Thrust bearing lubricant measurement and balance

• US 3,895,689 A
• Filed: 09/07/1973
• Issued: 07/22/1975
• Est. Priority Date: 01/07/1970
• Status: Expired due to Term

• Current Assignee: Rotoflow Corporation
• Original Assignee: Judson S. Swearingen
• Inventors: Swearingen, Judson S.
• Primary Examiner(s): Pinkham, Richard C.
• Assistant Examiner(s): Siskind, Marvin
• Application Number:
  US05/395,246
• Time in Patent Office: 683 Days
• Field of Search: 184/6R,6.4,1E,6.16 415/104,105,106,112,131 308/9,DIG.1 73/140,141R 277/3,15
• US Class Current: 184/6.4
• CPC Class Codes: F01D 25/168 for axial load mainly
• CPC Class Codes: F04D 27/001 Testing thereof; Determination or simulation of flow characteristics; Stall or surge detection, e.g. condition monitoring
• CPC Class Codes: F04D 29/0513 hydrostatic; hydrodynamic thrust bearings
• CPC Class Codes: F04D 29/0516 balancing pistons
• CPC Class Codes: F16C 17/04 for axial load only
• CPC Class Codes: F16C 17/24 with devices affected by abnormal or undesired positions, e.g. for preventing overheating, for safety
• CPC Class Codes: F16C 2233/00 Monitoring condition, e.g. temperature, load, vibration
• CPC Class Codes: F16C 2360/44 Centrifugal pumps
• CPC Class Codes: F16C 32/064 the liquid being supplied under pressure
• CPC Class Codes: F16C 32/0692 for axial load only
• CPC Class Codes: F16C 39/04 using hydraulic or pneumatic means
• CPC Class Codes: G01L 5/12 for measuring axial thrust in a rotary shaft, e.g. of propulsion plants

Abstract

A method of determining the axial thrust on a thrust bearing assembly having a fixed and a rotating component in which a lubricant is being forced between the mated faces of the respective components and where zones of pressure are built up during operation, comprising monitoring the pressure of the lubricant between the mated faces. The invention also provides for determining the axial thrust by measuring the pressure differential of the lubricant between the mated faces or as it enters therebetween and as it emerges from between said faces. To measure the axial thrust on a pair of opposing thrust bearing assemblies, the pressure differential of the lubricant between the respective mated faces of the two assemblies is obtained. The axial thrust measurement can be utilized in a method of adjusting the axial thrust on the bearing assemblies by changing manually or automatically a balancing apparatus separate from the thrust bearings and their lubricant and used to adjust the net thrust on the bearings in response to the respective pressure measurement. The invention also encompasses the combination of suitable pressure measuring devices with thrust bearing assemblies with balancing apparatus to carry out the above measurement and control methods.

Claims

1. The method of controlling the axial thrust on a thrust bearing assembly of a rotating machine wherein said thrust bearing assembly comprises a rotating component and a nonrotating component, one face of said rotating component and one face of said non-rotating component being in opposing relationship with each other, wherein a lubricant is forced in operation between the opposed faces of said components forming a first zone of pressure between said faces maintaining them separated and transmitting thrust load between them;

and wherein there is a balancing means operable to apply a desired end thrust to one of said components to adjust the thrust forces on said bearing;

said method comprising the steps of determining from time to time the axial thrust on said assembly by monitoring the pressure of said lubricant in said first zone and operating said balancing means in accordance with the axial thrust determination to produce a desired aggregate thrust on said bearing assembly.

2. In a rotating machine having a thrust bearing assembly, said bearing assembly having a rotating component and a non-rotating component, one face of said non-rotating component and one face of said rotating component being in opposing relationship with each other, wherein a lubricant is forced in operation between the opposed faces of said components forming a first zone of pressure which is between said faces, and is pressurized to a thrust sustaining pressure to maintain said components separated, and a second pressure zone is created in said lubricant differing from said thrust sustaining pressure by an amount indicative of the thrust on said bearing assembly;

the improvement which comprises a pressure determining means including a pressure sensing means exposed to said first zone, a pressure sensing means exposed to said second zone, and means for comparing the two, and a balancing means operable to adjust to a desired value, as indicated by said pressure determining means, the aggregate thrust force on said bearing assembly.

3. The combination of claim 2 wherein said balancing means is responsively connected to said pressure determining means and said pressure determining means contains means to automatically adjust said balancing means.

4. The combination of claim 2 wherein said rotating component of said machine is mounted on a shaft, wherein said machine further comprises a rotor mounted on said shaft distal said bearing assembly and designed to pass a working fluid therethrough and a fixed member between said rotor and said bearing assembly, wherein a portion of said working fluid is allowed to leak into a space between said rotor and said fixed member, and wherein said balancing means comprises means for controlling the pressure of the working fluid in said space.

5. A rotating machine according to claim 2 wherein said second zone is located downstream from between the mated faces.

6. The method of controlling the axial thrust on a thrust bearing assembly in a rotating machine in which machine said bearing assembly has a rotating component and a fixed component, one face of said fixed component and one face of said rotating component being in opposed mating relationship with one another, and in which machine a lubricant is forced into said assembly by the relative rotation of said components and them flows between the mated faces of said rotating and said fixed component, and the flow of lubricant between said mated faces generates zones of pressure, one of which is between said mated faces, sufficient to maintain said components separated, and the pressure of said zones differing from each other by an amount indicative of the Value of the thrust load, said machine having in addition to a balancing means to adjust the thrust force on said bearing assembly;

said method comprising the steps of monitoring the pressure of said lubricant in said one of said zones, monitoring the pressure of said lubricant in the other of said zones, determining the difference between the two pressures as an indication of the axial thrust on said assembly, and adjusting said balancing means in accordance with the axial thrust indication.

7. The method of claim 6 wherein said other of said zones is a zone of constant pressure of said lubricant.

8. In a rotating machine having a thrust bearing assembly having a rotating component and a fixed component, one face of said fixed component and one face of said rotating component being in mating relationship with one another, wherein a lubricant is forced into said assembly and then flows radially outward between the mated faces of said rotating and said fixed component, the flow of lubricant radially outward between said mated faces generating zones of pressure sufficient to maintain said components separated, and the difference in pressure of said zones being indicative of the value of the thrust load;

the improvement which comprises the combination therewith of a pressure measuring means connected so as to monitor the pressure gradient of said lubricant across said mated faces between successive ones of such zones, at least one of which is between said mated faces and a balancing means to adjust the thrust force on said bearing assembly.

9. The combination of claim 8 wherein said balancing means is responsively connected to said pressure measuring means to automatically adjust said balancing means.

10. In a rotating machine having a pair of opposing thrust bearing assemblies to maintain axial location of a shaft of said machine, each of said bearing assemblies having a rotating component mounted on said shaft and a non-rotating component, one face of said rotating component and one face of said non-rotating component being in opposing relationship with each other, wherein a bearing lubricant body is created in operation between the opposed faces of said components and maintained under pressure sufficient to keep said components separated and transmit any thrust forces between them, the combination of a differential pressure measuring device connected so as to measure the difference between the pressure of said lubricant between the opposed faces of one of said bearing assemblies and the pressure of said lubricant between the opposed faces of the other said bearing assemblies, whereby when said rotating components are displaced in one direction by an end thrust loading one of said bearing assemblies and unloading the other, said comparison will indicate the pressure in the loaded assembly compared to an unloaded assembly and hence the end thrust on the loaded assembly, and a balancing means to adjust the thrust force on said bearing assemblies.

11. The combination of claim 10 wherein said balancing means is responsively connected to said differential pressure measuring means and said differential pressure measuring means contains means to automatically adjust said balancing means.

12. A rotating machine according to claim 10 wherein the lubricant between each of the opposed bearing assemblies forms part of a common lubricant body.

13. A rotating machine according to claim 10 wherein said bearing lubricant bodies are created by the relative rotation of said components.