US3604205A - Hydraulic fluid circuit - Google Patents

Hydraulic fluid circuit Download PDF

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Publication number
US3604205A
US3604205A US3604205DA US3604205A US 3604205 A US3604205 A US 3604205A US 3604205D A US3604205D A US 3604205DA US 3604205 A US3604205 A US 3604205A
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US
United States
Prior art keywords
tank
hydraulic
fluid
pump
communication
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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English (en)
Inventor
Thomas H Geselbracht
David S Vinton
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.)
Caterpillar Inc
Original Assignee
Caterpillar Tractor Co
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 Caterpillar Tractor Co filed Critical Caterpillar Tractor Co
Application granted granted Critical
Publication of US3604205A publication Critical patent/US3604205A/en
Assigned to CATERPILLAR INC., A CORP. OF DE. reassignment CATERPILLAR INC., A CORP. OF DE. ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: CATERPILLAR TRACTOR CO., A CORP. OF CALIF.
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
    • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
    • F15B1/00—Installations or systems with accumulators; Supply reservoir or sump assemblies
    • F15B1/26—Supply reservoir or sump assemblies
    • F15B1/265—Supply reservoir or sump assemblies with pressurised main reservoir
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/2931—Diverse fluid containing pressure systems
    • Y10T137/3115—Gas pressure storage over or displacement of liquid
    • Y10T137/3118—Surge suppression

Definitions

  • ABSTRACT A hydraulic circuit having one or more pumps adjacent motor means in a machine with hydraulic motors which are supplied by the circuit being located in a relatively remote location from the pumps.
  • a control valve is associated with each hydraulic motor and includes a return line in communication with a first hydraulic fluid tank.
  • An assembly of one or more pumps for delivering fluid under pressure to the control valves is located adjacent the motor means and is driven by the motor means.
  • a second hydraulic fluid tank is associated with the pump assembly, the second tank providing fluid to the pumps and being in communication with the first tank by a return conduit for delivering fluid from the first tank to the second tank.
  • a baffle is preferably arranged within that tank to assure a constant I air pocket above the fluid.
  • dling vehicle such as a bucket loader having motor means for.” an engine on one articulated section and implements powered by hydraulic motors on the other articulated section.
  • pumps for the circuit closely adjacent the engine from which they are driven.
  • a hydraulic fluid tank or reservoir is commonly located adjacent the pumps with hydraulic fluid under pres sure being communicated to the remote hydraulic motors and' exhaust fluid from the motors being returned to the tank.
  • control valves for regulating fluid flow to the motors are located within the hydraulic fluid tank, as is common to place the control valves in a protective environment, numerous high-pressure supply lines and low-pressure return lines are necessary to properly communicate the tank and pumps with the hydraulic motors.
  • the arrangement of such circuits is particularly complicated on articulated vehicles of the type mentioned above since each of the lines must cross the articulated axis of the vehicle and accordingly must include a swivel joint.
  • the present invention substantially minimizes these problems and simplifies the hydraulic circuit through the use of two hydraulic fluid tanks.
  • One of the tanks is associated with the hydraulic pump or pumps while the other tank is associated with one or more remotely located hydraulic motors and regulating control valves.
  • one of the tanks commonly has.
  • inlet means for receiving fluid under pressure, for example,-
  • the tank also has outlet means through which fluid exits the tank. Normally, the tank is maintained in a condition where it is partly filled with fluid and has an air pocket above the fluid. Surges of fluid into the tank from the inlet means are normally prevented from rupturing the tank by the air pocket which tends to absorb any increased pressures. However, during operation, air commonly tends to leak out of the tank, for example, through gasket material used to close the tank particularly under high-pressure conditions caused by the fluid surges. If all of the air in the tank leaks into the atmosphere and the tank becomes filled with fluid, high pressures caused by subsequent fluid surges may tend to damage or rupture the tank.
  • the present invention contemplates the use of baffle means for maintaining an air pocket in the tank and preventing leakage of the air.
  • FIG. 1 is a schematic representation of the present hydraulic circuit with various components of the circuit being shown in section;
  • FIG. 2 is a side view in elevation of an articulated vehicle employing the present hydraulic circuit.
  • an articulated vehicle 11 for which the present hydraulic circuit is particularly contemplated has two sections 12 and 13 joined together by an articulated joint indicated at 14.
  • the vehicle is illustrated as a bucket loader having a bucket 16 pivotally supported by one or more lift arms such as that indicated at 17.
  • the position of the bucket is controlled by hydraulic tilt motors, one of which is indicated at 18, and hydraulic lift motors, one of which is indicated at 19.
  • Each tilt motor is interconnected between the vehicle and the bucket by tilt linkage generally indicated at 21.
  • Each hydraulic lift motor is pivotally interconnected between the vehicle and one of the lift arms 17.
  • the tilt motors and lift motors together with the bucket 16 are commonly supported by one of the articulated sections, for example that indicated at 13.
  • An engine 22 for driving the vehicle is commonly located on the other articulated section 12.
  • FIG. 1 A hydraulic circuit constructed according to-the present invention is illustrated in FIG. 1 to which reference is now made.
  • Components of the circuit in FIG. 1 are divided into two groups by a section line indicated at 31.
  • one group indicated generally at 12' and including those components to the left of the section line 31 in FIG. 1 are arranged upon the articulated vehicle section 12 including the engine 22.
  • Another group indicated at 13' and generally including those components to the right of the section line 31 in FIG. 1 are arranged upon the other articulated section 13 which also supports the bucket implement 16.
  • FIG. 1 A hydraulic circuit constructed according to-the present invention is illustrated in FIG. 1 to which reference is now made.
  • Components of the circuit in FIG. 1 are divided into two groups by a section line indicated at 31.
  • one group indicated generally at 12' and including those components to the left of the section line 31 in FIG. 1 are arranged upon the articulated vehicle section 12 including the engine 22.
  • Another group indicated at 13' and generally including those components to the right of the section line 31 in FIG. 1 are
  • the pump cluster 23 includes two doublesectioned pumps 32 and 33. Fluid under pressure from the pumps 32 and 33 is selectively directed to the hydraulic motors 18 and 19 by control valves 34 and 36 respectively.
  • the circuit also includes a first hydraulic fluid tank or reservoir 37 which receives fluid from the control valves 34, 36 and a second hydraulic fluid tank 38 from which fluid is drawn into the pumps 32 33 by an inlet conduit 39.
  • control valves are of a type suitable for immersion in hydraulic fluid. Accordingly, the control valves 34, 36 are shown within the first tank 37.
  • the tank 37 has a generally low, wide profile so that the control valves may be arranged in generally horizontally relation adjacent the bottom of the tank.
  • Fluid under pressure from the pump 32 is combined in a manifold 41 from where it passes into an outlet conduit 42.
  • the conduit 42 is also in communication with the control valve 34.
  • the valve 34 includes a spool, generally indicated at 43, which may be positioned to direct fluid from the conduit 42 into either end of the hydraulic motor 18 by respective conduits 44 and 46.
  • the spool 43 may also be positioned so that fluid from the conduit 42 passes directly into a fluid return line 47 which communicates the control valve 34 with the first tank 37.
  • the other pump 33 is similarly in communication with the control valve 36 by a manifold 51 and a high-pressure outlet conduit 52.
  • the control valve 36 includes a control spool generally indicated at 53.
  • the control valve 36 is similarly in communication with both ends of the hydraulic motor 19 through respective conduits 54 and 56 and with the first tank 37 by means of the same fluid return line 47.
  • the first tank 37 is in communication with the second tank 38 by means of a return conduit indicated at 61.
  • the return conduit 61 is in communication with the first tank 37 by means of a stand pipe 62 which normally establishes the fluid level in the first tank 37.
  • a bafile assembly 63 is arranged at one end of the return conduit 61 to prevent aeration of the fluid entering the second tank 38.
  • a similar baffle assembly 64 is mounted on the fluid return 47 in communication with the first tank 37. Under normal operating conditions, both tanks 37, 38 are partly filled with hydraulic fluid to form air pockets in the tops of the tanks. Fluid under pressure is delivered into the first tank 37 through the fluid return 47 which tends to increase pressure in its air pocket generally indicated at 66.
  • the present invention contemplates baffle means 71 forming a region 72 at the top of the tank 37.
  • the baffle 71 is preferably a cylindrical structure secured to the cover 68 and opening downwardly toward fluid within the tank 37 Since the cover 68 to which the baffle is secured is generally continuous, leakage of air from the region 72 is prevented so that a substantial air pocket is assured at the top of the first tank 37 during operation of the system. This air pocket provides a cushion for pressure surges within the tank and thereby prevents damage to the tank itself.
  • hydraulic fluid is first introduced into the first tank 37 until it reaches the top of stand pipe 62.
  • the second tank 38 is then filled with fluid to a somewhat lower level which may be determined for example by a sight gauge 73.
  • the pumps 32, 33 are then momentarily operated so that all of the conduits and other components of the circuit are filled with fluid.
  • the pumps are then shut down and the second tank 38 is again filled to a level somewhat lower than the fluid level determined by the stand pipe 62in the first tank 37.
  • the fluid may be added to the first and second tanks by means of filler caps indicated at 74 and 76 respectively.
  • a cylindrical pipe 77 supporting the cap 74 is hermetically secured to the cover 68 and extends downwardly at least as far as the baffle 71.
  • a hydraulic circuit for a machine having a motor means and a hydraulic motor remotely located from the motor means of the machine comprising at least one hydraulic pump associated in driven relation with the motor means a control valve associated with the hydraulic motor, said control valve being in communication with a fluid outlet conduit of said pump, said control valve being selectively operable to deliver fluid under pressure for operating the motor,
  • a first hydraulic fluid tank associated with said control valve, said first tank being in communication with a fluid return from said valve,
  • a second hydraulic fluid tank associated with said pump, said second tank being in communication with an inlet conduit to said pump, and a return conduit providing substantially free communication between said first and second tanks for delivering hydraulic fluid from said first tank to said second tank, said return conduit including a stand pipe in said first tank for establishing a normal fluid level therein.
  • control valve is of a type for immersion in hydraulic fluid and said valve is disposed within said first tank.
  • control valves are of a type suitable for immersion in hydraulic fluid, said control valves being arranged in generally horizontal relation within said first tank generally adjacent the bottom thereof.
  • baffle means are secured to a generally continuous portion of said first tank for maintaining an air pocket at the top of said first tank.
  • control valve hydraulically associated with the hydraulic motor, said control valve being in communication with said pump by a high-pressure fluid conduit,
  • a first hydraulic fluid tank associated with said control valve, said first tank being in communication with a fluid return line from said valve,
  • a second hydraulic fluid tank associated with said pump, said second tank being in communication with an inlet conduit for delivering hydraulic fluid to said pump, and
  • a return conduit substantially freely communicating said two tanks for delivering fluid from said first tank to said second tank, said return conduit including a stand pipe in said first tank for establishing a normal fluid level therein.
  • the vehicle includes a plurality of the hydraulic motors, a plurality of control valves being respectively associated with the hydraulic motors and arranged in generally horizontal relation within said first tank,

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Component Parts Of Construction Machinery (AREA)
  • Soil Working Implements (AREA)
US3604205D 1969-06-19 1969-06-19 Hydraulic fluid circuit Expired - Lifetime US3604205A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US83477669A 1969-06-19 1969-06-19

Publications (1)

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US3604205A true US3604205A (en) 1971-09-14

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ID=25267775

Family Applications (1)

Application Number Title Priority Date Filing Date
US3604205D Expired - Lifetime US3604205A (en) 1969-06-19 1969-06-19 Hydraulic fluid circuit

Country Status (3)

Country Link
US (1) US3604205A (enrdf_load_stackoverflow)
CA (1) CA918539A (enrdf_load_stackoverflow)
GB (2) GB1301752A (enrdf_load_stackoverflow)

Cited By (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795108A (en) * 1971-02-11 1974-03-05 Gewerk Eisenhuette Westfalia Pressure fluid drive systems for mine installations
JPS49104069A (enrdf_load_stackoverflow) * 1973-01-26 1974-10-02
US3910045A (en) * 1973-01-13 1975-10-07 Bosch Gmbh Robert Hydraulic control apparatus for hydraulic-lift end gates of moving vans and the like
US3960174A (en) * 1974-09-03 1976-06-01 Caterpillar Tractor Co. Hydraulic circuit with dual tank system and method for using the same
US3993094A (en) * 1975-04-21 1976-11-23 Allis-Chalmers Corporation Removable reservoir cover having internal parts of reservoir mounted thereon
US4243065A (en) * 1979-03-19 1981-01-06 Boc Limited Apparatus for removing gas from a liquid
US5906089A (en) * 1997-07-17 1999-05-25 Hay & Forage Industries Slave cylinder stabilizer for harvester header
US6183682B1 (en) * 1998-01-12 2001-02-06 Nissei Plastic Industrial Co., Ltd. Method for preventing occurrence of impact pressure in injection molding machine
JP2003021101A (ja) * 2001-07-09 2003-01-24 Yanmar Co Ltd 作動油タンク構造
US20110024204A1 (en) * 2008-04-14 2011-02-03 Volvo Construction Equipment Ab Construction vehicle with a split hydraulic holding unit
ITMO20110236A1 (it) * 2011-09-19 2013-03-20 Cnh Italia Spa Electronic oil level management.
US20150020995A1 (en) * 2013-07-17 2015-01-22 Gardner Denver, Inc. Slim mobile hydraulic fluid cooling assembly
US10030676B2 (en) 2014-04-23 2018-07-24 Hyster—Yale Group, Inc. Hydraulic fluid supply apparatus and methods

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20250034844A1 (en) * 2023-07-26 2025-01-30 Great Plains Manufacturing, Inc. Work machine with multiple hydraulic tanks

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3222866A (en) * 1964-12-21 1965-12-14 Case Co J I Hydraulic apparatus and method
US3222865A (en) * 1964-11-20 1965-12-14 Case Co J I Hydraulic apparatus and method
US3234855A (en) * 1964-09-29 1966-02-15 Caterpillar Tractor Co Hydraulic system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3234855A (en) * 1964-09-29 1966-02-15 Caterpillar Tractor Co Hydraulic system
US3222865A (en) * 1964-11-20 1965-12-14 Case Co J I Hydraulic apparatus and method
US3222866A (en) * 1964-12-21 1965-12-14 Case Co J I Hydraulic apparatus and method

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3795108A (en) * 1971-02-11 1974-03-05 Gewerk Eisenhuette Westfalia Pressure fluid drive systems for mine installations
US3910045A (en) * 1973-01-13 1975-10-07 Bosch Gmbh Robert Hydraulic control apparatus for hydraulic-lift end gates of moving vans and the like
JPS49104069A (enrdf_load_stackoverflow) * 1973-01-26 1974-10-02
US3877545A (en) * 1973-01-26 1975-04-15 Caterpillar Tractor Co Lubrication system for vehicle final drive
US3960174A (en) * 1974-09-03 1976-06-01 Caterpillar Tractor Co. Hydraulic circuit with dual tank system and method for using the same
US3993094A (en) * 1975-04-21 1976-11-23 Allis-Chalmers Corporation Removable reservoir cover having internal parts of reservoir mounted thereon
US4243065A (en) * 1979-03-19 1981-01-06 Boc Limited Apparatus for removing gas from a liquid
US5906089A (en) * 1997-07-17 1999-05-25 Hay & Forage Industries Slave cylinder stabilizer for harvester header
US6183682B1 (en) * 1998-01-12 2001-02-06 Nissei Plastic Industrial Co., Ltd. Method for preventing occurrence of impact pressure in injection molding machine
JP2003021101A (ja) * 2001-07-09 2003-01-24 Yanmar Co Ltd 作動油タンク構造
US20110024204A1 (en) * 2008-04-14 2011-02-03 Volvo Construction Equipment Ab Construction vehicle with a split hydraulic holding unit
ITMO20110236A1 (it) * 2011-09-19 2013-03-20 Cnh Italia Spa Electronic oil level management.
WO2013041493A1 (en) * 2011-09-19 2013-03-28 Cnh Italia Spa Oil level control device
US9618015B2 (en) 2011-09-19 2017-04-11 Cnh Industrial America Llc Oil level control device
US20150020995A1 (en) * 2013-07-17 2015-01-22 Gardner Denver, Inc. Slim mobile hydraulic fluid cooling assembly
US9611869B2 (en) * 2013-07-17 2017-04-04 Gardner Denver, Inc. Slim mobile hydraulic fluid cooling assembly
US10030676B2 (en) 2014-04-23 2018-07-24 Hyster—Yale Group, Inc. Hydraulic fluid supply apparatus and methods

Also Published As

Publication number Publication date
CA918539A (en) 1973-01-09
GB1301752A (enrdf_load_stackoverflow) 1973-01-04
GB1301751A (enrdf_load_stackoverflow) 1973-01-04

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Legal Events

Date Code Title Description
AS Assignment

Owner name: CATERPILLAR INC., A CORP. OF DE.,ILLINOIS

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

Effective date: 19860515

Owner name: CATERPILLAR INC., 100 N.E. ADAMS STREET, PEORIA, I

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:CATERPILLAR TRACTOR CO., A CORP. OF CALIF.;REEL/FRAME:004669/0905

Effective date: 19860515