Pump Device

Abstract

A pump device has a motor rotation shaft and a pump rotation shaft whose end portion is connected to an end portion of the motor rotation shaft and which drives a pump unit. The pump device includes: an outer circumferential seal portion that is arranged at either one or both of radially outer sides of the end portion of the pump rotation shaft and the end portion of the motor rotation shaft so as to overlap with either one or both of the end portion of the pump rotation shaft and the end portion of the motor rotation shaft in axial directions of the pump rotation shaft and the motor rotation shaft and has an outer circumferential seal surface; and a seal unit that makes sliding contact with the outer circumferential seal portion.

What is claimed is: 
     
         1 . A pump device having a motor rotation shaft and a pump rotation shaft whose end portion is connected to an end portion of the motor rotation shaft and which drives a pump unit, the pump device comprising:
 an outer circumferential seal portion that is arranged at either one or both of radially outer sides of the end portion of the pump rotation shaft and the end portion of the motor rotation shaft so as to overlap with either one or both of the end portion of the pump rotation shaft and the end portion of the motor rotation shaft in axial directions of the pump rotation shaft and the motor rotation shaft and has an outer circumferential seal surface; and   a seal unit that makes sliding contact with the outer circumferential seal portion.   
     
     
         2 . The pump device as claimed in  claim 1 , wherein:
 the seal unit is set in an area ranging from the end portion of the pump rotation shaft to the end portion of the motor rotation shaft in the X-axis direction.   
     
     
         3 . The pump device as claimed in  claim 1 , wherein:
 a collar member is provided at an outer circumference of the end portion of the pump rotation shaft and at an outer circumference of the end portion of the motor rotation shaft with the collar member ranging from the end portion of the pump rotation shaft to the end portion of the motor rotation shaft, and   the outer circumferential seal portion is formed at an outer circumference of the collar member.   
     
     
         4 . The pump device as claimed in  claim 3 , wherein:
 the collar member is fixedly connected to the pump rotation shaft.   
     
     
         5 . The pump device as claimed in  claim 4 , wherein:
 the collar member is press-fixed to the pump rotation shaft, and is connected to the motor rotation shaft in a whirl-stop connecting manner.   
     
     
         6 . The pump device as claimed in  claim 4 , wherein:
 the collar member is formed integrally with the pump rotation shaft, and is connected to the motor rotation shaft in a whirl-stop connecting manner.   
     
     
         7 . The pump device as claimed in  claim 4 , wherein:
 the pump rotation shaft has, at one end side thereof, a male screw portion, and   the collar member has a female screw portion that is screwed onto the male screw portion, and is connected to the motor rotation shaft in a whirl-stop connecting manner.   
     
     
         8 . The pump device as claimed in  claim 7 , wherein:
 the pump rotation shaft has an O-ring that seals a gap between the collar member and the pump rotation shaft and a ring groove that is formed at the pump rotation shaft and houses therein the O-ring.   
     
     
         9 . The pump device as claimed in  claim 4 , wherein:
 the seal unit has;
 a seal member that suppresses a leak of working fluid from an inside of the pump device to the outside; 
 a lip member that is disposed in an axial direction of the seal member and suppresses an external leak of the working fluid, which further leaks from the seal member to the outside; and 
 a retaining member that retains the seal member and the lip member. 
   
     
     
         10 . The pump device as claimed in  claim 9 , wherein: the seal unit is retained, through the retaining member, in a seal unit retaining hole that is formed in an outer peripheral area of an end portion of a housing. 
     
     
         11 . The pump device as claimed in  claim 10 , wherein:
 the pump rotation shaft has a stepped portion that is formed by a fact that a diameter of the end portion side of the pump rotation shaft is formed to be smaller, and   a disk member is provided so as to be sandwiched and supported between a bottom portion of the seal unit retaining hole and the seal unit, and the disk member has a penetration hole where the pump rotation shaft having the smaller diameter penetrates, and wherein   by a fact that an inner rim of the penetration hole of the disk member and the stepped portion of the pump rotation shaft interfere with each other, a movement of the pump rotation shaft to an axial direction one side is restrained.   
     
     
         12 . A pump device comprising:
 a motor rotation shaft;   a pump rotation shaft that is connected to the motor rotation shaft through a connecting portion of the pump rotation shaft and drives a pump unit; and   a seal unit that suppresses a leak of working fluid from the pump unit along an outer circumference of the pump rotation shaft, and   the connecting portion of the pump rotation shaft being located at a radially inner side of the seal unit.   
     
     
         13 . The pump device as claimed in  claim 12 , wherein:
 a collar member is provided at an outer circumference of the connecting portion, and   the seal unit makes sliding contact with an outer circumference of the collar member and suppresses the leak of the working fluid.   
     
     
         14 . The pump device as claimed in  claim 13 , wherein: the collar member is press-fixed to the pump rotation shaft. 
     
     
         15 . The pump device as claimed in  claim 12 , wherein: the collar member and the motor rotation shaft are connected together in a whirl-stop connecting manner. 
     
     
         16 . The pump device as claimed in  claim 13 , wherein: the collar member is formed integrally with the pump rotation shaft, and the collar member and the motor rotation shaft are connected together in a whirl-stop connecting manner. 
     
     
         17 . The pump device as claimed in  claim 12 , wherein:
 the seal unit has;
 a seal member that suppresses a leak of working fluid from an inside of the pump device to the outside; 
 a lip member that is disposed in an axial direction of the seal member and suppresses an external leak of the working fluid, which further leaks from the seal member to the outside; and 
 an annular retaining member that retains an outer peripheral side of the seal member and an outer peripheral side of the lip member. 
   
     
     
         18 . A pump device comprising:
 a housing;   a motor that is fixed to the housing and drives a pump unit provided in the housing, the motor having a motor rotation shaft that is connected to a pump rotation shaft of the pump unit through a connecting portion of the pump rotation shaft and drives the pump unit;   a cylindrical collar member that covers the connecting portion of the pump rotation shaft;   a seal unit that makes sliding contact with an outer circumferential surface of the cylindrical collar member; and   a seal unit retaining hole that is formed in the housing and retains therein the seal unit.   
     
     
         19 . The pump device as claimed in  claim 18 , wherein: the collar member is press-fixed to the pump rotation shaft, and is connected to the motor rotation shaft in a whirl-stop connecting manner. 
     
     
         20 . The pump device as claimed in  claim 19 , wherein:
 the pump rotation shaft has a stepped portion that is formed by a fact that a diameter of the end portion side of the pump rotation shaft is formed to be smaller, and   a disk member is provided so as to be sandwiched and supported between a bottom portion of the seal unit retaining hole and the seal unit, and the disk member has a penetration hole where the pump rotation shaft having the smaller diameter penetrates, and wherein   by a fact that an inner rim of the penetration hole of the disk member and the stepped portion of the pump rotation shaft interfere with each other, a movement of the pump rotation shaft to an axial direction one side is restrained, and   by a fact that the pump rotation shaft and the housing interfere with each other, a movement of the pump rotation shaft to an axial direction other side is restrained.