# US 2021/0277894 A1 · Pump device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2021/0277894 A1 - Document ID: US20210277894A1 - Status: Published application - Kind: A1 - Application number: 16/334,385 - Filed: 2017-09-25 - Published: 2021-09-09 - Earliest claimed: 2016-09-30 - Assignees: Nidec Tosok Corporation - Applicants: Nidec Tosok Corporation - Inventors: Kazuhiro HOMMA; Yosuke ITO - Web page: https://patentgrep.com/patent/US20210277894A1 ## CPC - F04C 15/06: Arrangements for admission or discharge of the working fluid, e.g. constructional features of the inlet or outlet - F04C 2/10: of internal-axis type with the outer member having more teeth or tooth-equivalents, e.g. rollers, than the inner member - F04C 2/102: {the two members rotating simultaneously around their respective axes} - F04C 11/008: {Enclosed motor pump units} - F04C 15/008: {Prime movers} - F04C 15/0088: {Lubrication (of machines or engines in general F01M)} - F04C 15/0096: {Heating; Cooling (of machines or engines in general F01P)} - F04C 29/045: {of the electric motor in hermetic pumps} - H02K 1/187: {to inner stators} - H02K 5/1735: {radially supporting the rotary shaft at only one end of the rotor (H02K5/1737 takes precedence)} - H02K 5/203: {specially adapted for liquids, e.g. cooling jackets} - H02K 9/19: for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil - H02K 16/02: Machines with one stator and two {or more} rotors - H02K 2201/03: Machines characterised by aspects of the air-gap between rotor and stator - F04C: ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS (engines F03C); ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract A pump device includes a shaft , a motor unit that rotates the shaft, and a pump driven by the motor via the shaft and discharges oil. The pump device includes a first flow path for the oil that connects the inside of the pump and the inside of a housing, a second flow path for the oil provided between a stator and a rotor, and a third flow path for the oil that is connected to a suction port of a pump through the outside of the stator and the rotor in a radial direction from the second flow path. One or a plurality of grooves are provided on the outer peripheral surface of the rotor or the inner peripheral surface of the stator, and the groove is inclined with respect to an oil flow direction. ## Claims ### Claim at position 1 1-20. (canceled) ### Claim 21 A pump device comprising: a shaft that rotates around a central axis that extends in an axial direction; a motor that rotates the shaft; and a pump that is positioned on one side of the motor in the axial direction, is driven by the motor via the shaft, and discharges oil; wherein the motor includes: a rotor that rotates around the shaft; a stator facing the rotor; and a housing in which the rotor and the stator are accommodated; the pump includes: a pump rotor that is attached to the shaft; and a pump case in which a suction port into which the oil is sucked and a discharge port from which the oil is discharged are provided and the pump rotor is accommodated; the pump device further comprises: a first flow path for the oil that connects an interior of the pump and an interior of the housing; a second flow path for the oil provided between the stator and the rotor; and a third flow path for the oil that is connected to a pump suction port through an outside of the stator and the rotor in a radial direction from the second flow path; at least one groove is provided on an inner peripheral surface of the rotor and the stator disposed in a radially outward direction or on an outer peripheral surface of the rotor and the stator disposed in a radially inward direction; and the at least one groove is inclined with respect to an oil flow direction. ### Claim 22 (depends on 21) The pump device according to claim 21, wherein the at least one groove includes a spiral groove. ### Claim 23 (depends on 21) The pump device according to claim 21, wherein the at least one groove includes a plurality of grooves, and each of the plurality of grooves is an annular groove extending around one circumference of a circumferential surface in which the groove is provided, and the plurality of grooves are provided in the axial direction. ### Claim 24 (depends on 21) The pump device according to claim 21, wherein an intermittent portion that protrudes from the at least one groove in the radial direction is provided on a circumferential surface in which the at least one groove is provided; and the intermittent portion extends in the axial direction. ### Claim 25 (depends on 21) The pump device according to claim 21, wherein an intermittent portion that protrudes from the at least one groove in the radial direction is provided on a circumferential surface in which the at least one groove is provided; and the intermittent portion extends in a circumferential direction. ### Claim 26 (depends on 21) The pump device according to claim 21, wherein the pump case includes a pump cover and a pump body; the pump body is open at both ends in the axial direction and the shaft passes therethrough; and the pump rotor rotates according to rotation of the shaft. ### Claim 27 (depends on 26) The pump device according to claim 26, wherein the stator and the pump body are capable of contacting each other. ### Claim 28 (depends on 21) The pump device according to claim 21, wherein the stator is an integrally molded article made of a resin. ### Claim 29 (depends on 28) The pump device according to claim 28, wherein the stator has the at least one groove included in the resin. ### Claim 30 (depends on 21) The pump device according to claim 21, wherein the rotor is an integrally molded article made of a resin. ### Claim 31 (depends on 30) The pump device according to claim 30, wherein the rotor has the at least one groove included in the resin. ### Claim 32 (depends on 21) The pump device according to claim 21, wherein the stator is positioned radially outward from the rotor; and the third flow path includes a flow path connected to the pump suction port through the outside of the stator in the radial direction from the second flow path. ### Claim 33 (depends on 32) The pump device according to claim 32, wherein the third flow path includes a space between the outer peripheral surface of the stator and the inner peripheral surface of the housing of the motor. ### Claim 34 (depends on 33) The pump device according to claim 33, wherein the third flow path includes a through-hole or a cutout provided in the stator or in the housing. ### Claim 35 (depends on 32) The pump device according to claim 32, wherein one end on a side of the motor of the first flow path is provided at or adjacent to a side of the motor of an opening through which the shaft passes in the pump case; and the second flow path is connected to one end on a side of the motor of the first flow path. ### Claim 36 (depends on 32) The pump device according to claim 32, further comprising a flow path that is provided between the outer peripheral surface of the shaft and the inner peripheral surface of the rotor. ### Claim 37 (depends on 32) The pump device according to claim 32, further comprising a flow path through which a through-hole provided in the rotor passes. ### Claim 38 A pump device comprising: a shaft that rotates around a central axis that extends in an axial direction; a motor that rotates the shaft; and a pump that is positioned on one side of the motor in the axial direction, is driven by the motor via the shaft, and discharges oil; wherein the motor includes: a rotor that rotates around the shaft; a stator that faces an inner side of the rotor in a radial direction; a housing in which the rotor and the stator are accommodated; the pump includes: a pump rotor that is attached to the shaft; and a pump case in which a suction port into which the oil is sucked and a discharge port from which the oil is discharged are provided and the pump rotor is accommodated; the pump device further comprises: a first flow path for the oil that connects an interior of the pump and an interior of the housing; a second flow path for the oil provided between the stator and the rotor; and a third flow path for the oil including a flow path connected to the second flow path through an interior of the stator and the rotor in the radial direction from the first flow path and a flow path connected to a pump suction port from the second flow path; wherein at least one groove is provided on an inner peripheral surface of the rotor and the stator disposed in a radially outward direction or on an outer peripheral surface of the rotor and the stator disposed in a radially inward direction; and the at least one groove is inclined with respect to an oil flow direction. ### Claim 39 A pump device comprising: a shaft that rotates around a central axis that extends in an axial direction; a motor that rotates the shaft; and a pump that is positioned on one side of the motor in the axial direction, is driven by the motor via the shaft, and discharges oil; wherein the motor includes: a rotor that rotates around the shaft; a stator that faces the rotor in the axial direction; and a housing in which the rotor and the stator are accommodated; the pump includes: a pump rotor that is attached to the shaft; and a pump case in which a suction port into which the oil is sucked and a discharge port from which the oil is discharged are provided and the pump rotor is accommodated; the pump device further comprises: a first flow path for the oil that connects an interior of the pump and an interior of the housing; a second flow path for the oil provided between the stator and the rotor; and a third flow path for the oil that is connected to a pump suction port through an outside of the stator and the rotor in a radial direction from the second flow path; at least one groove is provided on a facing surface in which the rotor and the stator face each other; and the at least one groove is inclined with respect to an oil flow direction. ### Claim 40 (depends on 39) The pump device according to claim 39, wherein the motor includes two rotors attached to the shaft with a predetermined interval therebetween in the axial direction; the stator is disposed between the two rotors; and the second flow path includes a flow path provided between a first of the two rotors and the stator, and a flow path provided between a second of the two rotors and the stator.