US3810418A - Center ring arrangement for a radial piston machine - Google Patents

Center ring arrangement for a radial piston machine Download PDF

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Publication number
US3810418A
US3810418A US00373961A US37396173A US3810418A US 3810418 A US3810418 A US 3810418A US 00373961 A US00373961 A US 00373961A US 37396173 A US37396173 A US 37396173A US 3810418 A US3810418 A US 3810418A
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United States
Prior art keywords
high pressure
low pressure
balancing grooves
control member
ports
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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 - Lifetime
Application number
US00373961A
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English (en)
Inventor
P Bosch
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Robert Bosch GmbH
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Robert Bosch GmbH
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Publication date
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Publication of US3810418A publication Critical patent/US3810418A/en
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    • 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
    • F03—MACHINES OR ENGINES FOR LIQUIDS; WIND, SPRING, OR WEIGHT MOTORS; PRODUCING MECHANICAL POWER OR A REACTIVE PROPULSIVE THRUST, NOT OTHERWISE PROVIDED FOR
    • F03C—POSITIVE-DISPLACEMENT ENGINES DRIVEN BY LIQUIDS
    • F03C1/00—Reciprocating-piston liquid engines
    • F03C1/02—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders
    • F03C1/04—Reciprocating-piston liquid engines with multiple-cylinders, characterised by the number or arrangement of cylinders with cylinders in star or fan arrangement
    • F03C1/0403—Details, component parts specially adapted of such engines
    • F03C1/0435—Particularities relating to the distribution members
    • F03C1/0438—Particularities relating to the distribution members to cylindrical distribution members

Definitions

  • ABSTRACT The rotary cylinder block of a radial piston machine surrounds a control member whose outer surface has high pressure ports and low pressure ports communicating with the cylinders during rotation.
  • the outer cylindrical surface of the control member also has a pair of circumferentially aligned first and second high pressure balancing grooves on either side of the high pressure ports and a pair of circumferentially aligned first and second low pressure balancing grooves on either side of the low pressure ports.
  • the control member is formed with preferably straight diametrical ducts connecting the first and second high pressure balancing grooves with the first and second low pressure balancing grooves located on the same side of the high pressure and low pressure ports, respectively.
  • the high pressure balancing grooves and the low pressure balancing grooves are filled, respectively, with high pressure fluid and low pressure fluid from the high pressure and low pressure ports, respectively, through the gap between the inner surface of the cylinder block and the outer surface of the control member so that the pressure fluid in the balancing grooves substantially centers the cylinder block on the control member.
  • the present invention relates to a radial piston machine, pump or hydraulic motor, with a rotary cylinder block in whose radially arranged cylinder bores, pistons are guided whose outer ends are in sliding engagement with an eccentric cam ring.
  • the cylinder block surrounds the outer cylindrical surface of a stationary control member which has two diametrically opposite circumferentially elongated low pressure and high pressure ports separated by sealing surface portions of the outer cylindrical surface of the control member.
  • a machine of this type is disclosed in the German OSl,45 3,628.
  • a pressure area extending over an angle of substantially 160 is provided.
  • the pressure areas are connected by bores with the high pressure port by check valves closing toward the high pressure side of the machine.
  • the forces acting in the pressure areas are to be so great that the effect of the pressureon the high pressure side of the machine on the bearing of the cylinder block is substantially compensated. Due to the fact that the pressure areas are directly connected with the high pressure side, .and that continuously pressure fluid flows from the high pressure side, the machine has great leakage losses,
  • Another object of the invention is to center the cylinder block on the control member.
  • two pressure areas are provided on either side of the high pressure and low pressure ports, of which always two pressure areas, associated with twodifferent ports, are connected with each other, while the inflow and outflow of the pressure fluid to and from the pressure areas takes place through the gap between the cylinder block and the control member.
  • FIG. 5 is a fragmentary view illustrating a modified construction of the outer cylindrical surface of the control member.
  • A, radial piston machine illustrated in the drawing which may operate as a pump or hydraulic motor, has a housing 1 closed by a cover plate 2 which has a cylindrical flange 2a and an arresting screw 2b for securing the control member 3 to the housing.
  • a high pressure conduit 4, and a low pressure conduit extend in axial direction in the control member 3, and are respectively connected with highpressure and low pressure ports 6 and 7 which extend in circumferential direction over almost half of the circumference of control member 3 and the outer cylindrical surface 3a thereof, so that narrow sealing portions 8 and 9 remain, as best seen in FIGS. 1 and 3.
  • control port 6 communicates with low pressure fluid
  • control port 7 communicates with high pressure fluid.
  • the circumferential width of the sealing surface portions 8 and '9 between the low pressure and high pressure ports 6 and 7, are dimensioned to prevent direct communication between the low pressure and high pressure ports 6,7.
  • balancing grooves 10 to 17 are arranged on either side of the control ports 6, 7, two balancing grooves 10 to 17 are arranged.
  • a pair of circumferentially aligned first and second high pressure balancing grooves 14, 15 and l6, 17 are provided on either side of the high pressure port 7, and a pair of circumferentially aligned first and second low pressure balancing grooves 10, 11 and '12, 13 are provided on either side of the low pressure port.
  • the rectangular outline of the balancing grooves 10-17 is best seen in FIG. 3, and the respective balancing grooves are so closely spaced in axial direction from the ports-6 and 7, that between the ports 6 and 7 and the balancing grooves, remains a sealing strip l8, 19 which extend around the entire circumfe rence in the'outer cylindrical surface 3a of control member 3.
  • the balancing grooves 10, ll, 12 and 13, whichare arranged at opposite sides of the low pressure port 6, have a greater axial width than the balancing grooves 14, 15, 16, 17 which are arranged on opposite sides on the high pressure port 7. Pairs of high pressure and low pressure grooves follow each other in a circumferential direction on either side of the low pressure ports and high pressure ports 6 and 7. Diammetrically disposed high pressure and low pressure balancing grooves, are connected by transverse ducts or bores 20-23, respectively. The position of the straight ducts 20-23 is best seen in FIG. 2, but FIG.
  • FIG. 3 shows schematically the ducts 10-23 connecting the balancing grooves as follows: Balancing groove 10 is connected with balancing groove 14 by duct 20, balancing groove 12 is connected with balancing groove 16 by duct 22, balancing groove 11 is connected with balancing groove by duct 21 and balancing groove 13 is connected with balancing groove 17 by duct 23.
  • Fluid conduits supplying or discharging fluid from the balancing grooves 10-17, are not provided, and the flow of fluid to and from the balancing grooves 10-17 takes places only through the gap between the outer cylindrical surface 3a of control member 3 and the inner cylindrical surface 24a of the cylinder block 24.
  • the cylinder block 24 is mounted in a bearing 25 supported by housing 1, and surrounds the control member 3.
  • a shaft 26, connected with the cylinder block 24, can be used as a vdrive shaft when the machine is operated as a pump, and as output shaft when the machine is operated as a motor.
  • a set of angularly spaced cylinder bores 27 is provided, of which only one cylinder bore 27 is shown.
  • Pistons 28 are guided in the cylinder bores 27 in sliding and sealing contact, and the working chambers in the cylinder bores 27 are connected by cylinder ports 29 with the high pressure port 7 or the low pressure port 6, depending on the angular position of the cylinder block 24.
  • Each piston 28 is connected by a ball joint 28a with a part circular slide shoe 30 which slides on the inner cylindrical surface 31 of an eccentric cam ring 31 so that the pistons 28 are reciprocated in radial direction in the cylinder bores 27 during rotation of cylinder block 24 by the drive shaft 26. Between the rotation,
  • the cylinder ports 29 successively communicate with the ports 6 and 7, and when a piston 28 is in the inner dead center position, fluid is discharged through high pressure port 7 and high pressure conduit 5.
  • the flow of the pressure fluid to and from the balancing grooves takes place through the narrow gap 40 between the surfaces 24 and 3a. Since the gap does not have the same radial height along the entire circumference of the control member 3, different throttling flow resistances result for the pressure fluid flowing to the balancing grooves.
  • the fluid pressures acting at the balancing grooves and on the marginal face portions surrounding the same depend on the throttle resistances acting'on the fluid flowing to and from the balancing grooves, respectively, and consequently depend on the radial thickness of gap 40 upstream and downstream the balancing grooves. ⁇
  • the force F is produced by the high pressure port 7, and has the effect to urge the cylinder block 24 away from the control member.
  • the force F is the resultant of all forces produced by the pistons 28 whose cylinders are connected with the high pressure port 7, and acting on the cylinder bores 27.
  • the magnitude of the force F depends on the pressure, and the selected stroke length of the piston 28, and the force F, urges the cylinder block 24, downward as viewed in FIG. 4, toward the control member 3.
  • the forces F, and F are not controlled by balancing grooves, the radial height of the gap 40 in the region of the high pressure port 7 would be very great, particularly if the average force F, is very small which would cause great leakage losses.
  • the pressure in the balancing groove 11 is greater than in the balancing grooves 14 and 10 which are connected by the duct 20 with each other. This is due to the fact that the flow toward the balancing groove 14 is throttled to a far greater extent than the flow to balancing groove 15 due to the small thickness of the gap 40 between the control member 3 and the cylinder block 24. Furthermore, the resistance against fluid flowing out of the balancing groove 10 is smaller than the resistance against flowing out downstream of the balancing groove 11, because the gap 40 between the control member surface 3a and the cylinder block surface 24, is higher in radial direction in the region of the balancing groove 10 than in the region of the balancing groove 11.
  • the pressure forces produced at the balancing grooves 10-17 result in the resultant F shown in FIG. 4.
  • the force F urges the cylinder block 24 against the pressure side of control member 3, since the balancing grooves 10-13 produce a greater pressure than the balancing grooves 14-17.
  • the magnitude of the force F,, and by the dimensions of the balancing grooves 10-17, the magnitude and angular position of the force F resulting therefrom, can be selected through certain relative positions of the cylinder block 24 and the control member 3.
  • Control member 3, modified in this manner, is illustrated in FIG. 5.
  • the flow resistance upstream of the balancing grooves 14 and 15 is made small by selecting narrow sealing strips 18' and 19'.
  • control member 3 If the position of the balancing grooves 10-17 on control member 3 is angularly displaced a predetermined angle in counterclockwise direction, as viewed in FIGS. 2 and 4, more favorable positions of control member 3 can be obtained for certain regions of the eccentricity of the camming ring 31, than in the symmetrical arrangement of FIG. 4.
  • a radial piston machine comprises a stationary control member 3 having an outer cylindrical surface 3a having an axis and being formed with circumferentially aligned diammetrical disposed high pressure and low pressure ports 7, 6; rotor means 24, 27, 28 mounted for rotation about the axis and including a cylinder block 24 having an inner cylindrical surface 24a surrounding the outer cylindrical surface 3a and forming a gap 40 therewith, the cylinder block 24 having radial cylinder bores 27 successively passing over the high pressure and 'low pressure ports 7, 6 during rotation of the rotor means, and pistons 28 in said cylinder bores 27; cam ring means 31 having an endless inner surface eccentric to said axis surrounding said cylinder block 24 and being slidingly engaged by the radially oute'r ends 30 of said pistons 28 for reciprocating said piston in said cylinder bores 27, said outer cylindrical surface 3a of said control member 3 having a pair of circumferentially aligned first and second high pressure balancing grooves l4, l5 and l6,
  • the control member 3 is formed with ducts -24 connecting the first and second high pressure balancing grooves l4, l5 and l6, 17 with the first and second low pressure balancing grooves l0, l1 and 12, 13 located on the same side of the high pressure and low pressure ports 7, 6, respectively.
  • the first and second high pressure balancing grooves 14-17 and the first and second low pressure balancing groove 10-13 are filled, respectively, with high pressure fluid and low pressure fluid from the high pressure and low pressure ports 7, 6, respectively, through the gap 40 between said inner surface 24a of the cylinder block 24 and the outer surface 30 of the control member 3 whereby the cylinder block 24 is substantially centered on the control member 3.
  • a stationary control member having an outer cylindrical surface having an axis and being formed with circumferentially aligned diametrically disposed high pressure and low pressure ports;
  • rotor means mounted for rotation about said axis and including a cylinder block having an inner cylindrical surface surrounding said outer cylindrical surface and forming a gap therewith, said cylinder block having radial cylinder bores successively passing over said high pressure and low pressure ports during rotation of said rotor means, and pistons in said cylinder bores;
  • cam ring means having an endless inner surface eccentric to said axis surrounding said cylinder block and being slidingly engaged by the radially outer ends of said pistons for reciprocating said pistons in said cylinder bores, said outer cylinderical surface of said control member having a pair of circumferentially aligned first and second high pressure balancing grooves on either-side of said high pressure port, and a pair of circumferentially aligned first and second low pressure balancing grooves on either side of said low

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Reciprocating Pumps (AREA)
  • Hydraulic Motors (AREA)
US00373961A 1972-08-12 1973-06-27 Center ring arrangement for a radial piston machine Expired - Lifetime US3810418A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2239757A DE2239757A1 (de) 1972-08-12 1972-08-12 Radialkolbenmaschine

Publications (1)

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US3810418A true US3810418A (en) 1974-05-14

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US00373961A Expired - Lifetime US3810418A (en) 1972-08-12 1973-06-27 Center ring arrangement for a radial piston machine

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US (1) US3810418A (enrdf_load_stackoverflow)
JP (1) JPS4952308A (enrdf_load_stackoverflow)
DE (1) DE2239757A1 (enrdf_load_stackoverflow)
FR (1) FR2329158A5 (enrdf_load_stackoverflow)
GB (1) GB1382928A (enrdf_load_stackoverflow)
IT (1) IT1001522B (enrdf_load_stackoverflow)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3906998A (en) * 1973-07-07 1975-09-23 Bosch Gmbh Robert Pintle for radial piston machines
US4137826A (en) * 1977-07-28 1979-02-06 Shimadzu Seisakushi, Ltd. Piston pump
US4465436A (en) * 1981-05-25 1984-08-14 Siemens Aktiengesellschaft Radial piston compressor
US4782737A (en) * 1978-05-30 1988-11-08 Karl Eickmann Control pintle including a thrust member for a radial flow device
US5391059A (en) * 1990-12-10 1995-02-21 H T C A/S Radial piston motor or pump

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2412718C2 (de) * 1974-03-16 1984-10-18 Robert Bosch Gmbh, 7000 Stuttgart Radialkolbenmaschine (Pumpe oder Motor)
DE7902865U1 (de) * 1979-02-02 1980-07-10 Robert Bosch Gmbh, 7000 Stuttgart Radialkolbenmaschine
DE3628769A1 (de) * 1986-08-25 1988-03-10 Teves Gmbh Alfred Radialkolbenpumpe
DE3816998A1 (de) * 1988-05-19 1989-11-30 Bosch Gmbh Robert Vorrichtung mit einer radialkolbeneinrichtung, insbesondere radialkolbenpumpe, -motor od. dgl.

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2021353A (en) * 1934-03-05 1935-11-19 Hydraulic Press Mfg Co Hydraulic pump or motor
US2205913A (en) * 1938-02-04 1940-06-25 French Oil Mill Machinery Pump
US3084633A (en) * 1957-09-09 1963-04-09 North American Aviation Inc Hydraulic pump or motor
GB958028A (en) * 1960-06-03 1964-05-13 Nat Res Dev Improvements relating to pressure fluid valve mechanisms
GB1239955A (en) * 1968-06-07 1971-07-21 Karl Eickmann Improvements in or relating to rotary machines

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2021353A (en) * 1934-03-05 1935-11-19 Hydraulic Press Mfg Co Hydraulic pump or motor
US2205913A (en) * 1938-02-04 1940-06-25 French Oil Mill Machinery Pump
US3084633A (en) * 1957-09-09 1963-04-09 North American Aviation Inc Hydraulic pump or motor
GB958028A (en) * 1960-06-03 1964-05-13 Nat Res Dev Improvements relating to pressure fluid valve mechanisms
GB1239955A (en) * 1968-06-07 1971-07-21 Karl Eickmann Improvements in or relating to rotary machines

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3906998A (en) * 1973-07-07 1975-09-23 Bosch Gmbh Robert Pintle for radial piston machines
US4137826A (en) * 1977-07-28 1979-02-06 Shimadzu Seisakushi, Ltd. Piston pump
US4782737A (en) * 1978-05-30 1988-11-08 Karl Eickmann Control pintle including a thrust member for a radial flow device
US4465436A (en) * 1981-05-25 1984-08-14 Siemens Aktiengesellschaft Radial piston compressor
US5391059A (en) * 1990-12-10 1995-02-21 H T C A/S Radial piston motor or pump

Also Published As

Publication number Publication date
GB1382928A (en) 1975-02-05
FR2329158A5 (fr) 1977-05-20
IT1001522B (it) 1976-04-30
DE2239757A1 (de) 1974-02-21
JPS4952308A (enrdf_load_stackoverflow) 1974-05-21

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