Deepwater oil-filled flat-pressing type telescopic and rotary integrated joint

Abstract

The invention provides an oil-filled flat-pressing type telescopic and rotary integrated joint for deep water. The oil-filled flat-pressing type telescopic and rotary integrated joint comprises an upper cover, a rotary joint, a shaft sleeve, an oil-filled seat, an integrated shell, a telescopic joint and a bottom cover, the upper end of the integrated shell is connected with the shaft sleeve and the upper cover; the integrated shell is statically sealed with the shaft sleeve and the bottom cover; the rotary joint and the shaft sleeve are dynamically sealed; the rotating joints and the telescopic joints are joints driven by a motor and are arranged in an inner cavity of the integrated shell in a staggered manner, the telescopic joints provide power for the rotating joints to slide along the shaft sleeve, and the output of the rotating joints is connected with the mechanical arm and provides rotating power for the mechanical arm; the oil filling base is installed on the integrated shell and connected with an external oil bag to achieve balance of internal pressure and external pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of underwater robots, and in particular to a high-pressure-resistant telescopic and rotating integrated joint for deep water areas. Background Art

[0002] The underwater robotic arms carried by small, autonomous deep-sea submersibles are a key development direction for multi-degree-of-freedom serial robotic arms. They can play an important role in deep-sea biorecovery, seafloor salvage, pipeline and cable inspection and maintenance, and other areas. However, robotic arm systems carried by underwater unmanned submersibles are not currently widely used in marine exploration and operations. This is mainly due to the limitations of the underwater unmanned submersible's structural dimensions, the dynamic and static seals of the underwater electric robotic arms, the structural pressure resistance, and the underwater visual detection capabilities.

[0003] As the underwater depth increases, the water pressure gradually becomes higher. High water pressure places higher demands on the pressure-bearing capacity of the device's materials. Traditional methods require increasing the wall thickness or using higher-strength materials to meet the requirements. This method will increase the device's own weight, seriously affecting the net buoyancy in the water, resulting in increased disturbances to the submersible platform. The oil-filled flat-pressure solution has the advantage of being able to work at full sea depth. At the same time, underwater submersibles have stricter space requirements for loads. Traditional independent mechanism design combinations waste a lot of space, so an integrated design is particularly necessary. For example, the patent [An underwater joint drive module, CN209224094U, authorized] uses a rotary joint design solution with an oil-filled frameless motor. The advantage is that it is a universal solution for robotic arm joints with only rotational freedom. Internal oil filling solves the problem of full-sea-depth operation. The disadvantage is that there is no telescopic unit. A small, high-torque underwater servo, CN108839787B, relates to a patent, CN117002645A, which states that the robot uses an underwater electric cylinder as a telescopic actuator to drive joint rotation. However, the robot only has a telescopic joint design. If combined with a rotary joint, the combined volume and mass are relatively large.

[0004] At the same time, the axial thrust caused by the balanced water pressure must also be considered for the telescopic mechanism. Summary of the Invention

[0005] The technical problem solved by the present invention is to provide a telescopic and rotating integrated joint for deep-sea operations, which solves the problem of multi-degree-of-freedom integration within a limited space and limited mass and the problem of full-sea-depth operations.

[0006] The technical solution of the present invention is: an oil-filled flat-pressure telescopic and rotary integrated joint for deep water use, comprising an upper cover, a rotary joint, a shaft sleeve, an oil-filled seat, an integrated housing, a telescopic joint and a bottom cover;

[0007] The upper end of the integrated housing is connected to the shaft sleeve and the upper cover, and the lower end of the integrated housing is connected to the bottom cover; the integrated housing and the shaft sleeve and the bottom cover are statically sealed; the rotary joint and the shaft sleeve are dynamically sealed;

[0008] The rotary joint and the telescopic joint are both motor-driven joints and are installed in an alternating arrangement in the inner cavity of the integrated shell. The telescopic joint provides the power for the rotary joint to slide along the shaft sleeve, and the output of the rotary joint is connected to the robotic arm and provides rotational power for the robotic arm; the oil filling seat is installed on the integrated shell and connected to the external oil bag to achieve a balance between the internal pressure and the external pressure inside the external oil bag and the integrated joint.

[0009] Preferably, the rotary joint includes a rotary joint housing, an output shaft, a harmonic output flange, a harmonic reducer, an input shaft, a bearing, an input shaft gear, a motor gear, a servo motor and a motor flange;

[0010] Among them, the input shaft is fixed by a bearing, and its upper end is connected to the input end of the harmonic reducer and the lower end is connected to the input shaft gear; the output shaft runs through the entire harmonic reducer and is located inside the input shaft, and its upper end is connected to the harmonic output flange, and the harmonic output flange is connected to the output end of the harmonic reducer, and the lower end of the output shaft is connected to the absolute encoder fixed on the motor flange; the motor flange is mounted on the rotary joint housing, the servo motor is mounted on the motor flange, and the motor gear is mounted on the servo motor output shaft and meshes with the input shaft gear. The torque of the servo motor is transmitted to the input shaft through the gear, and then transmitted to the input end of the harmonic reducer. The torque is transmitted to the output flange through deceleration of the harmonic reducer, and the position information is transmitted back through the output shaft.

[0011] Preferably, a rotary dynamic seal is mounted on the rotary joint housing to seal the gap between the harmonic output flange and the rotary joint housing.

[0012] Preferably, the rotary joint housing is a cylindrical shell with an inner cavity, and the inner cavity is divided into three cavities. The upper cavity is used to install the harmonic reducer, the output shaft, input shaft and its bearings pass through the upper cavity and the middle cavity, and the input shaft gear, motor gear, servo motor and motor flange are located in the middle cavity; the lower cavity is used to cooperate with the integrated housing to complete the installation of the telescopic joint.

[0013] Preferably, the outer wall of the upper end of the rotary joint housing is dynamically sealed with the shaft sleeve, and a gap is left between the upper end and the integrated housing.

[0014] Preferably, the telescopic joint includes a trapezoidal lead screw, a nut, a servo motor, a bearing frame, a bearing, a motor seat, a motor gear, a lead screw gear, and a locking nut;

[0015] The trapezoidal lead screw is fixed to the motor base through bearings and locking nuts, and a lead screw gear is installed between the bearing and the locking nut; the bearing is fixed to the bearing cover through the motor base, the lead screw cooperates with the nut, and the nut is installed on the rotary joint housing through a connector; the servo motor is fixed to the motor base, and the motor base is installed on the integrated housing, the servo motor output shaft is equipped with a motor gear, the motor gear is installed on the bearing frame, the motor gear is engaged with the lead screw gear, and the power of the servo motor is transmitted to the trapezoidal lead screw, and then the telescopic force is transmitted to the connector through the nut, thereby driving the telescopic movement of the rotary joint.

[0016] Preferably, the servo motor and the trapezoidal lead screw are installed on the same side of the click gear and the lead screw gear.

[0017] Compared with the existing technology, the present invention has the following advantages: through the integrated design and staggered layout, the central space of the telescopic joint is fully utilized, solving the problem of integrated design of telescopic and rotating joints in a limited space. The full sealing technology of oil filling and flat pressure solves the problem of full sea operation.

[0018] The rotary drive portion of this invention utilizes a nested input and output layout with an offset motor, facilitating a parallel and staggered arrangement with the lead screw lift. This results in a smaller integrated joint, making it more adaptable to compact environments. Furthermore, the smaller size of the flat-type oil bladder reduces the volume of the external bladder, resulting in a more lightweight overall layout. Oil filling effectively lubricates the internal transmission components.

[0019] The nested sealing form of the inner rotating dynamic seal, the middle axial dynamic seal and the outer static seal of the present invention can reduce the overall design height of the joint. The integrated joint design of rotation and translation can reduce the number of sealing rings used and improve the reliability of underwater sealing.

[0020] (1) The integrated joint consists of a telescopic joint and a rotary joint. The staggered layout takes up less space and is light in weight.

[0021] (2) The two-degree-of-freedom integrated design reduces the use of sealing structures and seals, while making the internal wiring simpler.

[0022] (3) The integrated oil-filled flat-pressure seal design prevents the telescopic mechanism from bearing additional axial force, making the shell structure lighter and thinner, and able to adapt to full-sea operations.

[0023] (4) The high precision and self-locking performance of the integrated joint are achieved through a harmonic reducer and a T-screw. The introduction of a cross-stick bearing between the two degrees of freedom allows the integrated joint to withstand a large bending moment. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Diagram of the telescopic and rotating integrated joint;

[0025] Figure 2 Diagram of the components of a revolute joint;

[0026] Figure 3 Diagram of the components of the telescopic joint. DETAILED DESCRIPTION

[0027] The present invention will be further described below in conjunction with the embodiments.

[0028] The telescopic and rotary integrated joint is characterized by comprising an upper cover 1, a rotary joint 2, a shaft sleeve 3, an O-ring 4, an oil-filling seat 5, an axial dynamic seal 6, a cable 7, an integrated housing 8, an O-ring 9, a telescopic joint 10, and a bottom cover 11. The integrated housing 8 connects the shaft sleeve 3 and the upper cover 1 on the upper side and is statically sealed by the O-ring 4, while the integrated housing 8 connects the bottom cover 11 on the lower side and is statically sealed by the O-ring 9. The rotary joint 2 slides along the shaft sleeve 3 under the action of the lead screw 10-1 in the telescopic joint 10 and is sealed by the axial dynamic seal 6. The oil-filling seat 5 is connected to the external oil sac to achieve internal and external pressure balance between the external oil sac and the integrated joint.

[0029] The rotary joint includes a rotary joint housing 2-1, an output shaft 2-2, a harmonic output flange 2-3, a rotary dynamic seal ring 2-4, a harmonic reducer 2-5, an input shaft 2-6, a bearing washer 2-7, a bearing 2-8, an input shaft gear 2-9, a motor gear 2-10, a servo motor 2-11, a motor housing 2-12 and a motor flange 2-13, and the motor housing 2-12 is connected to the side wall of the motor flange 2-13.

[0030] The rotating joint housing 2-1 is a cylindrical shell with an inner cavity, which is divided into three cavities. The upper cavity is used to install the harmonic reducer. The output shaft, input shaft and its bearings pass through the upper cavity and the middle cavity. The input shaft gear, motor gear, servo motor and motor flange are located in the middle cavity; the lower cavity is used to cooperate with the integrated housing to complete the installation of the telescopic joint.

[0031] Input shaft 2-6 is secured by bearing 2-8, its upper end connected to the input of harmonic reducer 2-5 and its lower end connected to input shaft gear 2-9. Output shaft 2-2 extends throughout the entire harmonic reducer, its upper end connected to harmonic output flange 2-3, which is connected to the output of the harmonic reducer, and its lower end connected to motor flange 2-13. Motor flange 2-13 is mounted to rotary joint housing 2-1, servo motor 2-11 is mounted to motor flange 2-13, and motor gear 2-10 is mounted to the servo motor output shaft and meshes with input shaft gear 2-9. The servo motor's torque is transmitted to the input shaft via the gears, and then to the input of the harmonic reducer. The torque is then reduced by the harmonic reducer and transferred to the output flange, where position information is transmitted back through the output shaft. A rotary dynamic seal 2-4 is mounted on rotary joint housing 2-1 to seal the gap between output flange 2-3 and the housing.

[0032] The telescopic joint includes a trapezoidal screw 10-1, a nut 10-2, a bearing cover 10-3, a servo motor 10-4, a connector 10-5, a bearing frame 10-6, a bearing 10-7, a bearing pad 10-8, a motor seat 10-9, a motor gear 10-10, a motor cover 10-11, a screw gear 10-12, and a screw locking nut 10-13. Among them, the trapezoidal screw 10-1 is fixed to the motor seat 10-9 through the bearing 10-7 and the locking nut 10-13, the bearing is fixed to the bearing cover 10-3 through the motor seat, the screw cooperates with the nut 10-2, and the nut is installed on the rotary joint housing 2-1 through the connector 10-5; the servo motor 10-4 is fixed on the motor seat 10-9, the motor seat is installed on the integrated housing 11, the servo motor output shaft is equipped with a motor gear 10-10, the motor gear is installed on the bearing frame 10-6, the motor gear is engaged with the screw gear 10-12, the power of the servo motor is transmitted to the trapezoidal screw 10-1, and then the telescopic force is transmitted to the connector 10-5 through the nut, thereby driving the telescopic movement of the rotary joint 2.

[0033] Although the present invention has been disclosed above in terms of preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications to the technical solutions 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 solutions of the present invention shall fall within the scope of protection of the technical solutions of the present invention.

Claims

1. An oil-filled flat-pressure telescopic and rotating integrated joint for deep water use, characterized in that: It includes an upper cover, a rotating joint, a shaft sleeve, an oil-filled seat, an integrated housing, a telescopic joint and a bottom cover; The upper end of the integrated housing is connected to the shaft sleeve and the upper cover, and the lower end of the integrated housing is connected to the bottom cover; there is a static seal between the integrated housing and the shaft sleeve and the bottom cover; there is a dynamic seal between the rotary joint and the shaft sleeve; The rotating joint and the telescopic joint are both motor-driven joints and are installed in the inner cavity of the integrated shell in a staggered layout. The telescopic joint provides the power for the rotating joint to slide along the shaft sleeve, and the output of the rotating joint is connected to the robotic arm and provides rotational power for the robotic arm. The oil filling seat is installed on the integrated shell and connected to the external oil bag to achieve the balance of internal pressure and external pressure between the external oil bag and the integrated joint.

2. The deep-water oil-filled flat-pressure telescopic and rotating integrated joint according to claim 1 is characterized in that: The rotary joint includes a rotary joint housing, an output shaft, a harmonic output flange, a harmonic reducer, an input shaft, a bearing, an input shaft gear, a motor gear, a servo motor and a motor flange; Among them, the input shaft is fixed by a bearing, and its upper end is connected to the input end of the harmonic reducer and the lower end is connected to the input shaft gear; the output shaft runs through the entire harmonic reducer and is located inside the input shaft, and its upper end is connected to the harmonic output flange, the harmonic output flange is connected to the output end of the harmonic reducer, and the lower end of the output shaft is connected to the absolute encoder fixed on the motor flange; the motor flange is installed on the rotating joint housing, the servo motor is installed on the motor flange, and the motor gear is installed on the servo motor output shaft and meshes with the input shaft gear. The torque of the servo motor is transmitted to the input shaft through the gear, and then transmitted to the input end of the harmonic reducer, and the torque is transmitted to the output flange through the deceleration of the harmonic reducer, and the position information is transmitted back through the output shaft.

3. The deep-water oil-filled flat-pressure telescopic and rotating integrated joint according to claim 2 is characterized in that: A rotary dynamic seal is arranged on the rotary joint housing to seal the gap between the harmonic output flange and the rotary joint housing.

4. The deep-water oil-filled flat-pressure telescopic and rotating integrated joint according to claim 2 is characterized in that: The rotating joint shell is a cylindrical shell with an inner cavity, and the inner cavity is divided into three cavities. The upper cavity is used to install the harmonic reducer. The output shaft, input shaft and their bearings pass through the upper cavity and the middle cavity. The input shaft gear, motor gear, servo motor and motor flange are located in the middle cavity; the lower cavity is used to cooperate with the integrated shell to complete the installation of the telescopic joint.

5. The deep-water oil-filled flat-pressure telescopic and rotating integrated joint according to claim 4 is characterized in that: The outer wall of the upper end of the rotating joint housing is dynamically sealed with the shaft sleeve, and a gap is left between the outer wall and the integrated housing.

6. The deep-water oil-filled flat-pressure telescopic and rotating integrated joint according to claim 1 is characterized in that: The telescopic joint includes a trapezoidal lead screw, a nut, a servo motor, a bearing frame, a bearing, a motor seat, a motor gear, a lead screw gear, and a locking nut; The trapezoidal lead screw is fixed to the motor seat through a bearing and a locking nut, and a lead screw gear is installed between the bearing and the locking nut; the bearing is fixed to the bearing cover through the motor seat, the lead screw cooperates with the nut, and the nut is installed on the rotating joint housing through a connecting piece; the servo motor is fixed to the motor seat, the motor seat is installed on the integrated housing, the servo motor output shaft is equipped with a motor gear, the motor gear is installed on the bearing frame, the motor gear is meshed with the lead screw gear, the power of the servo motor is transmitted to the trapezoidal lead screw, and then the telescopic force is transmitted to the connecting piece through the nut, thereby promoting the telescopic movement of the rotating joint.

7. The deep-water oil-filled flat-pressure telescopic and rotating integrated joint according to claim 6 is characterized in that: The servo motor and the trapezoidal lead screw are installed on the same side of the click gear and the lead screw gear.

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