CN104440939B - Secondary drive joint of small underwater hydraulic manipulator - Google Patents

Abstract

The purpose of the present invention is to provide a small-scale underwater hydraulic manipulator with a secondary drive joint, including a first-level linear motion claw-driven hydraulic cylinder assembly, a second-stage joint rotation assembly, a position detection assembly, and a rear end of the first-stage hydraulic cylinder assembly. It is connected with the front end of the second-level wrist joint by screws, the oil circuit inside the component is sealed by an O-ring, and the position detection component is in interference fit with the rear-end support shaft of the second-level wrist joint; through the middle part of the second-level joint mechanism The hydraulic oil at the /oil outlet drives the wrist joint to rotate and drives the first-stage gripper hydraulic cylinder assembly to rotate together. The hydraulic oil at the inlet/outlet port at the tail of the second-stage joint drives the first-stage gripper hydraulic pressure through the internal oil circuit of the component. The cylinder moves linearly to provide driving torque for the gripper. The invention avoids the interference of the hydraulic connection head connected with the oil inlet and outlet with the outer cylinder installed when the first stage hydraulic cylinder follows the rotation of the wrist joint in the front and rear oil inlet and outlet forms of the traditional hydraulic cylinder.

Description

Secondary drive joint of small underwater hydraulic manipulator

technical field

The invention relates to an underwater robot.

Background technique

Underwater robot is an important tool for modern marine environment monitoring and resource development; with the continuous improvement of its working scope and operating requirements, higher requirements are also put forward for its operating tools. At present, the autonomous underwater vehicle (AUV) has become a research hotspot due to its good concealment and wide use environment. However, due to the limitations of volume, weight and energy, there are few operating manipulators suitable for AUV; especially for AUV Miniaturized hydraulic manipulators with strong upper drive capabilities are especially rare.

At present, most of the domestic patents on the secondary drive joints of underwater manipulators or the rotary and rotary joints of manipulators are installed on underwater electric manipulators; Motors, brakes, harmonic reducers and rotary encoders generate rotary motion and feedback position signals, but they are large in size and belong to single-stage rotary joints. Compared with hydraulic drives, motor drives have relatively small drive torque; such as application number 201110127095 .X. The name is "small electric manipulator two-stage rotary mechanism". The two-stage rotary mechanism is integrated and the structure is relatively compact, but it is also driven by a motor. Compared with hydraulic drive, the driving torque is relatively small, and it is an integrated position detection device.

Contents of the invention

The object of the present invention is to provide a secondary drive joint of a small underwater hydraulic manipulator which is convenient for realizing automatic control.

The purpose of the present invention is achieved like this:

The secondary drive joint of the small-sized underwater hydraulic manipulator of the present invention is characterized in that it includes a claw connector, a piston, a front end cover of the cylinder, an outer cylinder, an outer cylinder for installation, a wrist joint shell, a drive stator, a drive rotor, a wrist shell, The joint rear end cover, the hydraulic cylinder end cover is fixed on the front end cover of the cylinder to form the end cover of the hand hydraulic cylinder, the outer cylinder is installed outside the end cover of the hand hydraulic cylinder, the installation outer cylinder is installed outside the outer cylinder, and the rear of the piston is located outside the outer cylinder. In the cylinder, the front part of the piston is located in the front end cover of the cylinder, and a protrusion is set in the middle of the piston. The guide ring and the gray ring between the protrusion and the outer cylinder realize the guidance and dynamic sealing between the piston and the outer cylinder. The grip connector is provided with an inner hole, the front end of the piston is installed in the inner hole of the grip connector, the tail of the outer cylinder is fixedly connected with the drive shaft, the tail of the outer cylinder is fixedly connected with the wrist joint shell, and the wrist joint shell is connected with the wrist shell Connected, part of the drive shaft is located in the wrist joint shell, the other part of the drive shaft is located in the wrist shell, the wrist shell is connected to the rear end cover of the joint, the drive stator and the drive rotor are located in the wrist joint shell, the drive stator is fixed with the wrist joint shell, and the drive The rotor is fixed to the drive shaft, and the first NPT threaded hole and the second NPT threaded hole for controlling the clockwise and counterclockwise relative rotation between the drive rotor and the drive stator are set on the wrist joint shell, and one end of the drive rotor is connected to the first end of the drive stator. When the two ends are in contact, there is a gap communicating with the first NPT threaded hole between the two, and when the second end of the driving rotor contacts the second end of the driving stator, there is a gap communicating with the second NPT threaded hole between the two. The third NPT threaded hole and the fourth NPT threaded hole that control the forward and backward movement of the piston are set on the wrist shell, the first channel and the second channel are set in the drive shaft, the third channel and the fourth channel are set in the outer cylinder, and the protrusion of the piston The fifth channel and the sixth channel are respectively formed between the front and rear sides of the piston and the outer cylinder, the seventh channel is set in the outer cylinder, the third NPT threaded hole, the first channel, the third channel, the seventh channel, and the third channel The five channels are connected in sequence, and the fourth NPT threaded hole, the second channel, the fourth channel, and the sixth channel are connected in sequence.

The present invention may also include:

1. An angle sensor is also included. The tail end of the wrist joint shell is connected to the support shaft, and the angle sensor is installed on the support shaft.

2. An O-ring radial static seal is used between the outer cylinder and the front end cover of the cylinder. A sliding bearing is installed between the outer cylinder and the outer cylinder. The outer cylinder and the sliding bearing are installed with interference fit. The wrist joint shell and Rolling bearings are installed between the drive shafts, and the rolling bearings are installed with an interference fit with the wrist joint shell, and sliding bearings are installed between the drive shaft and the wrist shell, and the sliding bearings are installed with an interference fit with the wrist shell.

The advantages of the present invention are:

1. The slewing mechanism and the linear motion mechanism are integrated, so that the mechanical arm has a compact structure, the ratio of volume weight to driving force is small, and the optimized hydraulically driven mechanical arm structure provides an ideal structure for miniaturized mechanical wrist joints and grippers. ;

2. The position detection device is integrated inside the joint, and the position detection device is used to collect the angle and angular acceleration signals of the joint operation of the underwater manipulator, and transmit them back to the manipulator control system to realize the closed-loop feedback control of the underwater manipulator;

3. The ingenious arrangement and combination of the first-stage claw hydraulic cylinder inlet and outlet oil passage through the cylinder body, the drive shaft and the internal oil passage of the wrist shell realizes that the claw hydraulic cylinder inlet and outlet are placed at the end of the joint, avoiding the traditional hydraulic cylinder The front and rear oil inlet and outlet forms interfere with the installation of the outer cylinder when the first-stage hydraulic cylinder follows the rotation of the wrist joint and the hydraulic connector connected to the oil inlet and outlet.

Description of drawings

Figure 1 is an overall cross-sectional view of the secondary drive joint of a small underwater hydraulic manipulator;

Fig. 2 is the A-A sectional view of the secondary drive joint of the small underwater hydraulic manipulator;

Fig. 3 is the overall sectional view of the hydraulic drive part of the secondary drive joint of the small underwater hydraulic manipulator;

Fig. 4 is a three-dimensional outline drawing of the hydraulic drive part of the secondary drive joint of the small underwater hydraulic manipulator;

Figure 5 is a diagram of the direction of the oil circuit when the piston of the first-stage claw hydraulic cylinder moves backward;

Fig. 6 is a diagram of the direction of the oil circuit when the piston of the first-stage claw hydraulic cylinder moves forward;

Fig. 7 is the overall appearance diagram of the secondary drive joint of the small underwater hydraulic manipulator.

detailed description

The present invention is described in more detail below in conjunction with accompanying drawing example:

1 to 7, the purpose of the present invention is achieved in this way: the secondary drive joint includes the first-level linear motion claw drive hydraulic cylinder assembly, the second-stage joint rotation assembly, the position detection assembly, and the first-stage hydraulic cylinder assembly. The rear end and the front end of the second-level wrist joint are connected by screws, the oil circuit inside the component is sealed by an O-ring, and the position detection component is in interference fit with the rear-end support shaft of the second-level wrist joint; through the middle part of the second-level joint mechanism The hydraulic oil at the oil inlet/outlet port drives the wrist joint to rotate and drives the first-stage gripper hydraulic cylinder assembly to rotate together, and the hydraulic oil at the oil inlet/outlet port at the tail of the second-stage joint drives the first-stage gripper through the internal oil circuit of the component. The claw hydraulic cylinder moves linearly to provide driving torque for the claw.

The first-stage claw drive hydraulic cylinder assembly is installed on the installation outer cylinder at the front of the second-stage joint through two sliding bearings, and is connected with the second-stage wrist joint shell by screws through the installation outer cylinder; the tail of the first-stage hydraulic cylinder is connected to the second-stage joint. The drive shaft of the secondary wrist joint is connected, and the oil circuit of the first stage hydraulic cylinder is matched with the internal oil circuit of the drive shaft with an O-ring to prevent mutual leakage between the two oil circuits. The oil inlet and outlet ports of the first stage hydraulic cylinder are placed at the rear of the joint to avoid inconvenient installation of the oil circuit when the wrist joint drives the first stage hydraulic cylinder to rotate.

The second-stage wrist joint rotation consists of a hydraulic drive part, a seal, a driving stator mounted on the wrist joint housing, and the wrist housing. The driving rotor is fixedly installed on the driving shaft, and the relative rotation occurs between the rotor and the stator. The rotor drives the driving shaft to generate the rotary motion of the wrist joint, and the second-level dynamic sealing of the wrist joint is realized through seals such as gray rings and O-rings. and static seal; the oil inlet and outlet ports on the wrist shell provide driving hydraulic oil for the first-stage claw hydraulic cylinder through the internal oil circuit of the drive shaft.

The support shaft is threadedly connected with the second-level wrist joint drive shaft, and sealed with thread sealant; the joint angle sensor is set on the support shaft, and the sensor and the support shaft are interference fit, and are installed and fixed by a semicircular installation snap ring. The cover and the wrist shell are connected by screws and sealed by an O-ring to form a closed sensor space, and the angle sensor signal output line is routed inside the watertight connector connected to the joint rear end cover.

The components included in the present invention are: claw connector 1, hydraulic cylinder end cover 2, sealing end cover 3, O-shaped sealing ring 4, gray ring 5, cylinder front end cover 6, installation front end cover 7, rotary oil seal 8, Install outer cylinder 9, sliding bearing A10, rolling bearing 11, wrist joint housing 12, driving shaft 13, sealing assembly 14, driving stator 15, rotor right end cover 16, sliding bearing 17, wrist housing 18, mounting support 19, mounting snap ring 20. Joint rear end cover 21, angle sensor 22, support shaft 23, wrist oil circuit sealing gray ring 24, rotor sealing gray ring 25, driving rotor 26, rotor gasket 27, outer cylinder 28, piston guide ring 29 , Piston 30, piston rod guide ring 31.

As shown in Fig. 1, the present invention describes a two-stage drive joint of a miniaturized underwater hydraulic manipulator, which is mainly composed of a first-stage linear motion, a second-stage joint rotation, and a position detection device. The gripper drive hydraulic cylinder assembly of the first stage linear motion mainly provides the linear driving torque of the gripper end effector, the inner hole of the gripper connector 1 is connected with the gripper end effector, and is threaded with the head of the piston 30; the piston rod guide ring 31. The gray ring 5 is installed inside the front end cover 6 of the cylinder and fixed by the sealing end cover 3. The piston rod guide ring 31 and the gray ring 5 are respectively used for guiding the piston 30 and its linear dynamic sealing. The hydraulic cylinder end cover 2 passes through Screws are installed on the front end cover 6 of the cylinder to form the end cover part of the claw hydraulic cylinder; the end cover part of the hydraulic cylinder is connected with the outer cylinder 28 by threads, and an O-shaped sealing ring 4 is used between the outer cylinder 28 and the front end cover 6 of the cylinder. Static seal; the hydraulic oil drives the piston 30 to move inside the outer cylinder 28 to provide the driving torque of the gripper, and seals the rod chamber and rodless chamber of the hydraulic cylinder through the gray ring, and the front and rear piston guide rings 29 are used for driving and guiding; the outer cylinder The tail of 28 is connected with the drive shaft 13 of the second-level wrist joint with screws, and the oil circuit of the hydraulic cylinder is sealed with an O-ring seal; the outer cylinder 28 is supported and positioned by two sliding bearings A10 and the wrist joint rolling bearing 11, and the sliding bearing A10 and The outer cylinder 9 is installed with interference fit; the dynamic seal uses a rotary oil seal 8, and the static seal adopts an O-shaped seal ring end face seal. The front end cover 7 is connected to the installation outer cylinder 9 through screws, and the tail of the installation outer cylinder 9 is connected to the second through a set of screws. The secondary wrist joint housing 12 is tightly fixed.

As shown in Figure 1, Figure 2 and Figure 3, the hydraulic drive part and the driving stator 15 installed on the wrist joint shell 12 relatively rotate under the action of hydraulic oil, which itself is installed on the wrist joint shell through rolling bearings 11 and sliding bearings 17 12 and the wrist shell 18, and the rolling bearing 11 and the sliding bearing 17 are respectively installed with the interference fit of the wrist joint shell 12 and the wrist shell 18, and the wrist joint shell 12 and the wrist shell 18 are tightly connected by a set of screws; the hydraulic drive part and the wrist shell 18 are tightly connected. The wrist shells 18 are sealed by a set of O-rings and the wrist oil circuit sealing gray ring 24, so as to prevent mutual leakage between the two oil circuits of the claw hydraulic cylinder and leakage of hydraulic oil to the angle sensor part and the wrist. Inside the joint housing 12; two NPT threaded holes (shown in Figure 2) on point B on the wrist housing 18 are used to install the threaded joint and connect with the external hydraulic oil pipe; The two ends of the rotor 26 are coated with sealant and installed on the driving shaft 13 through screws and positioning pins. The right end cover 16 of the rotor is matched with the O-ring and tightly connected to the driving rotor 26 through locking screws, and assembled with the driving shaft 13 and the driving rotor 26. The rotor assembly (as shown in Figure 3) is composed; the rotor assembly realizes radial dynamic sealing through the rotor sealing gray ring 25 to prevent external leakage of hydraulic oil; the sealing assembly 14 is sealed by a nitrile rubber ring and a square PTFE (polytetrafluoroethylene) It is composed of rings to solve the problem of circular arc surface dynamic sealing (as shown in Figure 2) that generates relative motion between the driving rotor 26, the driving stator 15 and the wrist joint casing 12 and the driving shaft 13 respectively; the supporting shaft 23 and the driving shaft 13 Threaded connection, and apply thread sealant to seal the threaded connection.

As shown in Figure 1, the angle sensor 22 collects the angle and angular acceleration signals of the wrist joint rotation, and transmits them back to the manipulator control system to realize the closed-loop feedback control of the underwater manipulator; the angle sensor 22 passes through the support shaft 23 of the hydraulic drive part The two semicircular mounting snap rings 20 are clamped, and the mounting snap ring 20 and the mounting support 19 are tightly connected to the wrist shell 18 through a set of screws; the joint rear end cover 21 is connected to the wrist shell 18 through screws , and sealed with an O-ring; the sensor signal line will be connected to the outside through a watertight head connected to the rear end cover 21 of the joint.

How this implementation works is:

The second-stage joint rotation principle is that the hydraulic oil enters the working chamber through the wrist shell 18 and the NPT threaded hole at point B (wrist joint oil inlet and outlet shown in Figure 2) to connect the threaded joint to act on the drive rotor 26, and drives the drive shaft 13, Rotor right end cover 16, hydraulic driving part composed of driving rotor 26 and driving stator 15 produce relative motion, and because the tail of the outer cylinder 28 of the first-stage claw hydraulic cylinder is connected and fixed with the driving shaft 13, so the first The first-stage claw hydraulic cylinder will rotate with the second-stage wrist joint; the hydraulic oil driven by the first-stage linear motion claw hydraulic cylinder will pass through the drive shaft 13 and the internal oil circuit of the outer cylinder 28 from the A and B inlet/outlet ports (The oil circuit shown by the arrow in Figure 4) acts on the end face of the piston 30, and the piston 30 moves linearly under the guidance of the piston guide ring 29 and the piston rod guide ring 31, and acts on the end of the hand claw through the claw connector 1 connected to the piston 30. On the actuator; the dynamic sealing part of the patent of the present invention adopts the gray ring 5 and the rotary oil seal 8, and the static sealing part adopts the traditional O-shaped sealing ring 4.

Claims (3)

1. The secondary drive joint of a small underwater hydraulic manipulator is characterized by: including claw connectors, pistons, cylinder front cover, outer cylinder, installation outer cylinder, wrist joint shell, drive stator, drive rotor, wrist shell, The joint rear end cover, the hydraulic cylinder end cover is fixed on the front end cover of the cylinder to form the end cover of the hand hydraulic cylinder, the outer cylinder is installed outside the end cover of the hand hydraulic cylinder, the installation outer cylinder is installed outside the outer cylinder, and the rear of the piston is located outside the outer cylinder. In the cylinder, the front part of the piston is located in the front end cover of the cylinder, and a protrusion is set in the middle of the piston. The guide ring and the gray ring between the protrusion and the outer cylinder realize the guidance and dynamic sealing between the piston and the outer cylinder. The grip connector is provided with an inner hole, the front end of the piston is installed in the inner hole of the grip connector, the tail of the outer cylinder is fixedly connected with the drive shaft, the tail of the outer cylinder is fixedly connected with the wrist joint shell, and the wrist joint shell is connected with the wrist shell Connected, part of the drive shaft is located in the wrist joint shell, the other part of the drive shaft is located in the wrist shell, the wrist shell is connected to the rear end cover of the joint, the drive stator and the drive rotor are located in the wrist joint shell, the drive stator is fixed with the wrist joint shell, and the drive The rotor is fixed to the drive shaft, and the first NPT threaded hole and the second NPT threaded hole for controlling the clockwise and counterclockwise relative rotation between the drive rotor and the drive stator are set on the wrist joint shell, and one end of the drive rotor is connected to the first end of the drive stator. When the two ends are in contact, there is a gap communicating with the first NPT threaded hole between the two, and when the second end of the driving rotor contacts the second end of the driving stator, there is a gap communicating with the second NPT threaded hole between the two. The third NPT threaded hole and the fourth NPT threaded hole that control the forward and backward movement of the piston are set on the wrist shell, the first channel and the second channel are set in the drive shaft, the third channel and the fourth channel are set in the outer cylinder, and the protrusion of the piston The fifth channel and the sixth channel are respectively formed between the front and rear sides of the piston and the outer cylinder, the seventh channel is set in the outer cylinder, the third NPT threaded hole, the first channel, the third channel, the seventh channel, and the third channel The five channels are connected in sequence, and the fourth NPT threaded hole, the second channel, the fourth channel, and the sixth channel are connected in sequence. 2. The secondary drive joint of the small underwater hydraulic manipulator according to claim 1, characterized in that: it also includes an angle sensor, the tail end of the wrist joint shell is connected to the support shaft, and the angle sensor is installed on the support shaft. 3. The secondary drive joint of a small underwater hydraulic manipulator according to claim 1 or 2, characterized in that: an O-ring seal is used for radial static sealing between the outer cylinder and the front end cover of the cylinder, and the outer cylinder and the outer cylinder are installed. Sliding bearings are installed between the cylinders, the outer cylinder and the sliding bearings are installed with an interference fit, rolling bearings are installed between the wrist joint shell and the drive shaft, the rolling bearings are installed with an interference fit with the wrist joint shell, and sliding bearings are installed between the drive shaft and the wrist shell , The sliding bearing and the wrist housing are installed with an interference fit.