US3584538A - Hydraulic system with improved changeover control unit - Google Patents

Hydraulic system with improved changeover control unit Download PDF

Info

Publication number
US3584538A
US3584538A US797468A US3584538DA US3584538A US 3584538 A US3584538 A US 3584538A US 797468 A US797468 A US 797468A US 3584538D A US3584538D A US 3584538DA US 3584538 A US3584538 A US 3584538A
Authority
US
United States
Prior art keywords
motor
pressure
fluid
restriction
sleeves
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
Application number
US797468A
Other languages
English (en)
Inventor
Alex Petersen
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.)
Danfoss AS
Original Assignee
Danfoss AS
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 Danfoss AS filed Critical Danfoss AS
Application granted granted Critical
Publication of US3584538A publication Critical patent/US3584538A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/46—Automatic regulation in accordance with output requirements
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41C—PROCESSES FOR THE MANUFACTURE OR REPRODUCTION OF PRINTING SURFACES
    • B41C1/00—Forme preparation
    • B41C1/10—Forme preparation for lithographic printing; Master sheets for transferring a lithographic image to the forme
    • 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
    • F15B11/00—Servomotor systems without provision for follow-up action; Circuits therefor
    • F15B11/02—Systems essentially incorporating special features for controlling the speed or actuating force of an output member
    • F15B11/04—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed
    • F15B11/05—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive
    • F15B11/055—Systems essentially incorporating special features for controlling the speed or actuating force of an output member for controlling the speed specially adapted to maintain constant speed, e.g. pressure-compensated, load-responsive by adjusting the pump output or bypass
    • 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
    • F15B13/0416—Fluid distribution or supply devices characterised by their adaptation to the control of servomotors for use with a single servomotor with means or adapted for load sensing
    • F15B13/0417—Load sensing elements; Internal fluid connections therefor; Anti-saturation or pressure-compensation valves
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/4035—Control of circuit flow
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/4061—Control related to directional control valves, e.g. change-over valves, for crossing the feeding conduits
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40515—Flow control characterised by the type of flow control means or valve with variable throttles or orifices
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/405—Flow control characterised by the type of flow control means or valve
    • F15B2211/40576—Assemblies of multiple valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/41—Flow control characterised by the positions of the valve element
    • F15B2211/413—Flow control characterised by the positions of the valve element the positions being continuously variable, e.g. as realised by proportional valves
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41554—Flow control characterised by the connections of the flow control means in the circuit being connected to a return line and a directional control valve
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/415—Flow control characterised by the connections of the flow control means in the circuit
    • F15B2211/41563—Flow control characterised by the connections of the flow control means in the circuit being connected to a pressure source and a return line
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/421—Flow control characterised by the type of actuation mechanically
    • F15B2211/423—Flow control characterised by the type of actuation mechanically manually, e.g. by using a lever or pedal
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/42—Flow control characterised by the type of actuation
    • F15B2211/428—Flow control characterised by the type of actuation actuated by fluid pressure
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/45—Control of bleed-off flow, e.g. control of bypass flow to the return line
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/40—Flow control
    • F15B2211/465—Flow control with pressure compensation
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/70—Output members, e.g. hydraulic motors or cylinders or control therefor
    • F15B2211/705—Output members, e.g. hydraulic motors or cylinders or control therefor characterised by the type of output members or actuators
    • F15B2211/7058—Rotary output members
    • 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
    • F15B2211/00—Circuits for servomotor systems
    • F15B2211/80—Other types of control related to particular problems or conditions
    • F15B2211/85—Control during special operating conditions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H59/00—Control inputs to control units of change-speed-, or reversing-gearings for conveying rotary motion
    • F16H59/68—Inputs being a function of gearing status
    • F16H2059/6838—Sensing gearing status of hydrostatic transmissions
    • F16H2059/6861—Sensing gearing status of hydrostatic transmissions the pressures, e.g. high, low or differential pressures
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16H—GEARING
    • F16H61/00—Control functions within control units of change-speed- or reversing-gearings for conveying rotary motion ; Control of exclusively fluid gearing, friction gearing, gearings with endless flexible members or other particular types of gearing
    • F16H61/38—Control of exclusively fluid gearing
    • F16H61/40—Control of exclusively fluid gearing hydrostatic
    • F16H61/4043—Control of a bypass valve
    • F16H61/4052—Control of a bypass valve by using a variable restriction, e.g. an orifice valve
    • 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
    • Y10T137/2496—Self-proportioning or correlating systems
    • Y10T137/2559—Self-controlled branched flow systems
    • Y10T137/2574—Bypass or relief controlled by main line fluid condition
    • Y10T137/2605—Pressure responsive

Definitions

  • a restrictor provided for controlling flow in the discharge line is variably opened and closed in response to operation of the changeover valve.
  • a metering valve in the control unit is responsive to pressure drops across the restrictor and operates to bypass supply fluid to the discharge line downstream of the restrictor to change over without damage to the system.
  • This invention relates generally to hydraulic motors and more particularly to a hydraulic system with a new and improved changeover control unit.
  • Hydraulic systems are known wherein the changeover valve for effecting motor reversal and the metering valve and restrictor are separate components
  • the restrictor in these systems is located in the pressure line leading to the changeover valve.
  • the restrictor To effect a change of direction of rotation of the motor the restrictor must be first so adjusted that the quantity of fluid supplied to the motor is very small, before the changeover can be carried out. If care is not taken to do this, the system can be damaged.
  • the braking of the motor is also accompanied by problems, since, due to the inertia of the moving parts, the motor acts as a pump and may produce a reduced pressure between the closed restrictor and itself.
  • the control arrangement for such systems is very expensive; it requires considerable space, numerous components and connecting passages.
  • a principal object of the invention is to eliminate the above disadvantages partially or completely.
  • this is achieved by connecting an adjustable part of a discharge flow restrictor to an adjustable part of a changeover valve, for reversing the motor, and arranging a metering valve in the changeover valve.
  • joint adjustment of the restrictor and the changeover valve is achieved, so that not only is operation simpler, but no changeover can take place without a prior reduction of the quantity of fluid supplied to the motor.
  • the changeover valve, the metering valve and the restrictor considerable spaceand expense are saved.
  • many of the connecting passages extending from one device to another can be dispensed with.
  • the adjustable restrictor is connected in the discharge line of the hydraulic motor.
  • the restrictor When the restrictor is closed, heavy forced braking of the motor results because the line through which the motor seeks to discharge fluid, as a result of its pumping action is blocked.
  • the motor has a very constant speed because the restrictor in the discharge line measures the fluid actually doing work in the motor but does not measure leakage fluid.
  • the restrictor is fully closed at that portion of two operating positions directly adjacent a neutral position. This causes a braking action to occur before the actual neutral position is reached and the neutral position itself can thus be free of any braking action.
  • the two working passages can be interconnected in the neutral position. This allows the motor to run light and this is very advantageous for many purposes.
  • the changeover valve according to the invention comprises two concentric sleeves, rotatable relatively to each other, one of which sleeves forms the restrictor and has at least one orifice and the other of which sleeves forms a cover for the orifices in a peripheral or circumferential direction.
  • the cover in the circumferential direction is somewhat wider than the orifice so that a braking position is obtained on both sides of the neutral position at which the orifices are covered.
  • the orifice in the restrictor is advantageously formed by extending at least one such longitudinal groove.
  • a piston axially displaceable against a spring force, is disposed inside the inner sleeve.
  • the end faces of the piston are acted upon by the pressure on the two sides of the restrictor and, together with an axially immobilized part, form the metering valve.
  • the longitudinal grooves connected to the restrictor carry out an additional function if they extend beyond the piston and are connected, by way of a transverse passage, to the end face chamber, beyond the piston.
  • the longitudinal grooves connected to the restrictor can communicate with the pressure line in the neutral position of the changeover valve. This results in the metering valve being exposed to the full pressure of the system in the neutral position and accordingly it opens fully, i.e. directs the entire quantity of fluid delivered by the pump past the changeover valve.
  • the outer sleeve of the changeover valve is made adjustable for adjusting relative to the pump output.
  • a cam can be used as the adjusting element.
  • the outer sleeve of the control unit prefferably be of increased diameter near an annular passage communicating with the pressure line, and. for a resilient element to be interposed between the adjusting element and the sleeve.
  • This resilient element consists of, for example, a resilient ring fitted round an eccentric pin on the adjusting element.
  • FIG. 1 is a schematic diagram of a hydraulic system according to the invention.
  • FIG. 2 is a longitudinal section view through a control unit according to the invention illustrating a. combined changeover and metering valve and taken on section line ll-Il of FIG. 4;
  • FIG. 3 is a fragmentary section view taken on section line llI-III of FIG. 2;
  • FIG. 4 is a fragmentary cross section view taken on section line IV-IV of FIG. 2;
  • FIG. 5 is a fragmentary cross section view taken on section line V-V of FIG. 2;
  • FIG. 6 is a fragmentary cross section view taken on section line VI-VI of FIG. 2;
  • FIG. 7 is a fragmentary cross section view taken on section line VII-VII of FIG. 2;
  • FIG. 8 is a fragmentary cross section. view taken on section line VIII-Vlll of FIG. 2.
  • FIG. I illustrates a hydraulic system having a pump 1, which supplies fluid under pressure from a source 2 to a control device 4 through a pressure line 3.
  • a reversible hydraulic motor 7 is connected to the control device through two working passages 5 and 6.
  • a discharge line 8 connects the control device to the source 2,,through a return hydraulic fluid filter 9.
  • a pressure relief valve 10 interconnects the pressure line 3 and the discharge line 8 and opens when a set pressure is exceeded.
  • a metering valve 1 l is arranged in parallel with the relief valve and is controlled by the pressure drop at a regulatable restrictor 12. The metering valve 11 is connected to discharge line 8 portions 8a and 8b upstream of and downstream of the restrictor 12, by two stepping lines 13 and 14 so that it will be controlled by the pressure drop across the restrictor 12.
  • a changeover valve 15 is provided for reversing the motor and is shown schematically. While the changeover valve is shown as axially operable it is constructed as a rotary valve as later described. It has five main positions, designated a through e, into which it can be positioned by outside actuating means, for example a hand lever or control 16. In a neutral position 0, the pressure line 3 is connected to the two working passages 5 and 6, and a connecting passage 17, while a blocking element 18 blocks the discharge line 8. In two operating positions, a and e, the pressure line 3 and the discharge line 8 are each connected with one of the two working passages 5 and 6. The changeover valve has two braking positions b and d.
  • pressure line 3 is connected to one of the two working passages 5 or 6, and blocking elements 19 and 20 block the discharge line.
  • a pressure relief valve 21, 22 which opens at a predetermined excess pressure and passes fluid under pressure to the discharge line 8, downstream of the restrictor 12, through a line 23.
  • the restrictor 12 is connected, through a mechanical coupling 24, to the movable part of the changeover valve 15 and is therefore likewise adjusted upon movement of the hand lever 16. Furthermore, the pressure applied in the pressure line 3 acts upon the restrictor through a stepping line 25. Finally, the restrictor 12 also forms the blocking elements 18, 19 and 20 in the neutral position c and in the two braking positions, b and d, of the changeover valve 15.
  • the two working passages 5, 6 are interconnected in the neutral position.
  • the motor 7 can therefore run light.
  • the quantity of fluid supplied by the pump is divided by the metering valve; the rest flows through the motor.
  • the opening position of the metering valve 11 is controlled by the pressure drop at the restrictor 12, through which all the fluid passing through the motor flows.
  • the increase in cross section of the restrictor is in linear relationship with the adjustment of the changeover valve.
  • valve is actually a rotary valve and the neutral position c is limited to a rotary angle of 3 on each side of the zero line, and the next 0.5 corresponds to the braking position. Further rotation of the valve up to 20 leads gradually to the restrictor 12 being fully opened.
  • FIGS. 2-7 An embodiment of some of the arrangement is shown in FIGS. 2-7.
  • the relief pressure valve 10 which is also housed in the control device 4, cannot be seen.
  • a through bore is closed by a cover 27.
  • a plurality of sleeves is arranged with the sleeves disposed concentrically one within the other.
  • a first sleeve 28 is nonrotatable but is axially displaceable.
  • a pin 29, which is mounted eccentrically on a screw 31 provided with an adjusting nut 30 and which has a resilient ring 32, engages in a complementary recess in the sleeve to preclude rotary motion but allows axial movement of the sleeve.
  • a second sleeve 33 is axially fixed between the cover 27 and a retaining element 34, but it can be rotated. It is provided with a toothed portion 35 for receiving a toothed spindle for rotation thereof.
  • a third sleeve 36 is axially held against the second sleeve 33 by means of a resilient spring 37 and a bearing edge 38. It can rotate with the second sleeve but need not do so.
  • a fourth sleeve or piston 39 is pressed against a circlip 42 by a spring 40, which abuts against a plate 41 near the toothed portion 35. It can move axially towards the plate 41 as far as the clearance between the end of a pin 43 and the plate 41 will allow.
  • the first sleeve 28 and housing define four annular chambers.
  • An annular chamber 49 communicates with a threaded connection passage or bore 50 for the pressure line, and an annular chamber 51 communicates a threaded connection passage or bore 52 for the discharge line.
  • Two intermediate annular chambers, 53 and 54, lead to passages 55 and 56 for communications with and connection to the working passages 5, 6.
  • Three openings 57, 58 and 59 distributed equidistantly over the periphery connect each of the annular chambers 49, 54 and 53 to the interior of the first sleeve 28.
  • the second sleeve has three fairly short longitudinal grooves 60 and, between these, three longer longitudinal grooves 61.
  • the shorter longitudinal grooves 60 can connect the openings 57 with the openings 58 and 59 respectively.
  • the longer longitudinal grooves 61 perform the same function, but in addition extend as far as the annular chamber 51. There, they are substantially fully covered by tabs 62 on the first sleeve 28.
  • openings 63 lead from the shorter longitudinal grooves 60 to the inside of the second sleeve 33, while openings 64 lead from the longer longitudinal grooves 61 to the interior.
  • Openings 65 are provided as extensions of the shorter longitudinal grooves, which openings connect the inner chamber 66 of the bore to the annular chamber 51.
  • the third sleeve 36 defines near the openings 63, an annular chamber 67 with openings 68, and, near the openings 64, an annular chamber 69 with openings 70. Moreover, openings 71 are provided on the left-hand side, and these lead into the inner chamber 66.
  • the piston 39 has a longitudinally extending annular chamber 72, which connects the openings 68 with the openings 71 in the third sleeve 36, when the sleeve 39 is axially displaced to the left.
  • the first sleeve 28 is of somewhat greater diameter than in its left-hand portion. It is therefore biased to the right side of the drawing by the pressure obtaining inthe annular chamber 49, the axial displacement depending upon the return force of the resilient ring 32.
  • the pressure in the longer longitudinal groove 61 obtains each time in a chamber 74 to the right of the piston 39, since this chamber communicates with this groove through the opening 64, the annular chamber 69 and the openings 70.
  • the pressure in the annular chamber 51 obtains each time in the inner chamber 66, since these two chambers are interconnected by the openings 65. Consequently, the piston 39 is subjected to the effect of the pressure drop at the restrictor, which is here formed by the longitudinal groove 61 and the tab 62. Consequently, the piston 39 moves a corresponding distance to the left against the spring 40 and the annular chamber 72 opens by the uncovering of a variable portion of the openings 71.
  • the annular chamber 72 and the openings 71 form the metering valve, which communicates with the pressure line connection 50 through the openings 60, the annular chamber 67, the openings 63, the shorter longitudinal grooves 60, the openings 57 and the annular chamber 49, and communicates with the discharge line connection 52 through the inner chamber 66, the openings 65 and the annular chamber 51.
  • the restrictor can be matched to the maximum cross section of the flow passage of the particular machine or motor connected in the system. It will be seen that this does not interfere with the linear increase in the opening of the restrictor. Furthermore, as already mentioned, the outer sleeve 28 is displaced axially against the return force of the resilient ring 32, in dependence upon the magnitude of the initial pressure, so that the restrictor opening can also be varied in dependence thereon.
  • FIGS. 2 to 7 show a condition which might correspond to a clockwise running or rotation of the motor and which coincides with the position a of the changeover valve.
  • fluid under pressure flows through the connection passage and passes through the annular chamber 49, the openings 57, the short longitudinal groove 60, the openings 58, the annular chamber 54 and the connection passage 56 to the working passage 5 of the motor.
  • the fluid flows through the passage 6, to the connection passage 55 and then through the annular chamber 53, the openings 59, the longer longitudinal groove 61, the restrictor, the annular chamber 51 and the connection passage 52, to the discharge line.
  • the second sleeve 33 is rotated toward the neutral position, then, shortly before the changeover opening, i.e. just before connection takes place between the longitudinal grooves 60, 61 and the openings 58, 59 is rendered noneffective, the left-hand end of the longitudinal groove 61 will have been fully covered by the tabs 62. No fluid can therefore continue to flow to the motor by the normal path. The motor is thus braked. The fluid can then flow only from the annular chambers 53 or 541, through the associated pressure relief valves 47 and 48 respectively, bypassing the restrictor 61, 62 and into the traverse bore 44 and then to the discharge line 8.
  • a neutral position spring 76 consisting of, FIG. 8, four spring plates 75, bears against both the first sleeve 28 and the second sleeve 33 in the nonoperating position. If the second sleeve is turned, the spring plates 75 are tensioned and permit the second sleeve to return to the nonoperating position again upon completion of rotation.
  • a reversible fluid-driven motor a source of pressure fluid for rotationally driving said motor
  • conduit means connecting said source of pressure fluid and said reversible motor comprising a pressure line to said motor and a discharge line from said motor
  • a changeover valve connected to said conduit means for reversing direction of rotation of said motor
  • a metering valve connected to said conduit means responsive to fluid pressure changes across said restriction bypassing at least some flow of fluid from said pressure line upstream of said motor to said discharge line in dependence upon pressure changes across said restriction
  • said means defining said restriction comprising means responsive to pressure changes in said pressure line increasing opening of said restriction in response to increases of pressure in said pressure line.
  • a reversible fluid-driven motor a source of pressure fluid for rotationally driving said motor
  • conduit means connecting said source of pressure fluid and said reversible motor comprising a pressure line to said motor and a discharge line from said motor
  • a changeover valve connected to said conduit means for reversing direction of rotation of said motor
  • a metering valve connected to said conduit means responsive to fluid pressure changes across said restriction bypassing at least some flow of fluid from said pressure line upstream.
  • said changeover Valve, said metering valve, and said means defining said restriction comprises at least some common parts defining jointly a unitary control device, control device comprising a plurality of coaxial sleeves relatively rotatable, one of said sleeves having a plurality of grooves providing communication between said pressure line, said motor and said discharge line for driving the motor in opposite direction, said means defining said restriction comprising means on another of said sleeves variably restricting flow through one of said grooves upon relative rotation of said sleeves, and means for relatively rotating said sleeves.
  • said metering valve comprises a piston reciprocable in an innermost of said sleeves in response to variations in pressure drop across said restriction.
  • said cam comprises an eccentric pin received in a recess in said outermost sleeve, and a resilient ring about said pin.
  • a reversible fluid-driven motor a source of pressure fluid for rotationally driving said motor
  • conduit means connecting said source of pressure fluid and said reversible motor comprising a pressure line to said motor and a discharge line from said motor, a changeover valve con nected to said conduit means for reversing direction of rotation of said motor, means defining a variable restriction restricting fluid flow in said discharge line variably opened and closed in response to change of settings of said changeover valve to different operating positions
  • a metering valve connected to said conduit means responsive to fluid pressure changes across said restriction bypassing at least some flow of fluid from said pressure line upstream of said motor to said discharging line in dependence upon pressure changes across said restriction and said changeover valve comprising two concentric sleeves relatively rotatable, defining said means defining said restriction, one of said sleeves having a groove defining in communication with said discharge line, the other sleeve having means variably controlling flow through said groove in dependence upon the relative angular positions of said sleeves.

Landscapes

  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • Manufacturing & Machinery (AREA)
  • Hydraulic Motors (AREA)
  • Fluid-Pressure Circuits (AREA)
US797468A 1968-02-09 1969-02-07 Hydraulic system with improved changeover control unit Expired - Lifetime US3584538A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681628119 DE1628119A1 (de) 1968-02-09 1968-02-09 Hydraulische Anlage mit einem Hydraulikmotor

Publications (1)

Publication Number Publication Date
US3584538A true US3584538A (en) 1971-06-15

Family

ID=5683133

Family Applications (1)

Application Number Title Priority Date Filing Date
US797468A Expired - Lifetime US3584538A (en) 1968-02-09 1969-02-07 Hydraulic system with improved changeover control unit

Country Status (9)

Country Link
US (1) US3584538A (da)
BE (2) BE726259A (da)
CH (1) CH485117A (da)
DE (1) DE1628119A1 (da)
DK (1) DK121958B (da)
FR (1) FR2001595A1 (da)
GB (1) GB1256601A (da)
NL (1) NL6901449A (da)
SE (1) SE350569B (da)

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3895560A (en) * 1973-11-12 1975-07-22 Leesona Corp Cylinder motion sensing
US3948146A (en) * 1972-06-22 1976-04-06 Zahnradfabrik Friedrichshafen Ag Control system for hydraulic coupling
US3979907A (en) * 1973-09-10 1976-09-14 Parker-Hannifin Corporation Priority control valve
US4218957A (en) * 1977-10-03 1980-08-26 Borg-Warner Corporation Flow control valve
DE3403338A1 (de) * 1984-02-01 1985-08-08 Duisburger Maschinenfabrik Herbert Pelzer GmbH & Co KG, 4100 Duisburg Steuerung fuer eine pneumatisch betriebene zylinderkolbenanordnung
US5016672A (en) * 1990-04-23 1991-05-21 Eaton Corporation Steering controller with integral parallel control
US5115640A (en) * 1990-04-23 1992-05-26 Eaton Corporation Fluid controller and logic control system for use therewith
US5329969A (en) * 1991-05-20 1994-07-19 Eaton Corporation Fluid controller with joystick capability and actuator therefor
CN109139583A (zh) * 2018-10-23 2019-01-04 河南垣发专用车辆集团有限公司 一种叉装机用液压控制系统

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2757660A1 (de) * 1977-12-23 1979-06-28 Bosch Gmbh Robert Hydraulische steuereinrichtung mit wenigstens einem wegeventil
DE3010913C2 (de) * 1980-03-21 1986-05-07 Zahnradfabrik Friedrichshafen Ag, 7990 Friedrichshafen Hydrostatisches Getriebe im offenen Kreislauf

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3948146A (en) * 1972-06-22 1976-04-06 Zahnradfabrik Friedrichshafen Ag Control system for hydraulic coupling
US3979907A (en) * 1973-09-10 1976-09-14 Parker-Hannifin Corporation Priority control valve
US3895560A (en) * 1973-11-12 1975-07-22 Leesona Corp Cylinder motion sensing
US4218957A (en) * 1977-10-03 1980-08-26 Borg-Warner Corporation Flow control valve
DE3403338A1 (de) * 1984-02-01 1985-08-08 Duisburger Maschinenfabrik Herbert Pelzer GmbH & Co KG, 4100 Duisburg Steuerung fuer eine pneumatisch betriebene zylinderkolbenanordnung
US5016672A (en) * 1990-04-23 1991-05-21 Eaton Corporation Steering controller with integral parallel control
US5115640A (en) * 1990-04-23 1992-05-26 Eaton Corporation Fluid controller and logic control system for use therewith
US5329969A (en) * 1991-05-20 1994-07-19 Eaton Corporation Fluid controller with joystick capability and actuator therefor
CN109139583A (zh) * 2018-10-23 2019-01-04 河南垣发专用车辆集团有限公司 一种叉装机用液压控制系统
CN109139583B (zh) * 2018-10-23 2024-05-17 河南垣发专用车辆集团有限公司 一种叉装机用液压控制系统

Also Published As

Publication number Publication date
NL6901449A (da) 1969-08-12
DE1628119A1 (de) 1971-03-04
GB1256601A (da) 1971-12-08
BE374653A (da) 1900-01-01
CH485117A (de) 1970-01-31
BE726259A (da) 1969-05-29
SE350569B (da) 1972-10-30
DK121958B (da) 1971-12-27
FR2001595A1 (da) 1969-09-26

Similar Documents

Publication Publication Date Title
US3722543A (en) Pressure compensated control valve
US3455210A (en) Adjustable,metered,directional flow control arrangement
US3584538A (en) Hydraulic system with improved changeover control unit
KR930001871B1 (ko) 유량증폭에 의한 스티어링 제어장치
SU736884A3 (ru) Система управлени объемным гидроприводом
US2238063A (en) Fluid pressure system and valve mechanism therefor
US4336687A (en) Load sensing controller
JPS6143228B2 (da)
US4167893A (en) Load sensing valve
DK142591B (da) Hydraulisk styreventil.
US3532104A (en) Pressure compensated flow control valve system
US4178962A (en) Control valve with flow control means
US4159723A (en) Control device for steering apparatus or the like
US3375756A (en) Multiple- or variable-speed motors notably hydraulic motors with monitoring system and its applications
US5058484A (en) Electrohydraulic control arrangement for controlling a hydraulic drive
JPH02249764A (ja) 流量増幅および手動ステアリング能力を備える制御装置
US3280842A (en) Valve
JPS5928762B2 (ja) 液圧式のかじ取り装置
US4436114A (en) Hydraulic valve mechanism
US3020890A (en) Pump control valve with bypass
US3543645A (en) Control equipment for hydrostatic drive of a vehicle
US4429619A (en) Control system for a hydraulic load
US2879745A (en) Dual throttling motor control circuit
US2384760A (en) Fluid-pressure operated apparatus
JPS6330613Y2 (da)