Centrifugal Pump

Abstract

A centrifugal pump includes an impeller and a housing defining a pump chamber that houses the impeller therein. The housing includes an inlet passage in fluid communication with the pump chamber and an outside of the housing. The inlet passage includes a connection passage part having a cylindrical shape extending from the pump chamber and a main passage part having a cylindrical shape connected to the connection passage part, so as to form a bent shape. A central axis of the main passage part is parallel to a reference plane that includes a central axis of the connection passage part. A flow direction of a fluid parallel the central axis of the main passage part is partly the same as the rotational direction of the impeller in a plan view along an axis of the impeller.

What is claimed is: 
     
         1 . A centrifugal pump, comprising:
 an impeller configured to rotate about a rotational axis in a rotational direction; and   a housing defining a pump chamber within which the impeller is disposed, wherein the housing includes an inlet passage and an outlet passage, wherein each of the inlet passage and the outlet passage is in fluid communication with the pump chamber and an outside of the housing, wherein:   the pump chamber has an inflow part at an upstream end thereof,   the inflow part of the pump chamber has an inflow end at an upstream end thereof and has a hollow tapered shape with a width that continuously decreases moving toward the inflow end,   the inlet passage includes a connection passage part having a cylindrical shape coupled to the inflow end of the inflow part and a main passage part having a cylindrical shape connected to the connection passage part so as to form a bent shape, and   a central axis of the main passage part is oriented parallel to a reference plane that includes a central axis of the connection passage part such that a flow direction of a fluid along the central axis of the main passage part is partly the same as the rotational direction of the impeller in a plan view along the rotational axis of the impeller.   
     
     
         2 . The centrifugal pump of  claim 1 , wherein:
 the housing includes a first pipe part defining the main passage part therein and a second pipe part defining the connection passage part therein,   the first pipe part and the second pipe part are coupled to each other to form a first connection part therebetween, and   a corner is formed at a part of the first connection part closer to the reference plane in the plan view.   
     
     
         3 . The centrifugal pump of  claim 1 , wherein a part of the main passage part is in direct fluid communication with the inflow part. 
     
     
         4 . The centrifugal pump of  claim 1 , wherein:
 the outlet passage has a cylindrical shape extending in a tangential direction from the pump chamber such that a flow direction of the fluid along a central axis of the outlet passage is substantially the same as the rotational direction of the impeller at a second connection part between the outlet passage and the pump chamber in the plan view, and   the central axis of the outlet passage is oriented parallel to the central axis of the main passage part in the plan view.   
     
     
         5 . A centrifugal pump, comprising:
 an impeller configured to be rotated about a rotational axis in a rotational direction; and   a housing defining a pump chamber housing the impeller therein, wherein the housing includes an inlet passage and an outlet passage, wherein each of the inlet passage and the outlet passage is in fluid communication with the pump chamber and an outside of the housing, wherein:   the pump chamber has an inflow part at an upstream end thereof,   the inflow part has an inflow end at an upstream end thereof and has a hollow tapered shape with a width that continuously decreases moving toward the inflow end,   the inlet passage includes a connection passage part having a cylindrical shape coupled to the inflow end of the inflow part and a main passage part having a cylindrical shape connected to the connection passage part so as to form a bent shape,   a central axis of the main passage part is oriented parallel to a reference plane that includes a central axis of the connection passage part,   the housing include a first pipe part defining the main passage part therein such that the first pipe part includes a front wall and a rear wall disposed rearward of the front wall relative to the rotational direction in a plan view along the rotational axis of the impeller, and   a first distance between the reference plane and the front wall is greater than a second distance between the reference plane and the rear wall in the plan view.   
     
     
         6 . The centrifugal pump of  claim 5 , wherein:
 the housing includes a second pipe part defining the connection passage part therein,   the first pipe part and the second pipe part are coupled to each other to form a first connection part therebetween, and   a corner is formed at a part of the first connection part closer to the reference plane in the plan view.   
     
     
         7 . The centrifugal pump of  claim 5 , wherein a part of the main passage part is in direct fluid communication with the inflow part. 
     
     
         8 . The centrifugal pump of  claim 5 , wherein:
 the outlet passage has a cylindrical shape extending in a tangential direction from the pump chamber, such that a flow direction of a fluid along a central axis of the outlet passage is substantially the same as the rotational direction of the impeller at a second connection part between the outlet passage and the pump chamber in the plan view, and   the central axis of the outlet passage is oriented parallel to the central axis of the main passage part in the plan view.