamic seal assembly and the reducer housing is achieved by the outer O-ring; when the steering gear works normally underwater, a closed air cavity is formed between the Glyd ring and the pan-seal, the water pressure on the left side of the Glyd ring is higher than the air cavity pressure, and the oil on the right side of the pan-seal is higher than the air cavity pressure on its left side.

[0019] Preferably, the steering gear housing is made of duplex stainless steel.

[0020] The beneficial effects of the present invention compared with the prior art are:

[0021] The self-locking high-reliability sealed underwater steering gear involved in the present invention is used in underwater vehicle rudder systems or underwater robot actuator joints that require large torque rotation output and self-locking. It provides efficient torque output, highly reliable underwater sealing and full-life dynamic monitoring, and large torque locking capabilities for the actuation system. The details are as follows:

[0022] (1) The steering gear adopts an integral oil-filled design and a self-pressurized oil tank to ensure that the oil pressure is higher than the external water pressure. A double-channel heterogeneous dynamic seal assembly and a double-channel radial static seal are set to improve the redundancy of underwater sealing. The steering gear has a built-in pressure sensor, which can greatly improve the sealing reliability and realize the full life monitoring of the sealing status of the steering gear.

[0023] (2) In order to solve the problem that the locking torque of the traditional friction plate brake decreases and cannot be effectively separated in a high-viscosity oil-filled environment, a gear-type electromagnetic brake is used. It can generate a large torque locking torque through the meshing of the tooth structure in the oil-filled environment and can quickly complete the unlocking and separation, so that the underwater servo has high reliability, low power consumption, fast and effective high-torque locking capability in a wet environment.

[0024] (3) The component-type RV reducer is used as a whole in oil, and the dynamic seals on both sides of the input and output are eliminated, which can achieve efficient and silent large torque output and reduce the axial size of the servo. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a schematic diagram of the composition of the underwater steering gear of the present invention;

[0026] Figure 2 It is a structural schematic diagram and a partial cross-sectional view of the underwater steering gear of the present invention;

[0027] Figure 3 It is a structural cross-sectional view of the self-pressurizing oil tank 8 of the present invention in the BB direction;

[0028] Figure 4 It is a sectional view of the components of the underwater steering gear electromagnetic brake assembly of the present invention. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments.

[0030] The present invention provides a self-locking high-reliability sealed underwater steering gear, the composition principle of which is as follows: Figure 1 As shown, the three-dimensional structure of the embodiment is as follows Figure 2 As shown. The steering gear is mainly composed of an output shaft 1, a dynamic seal assembly 2, an RV reducer 3, a servo motor 5, a motor rear end cover 6, a watertight electrical connector 7, a self-pressurizing oil tank 8, an electromagnetic brake assembly 9, a filling assembly 10, an angle measurement assembly 11, a pressure sensor 12, and an oil drain and exhaust port 13. The steering gear housing includes a reducer housing 4, a servo motor housing, a pressurized oil tank housing 81, and an electromagnetic brake housing 95; adjacent housings are connected and sealed by flanges, and the seal adopts a double-pass radial static seal.

[0031] The output shaft 1 is connected to the driven object through a rectangular spline; the servo motor uses a permanent magnet AC synchronous motor, and the front end of the motor shaft of the servo motor 5 drives the RV reducer 3 to rotate through the pinion shaft, thereby driving the output shaft 1 to rotate, and the rear end of the motor shaft of the servo motor 5 is connected to the angle measurement component 11 and the electromagnetic brake component 9, specifically, connected to the electromagnetic brake through a rectangular spline, thereby realizing the measurement of the motor angle and the output steering angle and the self-locking of the steering gear. The front end of the RV reducer 3 is connected to the steering gear output shaft through a flange, and the rear end is driven by a motor, which can achieve high-efficiency output of large torque in a compact axial space (transmission efficiency greater than 85%);

[0032] The angle measuring assembly 11, the self-pressurizing oil tank 8, the pressure sensor 12, the filling assembly 10 and the watertight electrical connector 7 are installed at the rear end of the servo motor; the angle measuring assembly 11 has the main function of directly measuring the motor rotation angle and indirectly measuring the steering angle output by the steering gear. This assembly is conducive to the compact layout of the steering gear structure, reduces the difficulty of assembly, and improves the accuracy of steering angle measurement; the steering gear housing is made of corrosion-resistant duplex stainless steel.

[0033] The high-reliability sealing of the underwater steering gear is mainly achieved through the dynamic sealing component 2, the self-pressurized oil tank 8, the pressure sensor 12, the watertight electrical connector 7 and the filling component 10. After the steering gear is assembled, the filling component 10 is used to evacuate the interior of the steering gear and fill it with lubricating oil of a certain pressure. The self-pressurized oil tank 8 can compensate for the change in oil volume caused by temperature change. During the working process of the steering gear, the internal pressure value can be monitored in real time through the pressure sensor 12 to judge the sealing status of the steering gear.

[0034] The composition cross-sectional view of the dynamic seal assembly 2 is as follows: Figure 1 As shown in the view A in FIG. The dynamic seal assembly 2 is composed of a dynamic seal end cover 21, a wear ring 22, a grid ring 23, an outer O-ring 24, a pan seal 25, an inner O-ring 26, a pan seal cover plate 27 and a number of fasteners. The above components are connected and installed into a complete dynamic seal assembly 2 through fasteners or mounting grooves, wherein the dynamic seal between the dynamic seal assembly 2 and the output shaft 1 is realized by the grid ring 23 and the pan seal, the wear ring 22 is used to support the output shaft 1 and reduce the friction of the dynamic seal end cover 21 during the rotation process, and the static seal between the dynamic seal assembly 2 and the reducer housing 4 is realized by the outer O-ring 24. When the steering gear works normally underwater, a closed air cavity is formed between the grid ring 23 and the pan seal 25, the water pressure on the left side of the grid ring 23 (the side close to the output end) is higher than the air cavity pressure, and the oil on the right side of the pan seal 25 is higher than the air cavity pressure on its left side. Under the action of pressure difference, the outer grid ring 23 can prevent the entry of seawater, and the inner grid plug seal 25 blocks the leakage of lubricating oil, thereby realizing heterogeneous redundancy of dynamic sealing, and the components can be disassembled and replaced separately for easy maintenance.

[0035] The structural cross-sectional view of the self-pressurized oil tank 8 in the BB direction is as follows Figure 3 As shown, it mainly consists of an oil tank housing 81, a spring support seat 82, a large spring 83, a small spring 84, an oil tank piston 85, a T-ring 86, an oil tank back nut 87, an oil tank wear-resistant ring 88 and an oil tank drain seal 89. The self-pressurized oil tank 8 adopts double spring pressurization, which can make the internal oil pressure of the steering gear higher than the external water pressure and compensate for the change in oil volume caused by the change in ambient temperature. The oil tank housing 81 is divided into an air chamber and an oil chamber by the oil tank piston, and the air chamber and the oil chamber are dynamically sealed and isolated by the T-ring 86. The oil chamber is connected with the inner chamber of the steering gear housing. A spring support seat is arranged at the static end of the air chamber, and a center rod is arranged at the center of the spring support seat. The stroke of the oil tank piston is limited by the length of the center rod and the distance between the piston rod. A limiting structure between large and small springs is arranged outside the center rod. The small spring is sleeved on the center rod and the oil tank piston rod, and the large spring is sleeved outside the small spring. Both springs are compression springs. An oil drain seal 89 is arranged at the tail of the oil tank, which is mainly used to release the lubricating oil accumulated in the air chamber for a long time. The self-pressurizing oil tank 8 can make the internal oil pressure of the steering gear higher than the external water pressure and compensate for the change in oil volume caused by the change in ambient temperature. The pre-pressure provided by the two springs is ≥ the maximum water pressure of the working water depth of the working environment. The oil tank volume corresponding to the maximum compression stroke of the spring of the self-pressurizing oil tank 8 can meet the compensation for the volume change of the oil in the underwater steering gear within the working temperature range. When the spring is compressed to the maximum stroke, the steering gear works at the highest temperature point. The preset pressure is the pressure generated by the compression spring of the corresponding internal oil volume change of the steering gear when the working environment temperature changes in the middle value of the range.

[0036] The pressure sensor adopts a watertight pressure sensor, which is immersed in pressurized lubricating oil and used to monitor the oil pressure inside the steering gear in real time. The control system can judge the sealing status of the steering gear according to the oil pressure value and provide alarm information when oil leakage occurs.

[0037] The structural cross-sectional view of the electromagnetic brake assembly 9 in the CC direction is as follows: Figure 4As shown, it is mainly composed of a wiring protection cover 91, a brake output shaft 92, a brake rotor support sleeve 93, an electromagnetic brake 94, a brake stator support seat 96, an adjustment gasket 97, a bearing 98, a back nut 99 and a number of fasteners. The electromagnetic brake 94 consists of two parts, a rotor and a stator, wherein the rotor is mounted on the brake rotor support sleeve 93, and this part is coaxially mounted with the brake stator support seat 96 through a bearing 98 and a back nut 99, and the brake output shaft 92 is connected to the motor shaft of the servo motor 5 through a rectangular spline interface; the stator of the electromagnetic brake 94 is fixedly connected to the brake stator support seat 96 and the brake housing 95 by screws, and the wires on the stator are led out to the watertight connector 7 through the wiring protection cover 91. When the electromagnetic brake 94 is powered on, the sliding teeth on its stator are separated from the rotor teeth under the action of the electromagnetic force to complete the unlocking,

[0038] When the power is turned off, the sliding teeth on the stator engage with the rotor teeth under the action of permanent magnetic force to complete the locking. The unique locking method of the electromagnetic brake 94 is not affected by the use environment. The brake can be locked and unlocked quickly and effectively in high-viscosity lubricating oil, and the locking torque generated is up to twice the rated output torque of the servo.

[0039] Although the present invention has been disclosed as above in the form of a preferred embodiment, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solution of the present invention by using the methods and technical contents disclosed above without departing from the spirit and scope of the present invention. Therefore, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope of the technical solution of the present invention.

Claims

1. A self-locking high-reliability sealed underwater steering gear, characterized in that Including output shaft, dynamic seal assembly, RV reducer, servo motor, watertight electrical connector, self-pressurized oil tank, electromagnetic brake assembly, filling assembly, angle measurement assembly, pressure sensor, steering gear housing; The front end of the motor shaft of the servo motor in the steering gear housing drives the RV reducer to rotate through the gear shaft, thereby driving the output shaft to rotate. The output shaft and the steering gear housing are sealed by a dynamic sealing assembly, and other components are sealed in the inner cavity of the steering gear housing through the dynamic sealing assembly; the output shaft is placed outside the steering gear housing for connection with the driven object; the rear end of the motor shaft in the inner cavity of the steering gear housing is connected to the angle measurement assembly and the electromagnetic brake assembly, which are used to achieve the measurement of the motor rotation angle and the output steering angle and the self-locking of the steering gear; a self-pressurizing oil tank is arranged in the motor housing, and a filling assembly is arranged on the motor housing; the inner cavity of the steering gear housing is evacuated and filled with lubricating oil of a preset pressure through the filling assembly, the lubricating oil fills the inner cavity of the steering gear housing and enters the self-pressurizing oil tank, and the self-pressurizing oil tank compensates for the oil volume change caused by temperature change, and the preset pressure is greater than the maximum water pressure of the working water depth of the working environment; the pressure sensor is installed in the inner cavity of the steering gear housing to detect the pressure value, thereby judging the sealing state of the steering gear.

2. The self-locking high-reliability sealed underwater steering gear according to claim 1 is characterized in that: The steering gear housing includes a reducer housing, a servo motor housing, a boost oil tank housing, and an electromagnetic brake housing in sequence; adjacent housings are connected and sealed by flanges, and the sealing adopts a double-pass radial static seal.

3. The self-locking high-reliability sealed underwater steering gear according to claim 1 is characterized in that: The electromagnetic brake assembly includes a wiring protection cover, a brake output shaft, a brake rotor support sleeve, an electromagnetic brake, a brake stator support seat, an adjustment gasket, a bearing, a back nut and a plurality of fasteners; The electromagnetic brake consists of two parts, a rotor and a stator. The rotor is installed on the brake rotor support sleeve and is coaxially installed with the brake stator support seat through bearings and back nuts. The brake output shaft is connected to the servo motor motor shaft. The stator of the electromagnetic brake is fixedly connected to the brake stator support seat and the steering gear housing. The wires on the stator are led out to the watertight electrical connector on the steering gear housing through the wiring protection cover. When the electromagnetic brake is powered on, the rotor and stator are separated and unlocked under the action of electromagnetic force; when the power is off, the rotor and stator are attracted and locked under the action of permanent magnetic force.

4. The self-locking high-reliability sealed underwater steering gear according to claim 3 is characterized in that: The locking torque is generated between the stator and the rotor through the engagement of the tooth structure.

5. The self-locking high-reliability sealed underwater steering gear according to claim 1 is characterized in that: The self-pressurizing oil tank comprises a T-ring, an oil tank back nut, an oil tank piston, a small spring, a large spring, a piston wear ring, a spring support seat and an oil tank drain seal plug; The oil tank is divided into an air chamber and an oil chamber by the oil tank piston, and dynamic sealing isolation of the air chamber and the oil chamber is achieved by a T-ring. The oil chamber is connected to the inner cavity of the steering gear housing; a spring support seat is arranged at the static end of the air chamber, and the maximum stroke of the oil tank piston is between the spring support seat and the oil tank piston rod. The large spring is sleeved outside the small spring and both are compression springs. The two springs are installed between the spring support seat and the oil tank piston. An oil drain seal is arranged at the tail of the oil tank, which is mainly used to release the lubricating oil accumulated in the air chamber after long-term use.

6. The self-locking high-reliability sealed underwater steering gear according to claim 5 is characterized in that: When the oil chamber is empty, the pre-pressure provided by the two springs is ≥ the maximum water pressure of the working water depth in the working environment.

7. The self-locking high-reliability sealed underwater steering gear according to claim 5 is characterized in that: The preset pressure is the pressure generated by the spring when the oil volume changes inside the steering gear corresponding to the middle value of the working environment temperature change range.

8. The self-locking high-reliability sealed underwater steering gear according to claim 5 is characterized in that: The oil tank volume corresponding to the maximum compression stroke can compensate for the volume change of the oil in the underwater servo within the operating temperature range. When the spring is compressed to the maximum stroke, the servo operates at the highest temperature point.

9. The self-locking high-reliability sealed underwater steering gear according to claim 1 is characterized in that: The dynamic seal assembly comprises a Glyd ring, a dynamic seal end cover, a wear-resistant ring, an O-ring, a pan-seal, and a pan-seal cover plate; the dynamic seal between the dynamic seal assembly and the output shaft is achieved by the Glyd ring and the pan-seal, the wear-resistant ring is used to support the output shaft and reduce the friction on the dynamic seal end cover during rotation, and the static seal between the dynamic seal assembly and the reducer housing is achieved by the outer O-ring; when the steering gear works normally underwater, a closed air cavity is formed between the Glyd ring and the pan-seal, the water pressure on the left side of the Glyd ring is higher than the air cavity pressure, and the oil on the right side of the pan-seal is higher than the air cavity pressure on its left side.

10. The self-locking high-reliability sealed underwater steering gear according to claim 1 is characterized in that: The steering gear housing is made of duplex stainless steel.

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