Piston compressor

Abstract

A piston compressor includes a rotary valve having a suction guide hole. A plurality of introducing passages are formed in a cylinder block to connect compression chambers to the rotary valve. The inner circumferential surface of each cylinder bore has a suction auxiliary recess, which is connected to the outlet of the corresponding introducing passage in the circumferential direction of the cylinder bore at the end of the cylinder bore facing a valve assembly. Therefore, the compressor reduces suction resistance of gas at the beginning of the suction stroke without enlarging introducing passages formed in the cylinder block.

1 . A piston compressor, comprising: 
 a drive shaft;    a housing, which rotatably supports the drive shaft, wherein the housing includes a cylinder block, which has a plurality of cylinder bores, each cylinder bore having openings on both axial ends, and the cylinder block has an accommodation hole surrounded by the cylinder bores;    a plurality of pistons, each of which is accommodated and reciprocates in one of the cylinder bores;    a valve assembly joined to the cylinder block, the pistons and the valve assembly define a plurality of compression chambers in each cylinder bore, the valve assembly has discharge ports and discharge valves, and each set of the discharge port and the discharge valve corresponds to one of the compression chambers;    a rotary valve accommodated in the accommodation hole, the rotary valve having a suction guide hole, which opens on the outer circumferential surface of the rotary valve;    a suction pressure zone, which communicates with the suction guide hole; and    a plurality of introducing passages formed in the cylinder block to connect the compression chambers to the rotary valve, each introducing passage has an inlet, which opens on the inner circumferential surface of the accommodation hole, and an outlet, which opens on the inner circumferential surface of the cylinder bore, when the rotary valve rotates in synchronization with the drive shaft, the suction guide hole sequentially communicates with the inlet of each introducing passage so that gas is drawn into the corresponding compression chamber through the suction guide hole and the introducing passage from the suction pressure zone, the inner circumferential surface of each cylinder bore has a suction auxiliary recess, which is connected to the outlet of the corresponding introducing passage in the circumferential direction of the cylinder bore at the end of the cylinder bore facing the valve assembly.    
   
   
       2 . The compressor according to  claim 1 , wherein the suction auxiliary recess is formed to widen the outlet of each introducing passage toward the valve assembly in the circumferential direction of the cylinder bore.  
   
   
       3 . The compressor according to  claim 1 , wherein the suction auxiliary recess is one of suction auxiliary recesses formed on both sides of the outlet of each introducing passage in the circumferential direction of the cylinder bore.  
   
   
       4 . The compressor according to  claim 1 , further comprising: 
 a crank chamber defined in the housing; and    a cam plate accommodated in the crank chamber, the cam plate being coupled to the drive shaft to rotate integrally with and tilt with respect to the drive shaft, and the pistons are coupled to the cam plate,    wherein rotation of the drive shaft is converted into reciprocation of the pistons via the cam plate, and adjusting the pressure in the crank chamber changes the difference between the pressure in the crank chamber and the pressure in the compression chambers with the pistons in between, which alters the inclination angle of the cam plate, thereby adjusting the displacement of the compressor.    
   
   
       5 . The compressor according to  claim 1 , 
 wherein the rotary valve includes a residual gas bypass passage, the residual gas bypass passage connects the introducing passage corresponding to the pressurized compression chamber that has completed a discharge stroke to the introducing passage corresponding to the low pressure compression chamber.    
   
   
       6 . A piston compressor, comprising: 
 a drive shaft;    a housing, which rotatably supports the drive shaft, wherein the housing includes a cylinder block, which has a plurality of cylinder bores, each cylinder bore having openings on both axial ends, and the cylinder block has an accommodation hole surrounded by the cylinder bores;    a plurality of pistons, each of which is accommodated and reciprocates in one of the cylinder bores;    a valve assembly joined to the cylinder block, the pistons and the valve assembly define a plurality of compression chambers in each cylinder bore, the valve assembly has discharge ports and discharge valves, and each set of the discharge port and the discharge valve corresponds to one of the compression chambers;    a rotary valve accommodated in the accommodation hole, the rotary valve having a suction guide hole, which opens on the outer circumferential surface of the rotary valve;    a suction pressure zone, which communicates with the suction guide hole;    a plurality of introducing passages formed in the cylinder block to connect the compression chambers to the rotary valve, each introducing passage has an inlet, which opens on the inner circumferential surface of the accommodation hole, and an outlet, which opens on the inner circumferential surface of the cylinder bore, when the rotary valve rotates in synchronization with the drive shaft, the suction guide hole sequentially communicates with the inlet of each introducing passage so that gas is drawn into the corresponding compression chamber through the suction guide hole and the introducing passage from the suction pressure zone; and    a suction auxiliary portion formed at the end portion of each piston facing the valve assembly, the suction auxiliary portion separates an area of the outer circumferential surface of the end portion that faces the outlet of the corresponding introducing passage from the outlet.    
   
   
       7 . The compressor according to  claim 6 , wherein each suction auxiliary portion is formed by cutting off the area of the corresponding piston.  
   
   
       8 . The compressor according to  claim 6 , further comprising: 
 a crank chamber defined in the housing;    a cam plate accommodated in the crank chamber, the cam plate being coupled to the drive shaft to rotate integrally with and tilt with respect to the drive shaft, and the pistons are coupled to the cam plate; and    wherein rotation of the drive shaft is converted into reciprocation of the pistons via the cam plate, and adjusting the pressure in the crank chamber changes the difference between the pressure in the crank chamber and the pressure in the compression chambers with the pistons in between, which alters the inclination angle of the cam plate, thereby adjusting the displacement of the compressor.    
   
   
       9 . The compressor according to  claim 6 , 
 wherein the rotary valve includes a residual gas bypass passage, the residual gas bypass passage connects the introducing passage corresponding to the pressurized compression chamber that has completed a discharge stroke to the introducing passage corresponding to the low pressure compression chamber.    
   
   
       10 . A piston compressor, comprising: 
 a drive shaft;    a housing, which rotatably supports the drive shaft, wherein the housing includes a cylinder block, which has a plurality of cylinder bores, each cylinder bore having openings on both axial ends, and the cylinder block has an accommodation hole surrounded by the cylinder bores;    a plurality of pistons, each of which is accommodated and reciprocates in one of the cylinder bores;    a valve assembly joined to the cylinder block, the pistons and the valve assembly define a plurality of compression chambers in each cylinder bore, the valve assembly has discharge ports and discharge valves, and each set of the discharge port and the discharge valve corresponds to one of the compression chambers;    a rotary valve accommodated in the accommodation hole, the rotary valve having a suction guide hole, which opens on the outer circumferential surface of the rotary valve;    a suction pressure zone, which communicates with the suction guide hole; and    a plurality of introducing passages formed in the cylinder block to connect the compression chambers to the rotary valve, each introducing passage has an inlet, which opens on the inner circumferential surface of the accommodation hole, and an outlet, which opens on the inner circumferential surface of the cylinder bore, when the rotary valve rotates in synchronization with the drive shaft, the suction guide hole sequentially communicates with the inlet of each introducing passage so that gas is drawn into the corresponding compression chamber through the suction guide hole and the introducing passage from the suction pressure zone, and a portion of the valve assembly facing the compression chambers has suction auxiliary recesses corresponding to the outlets of the introducing passages.    
   
   
       11 . The compressor according to  claim 10 , wherein the cylinder block has communication grooves, each of which connects the outlet of one of the introducing passages to the corresponding suction auxiliary recess, and each communication groove is located at the opening edge of one of the cylinder bores facing the valve assembly.  
   
   
       12 . The compressor according to  claim 10 , wherein each discharge port has an opening connected to the corresponding compression chamber, and the opening also serves as the suction auxiliary recess.  
   
   
       13 . The compressor according to  claim 10 , wherein the discharge ports are first discharge ports, 
 the valve assembly has a plurality of second discharge ports, each of which corresponds to one of the compression chambers, the second discharge ports are located closer to the rotary valve than the first discharge ports, each second discharge port has an opening connected to the corresponding compression chamber, and the opening also serves as the suction auxiliary recess.    
   
   
       14 . The compressor according to  claim 10 , further comprising: 
 a crank chamber defined in the housing;    a cam plate accommodated in the crank chamber, the cam plate being coupled to the drive shaft to rotate integrally with and tilt with respect to the drive shaft, and the pistons are coupled to the cam plate; and    wherein rotation of the drive shaft is converted into reciprocation of the pistons via the cam plate, and adjusting the pressure in the crank chamber changes the difference between the pressure in the crank chamber and the pressure in the compression chambers with the pistons in between, which alters the inclination angle of the cam plate, thereby adjusting the displacement of the compressor.    
   
   
       15 . The compressor according to  claim 10 , 
 wherein the rotary valve includes a residual gas bypass passage, the residual gas bypass passage connects the introducing passage corresponding to the pressurized compression chamber that has completed a discharge stroke to the introducing passage corresponding to the low pressure compression chamber.