Brushless motor integrated pump

Abstract

A brushless motor integrated pump may include a brushless motor having a rotary shaft, a rotor axially mounted on the rotary shaft, a stator disposed around the rotor, a motor case forming a part of a case body and in which the rotor and the stator are accommodated, a motor cover covering the motor case with the rotary shaft penetrating through and protruding from an opening of the motor case, and low and high pressure-side gear pumps sharing the rotary shaft as a driving source and accommodated in a multistage manner inside a pump cover disposed on a surface of the motor cover to form the case body with the motor case. A low-pressure-side outlet may be formed in a pressurizing space communicated with a high-pressure-side outlet formed in the pressurizing space, in which a working medium may be introduced from the low-pressure-side inlet to flow, in order, into the low and high pressure-side gear pumps and may be pressurized, introduced into the motor case via a connection port which may be a high-pressure-side outlet formed in the motor cover, and caused to flow out from a case body outlet formed in the motor case. Low and high pressure outflow paths may be provided in which the low pressure outflow path may be communicated with the low-pressure-side outlet of the low-pressure-side working medium discharged from a pressurizing space of the low-pressure-side gear pump, or the high-pressure-side inlet of the high-pressure-side gear pump, to cause the low-pressure-side working medium to flow out from the low-pressure-side outlet of the low-pressure-side gear pump formed in the pump cover, and the high pressure outflow path may discharge the high-pressure-side working medium from the case body outlet formed in the motor case and discharged from the pressurizing space of the high-pressure-side gear pump. The pump may further have a connection passage including a check valve that may open the low and high pressure-side outflow paths toward the low-pressure-side outflow path.

1 . A brushless motor integrated pump comprising:
 a brushless motor having a rotary shaft   a rotor axially mounted on the rotary shaft;   a stator disposed around the rotor;   a motor case forming a part of a case body and in which the rotor and the stator are accommodated;   a motor cover covering the motor case with the rotary shaft penetrating through and protruding from an opening of the motor case;   a low-pressure-side gear pump and a high-pressure-side gear pump that share the rotary shaft of the brushless motor as a driving source and are accommodated in a multistage manner inside a pump cover which is disposed on a surface of the motor cover to form the case body with the motor case;   a low-pressure-side outlet of the low-pressure-side gear pump formed in a pressurizing space communicated with a high-pressure-side outlet of the high-pressure-side gear pump formed in the pressurizing space, in which a working medium is introduced from the low-pressure-side inlet provided in the pump cover to flow into the low-pressure-side gear pump and the high-pressure-side gear pump in this order and is pressurized, introduced into the motor case via a connection port which is a high-pressure-side outlet of the high-pressure-side gear pump formed in the motor cover, and caused to flow out from a case body outlet formed in the motor case;   a low pressure outflow path provided for the low-pressure-side working medium and a high pressure outflow path provided for the high-pressure-side working medium, in which the low pressure outflow path is communicated with the low-pressure-side outlet of the low-pressure-side working medium discharged from a pressurizing space of the low-pressure-side gear pump, or the high-pressure-side inlet of the high-pressure-side gear pump, to cause the low-pressure-side working medium to flow out from the low-pressure-side outlet of the low-pressure-side gear pump formed in the pump cover, and the high pressure outflow path discharges the high-pressure-side working medium from the case body outlet formed in the motor case and discharged from the pressurizing space of the high-pressure-side gear pump; and   a connection passage including a check valve that opens the low-pressure-side outflow path and the high-pressure-side outflow path toward the low-pressure-side outflow path.   
     
     
         2 . The brushless motor integrated pump according to  claim 1 , wherein the check valve included in the connection passage is a solenoid valve. 
     
     
         3 . The brushless motor integrated pump according to  claim 1 , wherein a flow rate of the low-pressure-side gear pump is smaller than a flow rate of the high-pressure-side gear pump. 
     
     
         4 . The brushless motor integrated pump according to  claim 2 , wherein a flow rate of the low-pressure-side gear pump is smaller than a flow rate of the high-pressure-side gear pump.