Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D13/00—Pumping installations or systems
  • F04D13/02—Units comprising pumps and their driving means
  • F04D13/06—Units comprising pumps and their driving means the pump being electrically driven
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D13/00—Pumping installations or systems
  • F04D13/16—Pumping installations or systems with storage reservoirs
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/05—Shafts or bearings, or assemblies thereof, specially adapted for elastic fluid pumps
  • F04D29/051—Axial thrust balancing
  • F04D29/0513—Axial thrust balancing hydrostatic; hydrodynamic thrust bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04D—NON-POSITIVE-DISPLACEMENT PUMPS
  • F04D29/00—Details, component parts, or accessories
  • F04D29/06—Lubrication
  • F04D29/063—Lubrication specially adapted for elastic fluid pumps
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C17/00—Sliding-contact bearings for exclusively rotary movement
  • F16C17/04—Sliding-contact bearings for exclusively rotary movement for axial load only
  • F16C17/06—Sliding-contact bearings for exclusively rotary movement for axial load only with tiltably-supported segments, e.g. Michell bearings
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
  • F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
  • F16C33/00—Parts of bearings; Special methods for making bearings or parts thereof
  • F16C33/02—Parts of sliding-contact bearings
  • F16C33/04—Brasses; Bushes; Linings
  • F16C33/06—Sliding surface mainly made of metal
  • F16C33/10—Construction relative to lubrication

Definitions

• Fig. 1 is a cross-sectional view showing a conventional pad-type bearing.
• a bearing pad 4 comprises an upper bearing pad 2 provided above a bearing disk 5 and a lower bearing pad 3 provided below the bearing disk 5 so as to support thrust load in both of upper and lower directions.
• the bearing load is supported by hydrodynamic pressure action generated between the upper bearing pad 2 and the bearing disk 5 and between the lower bearing pad 3 and the bearing disk 5 by rotation of the bearing disk 5 fixed to a rotating shaft (main shaft) 6.
• the upper bearing pad 2 and the lower bearing pad 3 comprise a plurality of bearing pads, respectively, and these bearing pads 2,3 and the bearing disk 5 are housed in a bearing cover ⁇ comprising an upper bearing cover la and a lower bearing cover lb, thus constructing an integrated unit.
• Reference numeral 10 represents a bearing housing.
• a lift pump 8 for pressurizing and supplying a lubricating liquid to the bearing pad 4 from the outside is provided, as shown in FIG. 2.
• the lift pump 8 is configured to pressurize a lubricating liquid in a reservoir tank 9 and to supply the lubricating liquid to small holes formed in the lower bearing pad 3.
• the conventional technology cannot sufficiently deal with the requirement that pressure control of the lift pump 8 should be strictly performed in the case where the pressure Ph in the bearing housing 10 is high at the time of startup and the requirement that the pressure piping connecting the lift pump 8 and the bearing housing 10 has high pressure resistance and non-leakage quality, particularly the lift pump 8 and the pressure piping have non-leakage quality in the case where the rotating machine comprises a vertical seal-less motor pump having non-leakage quality.
• the lubricating liquid is water or water solution.
• the impeller of the lift pump is provided in the bearing housing of the thrust bearing, even if the lubricating liquid becomes high pressure, the lubricating liquid can be prevented from leaking.
• FIG. 3 is a top plan view showing a bearing pad having pressure liquid discharge holes according to the present invention.
• FIG. 6 is a schematic cross-sectional view showing a universal joint according to the present invention.
• Apad—type thrust bearing, a submergedmotor and a submerged motor pump according to embodiments of the present invention will be described below with reference to drawings. Like or corresponding parts are denoted by like or corresponding numerals throughout drawings and will not be described below repetitively.
• FIG. 4 is a cross-sectional view showing a pad-type thrust bearing according to an embodiment of present invention.
• the pad-type thrust bearing is provided with a built-in seal-less motor-type lift pump, and the lift pump is integrated with a bearing housing 10.
• the seal-less motor comprises a canned motor comprising a stator core and a stator winding which are enclosed by a can.
• an upper bearing pad 2 and a lower bearing pad 3 are provided in a bearing cover 1 comprising an upper bearing cover la and a lower bearing cover lb such that a bearing disk 5 fixed to a rotating shaft (main shaft) 6 of a rotating machine is located between the upper bearing pad 2 and the lower bearing pad 3.
• the upper bearing pad 2 comprises a plurality of bearing pads, and each of the bearing pads is supported by the upper bearing cover la through a tiltingmechanism 7.
• the lower bearing pad 3 comprises a plurality of bearing pads, and each of the bearing pads is supported by the lower bearing cover lb through a tilting mechanism 7.
• the pump casing 21 is inserted into the hole 17a at the central portion of the cover 17, and the upper pump casing member 21a for plugging up the hole 17a and the lower pump casing member 21b fixed to the motor housing 22 are joined together by a joint portion 24.
• a discharge-side guide vane 23 may be provided on an upper surface, of the pump casing 21.
• the j oint portion 24 may be formed as a suction-side guide vane in the lubricating liquid suction passage 18.
• the universal joint 16 is in the form of cylindrical tube and has substantially spherical heads at both ends of the universal joint 16.
• the universal joint 16 is inserted into the pressure liquid inlet hole lib of each bearing pad 11 of the lower bearing pad 3 and the through-hole lg formed in the lower bearing cover lb, and 0 rings 28 are mounted on the respective spherical heads of the universal joint 16 to seal the pressurized lubricating liquid.
• the outer diameter of the impeller 12a, the outer diameter of the pump casing 21 (comprising the upper pump casing member 21a and the lower pump casing member 21b) and the outer diameter of part of the motor housing 22 which is inserted into the bearing housing 10 are smaller than the inner diameter of the hole formed in the bottom of the bearing housing 10. Therefore, the lift pump 12 can be integrally inserted into the position adjacent to the lower bearing cover lb through the bottom of the bearing housing 10 and can be integrally removed from the bottom of the bearing housing 10.
• the pressure-resistant connection part can be limited only to the seal surface between the flange 22a provided on the motor casing 22 of the lift pump 12 and the bearing housing 10, and the lift pump 12 itself comprises a seal-less pump, thus reducing the chance of leakage of the lubricating liquid even if the lubricating liquid becomes high pressure.
• the submerged motor pump having the above structure can be used for a large-scale seal-less motor pump such as a cooling water circulating pump in a nuclear reactor in which an internal pressure is high enough to be in the range of 70 to 160 bar and leakage of the internal liquid is not allowable.
• a large-scale seal-less pump having output power of 5500kw class is used for a primary coolant pump of a pressurized water reactor
• static weight of a rotating body of about 12 tons acts on a thrust bearing of such seal-less pump.
• the submerged bearing comprises a pad-type thrust bearing having an outer diameter of about 900mm, when the bearing disk is floated by the external pressurization-type lift pump 8 (see FIG. 2) , the required head of the lift pump 8 necessitates about 164 bar including a pressure for resisting the internal pressure.
• the pressure required for controlling flotation of the rotating body can be estimated to be 4 bar. Only by 10 percent higher than this estimation, i.e. 0.4 bar higher than this estimation, the rotating body is moved to the upper bearing pad side and adheres to the upper bearing pad 2.
• the rotating body cannot be maintained in a stable flotation state.
• the power of the lift pump 12 becomes about 1/41 that of the external lift pump 8, and the rotating body can be maintained in a sufficiently stable flotation state with setting accuracy of 0.4 bar, i.e. about 10 percent accuracy.
• the impeller of the lift pump is provided in the bearing housing of the thrust bearing . Therefore, the present invention can be utilized for providing a pad-type thrust bearing which can prevent a lubricating liquid from leaking even if the lubricating liquid becomes high pressure . Further, the present invention can be utilized for providing a submerged motor having such pad-type thrust bearing and a vertical submerged motor pump hiving such pad-type thrust bearing.

Landscapes

• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Structures Of Non-Positive Displacement Pumps (AREA)
• Magnetic Bearings And Hydrostatic Bearings (AREA)
• Sliding-Contact Bearings (AREA)

Applications Claiming Priority (4)

Publications (1)

Family

ID=44483132

Family Applications (1)

Country Status (2)

Cited By (2)

Citations (5)

• 2010
  • 2010-02-19 JP JP2010035090A patent/JP5470085B2/ja not_active Expired - Fee Related
• 2011
  • 2011-02-21 WO PCT/JP2011/054411 patent/WO2011102558A1/en active Application Filing

Patent Citations (5)

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