GB2042083A - A device comprising two meshing gears to act as a pump and/or motor - Google Patents
A device comprising two meshing gears to act as a pump and/or motor Download PDFInfo
- Publication number
- GB2042083A GB2042083A GB8003714A GB8003714A GB2042083A GB 2042083 A GB2042083 A GB 2042083A GB 8003714 A GB8003714 A GB 8003714A GB 8003714 A GB8003714 A GB 8003714A GB 2042083 A GB2042083 A GB 2042083A
- Authority
- GB
- United Kingdom
- Prior art keywords
- pressure
- gears
- bearing sleeves
- pump
- faces
- 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.)
- Granted
Links
- 238000000576 coating method Methods 0.000 claims abstract description 31
- 239000004033 plastic Substances 0.000 claims abstract description 8
- 229920003023 plastic Polymers 0.000 claims abstract description 8
- 238000011067 equilibration Methods 0.000 claims abstract description 6
- 239000000463 material Substances 0.000 claims abstract description 6
- 239000011248 coating agent Substances 0.000 claims description 28
- 229920001343 polytetrafluoroethylene Polymers 0.000 claims description 8
- 229910000906 Bronze Inorganic materials 0.000 claims description 4
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 4
- 239000010974 bronze Substances 0.000 claims description 4
- KUNSUQLRTQLHQQ-UHFFFAOYSA-N copper tin Chemical compound [Cu].[Sn] KUNSUQLRTQLHQQ-UHFFFAOYSA-N 0.000 claims description 4
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 239000004810 polytetrafluoroethylene Substances 0.000 claims 1
- 239000000126 substance Substances 0.000 claims 1
- 239000003921 oil Substances 0.000 description 11
- 210000000515 tooth Anatomy 0.000 description 10
- 230000007423 decrease Effects 0.000 description 4
- 238000007789 sealing Methods 0.000 description 4
- 230000003247 decreasing effect Effects 0.000 description 3
- 230000012447 hatching Effects 0.000 description 3
- 239000012535 impurity Substances 0.000 description 3
- 239000010410 layer Substances 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 2
- 230000001627 detrimental effect Effects 0.000 description 2
- 238000000227 grinding Methods 0.000 description 2
- 239000010959 steel Substances 0.000 description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 206010013710 Drug interaction Diseases 0.000 description 1
- 229920006358 Fluon Polymers 0.000 description 1
- 238000006644 Lossen rearrangement reaction Methods 0.000 description 1
- 238000004026 adhesive bonding Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 229920001971 elastomer Polymers 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 229920000295 expanded polytetrafluoroethylene Polymers 0.000 description 1
- 239000010720 hydraulic oil Substances 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- -1 polytetrafluorethylene Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 230000010349 pulsation Effects 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 238000005476 soldering Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C2/00—Rotary-piston machines or pumps
- F04C2/08—Rotary-piston machines or pumps of intermeshing-engagement type, i.e. with engagement of co-operating members similar to that of toothed gearing
- F04C2/082—Details specially related to intermeshing engagement type machines or pumps
- F04C2/086—Carter
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
- F04C—ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; ROTARY-PISTON, OR OSCILLATING-PISTON, POSITIVE-DISPLACEMENT PUMPS
- F04C15/00—Component parts, details or accessories of machines, pumps or pumping installations, not provided for in groups F04C2/00 - F04C14/00
- F04C15/0003—Sealing arrangements in rotary-piston machines or pumps
- F04C15/0023—Axial sealings for working fluid
- F04C15/0026—Elements specially adapted for sealing of the lateral faces of intermeshing-engagement type machines or pumps, e.g. gear machines or pumps
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Rotary Pumps (AREA)
- Details And Applications Of Rotary Liquid Pumps (AREA)
- Hydraulic Motors (AREA)
Abstract
Two meshing gears 8, 9 are mounted on shafts 6, 7 supported in a body 1 by means of separate bearing sleeves 11, 12, 13, 14, against which the faces of the gears 8, 9 abut. These sleeves can move in the axial directions of the shafts, and are sealed against the faces of the gears 8, 9 by the pressure prevailing in the gear chamber. The pressure is conducted through pressure- equalizing holes 32 into partial pressure zones isolated from axial equilibration zones by seal members 22, 26, 27, 28. The pressure- equalizing holes 32 are located in the bearing sleeves 11, 12, 13, 14, most suitably at the essentially central point of the pressure increase area corresponding to the approximately operating condition of the device so as to eliminate any undue tilting of the bearing sleeves 11, 12, 13, 14 in varying operating conditions. The plane sides of the bearing sleeves 11, 12, 13, 14, abutting on the faces of the gears 8, 9, have coatings 40 containing PTFE-plastics or other plastics material such that the coatings are at least partially elastic and have a low coefficient of friction against the gears 8 and 9. <IMAGE>
Description
SPECIFICATION
A device comprising two meshing gears to act as a pump and/or motor
The invention relates to a gear pump and/or motor comprising two meshing gears, whose shafts are supported in the body by means of separate bearing sleeves, on whose ends the faces of the gears abut and which sleeves move in the direction of the shaft and are sealed against the faces of the gears by means of pressure, when the pressure prevailing in the tooth chamber is conducted through pressure equalizing holes into partial pressure fields isolated from the axial equilibration field by seal members, which pressure equalizing holes are located in the bearing sleeves, most suitably at the essentially central point of the pressure increase area corresponding to the approximate operating condition of the pump/motor, especially to eliminate the tilting of the bearing sleeves in varying operating conditions.
In gear pumps and motors of the prior art, the axial moment of the bearing sleeves caused by the operating conditions, e.g. by the variation of the oil viscosity, has not been eliminated, which moment tends to tilt the bearing sleeves, or the elimination has been performed either by means of several partial pressure fields or the pressure equalizing passages have been placed on the outer periphery of the bearing sleeves, whereupon the partial pressure field is alternately in contact with high pressure and alternately with low pressure thus causing detrimental pressure fluctuation in the partial pressure field, which wears both the face of the bearing sleeve and the seals.
The disadvantages mentioned above have been eliminated in gear pumps represented in the earlier Finnish patents Nos. 51 992 and 51 993 by the applicant. The previously known gear pump or motor represented in the first-mentioned patent is chiefly characterized in that the pressure prevailing in the pressure chamber is conducted through pressure equalizing holes into partial pressure fields isolated from the axial equilibration field by seal members, which pressure equalizing holes are located in the bearing sleeves at the essentially central point of the pressure increase area corresponding to the approximate operating condition, to eliminate the tilting of the bearing sleeves in varying operating conditions.
The general aim of the present invention is to further develop the gear pump and motor construction represented in the Finnish patents mentioned above, i.e. the intention is to achieve a pump/motor according to the kind defined above, whose volumetric and mechanical efficiency is better than that of the pumps of the prior art.
An additional intention is to extend the operating life of the pump/motor.
A problem, which has not been solved satisfactorily in the pumps of the prior art or in the pumps represented in the applicant's
Finnish patents mentioned above, has been the difficult sealing of the faces of the bearing sleeves and too fast wearing of the faces. The wearing has been especially fast at high revolution speeds of the pump, e.g. within the speed range 2000-3000 r/min. The wearing of the gear faces has especially been caused by the particlelike and grinding impurities in the hydraulic oil. Such impurities occur especially in pumps/motors used in the vehicle and work machine hydraulics. In addition, the wearing has been caused by the fact that these pumps are operated at outdoor temperatures varying in a very large scale. Indeed, an intention of the invention is to achieve a pump and/or motor, which is well adapted to the vehicle and work machine hydraulics operation.
A special intention of the invention is to achieve a device, which is adapted to be used both as a pump and a motor.
The difficulties related to the constructing of hydraulic motors have earlier especially been due to the fact that the motor is often started up in such a way that the motor is initially loaded by a high initial moment, whereupon the start-up pressure of the motor must be increased and the gears and their bearing sleeves are pressed against each other at an ever-increasing surface pressure, which results in a continuous increase in the friction moment counteracting the motor start-up, as pressure increases. This may furthermore result in that the motor does not start up at all.
The aim of the invention is to eliminate this disadvantage too.
To achieve the aims defined above and to eliminate the said disadvantages the hydraulic pump and/or motor according to the invention is chiefly characterized in that the planelike end sides of the bearing sleeves, which sides abut on the faces of the gears, are equipped with a coating containing PTFEplastics or other corresponding plastics, which coating is at least partially elastic and has a low friction coefficient.
When, in accordance with the invention, the bearing sleeves are equipped with a special coating, which is characterized by a low friction coefficient and a good wear resistance, the operating life of the pump and the tightness of the faces are essentially improved. An additional advantage is that the coatings of the faces in accordance with the invention are able to absorb grinding particles, which on its part decreases wearing and increases the tightness of the gear faces.
The following surprising advantages are realized in a pump/motor according to the invention: the pump efficiency is improved and the risk of seizing-up is decreased both at high revolution speeds ( > c. 1 500 r/min) and at low revolution speeds ( < c. 600 r/min). In pumps of the prior art, the pump output at low revolution speeds is decreased owing to increasing leaks, specially. However, when mechanical energy is continuously brought to the pump, and it does not flow out of the pump with the output, mechanical energy changes into thermal energy due to leakage losses, which produces an apparent risk of the seizing-up of the pump.At high operating speeds the friction losses start to increase proportionally more in comparison with lower speeds, which causes heating-up of the pump and of its bearings especially, and when bearing properties deteriorate, an apparent risk of seizing-up arises, which partially results from the decreasing of the oil viscosity due to heating-up. The general cause for seizing-up can be considered the fact that the internal parts of the pump expand owing to heatingup, whereas the external shell of the pump or motor remains cooler and expands proportionally less. In a pump/motor according to the invention, the revolution speed range thus becomes extended both at the bottom and the top which is a very valuable advantage in practise, especially in pumps/motors used in the vehicle and work machine hydraulics.An additional advantage is that the mechanical efficiency of the pump/motor improves within the entire revolution speed range.
The invention is described in detail with reference to an application example shown in the figures of the attached drawing, to whose details the invention is not confined.
Figure 1 represents a partially sectioned general view of a pump/motor according to the invention, and the dash-and-dot lines of this figure show in polar co-ordinates the tooth chamber pressure increase areas (Phk) corresponding to different operating conditions and the partial-pressure chamber pressure increase areas (Pok) corresponding to these; the central points of the shafts of the pump are used as the central point of the coordinates.
Figure 2 represents the section ll-ll in Figs.
1.
Figure 3 represents the section Ill-Ill in
Fig. 2, and this figure shows a fastening flange of the pump.
Figure 4 represents a bearing sleeve of the pump/motor according to the invention separately, partially sectioned.
Figure 5 represents the bearing sleeve seen from the opposite direction, from the direction of its coating.
Figure 6 represents a seal with its support members used in the pump according to the invention.
Figure 6A represents the section A-A in
Fig. 6, and Fig. 6B represents the section
B-B in Fig. 6.
Figure 7 represents seal supports and seal rings separately.
Figure 8 represents in rectangular co-ordinates both the tooth chamber and correspondingly the partial pressure field pressure increase areas (Phk and Pok) describing different operating conditions shown in polar co-ordinates of Fig. 1, and the letters A-H on the horizontal axis show the points marked correspondingly in Fig. 1.
The gear pump according to Fig. 1, 2 and 3 has a body 1 open on both sides, in which body is a housing 2 formed of two partially overlapping circular cylinders. The housing 2 is rigidly and tightly closed with a fastening flange 3 and an end flange 4. The fastening flange 3 has a hole 5, through which the drive shaft passes. The hole 5 has a shaft seal 10, which prevents oil leaks as well as the entering of both air and impurities into the pump.
In the pump housing 2, two meshing gears 8 and 9 are placed, whose shafts 6 and 7 are carried in sleeves 11, 12, 13 and 14. The journals 6 and 7 of the gears 8 and 9 are of an integral material with the actual gears 8 and 9. The slide sleeves 15, 16, 17 and 18 are clamped inside the bearing sleeves 11, 12, 13 and 14. The bearing sleeves 11-14 are fitted into the pump housing 2, most suitably by using slide fit. The outer diameter of the bearing sleeves 11-14 exceeds the top circle diameter of the gear 8, 9 by the amount of tolerance variation. The shafts 6, 7 of the gear 8, 9 are fitted into the slide sleeves 15-18 by using slide fit. The bearing sleeves 11-14 have on their periphery flats 19, at which the overlapping lines of the cylinders of the housing 2 meet.The center-to-center distance of the bearing sleeves 11 - 14 is dimensioned greater than the center-to-center distance of the housing cylinders. The bearing sleeves 11-14 are movable in the shaft direction and are located each with one side against a gear flank side. The bearing sleeves 11-14 are connected in pairs with a retainer pin 36, which is fitted into the holes of the bearing sleeves by a sufficient clearance, which allows free positioning of the bearing sleeves 11-14.
Annular grooves 21 are machined in the pump body 1 for a shaped seal 22. The gaps 23 and 24 between the flanges 3 and 4, the sleeves 11, 12, 13 and 14 as well as the faces are sealed by means of the shaped seal 22 to prevent external leaks. The shaped seal 22 has a rectangular cross-section and its height is greater than the grooves 21 to ensure efficient sealing.
By means of the solid shaped seal 22 and the seal supports 26, 27 and 28, part of the axial equilibration field 25 is isolated to form the partial pressure fields 29 and 30 as well as the low pressure field 31. The seal ring 28 around the neck of the bearing sleeve 11-14 has been shaped in such a way that the clearance increase due to the wearing of the bearings and of the faces of the gears 8 and 9 does not cause leaks from between the seal and the cover. As the gap 23 and 24 increases, the working pressure affecting the seal presses the seal rings tightly against the flanges 3 and 4. The shaped seal 22 is made of oil-resistant rubber and the seal supports 26, 27 and 28 of an incompressible material.
The seal ring 26 is provided with the grooving 38, into which the excess part of the shaped seal 22, produced by tolerance variation, presses thus preventing the seal from pressing the bearing sleeves into a tilted position.
By means of the pressure equalizing holes 32, the partial pressure fields 29 and 30 are in contact with the tooth chamber. By means of the channel 33, the axial equilibration field 32 is in a direct contact with the pump working pressure Pt on the high pressure side of the pump, and the low pressure field 31 is in contact with the intake side of the pump through the hole 34 and the channel 35.
The leak oils of the hydrodynamically lubricated sliding bearing are conducted through the bore 37 in the flanges 3 and 4 to the intake side of the pump (Fig. 3).
The shaped seal 22' represented in Fig. 6, 6A and 6B is adapted to a pump-motor combination, which will thus rotate in two opposite directions, for which purpose the shaped seal has two parallel partial pressure fields 29a, 29b and 30a, 30b, which are located symmetrically in regard to the central level of the seal. The shaped seal 22' has on its periphery a seal support 42, whose crosssection is presented in Fig. 3B. The low pressure field/high pressure field 25/31 also has strip-like seal supports 41, whose crosssections are presented in Fig. 6. The seal supports 41 and 42 are made of e.g. PTFEplastics or of some other corresponding material.
Attempts have been made in the gear pump according to the invention to eliminate the losses as follows: The transverse pressure ratio of the gears 8 and 9 has been chosen as high as possible (higher than 1.2), after which the meshing is continuous, and no leaks can occur at the meshing point of the gears 8 and 9. The faces of the bearing sleeves 11-14 on the side of the gear 8, 9 are provided with notches, through which the pressurized oil is forced back to the pressure side, owing to which the volumetric efficiency does not decrease. The periphery of the gears 8, 9 is dimensioned sufficiently large, due to which the working pressure presses the gears 8, 9 and the bearing sleeves 11-14 against the intake side of the body 1 and provides there metallic sealing.The bearing sleeves 11-14 are movable in the shaft direction, and the pump working pressure presses them against the faces of the gears 8, 9. The working pressure presses the shaped seal 22 and the seal ring 28 tightly against the flanges 3 and 4 thus preventing the oil leaks to the external and intake side of the pump.
Since the center-to-center distance of the bearing sleeves 11, 1 2 and 1 3, 14 is dimensioned greater than the center-to-center distance of the cylinders of the housing 2, the bearing sleeves 11-14 rise up to the periphery of the housing 2, and the force component thus produced presses the bearing sleeves 11-14 tightly together thus providing an efficient sealing between the plane surfaces. Furthermore, the pump working pressure presses the bearing sleeves 11, 1 2 and 13, 1 4 together.
Since the faces of the bearing sleeves 11 - 14 are provided with notches, through which oil passes back to the pressure side, no pressure peaks occur in the tooth gap at the meshing point, owing to which the bearing force and bearing friction remain low. To eliminate the tilting, and the friction between the gear 8, 9 and of the face of the bearing sleeves 11 - 14, the partial pressure field 29, 30 is arranged, whereby the forces from the outside against the bearing sleeves and the face of the gear 8, 9 will be only slightly greater than the counteracting axial forces from the inside of the pressure chamber, corresponding to the pressure increase Phk of the prevailing operating conditions.
The function of the pump presented in the
Figures is described in detail with reference to the schematic pressure increase curves Phk and Pok of Fig. 1 and 8. The pressure increase curves Phk represent the pressure chamber pressure in different positions and in different operating conditions TO1, TOmed and TO2, and the pressure increase curves Pok describe the pressure of the partial pressure fields 29, 30, which pressure is derived from the tooth chamber pressure through the pressure equalizing hole 32.The operating conditions TO, and TO2 can be imagined as the ultimate, opposite operating conditions in such a way that the operating condition TO, represents the lowest operating temperature and the highest oil viscosity, and the operating condition TO2 represents the highest operating temperature and the lowest oil viscosity. When the operating temperature of the pump increases and the oil viscosity decreases, which means a movement toward the operating condition TO2, the tooth chamber pressure increase area Phk moves simultaneously toward the inlet side of the pump. In this connection also the moment tilting the bearing sleeves form the tooth chamber sides increases, which presupposes a higher pressure in the partial pressure field 29, 30 to prevent the tilting of the bearing sleeves 11-14.The integral of the pressure increase curves Phk (represented in Fig. 8 as the area between the curves Phk and the horizontal axis, which area is limited by A-D) is in a certain way proportional to the moment tilting the bearing sleeves 11 - 1 4, and this integral increases during a shift from the operating condition TO, toward the operating condition TO2. By placing the pressure equalizing hole 32 at the essentially central point of the pressure increase area (in Fig. 1 and 8 essentially the same as the space B-C) corresponding to the approximate operating condition TOmed, a uniformly increasing pressure is obtained in the partial pressure field 29, 30 (space F-G in Fig. 8) in the manner illustrated in Fig. 1 and 8, and the tilting of the bearing sleeves 11-14 with its detrimental consequences is thus eliminated in all operating conditions.In Fig. 8, the area with slanting hatching schematically represents, in accordance with the invention, the positioning range of the pressure equalizing hole 32, and in Fig. 8, the pressure equalizing hole 32 is imagined to be positioned in the center of the area with slanting hatching. The structure of the bearing sleeves used in the pump/motor according to the invention is next described with reference to Fig. 4 and 5. Fig. 4 and 5 represent a bearing sleeve 11', but as is seen in Fig. 1 and 2, all the pump motor bearing sleeves 11, 12, 13 and 14 are alike. The top of the bearing sleeve 11' is in the form of a cylinder ring, and the sleeve has a flat 19.
The bearing sleeves are equipped with dry bearings 15', as which e.g. Glasier DU-bearings and bearing sleeves can be used (Glasier is a trade mark).
In accordance with the invention, the bearing sleeves are equipped with a coating 40 of polytetrafluorethylene (PTFE) or of some other corresponding, comparatively soft and elastic plastics material with a low friction coefficient, which coating faces the faces of the gears 8, 9. The coating 40 is marked with hatching in
Fig. 5 and with a dot-dash line in Fig. 4. The
PTFE-plastics concerned is also known in connection with the Teflon- and Fluon trade mark.
The coating 40 presses elastically against the faces of the gears 8 and 9. PTFE has a low friction coefficient and it withstands fairly high and low temperatures and is chemically passive. The fastening of the PTFE-coating 40 can be performed e.g. by glueing or soldering the PTFE-plate or by using some other analogous method in fastening it to one plane-like end of the bearing sleeves 11-14. A more durable coating 40 than the previous one is achieved by using various compounds of
PTFE and metals, which are produced and fastened e.g. by sintering to the sand-blasted side surface of the bearing sleeve. PTFE saturated with copper or tin bronze has the original friction coefficient. This produces a coating 40, which has an improved heat conductivity and heat expansion coefficient in comparison with pure PTFE. Lead powder can be used with PTFE too.Especially beneficial is a coating structure 40, which is formed of a porous tin bronze layer sintered to the end of the bearing sleeve 11 - 14, when tin bronze is filled with a mixture of PTFE and lead powder and when the surface layer of the coating 40 is formed of a layer of the same mixture, 0.03 mm in thickness. When such a coating 40 rubs against the steel side surface of the gears, the uppermost layer of the coating 40 lossens and partially adheres to the steel. This adherence is an important occurrence to the inter-action of the coating 40 and of the side surfaces of the gears.
In accordance with Fig. 4 and 5, the bearing sleeves 11' are provided with cavities 43, whose purpose is to decrease the pulsation of the tooth chambers forming between the tooths of the meshing gears by allowing the chambers concerned to discharge through the grooves 23. The bearing sleeves are additionally provided with a ring shoulder 44 on the opposite side of the coating 40.
Fig. 5 shows two pressure equalizing holes 32a and 32b, which are placed at the essentially central point of the partial pressure fields 29a, 29b; 30a, 30b limited by the shaped seal 22' (Fig. 6).
Although sliding speeds of only c. 1 m/s are recommended for plastic bearings, it has been discovered that since the pressure medium lubrication also affects on the surface of the coating 40, it is possible to use between the coating 40 and the faces of the gears a sliding speed of 10 m/s, which corresponds to the revolution speed of 3000 r/min in the pump/motor.
The fact that the PTFE-coating 40 described above is used especially in such a pump, in which the tilting of the bearing sleeves in varying operating conditions has been eliminated in the manner defined in the introduction of the main claim of this application, has a combination effect and synergy especially because all the advantages of the use of the coating 40 in accordance with the invention are emphasized and the coating becomes durable and such that it does adhere especially because the bearing sleeves do not tilt and no essential variation of the surface pressure between the faces of the gears 8, 9 and the coating occurs.
The invention is in no way strictly confined to the details presented only in the form of an example, which details can vary within the scope of the inventive idea presented below in the patent claims.
Claims (4)
1. A gear pump and/or motor comprising two meshing gears (8, 9), whose shafts (6, 7) are supported in the body (1) by means of separate bearing sleeves (11, 12, 13, 14), on whose ends the faces of the gears (8, 9) abut and which sleeves move in the direction of the shafts and are sealed against the faces of the gears (8, 9) by means of pressure, when the pressure (Phk) prevailing in the tooth cham ber is conducted through pressure equalizing holes (32, 32a, 32b) into partial pressure fields (29, 30; 29a, 29b, 30a, 30b) isolated from the axial equilibration field (25) by seal members (22, 26, 27, 28), which pressure equalizing holes (32) are located in the bearing sleeves (11, 12, 13, 14), most suitably at the essentially central point of the pressure increase area corresponding to the approximate operating condition (TOmed) of the pump/motor, especially to eliminate the tilting of the bearing sleeves (11, 12, 13, 14) in varying operating conditions (TO,-TO2), characterized in that the plane-like end sides of the bearing sleeves (11, 12, 13, 14), which sides abut on the faces of the gears (8, 9), are equipped with a coating (40) containing PTFEplastics or some other corresponding plastics, which coating is at least partially elastic and has a low friction coefficient.
2. A gear pump/motor in accordance with the patent claim 1, characterized in that the tilting of the bearing sleeves (11, 12, 13, 14) has been eliminated to such an extent that no essential variation of the surface pressure of the coating (40) and of the faces of the gears (8, 9) can occur, at least not to such an extent that the coating would loosen or be other wise locally damaged.
3. A gear pump/motor according to the patent claim 1 or 2, characterized in that the coating (40) containing PTFE-plastics is formed of a sintered porous layer of tin bronze or of some other analogous material, which layer is filled with a mixture of PTFE and lead powder or an analogous substance.
4. A device comprising two meshing gears to act as a pump and/or motor, constructed and arranged substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| FI790420A FI62712C (en) | 1979-02-08 | 1979-02-08 | KUGGHJULSPUMP OCH / ELLER -MOTOR |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| GB2042083A true GB2042083A (en) | 1980-09-17 |
| GB2042083B GB2042083B (en) | 1983-02-09 |
Family
ID=8512374
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB8003714A Expired GB2042083B (en) | 1979-02-08 | 1980-02-04 | Device comprising two meshing gears to act as a pump and/or motor |
Country Status (7)
| Country | Link |
|---|---|
| BR (1) | BR8000694A (en) |
| ES (1) | ES488239A1 (en) |
| FI (1) | FI62712C (en) |
| FR (1) | FR2448648A1 (en) |
| GB (1) | GB2042083B (en) |
| IT (1) | IT1140541B (en) |
| SE (1) | SE8001007L (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2544024A1 (en) * | 1983-04-09 | 1984-10-12 | Glyco Antriebstechnik Gmbh | HYDRAULIC PUMP FOR LOW VISCOUS FLUIDS |
| FR2669969A1 (en) * | 1990-11-30 | 1992-06-05 | Aeroquip Ag | GEAR PUMP FOR A DEVICE FOR DISPENSING A DOSED QUANTITY OF A LIQUID. |
| WO2009037100A1 (en) * | 2007-09-18 | 2009-03-26 | Robert Bosch Gmbh | Fuel pump, in particular for a fuel system of a reciprocating-piston internal combustion engine |
| US20160208611A1 (en) * | 2015-01-21 | 2016-07-21 | Hamilton Sundstrand Corporation | Bearing faces with fluid channels for gear pumps |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2772638A (en) * | 1950-09-13 | 1956-12-04 | John L Nagely | Gear pump or motor |
| GB1148651A (en) * | 1965-04-24 | 1969-04-16 | Armstrong Patents Co Ltd | Improvements in and relating to gear pumps |
| FR1532606A (en) * | 1967-06-01 | 1968-07-12 | Anti-friction device for pump or rotating hydraulic motor | |
| DE2114874A1 (en) * | 1971-03-27 | 1972-10-12 | Dowty Technical Developments Ltd., Brockhampton, Cheltenham (Großbritannien) | Hydraulic displacement pump |
| FR2133280A5 (en) * | 1971-04-15 | 1972-11-24 | Hydroperfect Internal | Bearing bushes - for hydraulic motors |
| DE2223325A1 (en) * | 1972-05-12 | 1973-11-22 | Valmet Oy | GEAR PUMP OR MOTOR |
-
1979
- 1979-02-08 FI FI790420A patent/FI62712C/en not_active IP Right Cessation
-
1980
- 1980-02-04 GB GB8003714A patent/GB2042083B/en not_active Expired
- 1980-02-04 ES ES488239A patent/ES488239A1/en not_active Expired
- 1980-02-05 BR BR8000694A patent/BR8000694A/en unknown
- 1980-02-08 SE SE8001007A patent/SE8001007L/en unknown
- 1980-02-08 FR FR8002817A patent/FR2448648A1/en active Pending
- 1980-02-08 IT IT19813/80A patent/IT1140541B/en active
Cited By (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2544024A1 (en) * | 1983-04-09 | 1984-10-12 | Glyco Antriebstechnik Gmbh | HYDRAULIC PUMP FOR LOW VISCOUS FLUIDS |
| FR2669969A1 (en) * | 1990-11-30 | 1992-06-05 | Aeroquip Ag | GEAR PUMP FOR A DEVICE FOR DISPENSING A DOSED QUANTITY OF A LIQUID. |
| US5244367A (en) * | 1990-11-30 | 1993-09-14 | Aeroquip Corporation | Gear pump with a resilient means for biasing a side wear plate |
| WO2009037100A1 (en) * | 2007-09-18 | 2009-03-26 | Robert Bosch Gmbh | Fuel pump, in particular for a fuel system of a reciprocating-piston internal combustion engine |
| CN101802386A (en) * | 2007-09-18 | 2010-08-11 | 罗伯特·博世有限公司 | Fuel pump, in particular for a fuel system of a reciprocating-piston internal combustion engine |
| US8261719B2 (en) | 2007-09-18 | 2012-09-11 | Robert Bosch Gmbh | Fuel pump, in particular for a fuel system of a piston engine |
| RU2492348C2 (en) * | 2007-09-18 | 2013-09-10 | Роберт Бош Гмбх | Fuel pump, mostly for system of power supply of piston internal combustion engine |
| CN101802386B (en) * | 2007-09-18 | 2015-05-06 | 罗伯特·博世有限公司 | Fuel pump, in particular for a fuel system of a reciprocating-piston internal combustion engine |
| US20160208611A1 (en) * | 2015-01-21 | 2016-07-21 | Hamilton Sundstrand Corporation | Bearing faces with fluid channels for gear pumps |
| GB2537001A (en) * | 2015-01-21 | 2016-10-05 | Hamilton Sundstrand Corp | Bearing faces with fluid channels for gear pumps |
| US9874208B2 (en) * | 2015-01-21 | 2018-01-23 | Hamilton Sunstrand Corporation | Bearing faces with fluid channels for gear pumps |
| GB2537001B (en) * | 2015-01-21 | 2020-06-03 | Hamilton Sundstrand Corp | Bearing faces with fluid channels for gear pumps |
Also Published As
| Publication number | Publication date |
|---|---|
| IT8019813A0 (en) | 1980-02-08 |
| ES488239A1 (en) | 1980-09-16 |
| FI790420A (en) | 1980-08-09 |
| IT1140541B (en) | 1986-10-01 |
| GB2042083B (en) | 1983-02-09 |
| FI62712C (en) | 1983-02-10 |
| FR2448648A1 (en) | 1980-09-05 |
| SE8001007L (en) | 1980-08-09 |
| BR8000694A (en) | 1980-10-14 |
| FI62712B (en) | 1982-10-29 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PCNP | Patent ceased through non-payment of renewal fee |