US3613730A - Power transmission - Google Patents

Power transmission Download PDF

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Publication number
US3613730A
US3613730A US3613730DA US3613730A US 3613730 A US3613730 A US 3613730A US 3613730D A US3613730D A US 3613730DA US 3613730 A US3613730 A US 3613730A
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United States
Prior art keywords
valve
spool
pressure
pilot
spring
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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
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English (en)
Inventor
Robert H Breeden
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Vickers Inc
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Sperry Rand Corp
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Publication of US3613730A publication Critical patent/US3613730A/en
Assigned to SPERRY CORPORATION reassignment SPERRY CORPORATION CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: SPERRY RAND CORPORATION
Assigned to VICKERS, INCORPORATED reassignment VICKERS, INCORPORATED ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: SPERRY CORPORATION A DE CORP.
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Expired - Lifetime legal-status Critical Current

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    • 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
    • F15B13/00—Details of servomotor systems ; Valves for servomotor systems
    • F15B13/02—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors
    • F15B13/04—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor
    • F15B13/0401—Valve members; Fluid interconnections therefor
    • F15B13/0402—Valve members; Fluid interconnections therefor for linearly sliding valves, e.g. spool valves
    • 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
    • Y10T137/8593—Systems
    • Y10T137/86493—Multi-way valve unit
    • Y10T137/86574—Supply and exhaust
    • Y10T137/86582—Pilot-actuated

Definitions

  • a flow rate limiter responsive to the pressure drop across an orifice in the main ,return flow line acts when this pressure drop becomes too high to override the remote control system and shift the main valve toward closed position.
  • the control system is especially useful in hydraulic systems having a central power supply operating at a constant pressure to make fluid available selectively to any of a number of independent hydraulic motors, as for example for operating deck machinery on a ship.
  • the sliding spool type of directional valve which is almost universally used in hydraulic systems does not lend itself readily to precise flow modulation because the rate of flow increase with each increment of spool travel is very high at small valve openings and falls off rapidly after the first few increments of spool travel. This characteristic increases the difficulty of achieving precise modulation when the spool travel is controlled from a distance.
  • a further object is to provide in a valve of this type a simple flow limiting control which may be adjusted to hold the maximum flow through the valve at any desired level.
  • the invention consists in a valve for controlling fluid flow comprising a body having a laterally ported bore, a spool slidable in the bore to control flow between ports of the bore, pressure actuated pilot means for shifting the spool, a high-rate spring means positioned to oppose the pilot means during a portion of the spool travel, a low-rate spring means positioned to oppose the pilot means during at least the remainder of the spool travel, a yieldable abutment between the spool and the high-rate spring, fluid-operated means for controlling the yieldable abutment and means for applying and modulating a supply of pressure fluid to the pilot means.
  • FIG. 1 is a top view of a valve incorporating a preferred form of the present invention.
  • FIG. 2 is a side view of the valve of FIG. 1.
  • FIG. 3 is an end view of the valve of FIG. 1.
  • FIG. 4 is a circuit diagram of the valve and its controls.
  • FIG. 5 is a sectional view of a bypass valve incorporated in the controls.
  • FIG. 6 is a fragmentary view on a larger scale showing a portion of the valve of FIG. I, partly in section.
  • FIG. 7 is a top view of a remote control station forming part of the controls.
  • FIG. 8 is a side view of the control station of FIG. 7.
  • FIG. 9 is an end view of the control station of FIG. 7.
  • FIG. 10 is a fragmentary sectional view taken on line 10- 10 of FIG. 7.
  • the main directional control valve illustrated in FIGS. 1, 2 and 3 comprises a main body 10 having a pair of end caps 12 which are identical and which has an internal bore provided with the usual series of lateral ports for pressure for exhaust and for supply to either of the motor connections A and B.
  • the central bore 14 in FIG. 6 carries a spool 16 for controlling the flow between the various lateral ports of the bore, as is well understood in the hydraulic art.
  • External connection flanges are provided at 18 and 20, FIG. 3, for pressure and exhaust and a common flange at 22 is provided for connections to the motor passages A and B.
  • Valves of this type have not heretofore been well suited for use in central hydraulic systems wherein flow from a substantially constant pressure source must be modulated to control the operation of a fluid motor, since the degree of valve opening required for a given motor speed varies widely depending upon the load which the motor has to overcome. At very light loads, only a slight opening through the valve is required since a high degree of throttling at this point is necessary in order to control the operating speed of the motor. On the other hand, when the load is high, very little throttling is required and much wider openings of the valve are necessary to produce a given motor speed. These problems have been overcome to some extent by providing long tapers or tapered grooves on the spool heads, but this greatly increases the required size of the valve and introduces problems when the valve is to be pilot operated by fluid pressure.
  • the main directional control valve as a whole is there designated as 24, being illustrated in accordance with the international standard diagrammatic conventions, and as contained within the block designated I0I2.
  • a circuit is established utilizing as a source of pressure the main pressure supply entering through the flange connection 18 and tapped off from the same by the line 26.
  • This line may be contained in a block or sandwich plate 28 which can be bolted to the top of the body 10 as shown in FIG. 3.
  • Line 26 leads to a second block or sandwich plate 30 within which the line 26 divides into branches 32 and 34 containing restrictions 36 and 38 respectively.
  • the branch 36 has an arm 40 extending to one of the end caps 12 of the valve 24 and the branch 34 similarly has an arm 42 extending to the opposite end cap of the valve 24.
  • Each of the arms 40 and 42 may have a variable restrictor with a check valve bypass as indicated at 44 for the purpose of regulating the rate of travel of the spool 16.
  • the branches 32 and 34 also have arms 46 and 48 respectively which serve as the remote control connectors between the main directional valve and the remote control station indicated by the block 50. The anns 46 and 48 connect to a four-way directional valve 52 which is manually controlled at the remote location as will later be described.
  • the directional valve 52 serves to reverse the connections of the two arms 46 and 48 to an adjustable pressure relief valve 54 and a direct exhaust line 56 respectively. That is to say, when one of the arms is connected to the relief valve 54, the other arm is connected directly to the exhaust line 56 and vice versa.
  • the spool of the main valve 24 may be given a modulating type of control from a remote location.
  • the arms 46 and 48 will be exhausted directly to the line 56 and the other will be exhausted thereto through the adjustable pressure relief valve 54.
  • the remote control station may be constructed as illustrated in FIGS. 7 through 10.
  • the block 50 may be provided with internal passages such as 58 which connect with four-way valve 52 at the port 62 and with the external exhaust connection 64.
  • passage 66 connects with valve 52 at port 68 and with valve 54 at port 70.
  • Ports 72 and 74 in the top of the four-way valve 52 are provided for connection with the remote control arms 46 and 48 respectively of the control circuit.
  • the valves 52 and 54 may be manually actuated from a single lever 76 through a suitable mechanical linkage such as provided by the double acting collapsible link 78 which has a pair of internal springs preloaded to yield only under a force significantly greater than that required to shift the four-way directional valve 52. When the later has reached its extreme position, one or the other of these springs will compress permitting further movement of the lever 76.
  • the output end of the link 78 is connected to an arm 80 rigidly secured to a rotatable shaft 82 joumaled in bearings 84 on the base 50.
  • a second arm 86 also rigidly secured to the shaft 82 is connected by a link 88 with the operating spool 90 of the valve 52.
  • Lever 76 is rigidly secured to a shaft 92 joumaled in a bearing block 94 and projecting from the opposite side thereof to engage within the central bore of an operating arm 96.
  • the relation between the shaft 92 and the arm 96 is illustrated in FIG. 10.
  • the arm 96 is pivoted to the base in a block 98 and has a link 100 pivoted at its upper end for exerting varying degrees of compression upon the spring of the adjustable relief valve 54.
  • the shaft 92 has abutment surfaces 102 and 104 which contact abutments 106 and 108 respectively in the arm 96 after a predetermined degree of angular motion of the shaft 92.
  • FIG. 6 there is illustrated the spring mechanism which offers differing force-displacement rates to oppose the manually varied pilot pressure at the opposite end of the main valve spool.
  • FIG. 6 illustrates a construction which is duplicated at each end cap 12. With a spool 16 which has square-end heads along its length, such as that illustrated at 1 10, it is necessary under conditions where the motor is lightly loaded that the opening movements of the spool be opposed by a very high-rate spring.
  • Such a spring is illustrated in the assembly of discs 112 which are positioned upon a pin 114 threaded at 116 in the end cap 12 and provided with a lock nut 118 and a closure cap 120. The disc springs 112 are retained on the pin 114 by a stop member 122 having a slot 124 which receives a pin 126 pressed into the pin 114.
  • the end of the spool 16 abuts a washer 128 which contacts a helical spring 130, the opposite end of which rests within the end of the cap 12.
  • This helical spring and its counterpart at the opposite end cap act as conventional preloaded centering springs.
  • the spool 16 has a recess 132 in its end which receives a piston 134 having an abutment face 136 on its outer end for the purpose of contacting the stop member 122 to compress the disc springs 112.
  • the chamber 132 is connected by a central passage 138 in the spool 16 with that groove or grooves on the spool which are in communication with the high-pressure supply and it thus serves to maintain high pressure within the recess 132 at all times.
  • a check valve 140 prevents displacement of fluid out of the chamber 132 through this path and the only escape from the chamber is that which occurs through leakage past the piston 134, the fit of which within the cylinder 132 is selected for this purpose.
  • a snapring 142 limits the outward movement of the piston 134.
  • the force-displacement rate of the spring 130 will be much lower than that of the spring assembly 112.
  • the pin 114 will be adjusted so that stop 122 isjust contacted by the abutment surface 136 at this point.
  • This motion will, of course, have been caused by the operator shifting the handle at the remote control station, first shifting the four-way directional valve so as to exhaust the end cap 12 in which the spring action is occurring and then to apply a progressively increasing pressure to the opposite end cap through progressively increasing the compression of the spring of the relief valve 54.
  • the disc springs l 12 commence to oppose the pilot pressure in the opposite end cap and from this point on, both the low-rate and the high-rate springs are opposing the pilot pressure.
  • pilot pressure for a given increment of pilot pressure, only a much smaller movement of the spool 16 occurs. In this way, precise modula tion of the flow at low motor loads may be achieved and, of course, at high motor loads as well.
  • the chamber 132 is maintained at full system pressure by admission of fluid through passage 138 and check valve 140.
  • the area of the piston 134 is so chosen in relation to the system pressure and the maximum force of the fully compressed disc springs 112 that piston 134 is maintained fully projected under these conditions.
  • the pilot control circuit may be overridden for the purpose of establishing a maximum limit upon flow through the main valve.
  • a bypass valve 144 is mounted on the side of the block 30, its internal construction being illustrated in FIG. 5 and diagrammed within the block 144 in FlG. 4.
  • the valve in FIG. 5 is illustrated in its open position in which the spool 146 connects the two ports 148 and 150 which are connected by lines 152 and 154 with the arms 46 and 48 respec tively of the pilot control circuit.
  • the spool 146 is biased to the left in FIG. 5 by a spring 156 and the ends of the spool are connected so as to be responsive to the pressure drop across an orifice in the main exhaust flow from the valve 24. This orifice is illustrated in FIG.
  • Suitable conduits such as 160 and 162 serve to sense the pressure in the flange 20 ahead of and beyond the orifice 158 and transmit these pressures through the block 30 to the left and the right ends of the spool 146 in FIG. 5.
  • a relief valve block 164 may be mounted atop the flange 22.
  • This carries internally a single main relief valve 166 connected across the main motor connection A and B.
  • a shuttle valve 168 is arranged to connect the sensing port 170 of relief valve 166 with which ever of the main ports A and B is at the moment under the higher pressure.
  • a drain conduit 172 may lead from the relief valve 166 to join with the conduit 162 for communication with the exhaust line.
  • the invention thus enables a standard sliding spool directional valve with a slight modification to be used for a modulating control in a central hydraulic system and to permit pilot control from a remote distance through manipulation of a simple pressure relief valve.
  • fully effective modulation is achieved, both under conditions requiring a high degree of throttling at the directional valve as well as under conditions which require very little throttling.
  • a valve for controlling fluid flow comprising a body having a laterally ported bore, a spool slidable in the bore to control flow between the ports of the bore, pressure actuated pilot means for shifting the spool, a high-rate spring means positioned to oppose the pilot means during a portion of the spool travel, a low-rate spring means positioned so as to oppose the pilot means during at least the remainder of the spool travel, a yieldable abutment contacting one end of the high-rate spring, fluid-operated means for controlling the yieldable abutment, and means for applying and modulating a supply of pressure fluid to the pilot means.
  • a valve as defined in claim 1 wherein the means for controlling the abutment comprises a piston slidable in the spool and supporting the yieldable abutment.
  • a valve as defined in claim 1 which includes means for holding the abutment against yielding during the compression of the high-rate spring and allowing yielding after the high-rate spring is fully compressed.
  • a directional control valve comprising a body having a laterally ported bore, a spool slidable in the bore to control flow between the ports of the bore, pressure actuated pilot means for shifting the spool, there being one pilot means at each end of the spool, spring means at each end of the spool to oppose with a predetermined gradient the pilot means at the opposite end of the spool, a pilot fluid pressure circuit comprising a high pressure source, a pair of branches, each containing a fixed restriction and a first arm connected to one of the pilot means and a second arm, a pilot four-way directional valve connected to each of the second arms, a variable pressure relief valve, and an open exhaust path selectively connectable to either of the second arms by shifting the four-way valve, and a single manual lever for shifting the four-way valve in one direction or the other and connected to operate the relief valve during the latter portion of its travel in either direction.
  • each branch includes a variable restrictor and a check valve in parallel in the first arm to limit the maximum rate of travel of the spool.
  • a valve as defined in claim 6 wherein there is provided a bypass valve which when open connects the two branches together, and means responsive to the flow rate controlled by the spool for actuating the bypass valve.
  • a directional control valve comprising a body having a laterally ported bore, a spool slidable in the bore to control flow between the ports of the bore, pressure actuated pilot means for shifting the spool, there being one pilot means at each end of the spool, means for applying and modulating pressure fluid at any desired level to one or the other of the pilot means, and spring means for opposing each pilot means and having a force-displacement rate which is high during initial flow across the spool and decreases thereafter.
  • the spring means includes a series of disc springs for imposing a high force-displacement rate and a helical spring for im osing a lower rate.
  • a valve as defined in claim 10 w erein fluid pressure operated means is provided to allow travel of the spool while the disc springs are fully compressed.
  • a valve as defined in claim 11 wherein the fluid pressure operated means includes a piston in the valve spool and means for applying system pressure to the piston.

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Servomotors (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Multiple-Way Valves (AREA)
US3613730D 1970-05-04 1970-05-04 Power transmission Expired - Lifetime US3613730A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US3400870A 1970-05-04 1970-05-04

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US3613730A true US3613730A (en) 1971-10-19

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US3613730D Expired - Lifetime US3613730A (en) 1970-05-04 1970-05-04 Power transmission

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US (1) US3613730A (enrdf_load_stackoverflow)
JP (1) JPS5337573B1 (enrdf_load_stackoverflow)
GB (1) GB1337837A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2349620A1 (de) * 1972-11-29 1974-06-12 Sperry Rand Corp Fernsteuersystem fuer hydraulische kraftuebertragungsgeraete
US6644168B1 (en) * 2002-08-12 2003-11-11 General Dynamics Armament And Technical Products, Inc. System and method for active control of recoil mechanism
US20130139909A1 (en) * 2011-12-01 2013-06-06 Liebherr-Hydraulikbagger Gmbh Hydraulic system

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5511513U (enrdf_load_stackoverflow) * 1978-07-06 1980-01-24

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2922440A (en) * 1954-06-08 1960-01-26 Klute
US3170484A (en) * 1962-06-20 1965-02-23 Ross Operating Valve Co Valve system
US3221770A (en) * 1961-03-03 1965-12-07 Faisandier Jacques Hydraulic distributor valve and by-pass means
US3279484A (en) * 1963-04-03 1966-10-18 Ross Operating Valve Co Pressure control system

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2922440A (en) * 1954-06-08 1960-01-26 Klute
US3221770A (en) * 1961-03-03 1965-12-07 Faisandier Jacques Hydraulic distributor valve and by-pass means
US3170484A (en) * 1962-06-20 1965-02-23 Ross Operating Valve Co Valve system
US3279484A (en) * 1963-04-03 1966-10-18 Ross Operating Valve Co Pressure control system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2349620A1 (de) * 1972-11-29 1974-06-12 Sperry Rand Corp Fernsteuersystem fuer hydraulische kraftuebertragungsgeraete
US6644168B1 (en) * 2002-08-12 2003-11-11 General Dynamics Armament And Technical Products, Inc. System and method for active control of recoil mechanism
US20130139909A1 (en) * 2011-12-01 2013-06-06 Liebherr-Hydraulikbagger Gmbh Hydraulic system
US9897115B2 (en) * 2011-12-01 2018-02-20 Liebherr-Hydraulikbagger Gmbh Hydraulic system

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Publication number Publication date
JPS5337573B1 (enrdf_load_stackoverflow) 1978-10-09
GB1337837A (en) 1973-11-21

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Date Code Title Description
AS Assignment

Owner name: SPERRY CORPORATION

Free format text: CHANGE OF NAME;ASSIGNOR:SPERRY RAND CORPORATION;REEL/FRAME:003794/0122

Effective date: 19790824

AS Assignment

Owner name: VICKERS, INCORPORATED TROY, MI A DE CORP

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST. EFFECTIVE NOVEMBER 2, 1983;ASSIGNOR:SPERRY CORPORATION A DE CORP.;REEL/FRAME:004337/0889

Effective date: 19831102

Owner name: VICKERS, INCORPORATED,MICHIGAN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SPERRY CORPORATION A DE CORP.;REEL/FRAME:004337/0889

Effective date: 19831102