Axial plunger pump or motor

Abstract

An axial plunger pump or motor comprises a casing ( 1 ), a main shaft ( 2 ), a rotor cylinder ( 14 ), a rotary swash plate ( 9 ) and a plurality of plunger assemblies ( 10 ), wherein a constant velocity universal coupling ( 11 ) transmits torque between the rotary swash plate and the main shaft, such that the main shaft ( 14 ) and the rotary swash plate ( 9 ) rotate about the main shaft axis ( 41 ) and the swash plate axis ( 91 ) forming an angle therebetween, respectively, so as to realize transition between hydraulic energy and rotary mechanical energy.

1 . A axial plunger pump or motor, comprising:
 a casing;   a main shaft rotatably supported on the casing;   a rotor cylinder with a plurality of plunger holes, which is coupled to the main shaft and is driven to rotate about a main shaft axis by the main shaft and which has an oil-distributing end surface;   an oil-distributing disk in cooperation with an oil-distributing end surface of the rotor cylinder;   a rotary swash plate whose end surface is disposed in a manner axially opposing the plurality of plunger holes of the rotor cylinder and which can rotate about a swash plate axis forming an angle with respect to the main shaft axis;   a plurality of plunger assemblies, an end of each being articulated to an end surface of the rotary swash plate and another end of each being slidably disposed in the plunger holes of the rotor cylinder;   a constant velocity universal coupling which is provided between the rotary swash plate and the main shaft and transmits torque therebetween, so that the main shaft and the rotary swash plate rotate about the main shaft axis and the swash plate axis forming an angle therebetween, respectively.   
   
   
       2 . The axial plunger pump or motor according to  claim 1 , characterized in that, said constant velocity universal coupling is a Rzeppa constant velocity universal coupling, a half angular Rzeppa constant velocity universal coupling, a ball joint constant velocity universal coupling or a Weiss constant velocity university coupling. 
   
   
       3 . The axial plunger pump or motor according to  claim 2 , characterized in that, said Rzeppa constant velocity universal coupling comprises an inner race ring with an outer raceway, a plurality of steel balls, a holder and an outer race ring with an inner raceway, wherein said steel balls are arranged on the holder and are located in the inner raceway and the outer raceway, said inner race ring is coupled to the main shaft, said outer race ring is coupled to the rotary swash plate, such that the main shaft and the rotary swash plate are respectively rotated about the main shaft axis and the swash plate axis via the Rzeppa constant velocity universal coupling, the cross point of the said two axis locate at the center point of the said Rzeppa constant velocity universal coupling. 
   
   
       4 . The axial plunger pump or motor according to  claim 1 , characterized in that, said rotary swash plate is supported on the casing via a swash plate bearing, so as to form a constant-capacity axial plunger pump or motor, or
 said rotary swash plate is supported on a pendulous disk via a swash plate bearing, the pendulous disk is supported on said casing via a pendulous disk bearing, said swash plate bearing is a combination bearing of a needle bearing and a cylinder or taper roller thrust bearing, said pendulous disk bearing is a needle bearing or sliding bearing in a crescent form, and the rotation axis of the pendulous disk is perpendicular to the main shaft axis and passes through the center of the constant velocity universal coupling, said pendulous disk is connected with a variable displacement adjustment mechanism for adjusting the deflection angle of the pendulous disk, such that an angle between the swash plate axis of the rotary swash plate supported thereon and the main shaft is adjusted through changing the deflection angle of the pendulous disk, so as to form a variable-capacity axial plunger pump or motor.   
   
   
       5 . The axial plunger pump or motor according to  claim 4 , characterized in that, said variable displacement adjustment mechanism is a variable displacement oil cylinder, the piston of which is connected to the pendulous disk so as to drive the pendulous disk to deflect through extending and retracting of the piston. 
   
   
       6 . The axial plunger pump or motor according to  claim 4 , characterized in that, the variable displacement adjustment mechanism is a variable displacement adjustment mechanism of a trunnion type, which includes a trunnion connected to the pendulous disk and a driving mechanism for driving the trunnion to rotate, a rotation axis of the trunnion is coincident with the rotation axis of the pendulous disk so as to drive the pendulous disk to deflect through rotation of the trunnion. 
   
   
       7 . The axial plunger pump or motor according to  claim 1 , characterized in that, said rotor cylinder is in a taper shape, a diameter thereof at the end closer to the rotary swash plate is larger than that at the other end;
 the plurality of plunger holes on said rotor cylinder are fairly distributed in a taper form accordingly.   
   
   
       8 . The axial plunger pump or motor according to  claim 1 , characterized in that, said plunger assembly is a plunger assembly of a ball joint type, which comprises a plunger and a ball-headed rod with a ball head at each of both ends thereof, said rotary swash plate is provided with a socket, a ball head at an end of the ball-headed rod is located in the socket to form a ball-joint connection with the rotary swash plate, and a ball head at the other end is located in the plunger to form a ball-joint connection with the plunger, and the plunger is slidably provided in the plunger hole. 
   
   
       9 . The axial plunger pump or motor according to  claim 8 , characterized in that, in the middle portion of the ball-headed rod and the plunger there is provided with a oil hole in communication with the plunger holes to introduce pressurized oil to lubricate the ball head at the both ends. 
   
   
       10 . The axial plunger pump or motor according to  claim 1 , characterized in that, articulation centers of said plurality of plunger assemblies on the rotary swash plate are located in a same plane, and an intersection point of the plane with the main shaft axis is coincident with the center of the constant velocity universal coupling. 
   
   
       11 . The axial plunger pump or motor according to  claim 1 , characterized in that, the rotor cylinder is axially positioned along the main shaft through a pressure spring and a pressure spring stop collar, an end of the main shaft is provided with an oil hole and a radial oil path, such that the pressure between the rotor cylinder and the oil-distribution disk is adjusted through introducing pressurized oil into the radial oil path. 
   
   
       12 . The axial plunger pump or motor according to  claim 1 , characterized in that, the oil-distribution end surface of said rotor cylinder is a spheric surface, said oil-distribution disk forms a spherical surface fit with the oil-distribution end surface.