Patent Description:
The present application relates to the technology field of robots, in particular to a micro electro-hydraulic linear actuator and a dexterous hand of an electro-hydraulic driven robot therewith.

A humanoid robot is an automatic equipment integrating advanced technologies in many fields such as electronics, machinery, control, sensing and artificial intelligence. It represents the high-tech development level of a country. The humanoid robot has the appearance of human beings, can adapt to the living and working environment of human beings and complete various operations instead of human beings, and can expand human capabilities in many aspects. At present, the humanoid robot has developed rapidly at home and abroad, and has been widely used in many fields, such as service, medical treatment, education, entertainment and so on. As the end effector of humanoid robot, the dexterous hand can help human beings to complete a lot of work. However, at present, the bionic dexterous hand at home and abroad is still in the development stage, and there are few practical applications.

At present, the robot power system mainly includes the motor scheme composed of servo motor and precision reducer and the hydraulic driving scheme. The motor scheme is the mainstream application at current, which drives the fingers to grasp through the steel wire, tendon rope and connecting rod. However, due to the rigid connection structure of motor and reducer, the impact resistance is poor, and the maximum grasping force provided by fingertip is very small, usually less than 10N, so the application is limited. At the same time, since the system lacks flexibility, the motor power density is low, and the power is insufficient in some occasions. The core components of the hydraulic drive scheme are the oil pump, servo valve and oil cylinder connected through the oil pipeline. Hydraulic power drive can increase the flexibility of the system and greatly improve the driving force of the system, especially the grasping force on the fingertip can be doubled. Therefore, hydraulic drive is an application research direction of robot drive, but the current hydraulic drive mode generally adopts centralized hydraulic source, the main power pump drives more than ten hydraulic actuators for centralized energy supply, with a large volume, a heavy weight and complex hardware pipelines. After the robot loads the hydraulic components, there is almost no large load capacity for effective scene application, especially in the application of bionic robot, quadruped robot, robot joint, robot finger and so on. Due to that the driving force needs to overcome the self weight resistance, the dexterous hand of the robot has a huge volume, increased weight and large power loss, the application thus is greatly limited. For robot fingers, due to the complex system and large volume, the effective grasping force of the fingertip is very small, and even cannot be used.

Spherical pump is a newly invented power machine in recent years, which can realize ultra miniaturization and high pressure. It can realize series direct drive in the field of robot dexterous hand. Compared with the traditional line drive and push rod motor drive, it has the characteristics of large torque, impact resistance and ultra miniaturization. The application of spherical pump in power source of dexterous hand of the robot has a good application prospect.

<CIT> discloses an integrated micro electro-hydraulic actuator, which includes a fuel tank, a pressure switch, a motor, a hydraulic pump, an integrated valve block, a hydraulic cylinder and connecting bolts. The fuel tank is composed of a cylindrical shell, an upper cover and a bottom cover. The hydraulic cylinder, the integrated valve block, the hydraulic pump and the motor are connected in sequence to form a cylinder. The connecting bolts connect the cylinder to the bolt seat of the bottom cover. The pressure switch is located at the integrated valve block and is connected to the control oil path. This application integrates the hydraulic cylinder, the integrated valve block, the hydraulic pump with the motor, so that the hydraulic drive station and the mechanical actuator are combined in the oil tank, which makes the size small, the structure compact, and ensure good stability and easy use.

<CIT> discloses an actuator comprises a pump-driving section which is driven and rotated by a current, and a pump mechanism which is connected to the pump-driving section and which sucks/discharges a pressure oil. A cylinder mechanism, which has a piston that is displaceable in the axial direction by being supplied with the pressure oil, is provided on the pump-driving section and the pump mechanism. The amount of discharge of the pressure oil to the cylinder mechanism is adjusted by freely changing the angle of inclination of a tilting member provided in the pump mechanism.

<CIT> discloses an energy-storage spherical pump electro-hydraulic actuator, which includes a motor, a spherical pump and a double piston rod cylinder assembly. The two oil inlets and outlets of the spherical pump are arranged at the cylinder cover. The double piston rod cylinder assembly includes an actuator and a double piston rod. The upper part of the actuator is provided with a connecting block connected to the cylinder cover. The connecting block fixes the actuator to the cylinder cover through two guide bolts. The two guide bolts connect the two oil inlets and outlets of the spherical pump to the working chamber and non-working chamber at both ends of the actuator respectively. The double piston rod is provided with a pressure relief hole and a floating piston. One end of the floating piston is abutted against an energy storage spring, and the other end is connected to the pressure relief hole to form a pressure relief channel. The above-mentioned energy-storage spherical pump electro-hydraulic actuator has a compact structure, and the floating piston can automatically adjust the volume of liquid in a closed system, which can be used in skeletal suits and autonomous walking robots.

A purpose of the present application is to design a micro electro-hydraulic linear actuator, which integrates pump, motor and hydraulic piston, adopts modular design, and acts as a distributed hydraulic source to provide power for the robot.

Another purpose of the present application is to design a dexterous hand of an electro-hydraulic driving robot, which adopts a spherical pump electro-hydraulic integrated modular ultra micro electro-hydraulic linear driver, a sensor is provided on the finger, an ultra micro electro-hydraulic linear driver is provided on the knuckle of each finger, and the distributed hydraulic pressure source is directly driven in series, so as to realize the flexible action of each finger of the dexterous hand of the robot, increase the grasping force of the fingertip and withstand the impact load, convenient control.

In order to achieve the above purpose, the present application provides a micro electro-hydraulic linear actuator, comprising: an actuator base, a spherical pump unit and a reciprocating piston mechanism; the actuator base being provided with a hydraulic cylinder and a cylinder liner; each of the hydraulic cylinder and the cylinder liner having a cylindrical chambers with an opening at one end, the reciprocating piston mechanism being provided in the hydraulic cylinder, and an opening end of the hydraulic cylinder being provided with an end cover of the hydraulic cylinder; a piston rod hinge hole being provided at an end of a piston rod of the reciprocating piston mechanism extending out from a bottom of the hydraulic cylinder, and an actuator hinge hole being provided on an end cover of the hydraulic cylinder; an open end of the cylinder liner being provided with an end cover of the motor; the spherical pump unit comprising a spherical pump and a motor, and the spherical pump and the motor being integrated in the cylinder liner; a first inlet-outlet hole and a second inlet-outlet hole of the spherical pump being respectively communicated with two working chambers in the hydraulic cylinder of the reciprocating piston mechanism; and the micro electro-hydraulic linear actuator being encapsulated in a closed elastic leather bag, and the end of the piston rod extending out from the elastic leather bag.

The present application provides a dexterous hand of an electro-hydraulic driving robot, comprising a palm, a thumb, an index finger, a middle finger, a ring finger and a little finger; structures of the index finger, the middle finger, the ring finger and the little finger being the same and all comprising a first knuckle, a second knuckle and a third knuckle hinged in turn; the first knuckle being hinged on the palm through a knuckle swing support; a knuckle micro electro-hydraulic linear actuator being respectively provided in the first knuckle, the second knuckle and the third knuckle; a piston rod of the knuckle micro electro-hydraulic linear actuator in the third knuckle being hinged with the second knuckle; a piston rod of the knuckle micro electro-hydraulic linear actuator in the second knuckle being hinged with the first knuckle; a piston rod of the knuckle micro electro-hydraulic linear actuator in the first knuckle being hinged with the knuckle swing support to form a connecting rod mechanism to transmit power; a corresponding knuckle being driven to bend and stretch back and forth when the piston rod of each knuckle micro electro-hydraulic linear actuator in the first knuckle, the second knuckle and the third knuckle expands and contracts; and.

Compared with the prior art, the advantages of the present application are as follows:
The micro electro-hydraulic linear actuator of the present application adopts the distributed hydraulic source as the driving force, does not need the directional valve, and can realize the integrated design of pump motor and cylinder. The system does not need to arrange complex oil pipeline, with small volume and high power density, and increases the effective hydraulic energy output and the flexibility of system movement, and can bear the impact load. Modular design is adopted, which is convenient for mass production, manufacturing, maintenance and use.

The dexterous hand of the electro-hydraulic driving robot of the present application adopts the distributed hydraulic source as the driving force, the spherical pump electro-hydraulic linear actuator has small volume and large output power, and a micro electro-hydraulic linear driver is arranged in the parts where each finger joint needs to move, which reduces the volume of each driving system, increases the flexibility of finger movement, can bear the impact load and increases the grasping force of the finger.

The specific embodiment of the present application is described in further detail below in combination with the accompanying drawings.

In order to have a clearer understanding of the technical solution, purpose and effect of the present application, the specific embodiment of the present application is described in combination with the accompanying drawings.

As shown in <FIG>, <FIG>, <FIG>, the micro electro-hydraulic linear actuator <NUM> is a super micro structure. "micro" means that the overall dimension of the electro-hydraulic linear actuator is very small and can be set in each knuckle of the finger and the palm <NUM>. The typical overall dimension of the micro electro-hydraulic linear actuator <NUM> in the present application is a rectangle with a length of <NUM>, a width of <NUM> and a height of <NUM>. The micro electro-hydraulic linear actuator <NUM> includes an actuator base <NUM>, a spherical pump unit and a reciprocating piston mechanism. The actuator base <NUM> is provided with a hydraulic cylinder <NUM> and a cylinder liner <NUM>, both of which have cylindrical chambers with an open at one end. An open end of the hydraulic cylinder <NUM> is provided with an end cover of the hydraulic cylinder <NUM>; a sealing ring III <NUM> is provided at a fitting position between the end cover of the hydraulic cylinder <NUM> and the hydraulic cylinder <NUM>. The reciprocating piston mechanism is a double piston rod mechanism. The reciprocating piston mechanism is provided in the hydraulic cylinder <NUM>. A diameter of the piston <NUM> of the reciprocating piston mechanism is matched with a diameter of the cylindrical inner chamber of the hydraulic cylinder <NUM>. The piston sealing ring V17 is provided at a fitting position between the piston <NUM> and the hydraulic cylinder <NUM>, so as to form two working chambers with a variable volume in the hydraulic cylinder <NUM>. The piston rod <NUM> on a side of the piston <NUM> extends from a piston rod through hole at a bottom of the cylindrical inner chamber of the hydraulic cylinder <NUM>. A sealing ring I <NUM> is provided at a fitting position of the piston rod <NUM> and a through hole on the actuator base <NUM>, the piston rod <NUM> on another side of the piston <NUM> slides in the hole (the piston rod hole) in a center of the end cover of the hydraulic cylinder <NUM>. A sealing ring II <NUM> is provided at a fitting position of the piston rod <NUM> and the end cover of the hydraulic cylinder <NUM>. A balance hole <NUM> is provided at a bottom of the piston rod hole on the end cover of the hydraulic cylinder <NUM>, and the balance hole <NUM> is communicated with a gap formed by the elastic leather bag <NUM> and the actuator base <NUM>. A piston rod hinge hole <NUM> is provided at an end of the piston rod <NUM> and extending from a bottom of the hydraulic cylinder <NUM>, and the piston rod hinge hole <NUM> is configured to hinge an end of the piston rod <NUM> with other components to transmit power. The end cover of the hydraulic cylinder <NUM> is provided with an actuator hinge hole <NUM>, which is configured to hinge the micro electro-hydraulic linear actuator <NUM> with other components.

The spherical pump and the motor are integrated into the cylinder liner <NUM> to form a spherical pump unit, and the open end of the cylinder liner <NUM> is provided with an end cover of the motor <NUM>. The spherical pump comprises a cylinder body <NUM>, a cylinder cover <NUM>, a spherical pump piston <NUM>, a rotary table <NUM> and a spherical pump main shaft <NUM>. Both the cylinder cover <NUM> and the cylinder body <NUM> have a hemispherical inner chamber, and the two hemispherical inner chambers are connected to form a spherical inner chamber. After the cylinder cover <NUM> is combined with the cylinder body <NUM>, a sleeve <NUM> is fastened on an outer circumference of the cylinder cover <NUM> and the cylinder body <NUM> by hot fitting, and then the sleeve <NUM> is fastened on an inner circumference at a bottom of the cylindrical chamber of the cylinder liner <NUM> by hot fitting. The cylinder cover <NUM> is provided with a piston shaft hole and two inlet-outlet holes. The two inlet-outlet holes are a first inlet-outlet hole <NUM> and a second inlet-outlet hole <NUM> respectively. Because the spherical pump can operate in clockwise direction as well as in counterclockwise direction, when the motor rotates in the clockwise direction, the first inlet-outlet hole <NUM> is an inlet hole and the second inlet-outlet hole <NUM> is an outlet hole. When the motor rotates in the counterclockwise direction, the first inlet-outlet hole <NUM> is an outlet hole and the second inlet-outlet hole <NUM> is an inlet hole.

The spherical pump piston <NUM> is hinged with the rotary table <NUM> through the cylindrical hinge to form a spherical rotor, which is placed in the spherical inner chamber. The coil winding of the motor stator <NUM> is fixed on an inner wall of the open end of the cylindrical chamber of the cylinder liner <NUM>, the silicon steel sheet of the rotor <NUM> of the motor surrounds an outer circumference of the main shaft <NUM>, and the end cover <NUM> of the motor is fixedly connected to the open end of the cylindrical chamber of the cylinder liner <NUM> through hot interference fitting. A rotary support is formed between the upper end of the main shaft <NUM> of the spherical pump and the sleeve <NUM> of the spherical pump, and a rotary support is formed between a lower end of the main shaft <NUM> and the end cover of the motor <NUM>. Specifically, a sliding fit is provided at a fitting position between the upper end of the main shaft <NUM> and the sleeve <NUM> to form a rotary support at the upper end of the main shaft <NUM>. A central shaft hole <NUM> is provided at a lower end of the main shaft <NUM>, and a support shaft <NUM> fitted with the central shaft hole <NUM> at the lower end of the main shaft <NUM> is provided on the end cover of the motor <NUM>. The support shaft <NUM> can rotate in the central shaft hole to form a rotary support at the lower end of a main shaft <NUM> of the spherical pump.

The micro electro-hydraulic linear actuator <NUM> is encapsulated in a closed elastic leather bag <NUM> filled with hydraulic oil, and the end of the piston rod <NUM> extends out from the elastic leather bag <NUM>. A telescopic sleeve <NUM> and a sealing ring <NUM> are provided at a connecting position between an end of the piston rod <NUM> extending out from the elastic leather bag <NUM> and the elastic leather bag <NUM>. The sealing ring <NUM> is fixedly clamped at the head of the piston rod <NUM>, and the telescopic sleeve <NUM> is connected between the sealing ring <NUM> and the elastic leather bag <NUM>. In practical application, in order to facilitate installation, the actuator hinge hole <NUM> on the end cover of the hydraulic cylinder <NUM> is exposed from the elastic leather bag <NUM>, and a sealing ring VI <NUM> is provided at a fitting position between the end cover of the hydraulic cylinder <NUM> and the elastic leather bag <NUM>. The sealing ring VI <NUM> is configured to fix the elastic leather bag <NUM> on the actuator base <NUM> and seal the liquid between the elastic leather bag <NUM> and the actuator base <NUM>.

As shown in <FIG>, the spherical pump piston <NUM> has a spherical top surface and two side surface formed a certain angle α therebetween (angle α is generally ranges from <NUM>° to <NUM>°) and a semi cylindrical piston pin seat <NUM> at a lower part of the both side surfaces. The spherical top surface of the spherical pump piston <NUM> has the same spherical center with the spherical inner chamber and forms a sealing dynamic fit. A piston shaft <NUM> protrudes from a center of the spherical top surface of the spherical pump piston <NUM>, and the axis of the piston shaft <NUM> passes through a spherical center of the spherical top surface of the spherical pump piston <NUM>. The rotary table <NUM> of the spherical pump has a rotary table pin seat <NUM> corresponding to the piston pin seat <NUM> at an upper part thereof. The outer peripheral surface between the upper end surface and lower end surface of the rotary table <NUM> of the spherical pump is a rotary table spherical surface, rotary table spherical surface has the same spherical center as the spherical inner chamber, tightly contacts the spherical inner chamber to form a sealed dynamic fit with the spherical inner chamber. The rotary table pin seat <NUM> is a semi cylindrical groove fitted with the piston pin seat <NUM>. A rotary table shaft <NUM> protrudes from a center of the lower end of the rotary table <NUM>. The rotary table shaft <NUM> passes through the spherical center of the spherical surface of the rotary table, and a slipper <NUM> is provided at the end of the rotary table shaft <NUM> of the rotary table <NUM>. A height of the semi cylindrical groove of the rotary table pin seat <NUM> is slightly higher than a center line of the semi cylinder, that is, the depth dimension of the semi cylindrical groove is slightly larger than the radius of the semi cylinder, that is, the section shape of the semi cylindrical groove is of a major arc shape, and the semi cylinder of the piston pin seat <NUM> needs to be inserted into the semi cylindrical groove of the rotary table pin seat <NUM> from the end of the cylinder to form a cylindrical hinge. The cylindrical hinge in this embodiment is a sleeve structure of C shape, and the circular arc of the groove part of the rotary table pin seat <NUM> of the rotary table <NUM> is wrapped on the outer cylindrical surface of the piston pin seat <NUM> to enable a rotation around a center line of the cylinder. In practical application, the cylindrical hinge can also be a hinge formed by other cylindrical forms.

The rotary shaft <NUM> of the rotary table <NUM> extends from a lower opening of the cylinder <NUM> and is movably connected with the upper end surface of the main shaft <NUM>. As shown in <FIG>, a sliding groove <NUM> is provided on the upper end surface of the main shaft <NUM> of the spherical pump, the slipper <NUM> is fitted with the sliding groove <NUM>, and the slipper <NUM> on the rotary table shaft <NUM> is inserted into the sliding groove <NUM> on the main shaft <NUM> to slide. The axes of the piston shaft hole and the rotary table shaft <NUM> pass through the spherical center of the spherical inner chamber, and the included angle between the axis of the piston shaft hole and the rotary table shaft <NUM> is α.

When the main shaft <NUM> of the spherical pump rotates, the rotary table <NUM> and the spherical pump piston <NUM> are driven to rotate in the spherical inner chamber of the spherical pump; the slipper <NUM> of the rotary table <NUM> swings back and forth in the sliding groove <NUM> of the main shaft <NUM>; the rotary table <NUM> and the spherical pump piston <NUM> swing relative to each other, and V1 and V2 working chambers with variable volume are formed between an upper end surface of the rotary table <NUM>, the two side surfaces of the spherical pump piston <NUM> and the spherical inner chamber. The two inlet-outlet holes (i.e., the first inlet-outlet hole <NUM> and the second inlet-outlet hole <NUM>) of the cylinder cover <NUM> are respectively connected with the two working chambers on both side of the hydraulic cylinder <NUM> of the piston <NUM> of the reciprocating piston mechanism through the first inlet-outlet channel <NUM> and the second inlet-outlet channel <NUM> provided in the actuator base <NUM> (two working chambers on both sides of the piston of the reciprocating piston mechanism are provided with inlet-outlet holes. One working chamber is provided with an inlet hole, and the other working chamber is provided with an outlet hole. The outlet hole of the spherical pump is connected with the inlet hole of the reciprocating piston mechanism, and the inlet hole of the spherical pump is connected with the outlet hole of the reciprocating piston mechanism). That is, the two inlet-outlet holes on the cylinder cover <NUM> of the spherical pump are respectively communicated with the working chambers on both sides of the piston <NUM> of the reciprocating piston mechanism.

As shown in <FIG> and <FIG>, in the second embodiment of the present application, except that the main shaft I 6A, the actuator base I 3A, the stator I 4A of the motor and the rotor I 5A of the motor are slightly different from the first embodiment, the others are exactly the same. In the second embodiment, the shaft diameter of the main shaft I 6A is smaller than that of the main shaft <NUM> in the first embodiment, the axial dimensions of the stator I 4A and the rotor I 5A of the motor are shorter than that of the stator <NUM> and the rotor <NUM> of the motor in the first embodiment. The rotor I 5A of the motor is provided on the outer circumference of the shaft at the lower end of the main shaft I 6A, and the stator I 4A of the motor and the rotor I 5A of the motor are opposite to each other in a radial direction. The stator I 4A of the motor is fitted with the actuator base I 3A, and the stator I 4A of the motor is fixedly provided on an inner wall of the cylindrical inner chamber of the open end of the spherical pump cylinder liner of the actuator base I 3A. This structure can compress a radial dimension of the main shaft of the spherical pump unit.

In the first embodiment, the radial dimension of the main shaft <NUM> is larger, the sleeve <NUM> of the spherical pump, together with the cylinder body <NUM> and the cylinder cover <NUM>, is mainly contained in the chamber formed at the upper end of the main shaft <NUM>, the axial length dimension of the rotor <NUM> and the stator <NUM> of the motor is larger, and the electromagnetic force is formed on the full axial length of the main shaft <NUM>. Under the same volume, the structural form of the first embodiment facilitates the spherical pump to obtain a larger motor torque and a larger driving force. Therefore, the first embodiment is the preferred structure of the present application.

As shown in <FIG>, the dexterous hand of the electro-hydraulic driving robot is a five finger structure, including a palm <NUM>, a thumb, an index finger, a middle finger, a ring finger and a little finger. The structures of the index finger, the middle finger, the ring finger and the little finger are the same, and all include a first knuckle <NUM>, a second knuckle <NUM> and a third knuckle <NUM> hinged in turn. The first knuckles of the index finger, the middle finger, the ring finger and the little finger are hinged on the palm <NUM> through a swing support <NUM> (i.e., knuckle swing support). A micro electro-hydraulic linear actuator <NUM> (i.e., a knuckle micro electro-hydraulic linear actuator) is hinged in each of the first knuckle <NUM>, the second knuckle <NUM> and the third knuckle <NUM>.

The swing support <NUM> is provided with a swing support and palm hinge hole <NUM>, a swing support and piston rod hinge hole I <NUM> (for hinge with the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the palm <NUM>), and a swing support and piston rod hinge hole II <NUM> (for hinge with the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the first knuckle <NUM>). The first knuckle <NUM> is provided with a first knuckle and swing support hinge hole <NUM>, a first knuckle and micro electro-hydraulic linear actuator hinge hole <NUM>, and a first knuckle and piston rod hinge hole <NUM>. The second knuckle <NUM> is provided with a second knuckle and first knuckle hinge hole <NUM>, a second knuckle and micro electro-hydraulic linear actuator hinge hole <NUM>, and a second knuckle and piston rod hinge hole <NUM>. The third knuckle <NUM> is provided with a third knuckle and second knuckle hinge hole <NUM>, and a third knuckle and micro electro-hydraulic linear actuator hinge hole <NUM>. In addition, the swing support <NUM> is also provided with a hinge hole connected with the first knuckle <NUM> (fitted with the first knuckle and the swing support hinge hole <NUM>), the first knuckle <NUM> is also provided with a hinge hole connected with the second knuckle <NUM> (fitted with the second knuckle and first knuckle hinge hole <NUM>), and the second knuckle <NUM> is also provided with a hinge hole connected with the third knuckle <NUM> (fitted with the third knuckle and second knuckle hinge hole <NUM>).

The piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> is provided with a piston rod hinge hole <NUM>, which is configured to hinge the end of the piston rod <NUM> with other components to transmit power. The end cover of the hydraulic cylinder <NUM> of the micro electro-hydraulic linear actuator <NUM> is provided with an actuator hinge hole <NUM>, which is configured to hinge the micro electro-hydraulic linear actuator <NUM> with other components.

The piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the third knuckle <NUM> is hinged with the second knuckle <NUM>, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the second knuckle <NUM> is hinged with the first knuckle <NUM>, and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the first knuckle <NUM> is hinged with the swing support <NUM>, so as to form a connecting rod mechanism to transmit power, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in each of the first knuckle <NUM>, the second knuckle <NUM> and the third knuckle <NUM> drives the corresponding knuckle to bend and stretch back and forth.

Five, from a first to a fifth micro electro-hydraulic linear actuators <NUM> (i.e., palm micro electro-hydraulic linear actuator) are provided in the palm <NUM>, that is, five micro electro-hydraulic linear actuators <NUM> are provided in the palm <NUM>. The five micro electro-hydraulic linear actuators <NUM> are the first micro electro-hydraulic linear actuator, the second micro electro-hydraulic linear actuator, the third micro electro-hydraulic linear actuator, the fourth micro electro-hydraulic linear actuator and the fifth micro electro-hydraulic linear actuator. The first micro electro-hydraulic linear actuator <NUM> is configured to control a thumb base <NUM>, and the second to fifth micro electro-hydraulic linear actuators <NUM> are configured to control the index finger, middle finger, ring finger and little finger respectively. The piston rod <NUM> of the second to fifth micro electro-hydraulic linear actuators <NUM> is hinged with the swing support <NUM> (i.e., palm swing support), and each swing support <NUM> is hinged with the first knuckle <NUM> of the corresponding index finger, middle finger, ring finger or little finger to form a connecting rod mechanism to transmit power. When the piston rod <NUM> of the second to fifth micro electro-hydraulic linear actuators <NUM> is retracted, the corresponding index finger, middle finger, ring finger and little finger swing left and right in the plane of the palm.

The swing supports <NUM> connected with the second to fifth micro electro-hydraulic linear actuators <NUM> in the palm <NUM> are hinged with palm <NUM>, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the palm <NUM> and the first knuckle <NUM> and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the first knuckle <NUM> through its four hinged holes. The first knuckle <NUM> is hinged with the swing support <NUM>, the micro electro-hydraulic linear actuator <NUM> on the first knuckle <NUM>, the second knuckle <NUM> and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the second knuckle <NUM> through four hinged holes thereon. The second knuckle <NUM> is hinged with the first knuckle <NUM>, the micro electro-hydraulic linear actuator <NUM> on the second knuckle <NUM>, the third knuckle <NUM> and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the third knuckle <NUM> through four hinged holes thereon. The third knuckle <NUM> is hinged with the second knuckle <NUM> and the micro electro-hydraulic linear actuator <NUM> on the third knuckle <NUM> respectively through two hinged holes thereon.

As shown in <FIG>, the connecting rod structure of each knuckle of the index finger, middle finger, ring finger and little finger is as follows: the first knuckle <NUM>, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> and the swing support <NUM> form a connecting rod mechanism. The second knuckle <NUM>, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> and the first knuckle <NUM> form a connecting rod mechanism. The third knuckle <NUM>, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> and the second knuckle <NUM> form a connecting rod mechanism. The swing support <NUM>, the palm <NUM> and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> form a connecting rod mechanism.

As shown in <FIG>, the thumb comprises a thumb base <NUM>, a first knuckle <NUM> of the thumb and a second knuckle <NUM> of the thumb hinged in turn. The first knuckle <NUM> of the thumb is hinged on the thumb base <NUM> through the swing support <NUM> (i.e., the thumb swing support), and a micro electro-hydraulic linear actuator <NUM> is hinged on the thumb base <NUM>, the first knuckle <NUM> of the thumb and the second knuckle <NUM> of the thumb respectively. The thumb base <NUM> is provided with a hole <NUM> for hinging the thumb base and the micro electro-hydraulic linear actuator, a hole <NUM> for hinging the thumb base and the palm, and a hole <NUM> for hinging the thumb base and the piston rod. The first knuckle <NUM> of the thumb is provided with a hole <NUM> for hinging the first knuckle of the thumb and the swing support, a hole <NUM> for hinging the first knuckle of the thumb and the micro electro-hydraulic linear actuator, and a hole <NUM> for hinging the first knuckle of the thumb and the piston rod; the second knuckle <NUM> of the thumb is provided with a hole <NUM> for hinging the second knuckle of the thumb and the first knuckle of the thumb, and a hole <NUM> for hinging second knuckle of the thumb and the micro electro-hydraulic linear actuator. In addition, the first knuckle <NUM> of the thumb is also provided with a hinge hole connected with the second knuckle <NUM> of the thumb (fitted with the hole <NUM> for hinging second knuckle of the thumb and first knuckle of the thumb), and the swing support <NUM> is also provided with a hinge hole connected with the first knuckle of the thumb (fitted with the hole <NUM> for hinging the first knuckle of the thumb and the swing support); and the thumb base <NUM> is also provided with a hinge hole connected with the swing support <NUM> (fitted with a hole <NUM> for hinging the swing support and the palm hinge).

The swing support <NUM> on the thumb base <NUM> is hinged with the thumb base <NUM>, the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the thumb base <NUM>, the first knuckle <NUM> of the thumb and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the first knuckle <NUM> of the thumb through four hinged holes thereon. The thumb base <NUM> is hinged with the palm <NUM>, the piston rod <NUM> of the first micro electro-hydraulic linear actuator <NUM> in the palm <NUM>, the micro electro-hydraulic linear actuator <NUM> on the thumb base <NUM> and the first knuckle <NUM> of the thumb respectively. The first knuckle <NUM> of the thumb is hinged with the swing support <NUM> connected to the thumb base <NUM>, the micro electro-hydraulic linear actuator <NUM> on the first knuckle <NUM> of the thumb, the second knuckle <NUM> of the thumb and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> on the second knuckle <NUM> of the thumb respectively. The second knuckle <NUM> of the thumb is hinged with the first knuckle <NUM> of the thumb and the micro electro-hydraulic linear actuator <NUM> on the second knuckle <NUM> of the thumb respectively.

The piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the second knuckle <NUM> of the thumb is hinged with the first knuckle <NUM> of the thumb, and the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the first knuckle <NUM> of the thumb is hinged with the thumb base <NUM> through the swing support <NUM> to form a connecting rod mechanism to transmit power. When the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the second knuckle <NUM> of the thumb is retracted, the corresponding knuckle can be bent and extended back and forth. When the piston rod <NUM> of the micro electro-hydraulic linear actuator <NUM> in the thumb base <NUM> is retracted, the thumb can swing left and right in the palm plane. The thumb base <NUM> is hinged on the palm <NUM>. The piston rod <NUM> of the first micro electro-hydraulic linear actuator <NUM> in the palm <NUM> is hinged with the thumb base <NUM> to form a connecting rod mechanism to transmit power. When the piston rod <NUM> of the first micro electro-hydraulic linear actuator <NUM> is retracted, the thumb can rotate back and forth to the palm.

A sensor <NUM> is provided on the fingertip of each finger, that is, on the fingertip of each of the third knuckles <NUM> and the second knuckle <NUM> of the thumb. The sensor <NUM> includes a position sensor and a force sensor. The position sensor is configured to sense the position change of the finger, and the force sensor is configured to detect the grasping force on the fingertip. Each sensor <NUM> and each micro electro-hydraulic linear actuator <NUM> are electrically connected with a controller of the robot through wires. The controller controls the motor operation of the micro electro-hydraulic linear actuator <NUM> according to robot commands, supplies power to the motor, receives and collects the information transmitted by the sensor <NUM>, adjusts and generates new commands, and realizes the intelligent control of finger action.

Claim 1:
A micro electro-hydraulic linear actuator (<NUM>), comprising an actuator base (<NUM>), a spherical pump unit and a reciprocating piston mechanism;
characterized by, the actuator base (<NUM>) being provided with a hydraulic cylinder (<NUM>) and a cylinder liner (<NUM>); each of the hydraulic cylinder (<NUM>) and the cylinder liner (<NUM>) having a cylindrical chambers with an opening at one end, the reciprocating piston mechanism being provided in the hydraulic cylinder (<NUM>), and an opening end of the hydraulic cylinder (<NUM>) being provided with an end cover of the hydraulic cylinder (<NUM>); a piston rod hinge hole (<NUM>) being provided at an end of a piston rod (<NUM>) of the reciprocating piston mechanism extending out from a bottom of the hydraulic cylinder (<NUM>), and an actuator hinge hole (<NUM>) being provided on an end cover of the hydraulic cylinder (<NUM>); an open end of the cylinder liner (<NUM>) being provided with an end cover of the motor (<NUM>); the spherical pump unit comprising a spherical pump and a motor, and the spherical pump and the motor being integrated in the cylinder liner (<NUM>); a first inlet-outlet hole (<NUM>) and a second inlet-outlet hole (<NUM>) of the spherical pump being respectively communicated with two working chambers in the hydraulic cylinder (<NUM>) of the reciprocating piston mechanism; and the micro electro-hydraulic linear actuator (<NUM>) being encapsulated in a closed elastic leather bag (<NUM>), and the end of the piston rod extending out from the elastic leather bag (<NUM>).