CA1094620A - Device for maintaining a required pressure in a hydrostatic bearing - Google Patents
Device for maintaining a required pressure in a hydrostatic bearingInfo
- Publication number
- CA1094620A CA1094620A CA310,420A CA310420A CA1094620A CA 1094620 A CA1094620 A CA 1094620A CA 310420 A CA310420 A CA 310420A CA 1094620 A CA1094620 A CA 1094620A
- Authority
- CA
- Canada
- Prior art keywords
- pressure
- liquid
- bearing
- accumulator
- pump
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000002706 hydrostatic effect Effects 0.000 title claims abstract description 12
- 239000007788 liquid Substances 0.000 claims abstract description 46
- 239000012530 fluid Substances 0.000 claims abstract 3
- 238000006073 displacement reaction Methods 0.000 claims 1
- 238000011144 upstream manufacturing Methods 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
Classifications
-
- 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
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0629—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion
- F16C32/064—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a liquid cushion, e.g. oil cushion the liquid being supplied under pressure
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Magnetic Bearings And Hydrostatic Bearings (AREA)
- Electrical Discharge Machining, Electrochemical Machining, And Combined Machining (AREA)
- Supply Devices, Intensifiers, Converters, And Telemotors (AREA)
Abstract
A B S T R A C T
A liquid supply system for a hydrostatic bearing is provided with an accumulator for maintaining a required liquid pressure in the bearing during its slow-down at times of pump failure. The accumulator has a movable piston and a pressurized gas system for maintaining a sufficient liquid pressure in the accumulator. A portion of the pressure liquid for the bearing is led through a pressure generating member, such as a metering unit, which provides liquid under a pressure higher than the maximum liquid pressure in the bearing.
The accumulator communicates with this higher pressure liquid. A part of the higher pressure liquid flows to the bearing via a constant flow valve which is in fluid communication with the accumulator. A return condiit in fluid communication with the accumulator has a one-way valve leading to a lower pressure position. The one-way valve opens when the liquid pressure upstream corresponds to the higher pressure so that the remainder of the portion of the pressure liquid flows to the lower pressure position.
A liquid supply system for a hydrostatic bearing is provided with an accumulator for maintaining a required liquid pressure in the bearing during its slow-down at times of pump failure. The accumulator has a movable piston and a pressurized gas system for maintaining a sufficient liquid pressure in the accumulator. A portion of the pressure liquid for the bearing is led through a pressure generating member, such as a metering unit, which provides liquid under a pressure higher than the maximum liquid pressure in the bearing.
The accumulator communicates with this higher pressure liquid. A part of the higher pressure liquid flows to the bearing via a constant flow valve which is in fluid communication with the accumulator. A return condiit in fluid communication with the accumulator has a one-way valve leading to a lower pressure position. The one-way valve opens when the liquid pressure upstream corresponds to the higher pressure so that the remainder of the portion of the pressure liquid flows to the lower pressure position.
Description
2~
This invention rela~es to a device for maintaining a required liquid pressure in a hydrostatic bearing during its slow-down time at pump failure for avoiding metallic contact between the cooperating bearing surfaces.
The device incorporates an accumulator connected in the liquid supply system of the bearing and having means for maintaining a sufficient liquid pressure on the liquid contained in the accumulatorO
In a hydrostatic bearing the cooperatir.g b~aring surfaces are spaced apart by means of a layer of a pressure liquid usually oil. The requir-ed oil pressure is generated by a pump systemO Such a bearing has a la~ge load carrying capacity and low friction. The low friction is however depending thereon that a required oil pressure is always maintained during operationO If the pressure for any reason should cease, eOg. at current interruption, whereby electric pump motors will stop, a metallic contact will result and consequently a high friction at the cooperating bearing surfaces which can easily lead to break-downO Such a failure can result in great damage due to the usually large loads carried by the bearing. It is therefore necessary for security reasons to arrange that the bearing eOgO at current interruption, is supplied with oil under suficient pressure during its slow-down time, iOeO the time which it takes to stop the member carried by the bearing.
In order to overcome this problem, it is known to accumulate a ~olume of oil under pressure, e.gO in a piston accumulator, which in principle consists of a cylinder wherein an axially freely movable piston divides the cylinder volume in two parts. Thus oil in communication with the bearing pressure oil system is contained in one part of the cylinder and pressure gas in the other part thereof. The oil pressure and the gas pressure at each side of the freely movable piston automatically will equalize themselves in order to balance the piston. As the gas is compressible, the gas volwme will vary in response to the oil pressure prevailing in the bearing, which bearing :`:
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pressure in turn will vary in relation to the bearing load. The oil volume contained in the accumulator will vary in response to the ch.mges caused by the bearing load. The oil volume in the accumulator furthermore always must be sufficient for attending to the slow-down time. At bearings subjected to large load variations e.g. at mills this means that the accumulator volume must be large and this volume is then only utilized to a very little part.
The cost for the accumulator unit will therefore be considerable and it will amount to a large part of the entire cost of the bearing system. The required space is furthermore large.
Other systems for preventing metallic contact between the bearing surfaces o hydrostatic bearings at pump failure have been suggested e.g. to connect the pump system to fly wheels which will drive the pumps during a certain time after a current interruption or to provide the supported member with auxiliary bearings such as roller bearings, which are put in function when the pressure ceases in the hydrostatic bearing. Such solutions are how-Aver technically complicated and expensive and they have often a not suffic-ient reliability.
The purpose of the present invention is to provide a device which by means of a comparatively small accumulator will function with suficient rellability and at very high bearing pressure variations. A space saving and safe device is ohtained at a low cost.
According to the invention, there iS provided a device for maintain-ing a required liquid pressure in a hydrostatic bearing having a pump actua-ted liquid supply system during its slow-down time at pump failure, comprising an accumulator connected in the liquid supply system of the bearing and having means for maintaining a sufficient liquid pressure on the liquid con-tained in the accumulator, characterized in that a portion of the liquid in ,;;.~, :. - . . . . .
.
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the system is led through a pressure genera~ing member wherein the liquid is raised to a pressure higher than the maximum liquid pressure in the bearing, that the accumulator is adapted to communicate with said portion of the pressure liquid whereby the liquid pressure inside the accumulator is greater than the maximum liquid pressure in the bearing, and ~hat a part of said portion of the pressure liquid is led to the bearing via at least one constant flow valve and the remainder to a lower pressure position in the liquid supply system via a return conduit provided with a one-way valve adapted to open when the liquid pressure in the accumulator corresponds to said higher pressure generated by said pressure generating member.
Preferred embodiments of the invention will hereinafter be further described with reference to the accompanying drawings, in which Figure 1 and , Figure 2 are schematic diagrams of two different liquid supply systems for hydrostatic bearings.
In Figure 1 there is shown diagrammatically a bearing incorporating `~ a rotatable ring 1, which is supported by three hydrostatic bearing blocks 2,
This invention rela~es to a device for maintaining a required liquid pressure in a hydrostatic bearing during its slow-down time at pump failure for avoiding metallic contact between the cooperating bearing surfaces.
The device incorporates an accumulator connected in the liquid supply system of the bearing and having means for maintaining a sufficient liquid pressure on the liquid contained in the accumulatorO
In a hydrostatic bearing the cooperatir.g b~aring surfaces are spaced apart by means of a layer of a pressure liquid usually oil. The requir-ed oil pressure is generated by a pump systemO Such a bearing has a la~ge load carrying capacity and low friction. The low friction is however depending thereon that a required oil pressure is always maintained during operationO If the pressure for any reason should cease, eOg. at current interruption, whereby electric pump motors will stop, a metallic contact will result and consequently a high friction at the cooperating bearing surfaces which can easily lead to break-downO Such a failure can result in great damage due to the usually large loads carried by the bearing. It is therefore necessary for security reasons to arrange that the bearing eOgO at current interruption, is supplied with oil under suficient pressure during its slow-down time, iOeO the time which it takes to stop the member carried by the bearing.
In order to overcome this problem, it is known to accumulate a ~olume of oil under pressure, e.gO in a piston accumulator, which in principle consists of a cylinder wherein an axially freely movable piston divides the cylinder volume in two parts. Thus oil in communication with the bearing pressure oil system is contained in one part of the cylinder and pressure gas in the other part thereof. The oil pressure and the gas pressure at each side of the freely movable piston automatically will equalize themselves in order to balance the piston. As the gas is compressible, the gas volwme will vary in response to the oil pressure prevailing in the bearing, which bearing :`:
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.
.. . . . .
- ' ,' ,.
', .
.. . . , ~ . .:
..
,': . : , : : .
.. . .
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pressure in turn will vary in relation to the bearing load. The oil volume contained in the accumulator will vary in response to the ch.mges caused by the bearing load. The oil volume in the accumulator furthermore always must be sufficient for attending to the slow-down time. At bearings subjected to large load variations e.g. at mills this means that the accumulator volume must be large and this volume is then only utilized to a very little part.
The cost for the accumulator unit will therefore be considerable and it will amount to a large part of the entire cost of the bearing system. The required space is furthermore large.
Other systems for preventing metallic contact between the bearing surfaces o hydrostatic bearings at pump failure have been suggested e.g. to connect the pump system to fly wheels which will drive the pumps during a certain time after a current interruption or to provide the supported member with auxiliary bearings such as roller bearings, which are put in function when the pressure ceases in the hydrostatic bearing. Such solutions are how-Aver technically complicated and expensive and they have often a not suffic-ient reliability.
The purpose of the present invention is to provide a device which by means of a comparatively small accumulator will function with suficient rellability and at very high bearing pressure variations. A space saving and safe device is ohtained at a low cost.
According to the invention, there iS provided a device for maintain-ing a required liquid pressure in a hydrostatic bearing having a pump actua-ted liquid supply system during its slow-down time at pump failure, comprising an accumulator connected in the liquid supply system of the bearing and having means for maintaining a sufficient liquid pressure on the liquid con-tained in the accumulator, characterized in that a portion of the liquid in ,;;.~, :. - . . . . .
.
--, , - . .
,, ", , '~
' ' .
z~
the system is led through a pressure genera~ing member wherein the liquid is raised to a pressure higher than the maximum liquid pressure in the bearing, that the accumulator is adapted to communicate with said portion of the pressure liquid whereby the liquid pressure inside the accumulator is greater than the maximum liquid pressure in the bearing, and ~hat a part of said portion of the pressure liquid is led to the bearing via at least one constant flow valve and the remainder to a lower pressure position in the liquid supply system via a return conduit provided with a one-way valve adapted to open when the liquid pressure in the accumulator corresponds to said higher pressure generated by said pressure generating member.
Preferred embodiments of the invention will hereinafter be further described with reference to the accompanying drawings, in which Figure 1 and , Figure 2 are schematic diagrams of two different liquid supply systems for hydrostatic bearings.
In Figure 1 there is shown diagrammatically a bearing incorporating `~ a rotatable ring 1, which is supported by three hydrostatic bearing blocks 2,
3, 4. The blocks are fed with pressure oil from an oil container 5 via two ; pumps 6, 7 having one motor 8, 9 each and the oil flow is distributed between the blocks by a 10w distribution member, which is known per se and which incorporates three in~erconnec~ed metering units 10, 11, 12, which are de-signed as positive displacemen~ pumps. A speed indicator 12a senses that a ~r~ ~ suficient amount of oil always flows to the blocks 2, 3> 4. The leakage flow rom the bearing is preferably lead via a filtering device (not shown) ~ ~ back to the container 5. In order to prevent oil from 10wing backwards in ? the system one-way valves 13, 14, 15, 16, 17 are arranged down-stream of each pump unit.
An accumulator which ascertains that oil under pressure is supplied to the blocks 2, 3, 4 during the slow-down time of the bearing a~ failure .:' ,.-:,, ., ' : ' . ~ . . . .
. . - - . -~: .
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.
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of the pumps 6J 7, incorporates a cylinder 18, the vol~e of which is divided into two chambers by means of an axially freely movable piston l9o As the piston is freely movable the pressure will always be equal in the two chambersO
In one chamber 20 there is contained a pressure gas and this chamber is pre-ferably connected to a particular pressure gas container 21 for ascertaining that the gas always has a sufficient pressureO
The other chamber 22 is, in a manner specified here beiow~
connected to the pressure oil system of the bearing and it is filled with oilO
A portion of the oil flowing from the pumps 6, 7 against the bearing is led through a particular pressure generating memberO In the embodiment according to figure 1 there is an additional metering unit 23 in the flow distribution member, wherein the oil is given a pressure higher than the maximum pressure appearing in the bearing~ Oil is lead from tlle metering unit 23 to each one of the bearing bloGks 2, 3, 4 via conduits in which constant flow valves 24, 25, 26 are arrangedO These valves are set in such a manner that only a part of the oil, which passes the metering unit 23, is lead to the bearing blocks 2, 37 4. During normal running the remainder is lead back to a position 27 up-stream of the flow distribution member, in which position the oil pressure is lower than downstreams o~ the metering unit 230 In order to make possible a setting of the desired oil pressure in the oil flowing from the metering unit 23, an adjustable constant pressure valve 28 is inserted in the return conduit upstream of the position 270 This valve is set in such a manner that it will open at the pressure desired on the oil in chamber 22 of the accumulatorO As long as the pressure is lower, eOg. at start, the valve is closed and as the flow through the unit 23 is larger than the flow through the lmits 24, 25, 26 the remainder of the oil will flow to chamber 227 which communicates with the metering unit 23 and with the return conduit having the valve 28 and with the conduits having the constant flow valves 24, 25, 26 to the bearing blocks 2, .
, ~ID~46~
3, ~. When the oil at start flows into the chamber 22 its volume will increase whereby the volume o~ the chamber 20 is reduced correspondingly, which means that the gas pressure will increase and so will also the pressure in the cham-ber 220 When the pressure reaches the pressure set on valve 28 this will open and the excess oil will flow through the return conduit instead of to the accumulator, which during operation thus always will be charged with oil of the desired pressure. At failure o~ the pumps 6, 7 the flow through the flow distribution member will stop and thus also through the metering unit 23, whereby the pressure downstreams of this will dropO The valve 28 will then close and oil is pressed out of the chamber 22 by the gas pressure in the chamber 20 through the conduits having the valves 24, 25, 26 during such a long period of time that the rotatable ring 1 has time to stop before the pressure in the blocks 2, 3, 4 will become so low that metallic contact will appear between the blocks and the ring. A non-return valve 29 prevents oil from the accumulator from flowing backwards through the metering unit 23. As it is possible to set the oil pressure in chamber 22 at the desired value by means of valve 28, which valve however shall exceed the maximum oil pressure in the bearing, the entire oil volume contained in chamber 22 will eOg. at pump failure, be supplied to the bearing with a required pressure. ~ccording to the present invention it lS thus not necessary to make the accumulator unit any larger than needed for storing exact the oil volume required by the bear-ing during its slow-down timeO
During the slow-down time of the bearing at pump failure a flow from the accumulator is required which flow is preferably about at least 10%
oE the normal flow during operation at a given bearing load. The bearing shall furthermore be able to de driven without restrictions with only one of the pumps 6, 7 running iOe~ with half the flow, in order to allow repairment and seryice of one of the pump~motor units during operation of the bearingO
_ 5 _ ~ ~ .
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Furthermore it is required that the oil amount through the metering unit 23 at half flow is at least 10% of the normal flow to the bearing iOeO at least as much as flows through valves 24, 25, 26 for ensuring that the pressure in the accumulator shall be maintainedO This means that at normal operation with both pumps running, more than half of the oil pumped ~hrough the unit 23 will flow through the return conduit. As however only about 25% of the total oil flow needs to pass through the unit 23 the total flow loss through the valves 24, 25, 2~ and 28 will be rather small.
In figure 2, there is shown a modified embodiment of a device according to the invention. The bearing and the hydraulic system have mainly the same design as those of figure 1 but the particular pressure generating member is in this embodiment designed as pump units 32~ 33, which are connected to the main pumps 30, 31 instead of an additional metering unit in the flow distribution member 34~ The other elements of the device correspond entirely to those described in figure 1 and the device operates in a corresponding mannerO
It is also possible to construct and use other embodiments of the inventionO If for instance only one bearing block is used there is required no flow distribution member and then only a constant flow valve in the conduit between the particular pressure generating me~ber and the bearing block is usedO
2Q Instead of a flow distribution member of the type described hereabo~e it is of course possible to use other systems e.g. restrictions in the conduits connected to each bearing block. It is also possible to arrange a particular ; driving motor for the pumps 10, 11, 12, 23 in figure 1 and 34 in figure 2, respectively, which constitute flow distribution members.
;~ :
.
' .
An accumulator which ascertains that oil under pressure is supplied to the blocks 2, 3, 4 during the slow-down time of the bearing a~ failure .:' ,.-:,, ., ' : ' . ~ . . . .
. . - - . -~: .
,', ' ' :
.
i2~
of the pumps 6J 7, incorporates a cylinder 18, the vol~e of which is divided into two chambers by means of an axially freely movable piston l9o As the piston is freely movable the pressure will always be equal in the two chambersO
In one chamber 20 there is contained a pressure gas and this chamber is pre-ferably connected to a particular pressure gas container 21 for ascertaining that the gas always has a sufficient pressureO
The other chamber 22 is, in a manner specified here beiow~
connected to the pressure oil system of the bearing and it is filled with oilO
A portion of the oil flowing from the pumps 6, 7 against the bearing is led through a particular pressure generating memberO In the embodiment according to figure 1 there is an additional metering unit 23 in the flow distribution member, wherein the oil is given a pressure higher than the maximum pressure appearing in the bearing~ Oil is lead from tlle metering unit 23 to each one of the bearing bloGks 2, 3, 4 via conduits in which constant flow valves 24, 25, 26 are arrangedO These valves are set in such a manner that only a part of the oil, which passes the metering unit 23, is lead to the bearing blocks 2, 37 4. During normal running the remainder is lead back to a position 27 up-stream of the flow distribution member, in which position the oil pressure is lower than downstreams o~ the metering unit 230 In order to make possible a setting of the desired oil pressure in the oil flowing from the metering unit 23, an adjustable constant pressure valve 28 is inserted in the return conduit upstream of the position 270 This valve is set in such a manner that it will open at the pressure desired on the oil in chamber 22 of the accumulatorO As long as the pressure is lower, eOg. at start, the valve is closed and as the flow through the unit 23 is larger than the flow through the lmits 24, 25, 26 the remainder of the oil will flow to chamber 227 which communicates with the metering unit 23 and with the return conduit having the valve 28 and with the conduits having the constant flow valves 24, 25, 26 to the bearing blocks 2, .
, ~ID~46~
3, ~. When the oil at start flows into the chamber 22 its volume will increase whereby the volume o~ the chamber 20 is reduced correspondingly, which means that the gas pressure will increase and so will also the pressure in the cham-ber 220 When the pressure reaches the pressure set on valve 28 this will open and the excess oil will flow through the return conduit instead of to the accumulator, which during operation thus always will be charged with oil of the desired pressure. At failure o~ the pumps 6, 7 the flow through the flow distribution member will stop and thus also through the metering unit 23, whereby the pressure downstreams of this will dropO The valve 28 will then close and oil is pressed out of the chamber 22 by the gas pressure in the chamber 20 through the conduits having the valves 24, 25, 26 during such a long period of time that the rotatable ring 1 has time to stop before the pressure in the blocks 2, 3, 4 will become so low that metallic contact will appear between the blocks and the ring. A non-return valve 29 prevents oil from the accumulator from flowing backwards through the metering unit 23. As it is possible to set the oil pressure in chamber 22 at the desired value by means of valve 28, which valve however shall exceed the maximum oil pressure in the bearing, the entire oil volume contained in chamber 22 will eOg. at pump failure, be supplied to the bearing with a required pressure. ~ccording to the present invention it lS thus not necessary to make the accumulator unit any larger than needed for storing exact the oil volume required by the bear-ing during its slow-down timeO
During the slow-down time of the bearing at pump failure a flow from the accumulator is required which flow is preferably about at least 10%
oE the normal flow during operation at a given bearing load. The bearing shall furthermore be able to de driven without restrictions with only one of the pumps 6, 7 running iOe~ with half the flow, in order to allow repairment and seryice of one of the pump~motor units during operation of the bearingO
_ 5 _ ~ ~ .
-9 ~ a62~
Furthermore it is required that the oil amount through the metering unit 23 at half flow is at least 10% of the normal flow to the bearing iOeO at least as much as flows through valves 24, 25, 26 for ensuring that the pressure in the accumulator shall be maintainedO This means that at normal operation with both pumps running, more than half of the oil pumped ~hrough the unit 23 will flow through the return conduit. As however only about 25% of the total oil flow needs to pass through the unit 23 the total flow loss through the valves 24, 25, 2~ and 28 will be rather small.
In figure 2, there is shown a modified embodiment of a device according to the invention. The bearing and the hydraulic system have mainly the same design as those of figure 1 but the particular pressure generating member is in this embodiment designed as pump units 32~ 33, which are connected to the main pumps 30, 31 instead of an additional metering unit in the flow distribution member 34~ The other elements of the device correspond entirely to those described in figure 1 and the device operates in a corresponding mannerO
It is also possible to construct and use other embodiments of the inventionO If for instance only one bearing block is used there is required no flow distribution member and then only a constant flow valve in the conduit between the particular pressure generating me~ber and the bearing block is usedO
2Q Instead of a flow distribution member of the type described hereabo~e it is of course possible to use other systems e.g. restrictions in the conduits connected to each bearing block. It is also possible to arrange a particular ; driving motor for the pumps 10, 11, 12, 23 in figure 1 and 34 in figure 2, respectively, which constitute flow distribution members.
;~ :
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Claims (4)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A device for maintaining a required liquid pressure in a hydro-static bearing having a pump actuated liquid supply system during its slow-down time at pump failure, comprising an accumulator connected in the liquid supply system of the bearing and having means for maintaining a sufficient liquid pressure on the liquid contained in the accumulator, characterized in that a portion of the liquid in the system is led through a pressure genera-ting member wherein the liquid is raised to a pressure higher than the maxi-mum liquid pressure in the bearing, that the accumulator is adapted to communicate with said portion of the pressure liquid whereby the liquid pressure inside the accumulator is greater than the maximum liquid pressure in the bearing, and that a part of said portion of the pressure liquid is led to the bearing via at least one constant flow valve and the remainder to a lower pressure position in the liquid supply system via a return conduit provided with a one-way valve adapted to open when the liquid pressure in the accumulator corresponds to said higher pressure generated by said pressure generating member.
2. A device as claimed in claim 1 intended for a hydrostatic bearing having a plurality of bearing pockets which are supplied with pressure liquid from a common pump system via a flow distribution member incorporating a number of interconnected metering units comprising positive displacement pumps, characterized in that an additional metering unit is provided in the flow distribution member and acts as said pressure generating member.
3. A device as claimed in claim 1, characterized in that the pressure generating member comprises at least one pump driven by the same motor which drives the main pump and which pump has a lower pump capacity than the main pump.
4. A device as claimed in claim 1 intended for a hydrostatic bearing having a plurality of bearing pockets, which are supplied with pressure fluid from a common system, characterized in that the bearing pockets are each supplied with pressure liquid from the pressure generating member via its own conduit, each of which conduits is provided with its own constant flow valve, which valves are dimensioned such that the total flow through the valves is less than the flow through the pressure generating member.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| SE7709826-7 | 1977-09-01 | ||
| SE7709826A SE416075B (en) | 1977-09-01 | 1977-09-01 | DEVICE FOR MAINTENANCE OF REQUIRED LIQUID PRINTING IN A HYDROSTATIC STOCK |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1094620A true CA1094620A (en) | 1981-01-27 |
Family
ID=20332147
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA310,420A Expired CA1094620A (en) | 1977-09-01 | 1978-08-31 | Device for maintaining a required pressure in a hydrostatic bearing |
Country Status (12)
| Country | Link |
|---|---|
| JP (1) | JPS5447054A (en) |
| AT (1) | AT382442B (en) |
| AU (1) | AU519128B2 (en) |
| BR (1) | BR7805699A (en) |
| CA (1) | CA1094620A (en) |
| DE (1) | DE2837346C3 (en) |
| FI (1) | FI65651C (en) |
| FR (1) | FR2402102A1 (en) |
| GB (1) | GB2003559B (en) |
| NO (1) | NO146407C (en) |
| SE (1) | SE416075B (en) |
| ZA (1) | ZA784955B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE3151001C2 (en) * | 1981-12-23 | 1986-04-24 | Kleinewefers Gmbh, 4150 Krefeld | Hydrostatically mounted roller, in particular pressure treatment roller |
| EP0208122B1 (en) * | 1985-06-10 | 1988-03-30 | INTERATOM Gesellschaft mit beschränkter Haftung | Aerostatic bearing having a double conical configuration |
| JPS62127512A (en) * | 1985-11-29 | 1987-06-09 | Hitachi Seiko Ltd | Power failure backup unit for air bearing |
| CN111637161B (en) * | 2020-05-18 | 2021-11-09 | 哈尔滨工程大学 | Forced lubrication bearing with distributed pores |
| CN111637159A (en) * | 2020-05-18 | 2020-09-08 | 哈尔滨工程大学 | Self-adaptive forced lubrication bearing with pressurizing hole |
| CN111637160B (en) * | 2020-05-18 | 2021-11-05 | 哈尔滨工程大学 | Forced lubrication bearing with uneven aperture |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE1525813A1 (en) * | 1966-10-18 | 1969-07-31 | Rexroth Gmbh G L | Circuit for a hydraulic system with a fluid reservoir |
| DE1600333A1 (en) * | 1967-02-03 | 1970-06-04 | Linde Ag | Pneumatic relubrication device for flow machines |
| FR2004064A1 (en) * | 1968-03-16 | 1969-11-21 | Hoechst Ag | |
| SE340200B (en) * | 1970-06-12 | 1971-11-08 | Skf Ind Handel En Onwikkeling | |
| US4002224A (en) * | 1975-02-26 | 1977-01-11 | Westinghouse Electric Corporation | Turbine lubrication and emergency gas system |
-
1977
- 1977-09-01 SE SE7709826A patent/SE416075B/en not_active IP Right Cessation
-
1978
- 1978-08-22 FI FI782563A patent/FI65651C/en not_active IP Right Cessation
- 1978-08-26 DE DE2837346A patent/DE2837346C3/en not_active Expired
- 1978-08-30 FR FR7825089A patent/FR2402102A1/en active Granted
- 1978-08-30 AU AU39370/78A patent/AU519128B2/en not_active Expired
- 1978-08-30 ZA ZA00784955A patent/ZA784955B/en unknown
- 1978-08-31 BR BR7805699A patent/BR7805699A/en unknown
- 1978-08-31 NO NO782966A patent/NO146407C/en unknown
- 1978-08-31 CA CA310,420A patent/CA1094620A/en not_active Expired
- 1978-08-31 JP JP10568778A patent/JPS5447054A/en active Granted
- 1978-09-01 AT AT0634378A patent/AT382442B/en not_active IP Right Cessation
- 1978-09-01 GB GB7835395A patent/GB2003559B/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB2003559A (en) | 1979-03-14 |
| NO782966L (en) | 1979-03-02 |
| AU3937078A (en) | 1980-03-06 |
| DE2837346A1 (en) | 1979-03-08 |
| FI782563A (en) | 1979-03-02 |
| JPS5447054A (en) | 1979-04-13 |
| GB2003559B (en) | 1982-02-10 |
| AT382442B (en) | 1987-02-25 |
| SE7709826L (en) | 1979-03-02 |
| SE416075B (en) | 1980-11-24 |
| DE2837346B2 (en) | 1981-05-27 |
| ZA784955B (en) | 1979-08-29 |
| NO146407C (en) | 1982-09-22 |
| BR7805699A (en) | 1979-04-17 |
| FI65651B (en) | 1984-02-29 |
| FR2402102B1 (en) | 1983-11-04 |
| AU519128B2 (en) | 1981-11-12 |
| FI65651C (en) | 1984-06-11 |
| FR2402102A1 (en) | 1979-03-30 |
| JPS6114364B2 (en) | 1986-04-18 |
| NO146407B (en) | 1982-06-14 |
| DE2837346C3 (en) | 1982-01-28 |
| ATA634378A (en) | 1986-07-15 |
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| Date | Code | Title | Description |
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| MKEX | Expiry |