Pump device

Abstract

A pump device includes a pump housing including a fluid chamber for inhaling a fluid flowing through the fluid chamber via an intake port and discharging the fluid to an outside via a discharge port, a motor housing including a stator, and a shaft whose one end projects into the pump housing and to which an impeller is assembled and whose the other end is rotatably supported by a first bearing portion within the motor housing. The pump device also includes a rotor assembled to the shaft and facing the stator, and a bearing plate disposed between the pump housing and the motor housing and including a second bearing portion rotatably supporting the shaft. The bearing plate is formed by a first fluid passage for leading the fluid to the bearing plate.

1 . A pump device comprising: 
 a pump housing including a fluid chamber for inhaling a fluid flowing through the fluid chamber via an intake port and discharging the fluid to an outside via a discharge port;    a motor housing including a stator:    a shaft whose one end projects into the pump housing and to which an impeller is assembled, and whose the other end is rotatably connected to a first bearing portion within the motor housing;    a rotor assembled to the shaft and facing the stator; and    a bearing plate disposed between the pump housing and the motor housing and including a second bearing portion rotatably supporting the shaft; wherein the bearing plate is formed with a first fluid passage for leading the fluid to inside of the bearing plate.    
   
   
       2 . A pump device according to  claim 1 , wherein the first fluid passage includes a first end including an opening facing the fluid chamber and a second end communicating with a bearing bore formed at the bearing plate and provided adjacent to the second bearing portion and having a larger diameter than the second bearing portion.  
   
   
       3 . A pump device according to  claim 2 , wherein the opening is provided in a second fluid chamber having a high fluid pressure in the pump housing.  
   
   
       4 . A pump device according to  claim 3 , wherein the opening includes a filter.  
   
   
       5 . A pump device according to  claim 1 , wherein the first fluid passage penetrates through both side faces of the bearing plate in an axial direction.  
   
   
       6 . A pump device according to  claim 2 , wherein the first bearing portion and the second bearing portion communicate with each other via a gap formed between the stator and the rotor.  
   
   
       7 . A pump device according to  claim 6 , wherein the shaft includes a fluid path for connecting the second bearing portion and a first fluid chamber provided on an intake side of the fluid chamber.  
   
   
       8 . A pump device according to  claim 7 , wherein a side end portion of the bearing bore on the motor side is formed by a slit in a radial direction of the shaft.  
   
   
       9 . A pump device according to  claim 5 , wherein the first fluid passage formed in the bearing plate and extending in a radial direction thereof keeps a predetermined angle with the shaft.  
   
   
       10 . A pump device comprising: 
 a pump housing including a fluid chamber for inhaling a fluid flowing through the fluid chamber via an intake port and discharging the fluid to an outside via a discharge port;    a motor housing including a stator:    a shaft whose one end projects into the pump housing and to which an impeller is assembled, and whose other end is rotatably connected to a first bearing portion within the motor housing; and    a rotor assembled to the shaft and facing the stator; wherein the impeller is formed with a first fluid passage extending in a radial direction of the impeller for leading the fluid to the first bearing portion.    
   
   
       11 . A pump device according to  claim 10 , wherein the shaft includes a second fluid passage communicating with the first fluid passage and leading the fluid to the first bearing portion.  
   
   
       12 . A pump device according to  claim 11 , wherein the first fluid passage includes a feed port to which the fluid is led and at which a filter is provided.  
   
   
       13 . A pump device according to  claim 10 , wherein the first fluid passage is formed in a base portion of the impeller for supporting a blade of the impeller.  
   
   
       14 . A pump device according to  claim 13 , wherein the base portion includes a penetrating bore penetrating through both sides of the base portion in an axial direction thereof.  
   
   
       15 . A pump device according to  claim 14 , wherein the fluid supplied from the first fluid passage is led to a first fluid chamber on an intake side of the fluid chamber via the second fluid passage, the first bearing portion, a gap formed between the stator and the rotor, a second bearing portion formed at a bearing plate disposed between the pump housing and the motor housing and rotatably supporting the shaft, a gap formed between the bearing plate and the base portion, and the penetrating bore.  
   
   
       16 . A pump device according to  claim 15 , further comprising a labyrinth formed between the base portion and the bearing plate radially outside of the penetrating bore.