Rotary Pump

Abstract

A rotary pump is provided having a chamber arranged in a body and a displacement member disposed in the chamber for reciprocating therein. A drive member is used to move the displacement member within the chamber in response to relative rotation between the body and the drive member. A radial valve arrangement may be used to time when the chamber is in fluid communication with inlet and outlet ports on the pump.

1 - 47 . (canceled) 
     
     
         48 . A rotary pump, comprising:
 a body rotatable about an axis;   a plurality of radially extending chambers arranged in the body;   a plurality of displacement members, each displacement member disposed in one of said plurality of chambers for reciprocating therein;   a drive member that moves the plurality of displacement members within the chambers in response to relative rotation between the body and the drive member; and   a radial valve arrangement presenting a fluid inlet opening during intake and an outlet opening during discharge to the plurality of displacement members, the drive member comprising a surface having a radial profile relative to the rotation axis of the body, the radial profile comprising a plurality of portions with different radius characteristics so that, when there is relative rotation between the drive member and the body, the displacement members in radially extending chambers that are discharging to the outlet opening move at different speed relative to each other according to the radial profile, the cumulative speed of the moving displacement members in the radially extending chambers that are discharging to the outlet opening being generally constant according to the radial profile, producing a generally constant fluid discharge rate during discharge.   
     
     
         49 . The rotary pump of  claim 48  wherein the plurality of displacement members move from a first position to a second position in response to sufficient inlet pressure from a fluid entering each of the plurality of chambers. 
     
     
         50 . The rotary pump of  claim 48  wherein the displacement members reciprocate between a first position and a second position and wherein the radial profile of the drive member surface during intake of the displacement members is steeper than the radial profile during discharge so that movement of the displacement members from the second position to the first position is slower than movement of the displacement member from the first position to the second position. 
     
     
         51 . The rotary pump according to  claim 48  wherein each of the displacement members includes an alignment device that prevents rotation of the displacement members in the chambers. 
     
     
         52 . The rotary pump according to  claim 51  wherein the alignment device includes an alignment pin received in a radial slot in the body. 
     
     
         53 . The rotary pump according to  claim 48  wherein the valve arrangement defines a pair of diametrically opposed inlet openings and a pair of diametrically opposed outlet openings. 
     
     
         54 . The rotary pump according to  claim 53  wherein the outlet openings are larger than the inlet openings. 
     
     
         55 . The rotary pump according to  claim 48  wherein the drive member comprises a cam having a radially inner drive surface that engages the plurality of displacement members, said inner drive surface comprises the radial profile having an accelerating portion, a decelerating portion and a generally constant velocity portion for discharge. 
     
     
         56 . The rotary pump according to  claim 48  wherein the outlet opening is sized to receive fluid from at least three chambers during discharge, wherein during discharge a first displacement member is accelerating, a second displacement member is decelerating and a third displacement member has a generally constant velocity. 
     
     
         57 . The rotary pump according to  claim 49  further comprising means for verifying that each of the plurality of displacement members has moved to the second position primarily in response to sufficient inlet pressure. 
     
     
         58 . A rotary pump, comprising:
 a body rotatable about an axis;   a plurality of radially extending chambers arranged in the body;   a plurality of displacement members, each displacement member disposed in one of said plurality of chambers for reciprocating therein;   an annular cam having a cam profile along a radially inner surface that moves the plurality of displacement members within the chambers in response to relative rotation between the body and the cam; and   a radial valve arrangement defining an outlet opening, the outlet opening being configured to be in fluid communication with at least three chambers simultaneously, wherein during operation, the displacement member in at least two of the at least three chambers is changing speed and the displacement member in at least one of the at least three chambers is at a constant speed, and wherein the cumulative speed of the displacement members that are changing speed is equal the speed of the displacement member that is at a constant speed according to the cam profile.   
     
     
         59 . The rotary pump of  claim 58  wherein the plurality of displacement members move from a first position to a second position in response to sufficient inlet pressure from a fluid entering each of the plurality of chambers. 
     
     
         60 . The rotary pump of  claim 58  wherein the displacement members reciprocate between a first position and a second position and wherein the radial profile of the drive member surface during an intake stroke of the displacement members is steeper than the radial profile during a discharge stroke so that movement of the displacement members from the second position to the first position is slower than movement of the displacement member from the first position to the second position. 
     
     
         61 . The rotary pump of  claim 58  wherein the valve arrangement further defines an inlet opening, and wherein the inlet opening is smaller than the outlet opening. 
     
     
         62 . A rotary pump, comprising:
 a body;   radially extending chambers arranged in the body;   displacement members, each displacement member disposed in one of said chambers for reciprocating therein;   a valve arrangement defining an outlet opening presented to a plurality of the chambers during discharge;   a drive member that moves the displacement members in the discharging chambers at different speeds with a cumulative speed that is generally constant during discharge so that fluid enters the outlet opening from the discharging chambers at a cumulative generally constant rate when the speed of relative rotation between the body and the radial valve arrangement is generally constant.   
     
     
         63 . A rotary pump, comprising:
 a chamber arranged in a body rotatable about an axis;   a displacement member disposed in the chamber for reciprocating therein between a first position and a second position, wherein the displacement member moves from the first position to the second position primarily in response to sufficient inlet pressure from a fluid entering the chamber;   a drive member that moves the plurality of displacement members within the chambers in response to relative rotation between the body and the drive member; and   a sensor positioned in the drive member for detecting when the displacement member is in the second position to indicate there is sufficient inlet pressure.   
     
     
         64 . The rotary pump of  claim 63  wherein the sensor is an inductive proximity sensor. 
     
     
         65 . The rotary pump of  claim 48  wherein said radial valve arrangement comprises two outlet openings with each outlet opening being in fluid communication with a respective dispensing outlet of the pump. 
     
     
         66 . The rotary pump of  claim 48  wherein the fluid inlet opening is isolated from the outlet opening so that each of the plurality of radially extending chambers are prevented from being in fluid communication with the fluid inlet opening and outlet opening at the same time. 
     
     
         67 . The rotary pump of  claim 66  wherein the inlet opening and the outlet opening are isolated by a land therebetween, and the radial profile of the drive member comprises a generally constant radius portion to produce a dwell time during which a displacement member is stationary within its chamber between an intake stroke and a discharge stroke. 
     
     
         68 . (canceled)