Pump device

Patent metadata

Field	Value
Publication number	US-11286940-B2
Application number	US-201916271894-A
Country	US
Kind code	B2
Filing date	Feb 11, 2019
Priority date	Feb 14, 2018
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A pump device is provided. In the pump device, a bottom portion of a case body with a suction port formed therein is provided with a through-hole through which a fluid sucked through the suction port passes, and the case body is provided with a shaft holding portion holding the lower end of the fixed shaft and a plurality of connection portions disposed with a space interposed therebetween in the circumferential direction of the rotor so as to surround the through-hole and connecting the shaft holding portion and the bottom portion. The upper end side of the connection portion is provided with a protrusion protruding upward beyond the upper end surface of the shaft holding portion, and at least one of the protrusions is a rotation preventing portion that prevents rotation of the thrust bearing in the circumferential direction of the rotor.

First claim

What is claimed is:

1. A pump device, comprising:
a motor, having a rotor and a stator; and
an impeller, fixed to the rotor and configured to be rotated by a power of the motor, wherein
a pump chamber through which a fluid sucked from a suction port passes toward a discharge port is provided inside a pump case, and the rotor, the stator and the impeller are housed in the pump case,
the motor includes:
a fixed shaft, extending in a first direction towards the suction port, and rotatably supporting the rotor and the impeller; and
a thrust bearing, when one side in an axial direction of the fixed shaft is the first direction and a direction opposite to the first direction is a second direction, the thrust bearing is disposed on an end side of the fixed shaft in the first direction to have the fixed shaft inserted therethrough, and the thrust bearing supports the rotor and the impeller in the axial direction of the fixed shaft,

the pump case includes: a case body provided with the suction port,
the case body is formed in a cylindrical shape with a bottom, and the case body including: a cylindrical portion formed in a cylindrical shape and a bottom portion covering one end of the cylindrical portion,
an axial direction of the cylindrical portion formed in a cylindrical shape coincides with the axial direction of the fixed shaft,
the bottom portion covers an end of the cylindrical portion in the first direction,
the bottom portion is provided with a through-hole penetrating the bottom portion in the axial direction of the fixed shaft and allowing passage of the fluid sucked through the suction port,
an axis center of the fixed shaft coincides with a center of the through-hole when viewed in the axial direction of the fixed shaft,
the case body is provided with a shaft holding portion disposed at a side of the bottom portion in the second direction to hold an end of the fixed shaft in the first direction and a plurality of connection portions disposed with a space interposed therebetween in a circumferential direction of the rotor to surround the through-hole and connects the shaft holding portion and the bottom portion,
after passing through the through-hole, the fluid flows into the pump chamber between the connection portions in the circumferential direction of the rotor,
end sides in the second direction of at least two of the connection portions are each provided with a respective protrusion that protrudes in the second direction beyond an end surface of the shaft holding portion at a side in the second direction,
the thrust bearing is disposed at a side of the shaft holding portion in the second direction, and at least part of the thrust bearing is located inside the protrusion in a radial direction of the rotor, and
a first one of the protrusions has a rotation preventing portion that prevents rotation of the thrust bearing in the circumferential direction of the rotor,
wherein
the rotation preventing portion is provided with an engagement protruding portion that bulges toward an inner side in the radial direction of the rotor, and
the thrust bearing is provided with an engagement recessed portion that is engaged with the engagement protruding portion to prevent rotation of the thrust bearing in the circumferential direction of the rotor,
the engagement protruding portion is a substantially semicircular column,
the engagement recessed portion is a circular shape wherein an end side in the second direction of the first one of the protrusions is provided with a removal preventing portion that prevents the thrust bearing from being removed to a side in the second direction, and wherein the removal preventing portion is monolithic with the first one of the protrusions.

2. The pump device according to claim 1 , wherein
the thrust bearing is provided with a first projection and a second projection projecting toward an outer circumference side of the thrust bearing,
the first projection is provided with a first contact surface that is capable of being in contact with the rotation preventing portion at one side in the circumferential direction of the rotor, and
the second projection is provided with a second contact surface that is capable of being in contact with the rotation preventing portion at other side in the circumferential direction of the rotor.

3. The pump device according to claim 2 , wherein
one of the protrusions is the rotation preventing portion, and
the rotation preventing portion is sandwiched between the first projection and the second projection in the circumferential direction of the rotor.

4. The pump device according to claim 1 , wherein
an end side of at least one of the protrusions in the second direction is provided with a removal preventing portion that prevents the thrust bearing from being removed to a side in the second direction.

5. The pump device according to claim 1 , wherein
the motor includes: a second thrust bearing, disposed on an end side of the fixed shaft in the second direction to have the fixed shaft inserted therethrough, and the second thrust bearing supports the rotor and the impeller in the axial direction of the fixed shaft,
the pump case includes: a motor case that forms part of the motor,
the motor case is provided with a second shaft holding portion that holds an end of the fixed shaft in the second direction, and
the second shaft holding portion is provided with a second rotation preventing portion that prevents rotation of the second thrust bearing in the circumferential direction of the rotor.

6. The pump device according to claim 1 , wherein
the impeller includes: a shaft bearing with a cylindrical shape through which the fixed shaft is inserted,
an end surface of the shaft bearing at a side in the first direction is opposed to the thrust bearing, and
the end surface of the shaft bearing at the side in the first direction is provided with a communicating groove that communicates from an inner circumference of the shaft bearing to an outer circumference thereof and is recessed toward a side in the second direction.

7. The pump device according to claim 1 , wherein
the motor includes: a second thrust bearing, disposed on an end side of the fixed shaft in the second direction to have the fixed shaft inserted therethrough, and the second thrust bearing supports the rotor and the impeller in the axial direction of the fixed shaft,
the pump case includes: a motor case that forms part of the motor,
the motor case is provided with a second shaft holding portion that holds an end of the fixed shaft in the second direction,
the second shaft holding portion is provided with a placement recessed portion that is recessed toward a side in the second direction and has the second thrust bearing placed therein,
a side surface of the placement recessed portion is provided with a second engagement protruding portion that bulges toward an inner side in the radial direction of the rotor,
the second thrust bearing is formed to have a shape identical to a shape of the thrust bearing, and
the second thrust bearing is provided with a second engagement recessed portion that is engaged with the second engagement protruding portion to prevent rotation of the second thrust bearing in the circumferential direction of the rotor.

8. The pump device according to claim 7 , wherein
the second engagement protruding portions are formed at equal to or more than three areas at a pitch of an equal angle with respect to an axis center of the fixed shaft.

9. The pump device according to claim 8 , wherein
the second engagement protruding portions are formed at three areas with a pitch of an equal angle with respect to the axis center of the fixed shaft, and
the second

Assignees

• Nidec Sankyo Corp

Inventors

• Otsuki Noboru
• Kuratani Hiroki

Classifications

• F04D13/0673 Primary

  the motor being of the inside-out type · CPC title

• F04D13/0606

  Canned motor pumps · CPC title

• F04D29/0413

  hydrostatic; hydrodynamic thrust bearings · CPC title

• F04D29/043

  Shafts · CPC title

• F04D29/041

  Axial thrust balancing · CPC title