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CN-224214466-U - Compact power unit and electrohydraulic actuator

CN224214466UCN 224214466 UCN224214466 UCN 224214466UCN-224214466-U

Abstract

The utility model discloses a compact power unit and an electrohydraulic actuator, which comprise a motor component for providing power, a plunger pump component for outputting hydraulic power and an oil tank for containing hydraulic medium, wherein the motor component comprises a driving shaft, a stator component, a rotor component and a motor front end cover, the plunger pump component is completely contained in the oil tank, the plunger pump component comprises a pump body, a valve plate, a cylinder body and a sloping cam plate, the shaft extension end of the driving shaft is directly inserted into a rotation center hole, the shaft extension end cantilever of the driving shaft supports the cylinder body and drives the cylinder body to synchronously operate through a key, the cylinder body is abutted against the valve plate under the action of hydraulic pressure, the valve plate is supported on the pump body, the end part of the pump body of the plunger pump component is fixedly connected with the motor front end cover of the motor component, and an oil inlet opening to the inner cavity of the oil tank is arranged on the pump body so that the cavity of the pump body is communicated with the inner cavity of the oil tank. The power unit has the advantages of compact structure, high power density and low manufacturing cost.

Inventors

  • ZHONG BIAO
  • TIAN YUNTAO
  • YANG BO

Assignees

  • 上海强田驱动技术有限公司

Dates

Publication Date
20260508
Application Date
20240105

Claims (12)

  1. 1. A compact power unit, comprising: The front end of a driving shaft (10) of the motor assembly (1) extends out of a front end cover of the motor to form a shaft extending end; The plunger pump assembly (3) comprises a pump body and is directly connected with the motor assembly through the pump body, the plunger pump assembly (3) further comprises a flow distribution pair and a sliding disc pair, a plurality of plungers are arranged in the pump body, one ends of the plungers are matched with the cylinder body, the other ends of the plungers are matched with the sloping cam plate through the sliding disc (50) and the pressure plate, the shaft extension end is directly inserted into the cylinder body in a cantilever state and supports the cylinder body, the shaft extension end is matched with the cylinder body to drive the plungers and the sliding disc (50) to rotate so as to realize reciprocating motion of the plungers for absorbing oil and pressing oil, and low-pressure oil enters the plunger hole from the flow distribution pair and/or the sliding disc pair and discharges high-pressure oil from the sliding disc pair; The oil tank is used for containing hydraulic oil and supplying oil to the plunger pump assembly (3), the shaft extension end stretches into the oil tank, the plunger pump assembly (3) is located in the oil tank and is immersed by the hydraulic oil, and the pump body is provided with an oil inlet communicated with the oil tank.
  2. 2. The compact power unit as claimed in claim 1, wherein the motor assembly (1) comprises a motor housing, one end of the motor housing is sealed by a motor front end cover in a matched manner, the driving shaft (10) is positioned in the motor housing, the driving shaft (10) is connected with a rotor assembly in a matched manner, a stator assembly matched with the rotor assembly in a matched manner is arranged on the inner surface of the motor housing, the front part of the driving shaft (10) is matched with the motor housing through a first bearing, and the rear part of the driving shaft (10) is matched with the motor housing through a second bearing.
  3. 3. The compact power unit as claimed in claim 1 or 2, wherein a heat insulation sealing gasket (2) is arranged between the motor assembly (1) and the oil tank and/or between the motor assembly (1) and the pump body, and the heat insulation sealing gasket (2) is used for preventing the temperature of oil in the oil tank from being conducted into the motor assembly (1).
  4. 4. The compact power unit according to claim 1 or 2, characterized in that an oil seal assembly is arranged between the drive shaft (10) and the motor front end cover, and the opening of the oil seal assembly faces the plunger pump assembly (3).
  5. 5. The compact power unit of claim 1, wherein plunger holes corresponding to the plungers one by one are formed in the cylinder body, the plungers enter the plunger holes in a matched mode from the rear end face of the cylinder body and slide back and forth relative to the plunger holes, the plunger holes extend to the front end face of the cylinder body and are covered by a valve plate of the front end face of the cylinder body, a low-pressure valve opening (92) is formed in the valve plate, and the cylinder body rotates relative to the valve plate and absorbs oil when the plunger holes are communicated with the low-pressure valve opening (92).
  6. 6. The compact power unit of claim 5, wherein plunger ball sockets corresponding to the plungers one by one are arranged on the front end face of the sliding plate (50), the plunger ball sockets penetrate through waist-shaped holes of the sliding plate (50) to the rear end face of the sliding plate (50), a sealing structure and an oil drainage structure are further arranged on the rear end face of the sliding plate (50), the pressing plate is attached to the sliding plate (50) and provided with pressing plate holes corresponding to the plunger ball sockets, and the pressing plate holes are matched with the plungers so that the end portions of the plungers are always located in the plunger ball sockets.
  7. 7. The compact power unit of claim 6, wherein the swash plate is provided with an inclined plane for the sliding plate (50) to be obliquely attached and placed, the swash plate is provided with a swash plate low-pressure port and a swash plate high-pressure port which are communicated with the inclined plane in a penetrating way, the swash plate low-pressure port is communicated with the cavity of the pump body and is immersed by hydraulic oil, the swash plate high-pressure port is communicated with an oil outlet on the rear end cover of the pump body, oil is absorbed when the sliding plate (50) rotates to the plunger waist-shaped hole to be communicated with the swash plate low-pressure port, and oil is absorbed when the sliding plate (50) rotates to the plunger waist-shaped hole to be communicated with the swash plate high-pressure port.
  8. 8. The compact power unit according to any one of claims 1, 5 to 7, wherein the pressure plate and the slide plate (50) are in connection fit with the swash plate through a fastening structure, the fastening structure comprises a fastening piece connected to the swash plate, the fastening piece comprises a fastening piece positioning part aligned with the swash plate, a fastening piece connecting part connected and fixed with the swash plate, and a rotary fit part connected and matched with the pressure plate and the slide plate (50), the fastening piece keeps the pressure plate and the slide plate (50) tightly fitted through a limiting structure, and the limiting structure is mounted to the fastening piece or integrally formed with the fastening piece through the connecting piece.
  9. 9. The compact power unit according to any one of claims 1, 5 to 7, wherein the pressure plate and the slide plate (50) are connected and matched with the swash plate through a fastening structure, the fastening structure comprises a rotary matching part protruding from the surface of the swash plate and forming a cylindrical bulge, the pressure plate and the slide plate (50) are connected and matched with the rotary matching part and rotate along the rotary matching part, the top end of the rotary matching part keeps the pressure plate and the slide plate (50) tightly attached through a limiting structure, and the limiting structure is mounted to the rotary matching part through a connecting piece.
  10. 10. The compact power unit according to any one of claims 1, 5 to 7, wherein the pressure plate and the slide plate (50) are connected and matched with the swash plate through a tightening structure, the tightening structure comprises a tightening piece, a tightening piece bolt, a tightening piece disc spring and a tightening piece limiting pin, the tightening piece is provided with a rotary matching part and a tightening piece positioning part, a limiting plate matched with the pressure plate slide plate is arranged between the tightening piece and the pressure plate, the tightening piece and the limiting plate are in a separated structure or are connected and fixed into an integrated structure, the tightening piece disc spring is arranged between the tightening piece bolt and the limiting plate, the tightening piece limiting pin is used for limiting the rotation of the tightening piece, and the tightening piece bolt penetrates through the tightening piece and is fixedly connected with the swash plate.
  11. 11. The compact power unit of claim 1, wherein the cylinder body is provided with a rotation center hole for connecting with the shaft extension end, the shaft extension end penetrates through the rotation center hole, the end part of the shaft extension end is provided with a fastener and a blocking piece, an elastic pre-tightening piece is arranged between the blocking piece and the rotation center hole, and the elastic pre-tightening piece applies elastic pre-tightening force to the cylinder body.
  12. 12. An electro-hydraulic actuator comprising the compact power unit according to any one of claims 1-11 is characterized in that an oil outlet structure of the compact power unit is communicated with an oil distribution pipeline, the oil distribution pipeline is communicated with a hydraulic cylinder assembly (6) for driving a load, the hydraulic cylinder assembly (6) comprises a cylinder barrel (6 a), a piston rod (6 b) is arranged in the cylinder barrel (6 a) and divides the cylinder barrel (6 a) into two action cavities at intervals, oil ports are arranged on the two action cavities, the oil distribution pipeline is respectively connected to the oil ports of the two action cavities and is controlled by a control valve (5) to feed oil, the front end of the piston rod (6 b) is provided with a driving connecting structure and is used for connecting and driving the load, and the hydraulic cylinder assembly (6) comprises an asymmetric single-outlet rod or a symmetric double-outlet-rod structure.

Description

Compact power unit and electrohydraulic actuator Technical Field The utility model belongs to the technical field of hydraulic transmission and control, and particularly relates to a compact power unit and an electrohydraulic actuator. Background The existing hydraulic system mostly adopts a centralized valve control system, and has the advantages of quick response and high precision, but also has the problems of large throttling loss, low system efficiency, more and complex pipelines, serious system heating and the like. For example, a driving system of an engine-variable pump-multiple-way valve-actuator or a driving system of an electric motor-variable pump-multiple-way valve-actuator is adopted, a hydraulic pump is driven by the engine or the electric motor, hydraulic energy is distributed to each actuator by the multiple-way valve, and the traditional hydraulic system has the following characteristics: (1) The existing centralized hydraulic system is based on an open valve control principle, a large amount of energy is consumed on a throttle orifice and overflow, and meanwhile, a large amount of along-distance loss and local loss exist in the process, namely, a pipeline part, pressure loss caused by a hydraulic valve and the like, the overall efficiency of the hydraulic system is about 30%, and the large amount of hydraulic energy is converted into heat energy after being lost to cause the system to generate heat, so that the system efficiency is lower. (2) The existing centralized hydraulic system driving system has the defects that a centralized pressure oil supply driving pipeline is long, the oil consumption is large, an additional oil tank and a cooling device are needed, and the volume and the cost of the system are further increased. (3) The traditional hydraulic power system has the advantages of huge volume, not compact structure, large vibration and noise, more connecting pipelines and interfaces, easy oil leakage and environmental pollution. Distributed pump-controlled hydraulic systems are emerging hydraulic systems in recent years, and particularly with the development of electric power, the distributed pump-controlled hydraulic systems will become an important technical development trend matching with the development of electric power in the future. The most important carrier of the distributed pump control hydraulic system is an electro-hydrostatic actuator (EHA), which integrates a motor, a hydraulic pump and an oil tank and directly adopts the pump control actuator. The Electro Hydrostatic Actuator (EHA) embodies the large direction of high fusion and integration of the hydraulic element and the electric control of the motor, and can fully exert the control advantages of the hydraulic high power-to-weight ratio and the electric control of the electric power. The core component of an electro-hydrostatic actuator (EHA) is a power unit for providing hydraulic power, and the following problems mainly exist at present: (1) The existing electro-hydrostatic actuator (EHA) power unit part is formed by simply integrating a motor, a hydraulic pump, a coupler, an oil tank, a hydraulic valve and the like in series-parallel connection, and each part occupies a large volume space, has large weight and has lower overall power weight. (2) Most of hydraulic pumps used in the existing electro-hydrostatic actuator (EHA) power units are gear pumps, and the working pressure of the hydraulic pumps is generally lower than the medium pressure, so that the hydraulic pumps are difficult to meet the requirement of being used in the fields of engineering machinery and the like applied to high-pressure working conditions for a long time. (3) The reversing of oil in the existing Electro Hydrostatic Actuator (EHA) power unit is realized through forward and reverse rotation of a motor, the motor is easy to damage due to repeated high-frequency reversing of high rotational inertia under a high-speed working condition, and meanwhile, a hydraulic pump can work in four quadrants, so that the overall price is high, and the motor is difficult to bear in the field of engineering machinery. (4) The plunger pump used in the existing electro-hydrostatic actuator (EHA) power unit is generally a sliding shoe type swash plate plunger pump, and the plunger pump has unbalanced force and moment due to the natural defects of the structural design, so that the problems of lateral force overturning, abrasion, tray burning and the like are easily caused by friction pairs, and particularly under the condition of being matched with a high-speed motor, the abrasion failure of the plunger pump is more serious, and meanwhile, the adopted sliding shoe type plunger pump is poor in high-speed and low-speed performance and cannot be matched with the wide rotating speed working condition of the motor. Disclosure of utility model The utility model discloses a compact power unit and an electrohydraulic actuator, and aims to provide a novel power uni