WO1991019902A1 - Pompes rotatives hydrauliques a pistons radiaux - Google Patents

Pompes rotatives hydrauliques a pistons radiaux Download PDF

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Publication number
WO1991019902A1
WO1991019902A1 PCT/GB1991/000974 GB9100974W WO9119902A1 WO 1991019902 A1 WO1991019902 A1 WO 1991019902A1 GB 9100974 W GB9100974 W GB 9100974W WO 9119902 A1 WO9119902 A1 WO 9119902A1
Authority
WO
WIPO (PCT)
Prior art keywords
unit
pintle
housing
fluid
hydrostatic
Prior art date
Application number
PCT/GB1991/000974
Other languages
English (en)
Inventor
Christian Helmut Thoma
George Duncan Mcrae Arnold
Arthur Atholl Blair
Original Assignee
Unipat Ag
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from GB909013748A external-priority patent/GB9013748D0/en
Priority claimed from GB909016709A external-priority patent/GB9016709D0/en
Priority claimed from GB919102480A external-priority patent/GB9102480D0/en
Application filed by Unipat Ag filed Critical Unipat Ag
Publication of WO1991019902A1 publication Critical patent/WO1991019902A1/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/0404—Details or component parts
    • F04B1/0452—Distribution members, e.g. valves
    • F04B1/0456—Cylindrical
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/10—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary
    • F04B1/107—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders
    • F04B1/1071—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders with rotary cylinder blocks
    • F04B1/1074—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders with rotary cylinder blocks with two or more serially arranged radial piston-cylinder units
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B1/00—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders
    • F04B1/04—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement
    • F04B1/10—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary
    • F04B1/107—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders
    • F04B1/1071—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders with rotary cylinder blocks
    • F04B1/1074—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders with rotary cylinder blocks with two or more serially arranged radial piston-cylinder units
    • F04B1/1077—Multi-cylinder machines or pumps characterised by number or arrangement of cylinders having cylinders in star- or fan-arrangement the cylinders being movable, e.g. rotary with actuating or actuated elements at the outer ends of the cylinders with rotary cylinder blocks with two or more serially arranged radial piston-cylinder units located side-by-side

Definitions

  • This invention makes a bold attempt at reducing the cost of radial piston hydraulic pumps for such hydrostatic equipment, and is achievable through the use of low cost pump components located within a simple housing structure, and where a single input drive shaft driving through bevel gearing disposed between the hydraulic pump components provides a device both small in bulk size and cost effective as identical hydraulic pump components are used.
  • the device can provide two or more independent and adjustable flow rates from a common source such as a fluid reservoir.
  • An important feature of this invention is the use of a large intake passage to the radial piston hydraulic pumps with minimum obstruction, and segregation of the chambers containing the rotary elements of the pumps from the chamber containing the intake passage.
  • the invention furthermore provides solutions in order to overcome certain current difficulties when two or more hydraulic pumps are closely coupled together through more economic use of housing members in order to not only help reduce the velocity of fluid intake into the pumps so avoiding cavitation type problems and the requirement of an auxiliary "charge” pump, but also through the use cf stiff internal structure members, the pumps can operate at higher fluid pressures without suffering from serious component load deflection.
  • FIG. 1 is a sectional side elevation through a radial piston hydraulic pumping device according to the invention.
  • FIG. 2 is an end view across line I-I of FIG. 1.
  • FIG. 3 is a sectioned side elevation across line II-II of
  • FIG. 4 is a sectional side elevation through a radial piston hydraulic pumping device according to a further embodiment of the invention.
  • FIG. 5 is a sectional side elevation through a radial piston hydraulic pumping device according to a further embodiment of the invention.
  • FIG. 6 is a sectional side elevation through a radial piston hydraulic pumping device according to a further embodiment of the invention.
  • FIG. 7 is a sectional side elevation through a radial piston hydraulic pumping device according to a further embodiment of the invention.
  • FIG. 8 is a sectional end view through III-III in FIG. 7.
  • FIG. 9 is a sectional end view through IV-IV in FIG. 7.
  • FIG. 10 is a sectional end view of the pintle through V-V in FIG. 7.
  • FIG. 11 is a sectional end view through VI-VI in FIG. 7.
  • FIG. 12 is a sectional side elevation through a radial piston hydraulic pumping device according to a further embodiment of the invention.
  • FIG. 13 is an end view across the pintle on line VII-VII of FIG. 12.
  • FIG. 14 is a sectional end view of the pumping device across line VIII-VIII of FIG. 12.
  • FIG. 15 is an end view across the pintle on line IX-IX of FIG. 12.
  • FIG. 16 is a modified form of the pumping device of FIG. 12.
  • the device illustrated in Figures 1 to 3 includes a static housing formed in two co-operating elements 1 and 2, the former supporting a drive shaft 5 via bearings 3.
  • An fluid seal 4 disposed between the bearings 3 prevents fluid from internal chamber 6 from seeping out to the environment.
  • the drive shaft 5 extends into the internal chamber 6 of the device and is engaged at its inner end 7 by splines a to bevel pinion gear 8.
  • Pintle valve members 10, 11 of hydraulic pumps 12, 13 are disposed within the housing elements 1 , 2 perpendicular to the rotary axis of the input drive shaft 5. Each pintle 10, 11 is supported respectively between semi-circular channels 27, 28 and 29, 33 in the housing element 1, 2. The pintles 10, 11 extend through respective end walls 67, 68 so as to be rigidly held to the housing elements 1, 2, and with their outer ends exposed. Respective nuts 17 and washers 18 further secure the pintles in place. Bevel gears 9, 14 are rotatably supported on respective pintles 10, 11 and engage with the pinion 8 to connect mechanically the drive shaft 5 to each hydraulic pump 12, 13.
  • Each pintle valve 10, 11 serves to support, and provides fluid connections, for its respective radial piston hydraulic pump 12, 13 and is preferably manufactured as a casting.
  • pintle valve 10, 11 may also be manufactured as a single piece where the ends of the pintle protrude out from the housing elements.
  • the pintle as illustrated is generally preferred for reasons of simplicity and ease of manufacture.
  • hydraulic pumps 12, 13, having respective rotary cylinder barrels 15, 16, are mounted to rotate on pintles 10, 11 respectively.
  • Each cylinder barrel 15, 16 has a number of radial bores 19 each of which communicates with a respective small "radial" port 20 formed in its closed end.
  • the ports 20 communicate in succession with two arcuate shaped ports 21 , 22 formed in the wall 23 of each pintle valve 10, 11, approximately at the midway point and on respective inclined sides of an internal inclined partition wall 24 which serves to divide the hollow interior into two chambers 25, 26 as shown in FIG. 3.
  • each pintle valve 10, 11 serves as a fluid entry duct 30 for each individual hydraulic pump 12, 13 so that the entry ducts 30 are purposely located centrally within the device.
  • a chamber 25, formed in the interior of the pintle valve, allows for fluid communication between the entry duct 30 and the arcuated shaped port 21.
  • the other arcuated shaped port 22 communicates via chamber 26 to a fluid exit connection 31 positioned at the outer end of each respective pintle valve 10, 11.
  • a hydraulic fitting 32 is shown screwed into the exit connection 31 so that pipe work can be attached to provide a hydraulic fluid circuit to the apparatus for which the hydraulic pumps provide the source of hydraulic energy.
  • each hydraulic pump 12, 13 are provided with cylindrical pistons 40 mounted in respective radial bores 19.
  • Each piston 40 has a ball joint 41 at its outer end engaging a slipper 42, which moves around a respective track cam ring 43, 44.
  • Track rings 43, 44 are arranged to be adjustable in displacement in relation to the centrally located and permanently statically held pintle valves 10, 11, and this is achieved by means of an adjustment rod 45 for each track ring 43, 44 such that movement of the rod 45 results in movement of the track ring 43, 44.
  • pistons 40 are urged to move radially inwards and outwards in their respective bores 19, and hence draw fluid from the port 21 in pintles 10, 11, during the suction phase in the piston cycle, and expel the fluid from port 22, during the delivery phase of the piston cycle.
  • a respective spring 39 is shown acting on each track ring 43, 44 for returning track ring 43, 44 into concentric relationship with pintles 10, 11, when the actuating force on rod 45 is removed.
  • rod 45 is manually operated although in practice, any number of control devices can be used to displace the track rings 43, 44 such as hydraulic servo valves or electrical servo motors. Furthermore, for some applications it may be desirable to bleed high pressure oil from the delivery chamber 26 to a purposely provided pressure ram that acts on the track ring 43, 44 to control pump displacement.
  • both pintles 10, 11 are fed from a common chamber 71 internally disposed within the housing elements and which is in turn fed from an intake connection 37 on housing member 2 as shown in FIG. 2.
  • a hydraulic fluid fitting 38 is screwed into the intake connection 37 and this connects through pipe work to a fluid reservoir (not shown) from which the hydraulic pumps 12, 13 draw their fluid.
  • inlet duct 30 at the end of each pintle valve 10, 11 should be as large as possible in order to reduce the velocity of the fluid entering at this point, thereby avoiding cavitation erosion of internal components and fluid starvation of either hydraulic pump 12, 13.
  • Usual prior practice for radial piston pumps operating at high rotational speed is to include an auxiliary "charge” or priming pump to fed fluid to the main pump.
  • this invention has the advantage over those hydraulic pumps known to date in that no obstruction exist in the inlet duct 30 at the end of the pintle valve 10, 11.
  • the shaft connection to the cylinder barrel imposes a certain degree of restriction at the end of the pintle and therefore would create difficulties for the smooth aspiration of the pump.
  • chamber 71 In order to maximise the advantages of mounting two or more radial piston hydraulic pumps within a common housing, it is especially important to provide ample area in chamber 71 for smooth fluid transit between the intake connection 37 in housing elements 1, 2, and the inlet ducts 30 at the ends of the pintle valve 10, 11. Furthermore, as inlet ducts 30 of each hydraulic pump 12, 13 oppose each other, and therefore draw fluid from the same source (chamber 71), it is important that chamber 71 be as large as practicable so that the fluid velocity is sufficiently low to avoid fluid starvation of either hydraulic pump.
  • Bevel gears 9, 14 are engaged, by means of drive dogs 50, 51, to each respective end face 52, 53 of cylinder barrels 15, 16, and are advantageously supported on bearings 55, 56 directly upon cylindrical surfaces 58, 59 of the pintle valves 10, 11.
  • each pintle valve 10, 11 is therefore straddle mounted at both its ends in the housing structure in order to provide substantial rigidity to each pintle valve 10, 11 and where the cylinder barrel and bevel gearing is disposed in the centre between such housing support.
  • This feature overcomes the usual weakness of radial piston pumps that utilise a cantilevered mounted pintle valve supported at only one end in the housing, and as a result, the hydraulic pumps in this device can operate at higher pressures, and furthermore provide sufficient support for the bevel gears in order to avoid severe wear and possible failure through poor engagement of the meshing gears when under high load.
  • cylinder barrels 15, 16 may be formed to include tooth profiles on their end faces. However, this may require higher degrees of accuracy in machining in order to get the gears to mesh correctly, whereas as in the above described embodiment, a degree of misalignment can be accommodated in the drive dog coupling 51, 52 between cylinder barrel 15, 16 and bevel gear 9, 14.
  • the bevel pinion gear 8, splined at 7 to drive shaft 5, is permanently in mesh with both bevel gears 9, 14.
  • the invention teaches the location of bevel gearing at the end face of each cylinder barrel.
  • the high degree of compactness for the device is defined by the centre distance between the hydraulic pumps 12, 13. This centre distance is a function of the diameter of the bevel pinion 8 in addition to the width of both bevel gears 9, 14, and as such is simply a limitation of the bevel gears rather than of the hydraulic pumps.
  • any axial forces imposed on the cylinder barrels 15, 16 by the bevel gearing 9, 13 can be overcome and opposed by inserting thrust washers 65, 66 between each cylinder barrel 15, 16 and its respective end wall 67, 68 in housing elements 1, 2.
  • Intake fluid from a fluid reservoir (not shown) is drawn into the device by the reciprocating action of the pistons 40 within their respective cylinder bores 19.
  • a large bore pipe connected to a hydraulic fitting 38 screwed into the device at intake connection 37 provides a source of fluid which is drawn into a large chamber 71 as shown in Figure. 2, from where the fluid flows into the intake duct 30 located at the inner end of both pintle valves 10, 11.
  • the fluid is then expelled through port 22 into chamber 26 in the pintle valve 10, 11 and from here the fluid is fed from the device via exit connection 31 and hydraulic fitting 32.
  • a simple housing structure will provide a significant cost savings over hydraulic pumps currently manufactured. This may be achieved by providing a housing structure comprising only two, preferably aluminium die-cast, housing elements that attach together on a parting plane that includes the longitudinal axis of the pintle valves. As such, pintle valves 10, 11 are held in position within an extremely stiff package.
  • An "0" ring type seal 72 is positioned between the housing elements 1, 2 on the parting plane during assembly of the device, seal 72 being compressed when housing elements 1, 2 are bolted together, and thereby acts to prevent fluid from inside chamber 6 from seeping out of the device.
  • Leakage fluid that collects in chamber 6 during the operation of the device is allowed to return to the fluid reservoir by means of an additional pipe (not shown) or by passing through a low-cost filter (not shown) such as a sintered metal porous type, into intake chamber 71.
  • a low-cost filter such as a sintered metal porous type
  • FIG. 4 illustrates a further embodiment of the invention where either pump is able to draw fluid from its own independent intake and exit passages.
  • the output fluid direction of either pump is reversible, and independent in action to its neighbouring pump. Therefore the hydraulic pumps are reversible flow types so as to be able to service two different hydraulic circuits.
  • a further feature disclosed in this embodiment teaches the use of three housing members comprising the support structure for the pumping device.
  • this particular housing form is applicable to all the various embodiments shown in this invention, it will be fully described for just this emboidment.
  • the central housing element 73 is manufactured so as the provide support for the same drive shaft 5 and pinion 8 elements as shown in FIG. 1.
  • Each end face 74, 75 of the central element 73 mates with a respective cover housing elements 76, 77 in order to encapsulate the radial piston hydraulic pumps 12, 13 within the device.
  • the bevel pinion 8 on shaft 5 is engaged to drive respective bevel gears 9, 14.
  • Bevel gears 9, 14 being supported on each respective cylindrical pintle valves 10, 11 and connected to a respective cylinder barrel 15, 16.
  • each housing cover element 76, 77 a groove 78 is provided for an "0" ring type seal 79, seals 79 being compressed when housing cover elements 76, 77 are attached to the central housing element 73 in order to prevent hydraulic fluid contained within the device from seeping out into the environment.
  • the central housing element 73 is preferably manufactured as a casting that includes a support wall 80 for the ends 81, 82 of each respective pintle valves 10, 11.
  • the support wall 80 also includes a further wall 83 set at right-angles to the support wall 80, and wall 83 acts to form an independent and segregated fluid chamber 84, 85 for each respective hydraulic pump 12, 13.
  • the end 81 of pintle valve 10 is fluidly linked via chamber 84 to a hydraulic connection 86 provided in the central housing element 73.
  • the end 82 of the pintle valve 11 is fluidly linked via chamber 85 to a hydraulic connection 87 also provided in the central housing member 73.
  • each pump 12, 13 is operable by its own respective track ring 120, 121.
  • each track ring 120, 121 can be pivotally displaced about its respective fixed pin 122, 123 in order to independently vary and when required, reverse the fluid flow through the pumps.
  • Both track ring 120, 121 are identical and each is provided with a hole 124 into which a pivotable shaft 125 is inserted which engages with a projecting arm 126 attached to the control shaft 127.
  • Projecting arm 126 and pivotable shaft 125 allow movement of the control shaft 127 and translates the rotary movement of an externally operated lever (not shown) attached to the outer end of the control shaft 127 into lateral swinging movement of the track rings 120, 121.
  • each hydraulic pump 12, 13 is altered as the track ring 120, 121 pivots about its respective pin 122, 123, thus varying the eccentric position of the track ring 120, 121 relative to the cylindrical pintle valves 10, 11.
  • each hydraulic pumps 12, 13 can provide independent fluid flow in either forward or reverse directions.
  • hydraulic pump 12 could draw its fluid from a fluid reservoir (not shown) through hydraulic connection 86 and via chamber 84 into the open end 81 of the pintle valve 10.
  • the pressurized fluid once through the operating mechanism of the pump 12, is then expelled via chamber 130 linked to hydraulic connection 131 to service any hydraulic circuit that the pump 12 is connected to.
  • hydraulic pump 13 can be arranged to draw fluid from the same fluid reservoir as already mentioned, through hydraulic connection 134 (located at the end of the pintle valve 11) that leads to the operating mechanism of the pump 13 via chamber 135.
  • the fluid once through the operating mechanism of the pump 13, is then expelled through the end 82 of the pintle 11 via chamber 85 and flows out of the pump 13 by way of hydraulic connection 87 to provide pressurized fluid to service a further hydraulic circuit.
  • both hydraulic pumps 12, 13 can be controlled so as to draw or expel their fluid through either of their respective hydraulic connections 131, 86, and 134, 87 as desired.
  • FIG. 5 illustrates a further embodiment of the invention where drive shaft 5 is extended to pass through the device in order to connect with further power driven apparatus such as an auxiliary pump, or pumps.
  • further power driven apparatus such as an auxiliary pump, or pumps.
  • Each hydraulic pump 12, 13 is provided with a respective pintle valve 140, 141, and each pintle 140, 141 comprises a generally cylindrical member into which two axial passages 142, 143 are machined or cast.
  • Arcuate ports 144, 145 are formed in each pintle 140, 141 which fluidly connect each respective axial passages 142, 143 to each individual cylinders 19 via port 20 during rotation of the cylinder barrel 15, 16.
  • axial passage 142, 143 are arranged to connect via a corresponding slot 144, 145 to respective hydraulic connections 148, 149 provided in the end cover housings 150, 151.
  • the open ends of each axial passage 142, 143 is closed by the insertion of a plug 152.
  • pintles 140, 141 are straddle mounted at both ends in the housing. Therefore support of pintles 140, 141 in the housing cover element 150, 151 is achieved by providing a hole 154 into which one end of each respective pintles 140, 141 is inserted for support. The other end of each pintles 140, 141 is supported in the central housing element 156 by being inserted and located in hole 155.
  • both hydraulic pumps 12, 13 are capable of operating under high pressure without any problem of cantilever deflection.
  • fluid can be drawn or expelled from either of the two hydraulic connections 148, 149 in each pump 12, 13, and where the direction of fluid motion depends on the relative position of the track ring 120, 121 to the pintle valve 140, 141 as already described for Figure 5.
  • the shaft extension 159 shown as an integral part of drive shaft 5, is thereby supported by bearings 3 at one side of the central housing element 156 and by bearing 161 located the opposite side of the central housing element 156.
  • the shaft extension 159 passes through a fluid seal 162 and is shown protruding through the device as shaft 163 to couple with any auxiliary device.
  • FIG. 6 illustrates a further example of the invention and combines certain features already described and illustrated in the first and fourth embodiments.
  • a second pinion gear 92 is included which is splined at 93 to an output drive shaft 94 for the purpose of driving ancillary machinery.
  • Output drive shaft 94 is supported by bearings 96 in the central housing member 97, and a fluid seal 99 is provided to prevent fluid within chamber 100 from escaping.
  • Second pinion 92 is connected to both bevel gears 9, 14 and as a result, rotation of input shaft 5 and first pinion 8 is transmitted through bevel gears 9, 14 to drive second pinion 92 and output shaft 94.
  • the advantage of this arrangement over that disclosed in FIG. 5 is that fluid entry chamber 25 can be positioned in the ends of the pintle valve 10, 11 in like manner as shown in FIG. 3. Chamber 103 in the central housing element 97 which fluidly connects with the open ends 30 of the pintles 10, 11 is in this example located more centrally in the device.
  • the fifth embodiment of the invention illustrated in FIGS. 7 to 11 has particular merit when three or more radial piston hydraulic pumps are required within a single pumping device, and where such hydraulic pumps may either comprise twin row radial piston hydraulic pumps or single row multiple pumps or any such combination that may be disposed on each side of the bevel gear driving means.
  • This pump 170 comprises a single cylinder barrel 171 in which are disposed two rows or banks of cylinders 172, 173 for respective pistons groups 174, 175.
  • the fluid inlet for the device communicates through chamber 71 and passage 178 to the internally exposed end of the pintle valve 179 to connect with two axial suction passages 180, 181 that are provided as shown in FIG. 8.
  • Passages 180, 181 connect with respective arcuate shaped ports 182, 183 formed in the pintle valve 179.
  • Each arcuate shaped port 182, 183 is arranged to serve each respective bank of cylinders 172, 173 by means of radial ports 184, 185 provided in the rotating cylinder barrel 171 and thereby fluid is drawn into the respective banks of cylinder 172, 173.
  • Axial passage 190 connects through a slot 193 to a hydraulic connection 194 set at right-angles, and formed in housing cover element 196.
  • plugs 197 are fitted to the ends of each passage 190, 191 in order that all exit fluid is directed to their respective hydraulic connections and not lost through leakage at either end of the pintle valve 179.
  • Pump 170 therefore acts as a fluid divider as there are respective exit passages 190, 191 for each row of pistons 174, 175 so that two separate hydraulic circuits can be serviced from one single rotating cylinder barrel 171.
  • pump 198 contains piston group 211 and pump 199 contains piston group 212.
  • the configuration for two pumps 198, 199 in tandem or back-to-back arrangement is ideally achieved by coupling a further cylinder barrel 201 to the end face of the first cylinder barrel 200 by means of a drive dog connection 202.
  • the pintle valve 205 is provided with four arcuate shaped ports, 206, 207, 208, 209 and where arcuate ports 206 and 207 communicate with an axial passage 210, and where the end of axial passage 210 opens into passage 178 and duct 71 in the device.
  • respective piston groups 211, 212 in cylinder barrels 200, 201 are fed from the same fluid intake passage 210.
  • Fluid from the intake duct 71 therefore feeds the piston groups 211, 212 through axial passage 210 which is shown in FIG. 9 to be larger in diameter than the two exit axial passages 215, 216.
  • Arcuate shaped ports 208, 209 formed on the opposite side of the pintle valve 205 are each fed by respective piston groups 211 and 212, and where arcuate port 208 servicing pump 198 communicates through axial exit passage 215 and slot 217 to hydraulic connection 218.
  • Arcuate port 209 servicing pump 199 communicates through axial exit passage 216 and slot 220 to hydraulic connection 221.
  • each piston group 211, 212 can be operated by its own independently adjustable track ring as shown.
  • FIGS. 12 to 16 disclose further embodiments of the invention that differ in one main respect from all the prior embodiments in that two or more hydraulic pumps are disposed to one side only of bevel pinion gear.
  • the device illustrated in FIGS. 12 to 15 comprises a static housing formed in two co-operating elements 230, 231 and where housing elements 230, 231 supports a drive shaft 233 via bearings 234.
  • Drive shaft 233 extends into the internal chamber 237 of the device and is engaged at it inner end by splines 238 to a bevel pinion gear 240.
  • a cylindrical pintle valve 241 is supported between a semi-circular channel 242, 243 and 244, 245 formed in each respective housing element 230, 231. Therefore pintle valve 241 is shown extending through the end walls in housing elements 230, 231 in order that it can be rigidly held between these elements 230, 231 and where the ends are exposed to the exterior of the device.
  • a bevel gear 247 rotatably supported on the pintle valve 241 by bearing 248 is arranged to mesh with pinion 240.
  • Gear 247 is connected through drive dogs 250 to the cylinder barrel 251 of the first hydraulic pump 252, and where cylinder barrel 253 of the second hydraulic pump 254 is connected to the first cylinder barrel 251 by means of further drive dogs 256.
  • Cylinder barrels 251, 253 are mounted to rotate on the cylindrical pintle valve 241. As a result, rotation of the input shaft 233 is transmitted through gearing 240, 247 to both first and second cylinder barrels 251, 253 which rotate together in unison.
  • pintle valve 241 serves as the inlet opening 260 and is threaded to take a hydraulic pipe fitting which is attached by pipe work to a fluid reservoir.
  • Inlet opening 260 connects with passage 261 within the pintle 241 to service both individual pump units 252, 254.
  • Arcuate ports 263, 264 in the pintle 241 link with passage 261, whereas arcuate ports 266, 267 of each respective pump unit 252, 254 connect with their own axial fluid delivery passages 268, 269 leading to a respective outlet connections 270, 271 each formed in one of the housing elements 230, 231 as shown in FIG. 15.
  • Each respective outlet connection 270, 271 is threaded to take a hydraulic fitting (not shown) in order that pipe work can be attached to provide a hydraulic fluid circuit to any apparatus for which the hydraulic pumps provide the source of hydraulic energy.
  • fluid is delivered along axial passage 268 to radial passage 272 and outlet connection 270.
  • fluid is delivered along axial passage 269 to radial passage 273 and threaded end connection 271.
  • Each hydraulic pump is shown with a respective track ring 275, 276 in order that each hydraulic pump can be independently adjusted in fluid displacement.
  • track rings 275, 276 may be formed as one component if, at all times, only identical fluid outputs are required from each pump unit 252, 254.
  • each pump unit 252, 254 is provided with its own respective control rod actuating means for altering the eccentricity of its respective track ring.
  • pistons 280 are urged through centrifugal force to move radially outwards in their respective cylinder bores 281, and hence fluid is drawn into their respective cylinders 281 via port 282, arcuate port 263 and intake passage 261.
  • pistons 280 moves radially inwards in their respective cylinders 281, and fluid contained within cylinders 281 is expelled through port 282 into arcuate port 266 and through axial passage 268, radial passage 272 and connection 270 to exit the device.
  • pistons 284 are urged through centrifugal force to move radially outwards in their respective cylinder bores 285, and hence fluid is drawn into their respective cylinders 285 via port 287, arcuate port 264 and intake passage 261.
  • pistons 284 moves radially inwards in their respective cylinders 285, and fluid contained within cylinders 285 is expelled through port 287 into arcuate port 267 and through axial passage 269, radial passage 273 and connection 271 to exit the device.
  • spring 289 acts to return track ring 276 to a concentric relationship with pintle valve 241 when the actuating force on rod 290 is removed.
  • An identical spring acts in same manner for track ring 275.
  • the final embodiment shown as FIG. 16 departs from the last embodiment in respect that a single cylinder barrel is required to enable the pumping device to provide two variable and independent hydraulic outputs.
  • Cylinder barrel 295 is mounted to rotate on the cylindrical pintle valve 241, and is provided with two rows of radial cylinders 296, 297.
  • the first row of cylinders 296 containing pistons 280 comprises the first pump unit 298 and the second row of cylinders 297 containing pistons 284 comprises the second pump unit 299.
  • Each cylinder 296 of the first pump unit 298 communicates through its respective "radial" port 300 formed in its closed end, and each port 300 communicates in succession with two arcuate shaped ports 253, 266 formed in the wall 301 of the pintle valve 241.
  • each cylinder 297 of the second pump unit 299 communicates through its respective "radial" port 302 formed in its closed end, and each port 302 communicates in succession with two arcuate shaped ports 264, 267 formed in the wall 301 of the pintle valve 241.
  • Arcuate ports 263, 264 feed from a common intake passage 261 provided in the pintle valve 241, whereas arcuate ports 256, 267 of each respective pump unit 298, 299 connects with their own axial fluid delivery passages 268, 269 in similar manner as illustrated in FIG. 14.
  • Fluid delivered by the row of pistons 280 of first pump unit 298 passes through port 300 into arcuate port 266. From here the fluid is directed along axial passage 268 and radial passage 272 to connection 270 to exit the device.
  • Fluid delivered by the row of pistons 284 of second pump unit 299 passes through port 302 into arcuate port 267. From here the fluid is directed along axial passage 269 and radial passage 273 to connection 271 to exit the device.
  • a further advantage of this invention and applicable to all the embodiments is that by small changes in the ratio in the pinion and bevel gear, (by changing the pitch and number of teeth in the gears) the maximum output delivery of the pump units can be altered without changing the internal components in either of the pump units.
  • simple ratio changes in the gears will allow the same size of pumps to be used for a larger range of delivery requirements that would otherwise require alternative displacement capacity pumps.
  • the invention may further be adapted for a double hydrostatic transmission located with the simple housing structure of the invention.
  • a fixed displacement hydrostatic hydraulic motor would be fluidly coupled to each hydraulic pump.
  • This would provide a very compact double hydrostatic transmission for use, in for instance, a vehicle transmission for tracked vehicles, such as snow-cats, where independent drive to each track is an essential feature for ease of manoeuvrability in tight spaces and for stering over slippery surfaces such as snow and ice.
  • An advantage of the invention is that it can be applied to such vehicle transmissions through the addition of two hydraulic motors and associated fluid valving.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Reciprocating Pumps (AREA)

Abstract

Pompes hydrauliques (12, 13) à deux pistons radiaux ou plus disposées à l'intérieur d'une structure de carter simple, dans laquelle un arbre d'entrée (5) assurant un entraînement par l'intermédiaire d'un engrenage conique (8, 9, 14) sert à transmettre de la puissance aux corps de cylindre (12, 13) des pompes hydrauliques (15, 16). Au moins un corps de cylindre (12, 13) est monté de manière à tourner sur chaque aiguille respective (10, 11), chaque corps de cylindre (12, 13) ayant des cavités de cylindres radiales (19) logeant chacune un piston (40) connecté fonctionnellement à un patin (42) venant au contact d'un anneau à voie annulaire périphérique (43, 44). L'aiguille (10, 11) est dotée d'un conduit d'admission de fluide (30) positionné centralement à l'intérieur du carter, et où le conduit d'admission (30) n'est obstrué par aucun constituant rotatif ou fixe de la pompe. Le conduit d'admission (30) situé à l'extrémité de l'aiguille est de grande taille de manière à réduire la vitesse du fluide pénétrant dans la pompe et ainsi débiter l'érosion par cavitation des constituants internes de la pompe. Les aiguilles (10, 11) sont supportées au niveau des deux extrémités, à l'intérieur du logement, de manière à permettre aux pompes de fonctionner sous haute pression sans problème de forces hydrauliques tendant à défléchir les éléments des aiguilles.
PCT/GB1991/000974 1990-06-20 1991-06-17 Pompes rotatives hydrauliques a pistons radiaux WO1991019902A1 (fr)

Applications Claiming Priority (6)

Application Number Priority Date Filing Date Title
GB9013748.0 1990-06-20
GB909013748A GB9013748D0 (en) 1990-06-20 1990-06-20 Hydraulic rotary radial piston pumps
GB909016709A GB9016709D0 (en) 1990-07-30 1990-07-30 Hydraulic rotary radial piston pumps
GB9016709.9 1990-07-30
GB919102480A GB9102480D0 (en) 1991-02-05 1991-02-05 Hydraulic rotary radial piston pump
GB9102480.2 1991-02-05

Publications (1)

Publication Number Publication Date
WO1991019902A1 true WO1991019902A1 (fr) 1991-12-26

Family

ID=27265148

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/GB1991/000974 WO1991019902A1 (fr) 1990-06-20 1991-06-17 Pompes rotatives hydrauliques a pistons radiaux

Country Status (1)

Country Link
WO (1) WO1991019902A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5503535A (en) * 1992-05-27 1996-04-02 Unipat Ag Hydraulic radial piston machines
WO2015103271A3 (fr) * 2013-12-31 2015-08-27 Eaton Corporation Dispositifs à pistons radiaux hydrauliques
US9670915B2 (en) 2014-03-27 2017-06-06 Caterpillar Inc. SBS piston pump housing assembly
GB2611506A (en) * 2021-05-06 2023-04-12 Domin Fluid Power Ltd Radial piston pumps

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB146158A (en) * 1915-11-20 1921-04-21 Daimler Motoren Improvements in and connected with rotary pumps
CH599466A5 (fr) * 1976-02-25 1978-05-31 Bosch Gmbh Robert

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB146158A (en) * 1915-11-20 1921-04-21 Daimler Motoren Improvements in and connected with rotary pumps
CH599466A5 (fr) * 1976-02-25 1978-05-31 Bosch Gmbh Robert

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5503535A (en) * 1992-05-27 1996-04-02 Unipat Ag Hydraulic radial piston machines
WO2015103271A3 (fr) * 2013-12-31 2015-08-27 Eaton Corporation Dispositifs à pistons radiaux hydrauliques
US9670915B2 (en) 2014-03-27 2017-06-06 Caterpillar Inc. SBS piston pump housing assembly
GB2611506A (en) * 2021-05-06 2023-04-12 Domin Fluid Power Ltd Radial piston pumps

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