Pump device

Abstract

A pump device ( 1 ) according to an embodiment of the present invention includes a drive motor (M), a first pump unit for evacuation ( 11 ) including a first pump chamber and a first piston ( 21 v ), and a second pump unit for pressurization ( 12 ) including a second pump chamber and a second piston ( 21 c ). The second piston ( 21 c ) has a phase advanced with a rotational phase difference (φ) of more than 0° and less than 80° with respect to the first piston ( 21 v ).

1 . A pump device, comprising:
 a drive motor including a first drive shaft and a second drive shaft and being capable of rotating the first drive shaft and the second drive shaft in synchronization about a first axis;   a first pump unit for evacuation, including a first piston that reciprocates in a direction of a second axis orthogonal to the first axis by a rotation of the first drive shaft, and a first pump chamber that has an internal pressure changing in accordance with a reciprocating movement of the first piston; and   a second pump unit for pressurization, including a second piston that reciprocates in the direction of the second axis by a rotation of the second drive shaft, and a second pump chamber that has an internal pressure changing in accordance with a reciprocating movement of the second piston, the second piston having a phase advanced with a rotational phase difference of more than 0° and less than 80° with respect to the first piston.   
     
     
         2 . The pump device according to  claim 1 , wherein the rotational phase difference is 40°±15°. 
     
     
         3 . The pump device according to  claim 1 , wherein
 the first pump unit further includes a first counterweight that rotates about the first drive shaft together with the first piston, and   the second pump unit further includes a second counterweight that rotates about the second drive shaft together with the second piston, with the rotational phase difference with respect to the first counterweight.