Electric pump and method for producing same

Abstract

An electric pump includes a pump portion including a pump housing and a gear pump which is housed in the pump housing, the pump portion suctioning and discharging a hydraulic fluid by a rotation of the gear pump. The electric pump also includes a motor portion arranged adjacent to the pump portion in a direction along an axis of the pump portion and including a rotor which rotates synchronously with the gear pump and coaxially with the axis, the motor portion including a stator which is arranged at an outer periphery of the rotor and disposed coaxially with the axis, the stator applying a rotation drive force to the rotor. The electric pump further includes a resin portion integrally surrounding at least an outer periphery of the pump housing and an outer periphery of the stator.

1 : An electric pump comprising:
 a pump portion including a pump housing and a gear pump which is housed in the pump housing, the pump portion suctioning and discharging a hydraulic fluid by a rotation of the gear pump;   a motor portion arranged adjacent to the pump portion in a direction along an axis of the pump portion and including a rotor which rotates synchronously with the gear pump and coaxially with the axis, the motor portion including a stator which is arranged at an outer periphery of the rotor and disposed coaxially with the axis, the stator applying a rotation drive force to the rotor; and   a resin portion integrally surrounding at least an outer periphery of the pump housing and an outer periphery of the stator.   
     
     
         2 : The electric pump according to  claim 1 , wherein
 each of the pump housing and the stator includes a circular outermost configuration as viewed in the direction along the axis,   the pump housing and the stator include same outermost diameters as each other.   
     
     
         3 : The electric pump according to  claim 1 , wherein the resin portion includes a constant thickness in a radial direction of the resin portion. 
     
     
         4 : The electric pump according to  claim 1 , wherein each of the pump housing and the gear pump is made of a ferrous material. 
     
     
         5 : The electric pump according to  claim 1 , wherein the pump housing includes a recess portion at an outer surface, the recess portion into which resin of the resin portion is fitted. 
     
     
         6 : A method for producing an electric pump, comprising:
 a step for placing a stator in a cylindrical form onto an outer peripheral surface of a fixed die of a forming die in a state where an inner peripheral surface of the stator makes contact with the outer peripheral surface of the fixed die, the forming die being configured to open and close and including the fixed die and a movable die;   a step for placing a pump housing which includes a protruding portion in a cylindrical form in a state where an outer peripheral surface of the protruding portion makes contact with an inner peripheral surface of a dent which is provided at an upper surface of the fixed die, the dent including a circular cross-section in a direction orthogonal to an axis of the fixed die; and   a step for forming a resin portion by flowing resin into the forming die to harden the resin after the movable die is pressed against the fixed die to close the forming die, the resin portion integrally surrounding at least an outer periphery of the pump housing and an outer periphery of the stator.