EP0745774A2 - Pumpe mit veränderlicher Durchflussmenge - Google Patents

Pumpe mit veränderlicher Durchflussmenge Download PDF

Info

Publication number
EP0745774A2
EP0745774A2 EP96108447A EP96108447A EP0745774A2 EP 0745774 A2 EP0745774 A2 EP 0745774A2 EP 96108447 A EP96108447 A EP 96108447A EP 96108447 A EP96108447 A EP 96108447A EP 0745774 A2 EP0745774 A2 EP 0745774A2
Authority
EP
European Patent Office
Prior art keywords
pump according
stage
inlet
exhaust passages
passages
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
Application number
EP96108447A
Other languages
English (en)
French (fr)
Other versions
EP0745774B1 (de
EP0745774A3 (de
Inventor
Carlo Pachetti
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Pierburg Pump Technology Italy SpA
Original Assignee
Magneti Marelli SpA
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
Application filed by Magneti Marelli SpA filed Critical Magneti Marelli SpA
Publication of EP0745774A2 publication Critical patent/EP0745774A2/de
Publication of EP0745774A3 publication Critical patent/EP0745774A3/de
Application granted granted Critical
Publication of EP0745774B1 publication Critical patent/EP0745774B1/de
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

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
    • F04C14/00—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations
    • F04C14/10—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by changing the positions of the inlet or outlet openings with respect to the working chamber
    • F04C14/12—Control of, monitoring of, or safety arrangements for, machines, pumps or pumping installations characterised by changing the positions of the inlet or outlet openings with respect to the working chamber using sliding valves
    • 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
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/05—Speed
    • F04C2270/052—Speed angular
    • 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
    • F04C2270/00—Control; Monitoring or safety arrangements
    • F04C2270/56—Number of pump/machine units in operation

Definitions

  • the present invention relates to a variable-delivery pump.
  • the present invention relates to a fixed-displacement pump with a delivery which is variable in discrete increments.
  • pumps are currently used which have different constructions and which operate differently from each other and, in particular, fixed-displacement and variable-delivery rotary pumps are used to which the description below will make explicit reference without thereby losing the generality of the invention.
  • the pump includes a by-pass valve system which is associated with the delivery outlet of the pump and is controlled so that, under low running conditions, it is inactive and the entire flow supplied by the pump is delivered to theteil while, when the rate of rotation exceeds a predetermined threshold, it is activated and causes part or, at the limit, the entire flow supplied by the pump to be discharged.
  • a by-pass valve system which is associated with the delivery outlet of the pump and is controlled so that, under low running conditions, it is inactive and the entire flow supplied by the pump is delivered to theteil while, when the rate of rotation exceeds a predetermined threshold, it is activated and causes part or, at the limit, the entire flow supplied by the pump to be discharged.
  • the known pumps are usually very bulky and difficult to locate, not only in existing systems but, in particular, in newly designed systems.
  • the object of the present invention is to provide a variable-delivery pump which enables the problems explained above to be overcome in a simple manner and, in particular, allows a large flow to be provided under low running conditions while performing efficiently over its entire operating range and, at the same time, having a relatively small bulk.
  • variable-delivery pump including an inlet and a delivery outlet and characterised in that it further includes a first compression stage and at least one second compression stage having respective inlet passages for communicating with the inlet and respective exhaust passages for communicating with the delivery outlet; selector means being associated with the inlet passages and exhaust passages for selecting different operative conditions for the two compression stages as the pressure of the fluid directed to the delivery outlet varies.
  • the selector means comprise first valve means associated with the exhaust passages of the first and second stages and first switch means for switching the first valve means between a connecting position, in which the exhaust passages are connected together and an isolating position in which the exhaust passages are isolated from each other.
  • selector means further include second valve means associated with the first stage and second switch means for switching the second valve means between a connecting position in which they interconnect the inlet and exhaust passages of the first compression stage and an isolating position in which these inlet and exhaust passages are isolated from each other.
  • a variable-delivery, fixed-displacement rotary pump is indicated 1 which includes a rear body 2 for connection in known manner to a fixed framework (not illustrated) and a flanged front cover 3 fixed to the body 2 by a plurality of screws 4 ( Figure 1) and, together with the body 2, defining a chamber 5.
  • the pump 1 has an inlet 6 and a delivery outlet 7 formed in the body 2 and includes a motor-driven input shaft 8 defining its own axis 9.
  • the shaft 8 in turn comprises an intermediate portion 10 which is fixed axially but rotatably engaged in a through-hole 11 in the cover 3 and two end portions, indicated 12 and 13, of which the portion 12 projects from the cover 3 and has keyed thereto a gear 14 of a drive-transmission, not illustrated, for driving the shaft 8.
  • the portion 13, extends through the chamber 5 to terminate in a seat 15 in the body 2 formed co-axially with the axis 9 and has keyed thereto a gear 16 with external teeth 17 ( Figures 2 and 3).
  • the gear 16 constitutes the inner gear of a first geared compression stage 18 which also includes an outer gear defined by a second ring gear 19 with internal teeth 20 (Figure 2) in mesh with the teeth 17 and having one more tooth than the teeth 17.
  • This stage 18 communicates, in use, with the inlet aperture 6 through its own intake passage 21 ( Figures 2 and 3), which is substantially semi-cylindrical, and with the delivery outlet 7 of the pump 1 through its own exhaust passage 22 ( Figures 2 and 3), also substantially semi-cylindrical, and has a linear characteristic represented by the straight line A in Figure 8.
  • the chamber 5 further houses a second geared compression stage 23 surrounding the first stage 18 and comprising a gear 24 integral with an outer peripheral portion of the gear 19 and having external teeth 25.
  • the gear 24 constitutes the inner gear of the stage 23 which further includes an outer gear constituted by a ring gear 26.
  • the ring gear 26 is coupled to the body 2 so as to be rotatable about an axis coincident with the axis 9 and has internal teeth 27 in mesh with the teeth 25 of the gear 24, with one more tooth than the teeth 25.
  • the second stage 23 communicates permanently with the inlet 6 through its own inlet passage 28 ( Figures 2 and 3) which is substantially semi-cylindrical and formed in the body 2 and partly in the cap 3 outside the passage 21.
  • the second stage 23 also communicates with the delivery outlet 7 of the pump 1 through an exhaust passage 29 ( Figures 2 and 3) also formed in the body 2 outside the passage 22 and has a characteristic which, in this particular case, coincides with the characteristic of the stage 18.
  • the pump 1 also includes a valved selector unit 30 associated with the passages 21, 22, 28 and 29 of the compression stages 18 and 23 for selecting different operative conditions for the compression stages 18 and 23 as the rate of rotation of the shaft 8 varies, and hence the pressure of the fluid supplied by the stages 18 and 23 to the delivery outlet 7 varies.
  • a valved selector unit 30 associated with the passages 21, 22, 28 and 29 of the compression stages 18 and 23 for selecting different operative conditions for the compression stages 18 and 23 as the rate of rotation of the shaft 8 varies, and hence the pressure of the fluid supplied by the stages 18 and 23 to the delivery outlet 7 varies.
  • a cylindrical blind seat 31 ( Figure 2) formed in the body 2 between the passages 21, 22, 23 and 24 with its axis 32 perpendicular to the axis 9 and which houses a tubular cylindrical body 33 which extends co-axially with the axis 32 and in turn comprises a peripheral wall 34 bounded internally by a cylindrical surface 35.
  • the body 33 has two portions 36 and 37 of which the portion 36 engages the seat 31 positively and is closed by an end wall 38 which bears against an end face of the seat 31 while the portion 37 projects from the body 2 ( Figures 1, 2 and 4) and is closed by a cup-shaped cap 39 inserted in the portion 37 itself with its concavity facing into the body 33.
  • the body 33 defines, together with the wall 38 and the cap 39, a cylindrical chamber 40 which communicates with the inlet passages 21 and 29 of the stages 18 and 23 through two respective apertures 41 and 42 in the wall 34 of the portion 36 in adjacent positions and with the exhaust passages 22 and 29 of the stages 18 and 23 through two apertures 43 and 44 also formed in the wall 34 of the portion 36 in adjacent positions.
  • the chamber 40 also communicates with the exhaust passage 29 of the second stage 23 through a further aperture 45, again formed in the wall 34 of the portion 36 adjacent the aperture 43 but alongside the wall 38.
  • the unit 30 further includes a slide 46 housed in the chamber 40 and slidable within the chamber 40 itself along the axis 32 to open and close the apertures 41, 42, 43, 44 and 45 and select different operating conditions for the stages 18 and 32.
  • the slide 46 includes, starting from its end facing the wall 38, a first piston head 47 which is coupled with the surface 35 with a fluid-tight seal and has a length in a direction parallel to the axis 32 which is less than the maximum length of the aperture 42 measured in the same direction.
  • the piston 47 together with the wall 38 and an end portion of the wall 34, defines a variable-volume chamber 48 which communicates permanently with the exhaust passage 29 of the stage 23 through the aperture 45 and is arranged to communicate, in use, with the inlet passage 28 through the aperture 42.
  • the piston head 47 and the chamber 48 define the movable member and the internal chamber respectively of a linear actuator 49 for driving the slide 46.
  • the piston head 47 is connected by a rod 50 to an end wall 51 of a second piston head 52 which also includes a cylindrical peripheral wall 53 which is slidable in fluid-tight contact with the surface 35 and which extends from the wall 51 towards the piston head 47 surrounding an end portion of the rod 50.
  • the wall 51 further defines the end wall of a third piston 54 having the same dimensions as the piston 52 and the cylindrical peripheral wall 55 of which extends from the wall 51 itself in the opposite direction from the cylindrical wall 53 and towards the cap 39.
  • the cylindrical walls 53 and 55 have respective lengths, measured in a direction parallel to the axis 32, the sum of which is less than the maximum length of the aperture 43 measured in the same direction.
  • the wall 51 is rigidly connected by a rod 56 to an end wall 57 of a further cup-shaped piston head 58 which also includes a cylindrical peripheral wall 59 sealingly cooperating with the surface 35 and extending from the wall 57 towards the cap 39.
  • the piston head 58 is releasably connected to the rod 56 by a screw connection and is adapted to be located, in use, against an axial shoulder defined by a resilient split ring 60 housed in a seat formed in the surface 35 between the aperture 44 and the cap 39.
  • the piston head 58 together with the cap 39 and the portion 37, defines a chamber 61 which houses a helical spring 62 compressed between the piston 58 and the cap 39 so as to exert a force, in use, opposing the force exerted by the linear actuator 49 in use.
  • the stage 23 starts to deliver fluid to the delivery outlet 7, causing an immediate rise in the pressure both in the exhaust passage 29 and in the chamber 48.
  • a force is exerted on the piston 47 which overcomes the action of the spring 62 and moves the slide 46 progressively towards the cap 39.
  • the piston head 52 opens the aperture 41 progressively and puts the inlet passages 21 and 28 of the two stages 18 and 23 into communication, as illustrated in Figure 5.
  • the stages 18 and 23, connected in parallel, supply respective flows which, in this particular case, are identical and which vary as the rate of rotation of the shaft 8 varies in accordance with a law represented by the straight line A in Figure 8.
  • the pump 1 thus supplies a flow through the delivery outlet 7 which, for any value of the rate of rotation, is exactly equal to the sum of the flows from the individual stages, as shown by the line OB in Figure 8.
  • the slide 46 Immediately the pressure of the fluid supplied through the exhaust passage 29 exceeds the value p1, the slide 46 is moved further towards the cap 39. As a result of this movement, the piston head 52 progressively opens the passage 22 while the piston head 54 progressively prevents the movement of fluid away from and towards the aperture 44 by closing that portion of the aperture 43 adjacent the aperture 44 itself.
  • the exhaust passage 22 of the stage 18 is put progressively in communication with the inlet passage 21 of this same stage 18 and is simultaneously isolated from the exhaust passage 29 of the stage 23 whereby, while the stage 23 continues to deliver fluid to the delivery outlet 7, further increasing the pressure in the delivery outlet 7 itself, the stage 18 is progressively isolated and short-circuited and hence the delivery supplied by the stage 18 is kept first constant, up to a rate of rotation n2 ( Figure 8), and then decreases progressively, to reach zero when the shaft 8 reaches the rate of rotation n3 and the slide 46 has reached an isolating operative position illustrated in Figure 6.
  • stage 23 remains active and delivers its own variable flow to the delivery outlet 7 which flow varies with the rate of rotation in accordance with the portion DE of its characteristic curve A while the slide 46 continues to move towards the cap 39 as a result of the force exerted by pressure in the chamber 48.
  • the pump 1 differs from known pumps in that it performs efficiently and substantially consistently whatever the rate of rotation of the shaft 8.
  • the excess flow supplied by the pumps at high rates of rotation is discharged in such a way that a considerable quantity of the energy used in compressing the fluid is wasted
  • the reduction in the flow rate at high rates of rotation is achieved simply by the inhibition or short-circuiting of one of the two stages, and, in particular, the stage 18, that is by the interconnection or short-circuiting of the inlet and exhaust passages of this stage 18, the stage 23 being left to function normally.
  • the flow of fluid to the delivery outlet 7 is reduced, but this reduction occurs without a substantial waste of energy.
  • valve unit 30 it is possible to short-circuit, in addition to a predetermined delivery pressure, the stage 23 as well and hence to vary or regulate the flow supplied through the delivery outlet 7 even when only one of the two stages is operating. It is thus clear that, in these conditions, while an effect similar to that achieved by known pumps with the aid of the by-pass system is achieved, the efficiency of the pump 1 continues to be acceptable, no additional energy being expended in compressing some of the fluid which is immediately exhausted without serving theteil.
  • the two geared stages 18 and 23 may be replaced by two or more compression stages of a different type and are not necessarily the same as each other with regard, for example, to their displacements.
  • valve unit 30 may be replaced by a valve unit having different characteristics and, in particular, including, for example, several valves which are not necessarily slide valves located separately from each other and switched by one or more actuators which need not necessarily be pneumatic.
  • valve unit 30 could be arranged so that the inlet passages 21 and 28 are permanently connected to the inlet 6.
EP96108447A 1995-05-30 1996-05-28 Pumpe mit veränderlicher Durchflussmenge Expired - Lifetime EP0745774B1 (de)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ITTO950441 1995-05-30
IT95TO000441A IT1279571B1 (it) 1995-05-30 1995-05-30 Pompa a portata variabile.

Publications (3)

Publication Number Publication Date
EP0745774A2 true EP0745774A2 (de) 1996-12-04
EP0745774A3 EP0745774A3 (de) 1997-06-04
EP0745774B1 EP0745774B1 (de) 2002-02-20

Family

ID=11413599

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96108447A Expired - Lifetime EP0745774B1 (de) 1995-05-30 1996-05-28 Pumpe mit veränderlicher Durchflussmenge

Country Status (4)

Country Link
EP (1) EP0745774B1 (de)
DE (1) DE69619298T2 (de)
ES (1) ES2173222T3 (de)
IT (1) IT1279571B1 (de)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102014205970A1 (de) 2014-03-31 2015-10-01 Schaeffler Technologies AG & Co. KG Verstellpumpe

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4502845A (en) * 1983-03-24 1985-03-05 General Motors Corporation Multistage gear pump and control valve arrangement
DE3520884A1 (de) * 1984-06-11 1986-01-02 Trw Inc., Cleveland, Ohio Zweistufige einbau-kreiselpumpe mit mengensteuerung
DE3837599A1 (de) * 1988-11-05 1990-05-10 Daimler Benz Ag Zahnradpumpe mit zwei im pumpengehaeuse nebeneinander angeordneten zahnradpaaren
EP0499794A1 (de) * 1991-02-19 1992-08-26 Mercedes-Benz Ag Hydropumpe

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4502845A (en) * 1983-03-24 1985-03-05 General Motors Corporation Multistage gear pump and control valve arrangement
DE3520884A1 (de) * 1984-06-11 1986-01-02 Trw Inc., Cleveland, Ohio Zweistufige einbau-kreiselpumpe mit mengensteuerung
DE3837599A1 (de) * 1988-11-05 1990-05-10 Daimler Benz Ag Zahnradpumpe mit zwei im pumpengehaeuse nebeneinander angeordneten zahnradpaaren
EP0499794A1 (de) * 1991-02-19 1992-08-26 Mercedes-Benz Ag Hydropumpe

Also Published As

Publication number Publication date
DE69619298D1 (de) 2002-03-28
IT1279571B1 (it) 1997-12-16
ES2173222T3 (es) 2002-10-16
ITTO950441A0 (it) 1995-05-30
EP0745774B1 (de) 2002-02-20
DE69619298T2 (de) 2002-11-07
EP0745774A3 (de) 1997-06-04
ITTO950441A1 (it) 1996-11-30

Similar Documents

Publication Publication Date Title
CN101379296B (zh) 变排量变压叶片泵系统
US7588431B2 (en) Variable capacity pump/motor
EP0785361B1 (de) Ölpumpenanlage
US8297943B2 (en) Pump control using overpressure source
US7179070B2 (en) Variable capacity pump/motor
WO1998050698A1 (en) Multiple pump control arrangement
US4204811A (en) Fluid pumping system
AU6097894A (en) Cyclic hydraulic pump
US5800136A (en) Pump with bypass valve
EP0745774B1 (de) Pumpe mit veränderlicher Durchflussmenge
JP2014077488A (ja) シリンダ駆動装置
CN111017014B (zh) 一种液压转向装置
EP0786052B1 (de) Hydraulische betätigungsvorrichtung und schaltgetriebe mit einer solchen betätigungsvorrichtung
US6162024A (en) Constant horsepower continuously variable volume pump
CN112855529A (zh) 一种齿轮泵
JP2009236074A (ja) 二連歯車ポンプ
US6832903B2 (en) Functionalties of axially movable spool valve
EP3775549B1 (de) Ventileinheit für pumpen
JP2003193819A (ja) 内燃機関のオイルポンプ装置
US6884048B2 (en) Transition valving by means of non-return valves
DE19522448C1 (de) Hydromotor mit Spülventil
CN110469500B (zh) 一种恒压变量泵
DE102005043977B4 (de) Rotationspumpe
FR2500563A1 (fr) Valve a debit et pression compenses et circuit a valve et pompe hydraulique
EP1213481B1 (de) Drehkolbenpumpe mit veränderlicher Durchflussmenge, insbesondere für Öl

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): DE ES FR GB

PUAL Search report despatched

Free format text: ORIGINAL CODE: 0009013

AK Designated contracting states

Kind code of ref document: A3

Designated state(s): DE ES FR GB

17P Request for examination filed

Effective date: 19970916

17Q First examination report despatched

Effective date: 19990610

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAG Despatch of communication of intention to grant

Free format text: ORIGINAL CODE: EPIDOS AGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

GRAH Despatch of communication of intention to grant a patent

Free format text: ORIGINAL CODE: EPIDOS IGRA

REG Reference to a national code

Ref country code: GB

Ref legal event code: IF02

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

RAP1 Party data changed (applicant data changed or rights of an application transferred)

Owner name: PIERBURG S.P.A.

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE ES FR GB

REF Corresponds to:

Ref document number: 69619298

Country of ref document: DE

Date of ref document: 20020328

ET Fr: translation filed
REG Reference to a national code

Ref country code: ES

Ref legal event code: FG2A

Ref document number: 2173222

Country of ref document: ES

Kind code of ref document: T3

PLBE No opposition filed within time limit

Free format text: ORIGINAL CODE: 0009261

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT

26N No opposition filed

Effective date: 20021121

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: ES

Payment date: 20090522

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: FR

Payment date: 20090519

Year of fee payment: 14

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 20090528

Year of fee payment: 14

Ref country code: DE

Payment date: 20090727

Year of fee payment: 14

GBPC Gb: european patent ceased through non-payment of renewal fee

Effective date: 20100528

REG Reference to a national code

Ref country code: FR

Ref legal event code: ST

Effective date: 20110131

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: DE

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20101201

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100531

REG Reference to a national code

Ref country code: ES

Ref legal event code: FD2A

Effective date: 20110715

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20110705

Ref country code: GB

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100528

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: ES

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 20100529