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
  • F16H61/465—Automatic regulation in accordance with output requirements for achieving a target input speed
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B49/00—Control, e.g. of pump delivery, or pump pressure of, or safety measures for, machines, pumps, or pumping installations, not otherwise provided for, or of interest apart from, groups F04B1/00 - F04B47/00
  • F04B49/002—Hydraulic systems to change the pump delivery
• • 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
  • F16H61/42—Control of exclusively fluid gearing hydrostatic involving adjustment of a pump or motor with adjustable output or capacity
  • F16H61/433—Pump capacity control by fluid pressure control means
• • 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

Definitions

• the subject of this present invention is a governor which acts on the servocontrol of. a variable-delivery pump, the latter being suitable for a closed circuit and such as to drive the motor at constant revs, whatever the number of revs of the prime mover driving the pump.
• Said servocontrol normally consists of a distributor which continues to oscillate in its equilibrium position, determined by a manual control lever connected to the distributor by means of gears. These also comprise an elastic means which can istantaneously free said manual control lever from said servocontrol.
• the proposed governor may be used for any kind of automatic control of the variable-delivery pump, without excluding the possibility of also controlling said pump manually. For example, using the 5. proposed device, the r.p.m. of the drum in truck mixers or other mixing equipment, agitators or the like can be maintained constant, the movement of vehicles in general can be controlled and also the actuating of auxiliary movement in road finishing machines, steamrollers, etc.
• variable-delivery pump has been controlled only by using very complicated devices, which frequently break down.
• patent US-A-3,212,263 illustrates a known type of variable-delivery hydraulic pump.
• French patent application 2,264,991 describes a device 15. suitable for limiting the pressure in an open hydraulic circui .
• German patent application 1,943,601 only describes the power control, not the governing of the motor speed.
• German patent application 2,252,557 describes an 20. aut ⁇ natic device suitable for allowing variation in the number of revs of a pump. There is no mention at all of being able to obtain a constant number of revs in a motor.
• the problem of transmitting motion from a variable-delivery pump to a hydraulic motor has never been completely sa ⁇ tisfactorily solved, especially where the variable-delivery pump is a second use of a variable-revs prime mover.
• the latter also drives -a first use; for example, in truck mixers it provides for vehicle movement.
• this first use requires the number of revs of the prime mover to be increased - for example, need to accelerate the engine because the vehicle is driving up a slope or overtaking - the hydraulic
• the object of this invention is to carry out an 20. automatic control of the variable-delivery pump, while allowing also a manual control of the pump at the same time.
• the proposed governor allows hydraulic driving of the second use at constant speed, 25. even when the number of revs of the prime mover varies.
• the aforesaid object has been carried out by providing for the variable-delivery pump servocontrol to be actuated automatic ⁇ ally by means of a single-acting cylinder, the piston of which, subjected to the action of a spring, comprises 5. internally a slider .with free abutting end, which is connected to the servocontrol.
• a preferred embodiment provides for the piston to be subjected to the action of a set of springs arranged in a pack, which have been calibrated differently one from the other so as to 10. adapt to the pressure curve imparted to the cylinder when being actuated.
• a specific embodiment provides for the cylinder to be actuated by using the pressure produced by an auxiliary pump which, for example, is fitted directly on the prime mover.
• Fig. 1 shows the hydraulic diagram of the proposed governor and, purely as an indication, its main mechanical 20. parts;
• Fig. 2 shows a longitudinal section of the governor
• Fig. 3 shows a section similar to Fig. 2, but forming part of a second embodiment
• Fig. 4 is a cross section 4-4 of Fig. 2.
• the proposed governor has been used in the examples which will be described as a governor for a variable-delivery pump 1 , connected to an motor M which must run at constant speed. This should however in no way be considered as binding.
• variable-delivery pump 1 is driven by a prime mover MP, which impresses motion to the shaft 1A whereto is also splined the gear pump 1E.
• the variable-delivery pump now being described, has an oscillating plate 1B pivoted at a fixed central point
• variable-delivery pumps are fitted with a system for controlling the oscillating plate 1B driven by cylinders 20. 1D.
• the external manual control 12 consisting of a lever with fulcrum 2A (Figs. 1 and 4)
• pin 6B integral with said manual control 12 is displaced.
• lever 21 is displaced. Said lever 21 connected to the connecting rod 23 thus moves pin 7B into a position such as to close the forked spring 2B. At the same time lever 21 moves rod 2C into the neutral position thereby stopping the flow of oil to the servocylinder 1D. As a result
• control 17 from its neutral position. Through this play of balance between opening and closing of rod 2C of servocontrol 17 the displacement determined by the manual control 12 or the proposed governor is maintained constant.
• a cylinder 11 which is typically fitted so as to be integral with the servocontrol 17, as can be seen in Figs. 2 and 3.
• the cylinder 11 is actuated by a lever 2, integral with pin 7B, and having its fulcrum at 2A.
• cylinder 11 overides manual control 12 because it acts directly on pin 7B and through the latter on connecting rod 23, and thereby on lever 21 and rod 2C.
• Lever 2 is linked to connecting rod 24 and the latter to the slider 62, said lever not being however integral with the piston 61 in order
• variable pump 1 available the variable pump 1 , the servocontrol 17 and a pump 1E directly connected to the prime mover MP.
• the signal obtained before the throttling 2E is directly proportional to the revs of the prime mover MP.
• the spings 4 arranged in a pack and suitably calibrated, oppose the force exerted by the piston 61 due to the variable pressure signal, allowing said piston 61 to be displaced in proportion to the said pressure.
• Fig. 2 shows the constructional anbodiment of the proposed governing body 11. As stated above, it is constructed in such a way as to be integral with the servocontrol 17; in particular, it is placed above the latter and connected thereto by lever 2. This governing body may be used for a given direction of rotation of the hydraulic motor M; if the hydraulic motor rotates in the opposite direction, the 5. proposed governor is constructed as can be seen in Fig. 3. However, it is possible to provide a governor which governs for both directions of rotation of the hydraulic motor M.
• the proposed governor works as follows-
• selector 9 is positioned as shown in Fig.- 1.
• this pressure is a function of the speed of the shaft 1A in the prime mover means - displaces the piston 61 as a function

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• Engineering & Computer Science (AREA)
• General Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• Control Of Positive-Displacement Pumps (AREA)
• Control Of Fluid Gearings (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=11191850

Family Applications (1)

Country Status (5)

Families Citing this family (10)

Family Cites Families (7)

• 1984
  • 1984-07-30 IT IT22124/84A patent/IT1174619B/it active
• 1985
  • 1985-07-15 JP JP60503707A patent/JPS61502832A/ja active Pending
  • 1985-07-15 AU AU47731/85A patent/AU4773185A/en not_active Abandoned
  • 1985-07-15 EP EP85904097A patent/EP0222764A1/en not_active Withdrawn
  • 1985-07-15 WO PCT/EP1985/000349 patent/WO1986000963A1/en unknown

Non-Patent Citations (1)

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