Pump bearing retainer
AssigneeGrundfos Holding A/S
InventorGunnar Gaba
Life of this patent
Estimating the term…
Abstract
A wet-running pump bearing retainer (29) includes a radial bearing configured for a lubrication film between an inner sliding surface (41) and a rotor shaft (13) of a pump (1). The radial bearing is fitted into a radially inner section (49) that defines an axial fluid channel (45), located at a first radial distance (D1) to a rotor axis (R) and providing a fluid flow path (F1) in a first axial flow direction. The first radial distance is larger than a radius (D0) of the inner sliding surface. A radially outer section (51) extends from the inner section and defines a second axial fluid channel (47) for a flow path (F2) in a second axial flow direction, opposite to the first flow direction. The second axial fluid channel is located at a second radial distance (D2) to the rotor axis, which is larger than the first radial distance.
Claims21
A pump bearing retainer for a wet-running pump with a rotor shaft, the pump bearing retainer comprising:
- a radially inner section;
- a radial bearing with an inner sliding surface configured to allow a lubrication film between the inner sliding surface and the rotor shaft of the pump, the radial bearing being fitted into the radially inner section;
- and
- a radially outer section extending radially outward from the inner section, wherein:
- the radially inner section defines at least one first axial fluid channel providing a first fluid flow path in a first axial flow direction;
- the at least one first axial fluid channel is located at a first radial distance to a rotor axis;
- the first radial distance is larger than the radius of the inner sliding surface;
- the radially outer section defines at least one second axial fluid channel providing a fluid flow path in a second axial flow direction through the at least one second axial fluid channel;
- the at least one second axial fluid channel is located at a second radial distance to the rotor axis;
- the second radial distance is larger than the first radial distance;
- the second axial flow direction is opposite to the first axial flow direction;
- and
- the at least one second axial fluid channel is formed as an arc-shaped slot having an arc radius equal to the second radial distance.
A wet-running centrifugal pump comprising:
- a permanent-magnet synchronous motor;
- a rotor shaft;
- an impeller mounted to the rotor shaft;
- and
- a pump bearing retainer comprising:
- a radially inner section;
- a radial bearing fitted into the radially inner section, the rotor shaft being arranged in the radial bearing with a clearance to an inner sliding surface of the radial bearing for establishing a lubrication film;
- and
- a radially outer section extending radially outward from the inner section, wherein:
- the radially inner section defines at least one first axial fluid channel providing a first fluid flow path in a first axial flow direction;
- the at least one first axial fluid channel is located at a first radial distance to a rotor axis;
- the first radial distance is larger than the radius of the inner sliding surface;
- the radially outer section defines at least one second axial fluid channel providing a fluid flow path in a second axial flow direction through the at least one second axial fluid channel;
- the at least one second axial fluid channel is located at a second radial distance to the rotor axis;
- the second radial distance is larger than the first radial distance;
- the second axial flow direction is opposite to the first axial flow direction;
- and
- the at least one second axial fluid channel is formed as an arc-shaped slot having an arc radius equal to the second radial distance.
A method of operating a wet-running centrifugal pump comprising a permanent-magnet synchronous motor, the method comprising:
- providing, when the motor is running, a first flow path from a rotor chamber into an impeller chamber through at least one first axial fluid channel defined by a radially inner section of a pump bearing retainer of the pump, the at least one first axial fluid channel being located at a first radial distance to a rotor axis;
- and
- providing, when the motor is running, a second flow path from the impeller chamber into the rotor chamber through at least one second axial fluid channel defined by a radially outer section of the pump bearing retainer, the at least one second axial fluid channel being located at a second radial distance to the rotor axis, wherein the at least one second axial fluid channel is formed as an arc-shaped slot having an arc radius equal to the second radial distance.
Dependencies are inferred from the claim text.