EP0804685A2 - Actuateur hydraulique - Google Patents

Actuateur hydraulique

Info

Publication number
EP0804685A2
EP0804685A2 EP96900641A EP96900641A EP0804685A2 EP 0804685 A2 EP0804685 A2 EP 0804685A2 EP 96900641 A EP96900641 A EP 96900641A EP 96900641 A EP96900641 A EP 96900641A EP 0804685 A2 EP0804685 A2 EP 0804685A2
Authority
EP
European Patent Office
Prior art keywords
valve
cylinder
piston
operator
actuator
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.)
Withdrawn
Application number
EP96900641A
Other languages
German (de)
English (en)
Inventor
John Varga
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.)
Carding Specialists Canada Ltd
Original Assignee
Carding Specialists Canada Ltd
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 Carding Specialists Canada Ltd filed Critical Carding Specialists Canada Ltd
Publication of EP0804685A2 publication Critical patent/EP0804685A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • 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
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/08—Actuation of distribution members
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01L—CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES
    • F01L9/00—Valve-gear or valve arrangements actuated non-mechanically
    • F01L9/10—Valve-gear or valve arrangements actuated non-mechanically by fluid means, e.g. hydraulic

Definitions

  • This invention relates to a hydraulically operated actuator for controlling the reciprocation e.g. angular and/or linear of a working element, such as the actuating stem of a valve, and is particularly, though not exclusively concerned with the hydraulic actuation of inlet and exhaust valves of positive displacement type air compressors (linearly displaceable piston type air compressors). It should be understood, however, that the invention is not restricted to such use, and may be applied to the hydraulic actuation of other types of valve controlled pressure chambers which are filled with a fluid medium which is then pressurised, and exhausted, in repeated cycles of operation; or to the control of a reciprocating working element, such as a punch, stamp or forging device.
  • a piston In the operation of a positive displacement type of air compressor, a piston is driven back and forth within a cylinder at relatively low speed, and inlet and outlet valves are operated in timed sequence with the movement of the piston so as to control (1 ) the induction of a charge of air (2) compression of the charge and (3) discharge of the compressed charge in a repeated cycle of operations.
  • the inlet valve is normally held open throughout the major part of the induction stroke of the piston, and is held closed against its valve seat during the compression and discharge stroke of the piston, whereas the exhaust valve is normally held closed against its valve seat during the induction stroke and also the major part of the compression stroke, and is only held open for a short time interval at or near the end of the compression stroke to allow the compressed charge to be discharged.
  • positive displacement compressors are of the double acting type, so that each side of the piston can carry out its own cycle of operation with respect to the air chamber defined within the cylinder between that piston side and the facing end of the cylinder, and corresponding inlet and outlet valves are provided to control the air chambers defined on each side of the piston.
  • Each valve is movable towards and away from the respective valve seat as it moves between the open and closed position, and in some applications it is desirable to provide some form of resiliently deformable seal which is engaged by the valve as it moves to the closed position. In order for the seal to have a useful life, it is desirable to provide some means of actuation of each valve which minimises the impact of the closing force of the valve on the respective seal.
  • a hydraulic actuator for a cylinder valve which comprises: a cyclic hydraulic flow generator for producing repeated cycles of hydraulic flow output in which each cycle has an oscillating waveform; a master circuit communicable with said generator; a slave section communicable with said master circuit; a valve operator communicable with said slave section and connectable to a cylinder valve, said operator being operable in a release mode to move the valve away from its valve seat and in a valve-closing mode to move the valve towards its valve seat; and, valve means for controlling the flow of hydraulic fluid in the master circuit and the slave section and operable at predetermined time intervals within each cycle of operation of the generator in order to apply selected samples of the oscillating waveform of the generator output to operate the valve operator in at least one of its modes of operation.
  • the selected sample of the oscillating waveform of the generator output will be taken from a portion of the waveform in which the flow is reducing i.e. in a portion of the waveform between a peak and a succeeding trough.
  • each valve makes a relatively gentle engagement with its seal as it completes its closing movement, and this will enhance the working life of such seals and reduce maintenance costs.
  • the invention is not, however, restricted to use either in a positive displacement type compressor having soft seals, or indeed in a positive displacement compressor as such, but has general application to hydraulic actuation of cylinder valves of other types of engine (pumps or motors) having valve controlled fluid pressure chambers which are filled, pressurised and then discharge pressure fluid in repeated cycles of operation.
  • a hydraulically actuated cylinder valve which comprises: a valve seat; a linearly reciprocable valve element movable between open and closed positions with respect to the valve seat; a valve operator connected to the valve element and operable in a release mode to move the valve element away from its valve seat and in a valve-closing mode to move the valve element towards its valve seat; and, a hydraulic actuator circuit communicable with said valve operator and operable to apply or permit a closing motion of the valve element via the valve operator which reduces in speed as the valve element moves towards the valve seat and engages with the valve seat.
  • a valve seal may be provided which comprises a resiliently deformable seal which may be an O-ring or other soft packing, and which may be housed in- the closing face of the valve element, or in the portion of the valve seat engageable by a head of the valve element.
  • a resiliently deformable seal which may be an O-ring or other soft packing, and which may be housed in- the closing face of the valve element, or in the portion of the valve seat engageable by a head of the valve element.
  • a linearly reciprocating piston type compressor which comprises a cylinder, a floating piston mounted for linear reciprocation in said cylinder, a piston rod coupled with said piston and guided so as to control the reciprocating movement of the piston in said cylinder so as to be substantially without direct metal to metal contact with the internal wall of the cylinder, at least one cylinder valve for controlling the admission, or exhaust, of gas relative to the cylinder, a valve seat co-operable with said cylinder valve, a hydraulically operated actuator coupled with said cylinder valve and control means controlling the operator of the actuator so that it is operable to move the valve towards its valve seat, in sequence with the reciprocation of the piston, and with a speed which reduces as the valve approaches and then engages the valve seat.
  • this invention is not restricted to use in controlling at least part of the linear movement of a reciprocating working element e.g. in the form of a valve actuator stem which is just one preferred use, but may be applied to control the reciprocating movement of other working elements, such as stamps, punches and forging devices.
  • a hydraulically controlled actuator for controlling the reciprocation of a working element, said element being moveable in one direction in a working mode and in an opposite direction in a release mode
  • the actuator comprises: a cyclic hydraulic flow generator for producing repeated cycles of hydraulic flow output in which each cycle has an oscillating wave form; a master circuit communicable with said generator; a slave section communicable with said master circuit; an operator communicable with said slave section and connectable to said working element, said operator being moveable in one direction to operate the working element in one of its modes and being moveable in an opposite direction to operate the working element in the other of its modes; and valve means for controlling the flow of hydraulic fluid in the master circuit and the slave section and operable at predetermined time intervals in order to apply selected samples of the oscillating waveform of the generator output to operate said operator, whereby said operator can cause or allow the working element to operate in at least one of its modes of operation.
  • the valve means may be arranged to select any suitable samples of the oscillating waveform of the generator output, and in which each selected sample may be taken from more than one cycle of operation of the generator. Alternatively, a selected sample may be taken from a portion of each cycle of operation of the generator.
  • the hydraulically controlled actuator may be utilised to control the linear (or angular) reciprocation of many different types of working element, such as the working element of a punch, stamp or forging device.
  • the hydraulic circuit may be designed to provide any required linear speed/displacement profile of the reciprocating working element, to provide any required characteristics e.g. to provide any required acceleration/deceleration of the working element as it approaches a workpiece, or as it moves away from working engagement with the workpiece.
  • Figure 1 is a schematic illustration of a hydraulic actuator circuit for a cylinder valve according to the invention
  • Figure la is a detail of an alternative arrangement of part of the circuit shown in Figure 1 ;
  • Figure 2 is a series of graphs showing the operating cycles of the component parts of the circuit shown in Figure 1 ;
  • Figure 3 is a schematic illustration of a further circuit arrangement
  • Figure 4 is a schematic illustration of a still further actuator circuit arrangement according to the invention.
  • the invention has general application to the control of the linear movement of a reciprocating working element, and so as to provide any required profile of an acceleration/displacement graph and especially those parts of the graph corresponding to engagement with, and separation from a workpiece.
  • Figure 1 shows a hydraulic actuator circuit for a cylinder valve, which can be the inlet valve or the exhaust valve, and Figure 2 shows cycles of operation of the inlet and exhaust valves.
  • the hydraulic actuator shown in Figure 1 is intended to operate a cylinder valve, shown schematically by reference 10, and which comprises a valve seat 11, and a valve element 12 which is linearly reciprocable between open and closed positions with respect to valve seat 11, element 12 having a valve head 13 which is engageable with valve seat 11 when in the closed position.
  • a resiliently deformable valve seal may be provided, which may take the form of an O-ring or soft packing, and which is housed either in the closing face of head 13, or in a part of the valve seat 11 engaged by the head 13.
  • the hydraulic actuator which controls the linear reciprocation of valve element 12, will now be described in detail.
  • the actuator comprises a cyclic hydraulic motion generator for producing repeated cycles of hydraulic flow output having an oscillating waveform, and in the schematic illustration comprises a master cylinder 14 having a piston 15 which is driven back and forth within cylinder 14 under the action of a rotary crank mechanism 16.
  • the crank mechanism 16 will rotate in an (integral) proportional relationship to the operation of the cylinder whose valves are to be controlled, so that the inlet and exhaust valves can be operated at required time intervals during the induction, compression and exhaust stages of the air compressor i.e. for two revolutions of the compressor input, there will be a whole number of revolutions of master crank mechanism 16.
  • Each cycle of operation of the hydraulic flow generator has an integral number of peaks and troughs per compressor cycle, and in the illustrated arrangement has six peaks and troughs of a sinusoidal waveform, as can be seen at graphs b and c in Figure 2.
  • peaks and troughs of a sinusoidal waveform as can be seen at graphs b and c in Figure 2.
  • other shapes of waveform may be suitable i.e. not necessarily sinusoidal and input drive to obtain the required waveform may take other forms e.g. a rotary cam drive.
  • Graph 2a shows a graph of movement of piston 17 of compressor cylinder 18 and the selected intervals of operation of the inlet and exhaust valves during each cycle of operation of the compressor.
  • Figure 2a shows that the suction valve is closed from the "bottom dead centre" of the compressor 18 for 180° until it reaches "top dead centre". It should be appreciated that in practice it will be allowed to remain closed for a little time longer to allow the retreating piston 17 to decompress trapped air to atmospheric pressure before opening.
  • the master cylinder 14 of the cyclic motion generator is communicable with a master circuit 19 having flow and return lines which communicate with opposite ends of the master cylinder 14, and which include a valve-controlled bridging line 20 provided with a diverter valve 21 whose operation between open and closed positions is controlled as part of the operating sequence of the hydraulic actuator, as will be discussed in more detail below.
  • a slave section 22 is communicable with master circuit 19, and is connected to opposite ends of a slave cylinder 23 having actuator piston 24 coupled with the valve stem of valve element 12, and which thereby forms a valve operator which is operable in a release mode to move the valve element 12 away from valve seat 11 , and in a valve-closing mode to move the valve element 12 towards the valve seat 11.
  • valve means (21 ) The operation of the valve means (21 ) is controlled in such a way that the closing speed applied to the stem of the valve element 12 reduces as the head 13 approaches and then moves into engagement with the valve seat 11 i.e. at or near the end of the closing stroke of movement.
  • This minimises valve seat and valve wear and bearing in mind that this may be direct metal to metal contact, this will reduce noise and minimise metal fatigue and "pitting".
  • this enhances seal life, and therefore reduces maintenance costs.
  • the suction valve for instance (for maintenance, unloading or safety purposes) is on the outside, then a discrete force to resist the air pressure is needed during the compression strokes. Similarly, the exhaust valve may also need locking down if premature opening is not desired.
  • valves 21, 25 and 27, provide controlled application of selected portions only of the oscillating waveform produced by the master cylinder 14, in order to move the valve element 12 towards and away from the closed position, preferably a separate hydraulic pressure device is provided to maintain the valve element "locked" in the closed position when it has been moved to that position. Therefore, a high pressure source 26 is provided which is communicable with the slave section 22 via control valve 27, to apply a constant biasing force to piston 24 after the latter has been moved to the left upon completion of a closing movement under the control of valves 21 and 25 of the master circuit 19 and slave section 22.
  • the sequence of operation of valves 21, 25 and 27, for a typical cycle of operation will be described in more detail below.
  • Figure 2b shows the oscillating waveform produced by the suction valve master cylinder
  • Figure 2a shows the time intervals, during a cycle of operation, in which the suction valve carries out opening movement, as shown by the relatively short section 28 of the graph, and by longer section 29 in which the valve is maintained open (preferably by means of a small spring biasing force), followed by short section 30 in which valve closing movement takes place, followed by further longer section 31 in which the valve remains closed.
  • Figure 2b shows the oscillating waveform of the suction valve master cylinder, and the two marked samples of this waveform, shown by references 32 comprise short duration predetermined time intervals at which diverter valve 21 is closed, in order to initiate suction valve opening at section 28 and suction valve closing shown by reference 30 in Figure 2a.
  • FIG. 2c shows the oscillating (sinusoidal) waveform generated by the exhaust valve master, and very short predetermined selected sample of this waveform shown by reference 33 is the interval at which the diverter valve 21 of the exhaust valve master circuit is closed, it being understood that inlet valve master circuit has its own diverter valve 21 operated at predetermined short term intervals 32 described above with reference to Figure 2b.
  • the diverter valve 21 is only closed when valve 25 is open and control valve 27 closed, so that the piston 24 can move.
  • the high pressure from source 26 is used to keep the suction air valve closed during the compression stroke when, as is preferred, the air valve is located on top of the cylinder end plate which is convenient for some applications.
  • the master circuit and slave section described so far with reference to Figure 1 will be provided with replenishment lines and pressure relief lines, as shown schematically by reference 40 and 41 for the replenishment lines and relief lines respectively, and coupled with the master circuit 19, and operating in a manner which will be well known to those of ordinary skill in the art.
  • Figure 1 provides an arrangement for controlling the movement of actuator piston 24, and an alternative arrangement for diverter valve 21 is shown in Figure la, and as designated by reference 21a.
  • the valve 21a has an unload portion a, a dwell or by-pass portion b, and an actuating portion c. as shown.
  • the slave section is locked in position, rather than being free to move as would be possible in the case of valve 21 in the Figure 1 arrangement.
  • valve head 13 is free to move when acted on by external forces and can then be unloaded if e.g. biasing spring S is applied.
  • variable differential drive input may be provided (not shown), which enables variation in the sampled waveform.
  • other cyclic drive input may be provided e.g. a rotary cam drive.
  • control valves which are illustrated schematically will preferably be electrically controlled valves e.g. solenoid valves.
  • FIG. 3 An alternative circuit arrangement is shown in Figure 3, and in which parts corresponding with those already described are given the same reference numerals.
  • This is a "piggyback" type of arrangement, in which a double piston rod type of actuator has piston rods 1 and 2 of the same diameter, and respective pistons 24 and 24a. (In practice the area of piston 24a is much larger than the area of piston 24, for a purpose which is described subsequently). This is necessary, because otherwise short circuiting would not be possible, in that it would be self-locking.
  • the piston 24 therefore normally operates the valve element 13 under the control of the actuating circuit, and piston 24a idly follows the movement of piston 24. However, when the valve element 13 reaches the closed position, it can be locked in this position by energisation of the larger area piston 24a via its solenoid or mechanically controlled pressure circuit shown in Figure 3.
  • An objective of this arrangement is to avoid absorbing an unacceptable amount of energy.
  • the locking piston must travel forwards (to the left in the drawing). Then, when the locking pressure is switched on, it must not allow any more fluid than the compressibility of the fluid in volume 3 allows.
  • the master circuit and slave sections shown in Figure 1 provide a hydraulic actuator arrangement which is effective to operate the valve head 13 in both the valve-closing mode, and the valve-release mode.
  • the present invention is concerned with a hydraulic actuator arrangement which is capable of effecting operation (driving the movement) of a valve head (13) in at least one of its modes (valve-opening or valve-closing), or both modes, according to requirements.
  • a separate biasing or control arrangement e.g. a biasing spring may be provided to control the operation in the remaining mode with the hydraulic control being inoperative or rendered ineffective.
  • FIG. 4 A further arrangement of hydraulically operated control means according to the invention is shown in Figure 4, and will now be described in detail.
  • the master cylinder circuit and slave section described above with reference to Figures 1 to 3 comprise arrangements which allow a valve operator to be driven hydraulically in both of its modes of operation i.e. in a valve-closing mode and in a valve-opening mode as required.
  • the slave section comprises a slave circuit, which can apply a hydraulic actuating force to slave piston 24 in either mode of direction.
  • the circuit arrangement shown in Figure 4 includes a slave section i.e. not a complete circuit, and which is effective to drive the valve operator in one direction only. Spring or other biasing is provided to urge the slave piston of the valve actuator in an opposite direction i.e.
  • a master circuit is arranged to be pressurised by master piston 15, and is designated generally by reference 50, and includes a pressure line 51 which communicates at one end with one end of cylinder 14, on one side of piston 15, and at its other end with an opposite end chamber of cylinder 14 and on the opposite side of piston 15.
  • Pressure line 51 will transmit hydraulic fluid under pressure under the actuation of piston 15 in similar manner to that described above with reference to Figure 1 , but its effect on the actuation of the valve operator is via a solenoid controlled valve 52 and a slave section or line 53 which extends between suitable outlet of a housing of the valve 52 and an inlet 54 in the housing 55 a of a piston and cylinder type of valve actuator which controls the reciprocation of valve operating stem 55.
  • stem 55 has a valve head 56 which is located internally of compressor cylinder 57 having "floating" piston 58 mounted for linear reciprocation therein, substantially without metal-to-metal contact with the internal wall of cylinder 57 by reason of guidance of piston rod 59, in similar manner to that already described for the previous arrangement.
  • a biasing arrangement is provided to apply valve-closing movement to valve stem 55, and in the illustrated arrangement comprises a compression spring 60 housed within cylinder 55a and reacting against valve-operating piston 61.
  • a compression spring 60 housed within cylinder 55a and reacting against valve-operating piston 61.
  • Application of hydraulic pressure to chamber 62 in cylinder 55 i.e. the chamber defined on the opposite side of piston 61 to spring 60, will cause piston 61 to move to the left, as shown in Figure 4, in order to lift off the valve head 56 from valve seat 63 i.e. to drive the actuator in the release mode.
  • Figure 4 therefore shows an embodiment of the invention in which a slave section can be used, when pressurised by master cylinder circuit 50 via appropriate actuation of valve 52, to move the valve operator in a valve-opening direction.
  • the valve 52 will be operated under the action of its solenoid, and actuator cylinder 14 will be replenished, or altered to overflow in conjunction with a pressure controlled replenishing system (accumulator) 64.
  • accumulator pressure controlled replenishing system
  • a locking facility may be provided, generally similar to that described above for the other circuit arrangement, when the valve head is on the outside of the compressor.
  • the hydraulic circuit and the component parts thereof will be designed so that any required profile of any acceleration/displacement graph can be obtained for the working element concerned, and particularly the parts of the graph corresponding to engagement with, and separation from a workpiece.
  • the required profile at these parts of the graph may comprise rapid acceleration, or deceleration, according to requirements.
  • it may desirable for the working element to undergo rapid acceleration as it comes into contact with the workpiece whereas in other instances it may desirable for the engaging motion of the working element to be decelerating as it moves into engagement with the workpiece.
  • the separating movement of the working element e.g. as it commences its return stroke and moves out of engagement with the workpiece, may be controlled to be rapidly accelerating, or otherwise varied, to suit requirements..
  • a hydraulically controlled actuator having a cyclic hydraulic flow generator to produce repeated cycles of hydraulic flow output in which each cycle has an oscillating wave form; a master circuit communicating with the generator; a slave section communicating with the master circuit; an operator communicating with the slave section and connectable in any suitable way to the working element concerned and which operator can be moved in one direction to operate the working element in one mode and in an opposite direction to cause the working element to operate in the other mode; and valve means to control the flow of hydraulic fluid in the master circuit and the slave section and operable at predetermined time intervals to apply selected samples of the oscillating waveform of the generator output to operate the operator so that it can cause, or allow the working element to operate in at least one of its modes of operation.
  • the selected samples of the oscillating wave form of the generator output may be taken from more than one complete cycle of the wave form, or be a selected sample taken from one cycle, as may be required to provide a required profile of the acceleration/displacement graph of the working element.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Valve Device For Special Equipments (AREA)

Abstract

Un actuateur hydraulique (10) commande de fonctionnement d'une soupape de cylindre, dotée d'un siège de soupape (11) et d'un élément (12) de soupape pouvant aller et venir entre des positions ouverte et fermée par rapport au siège (11) de soupape, d'un joint de soupape logé dans la face d'obturation de la tête (13) de soupape, (ou d'une partie du siège (11) de soupape avec laquelle cette tête (13) entre en prise), d'un mécanisme de commande de soupape raccordé à l'élément (12) de soupape et de fonctionnement en mode d'ouverture, pour séparer cet élément de soupape du siège de soupape, et en mode de fermeture de soupape pour rapprocher cet élément de ce siège, ainsi que d'un circuit d'actuateur hydraulique (19, 22) communiquant avec le mécanisme de commande de soupape et imprimant un mouvement de fermeture à l'élément (12) de soupape par l'intermédiaire du mécanisme de commande de soupape, mouvement dont la vitesse diminue à mesure que l'élément (12) de soupape se rapproche du siège (11) de soupape et entre en prise avec le joint de soupape. Cet actuateur hydraulique convient particulièrement pour commander le fonctionnement d'une soupape de cylindre propre à un compresseur de type volumétrique doté de joints 'doux', même si on peut l'utiliser de façon générale pour la commande hydraulique de soupapes de cylindres propres à d'autres types de moteurs dotés de chambres de mise en pression de fluides commandés par soupapes, chambres qui sont remplies et mises en pression puis rejettent un fluide de pression lors de cycles de fonctionnement répétitifs.
EP96900641A 1995-01-20 1996-01-22 Actuateur hydraulique Withdrawn EP0804685A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
GBGB9501118.5A GB9501118D0 (en) 1995-01-20 1995-01-20 Hydraulically operated actuator
GB9501118 1995-01-20
PCT/GB1996/000127 WO1996022466A2 (fr) 1995-01-20 1996-01-22 Actuateur hydraulique

Publications (1)

Publication Number Publication Date
EP0804685A2 true EP0804685A2 (fr) 1997-11-05

Family

ID=10768313

Family Applications (1)

Application Number Title Priority Date Filing Date
EP96900641A Withdrawn EP0804685A2 (fr) 1995-01-20 1996-01-22 Actuateur hydraulique

Country Status (4)

Country Link
EP (1) EP0804685A2 (fr)
JP (1) JPH10512658A (fr)
GB (1) GB9501118D0 (fr)
WO (1) WO1996022466A2 (fr)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0017425D0 (en) * 2000-07-14 2000-08-30 Lotus Car A valve system for controlling flow of gas into or out of a variable volume chamber of an internal combustion engine or a compressor
AT413234B (de) 2002-09-19 2005-12-15 Hoerbiger Kompressortech Hold Hubkolbenkompressor und verfahren zur stufenlosen fördermengenregelung desselben
DE102012206834A1 (de) * 2012-04-25 2013-10-31 Siemens Aktiengesellschaft Aktorvorrichtung und Verfahren zum Einstellen einer Position eines linear beweglichen Elements
CN103742217B (zh) * 2013-12-28 2015-11-18 大连理工大学 一种用于6缸内燃机的模块化多功能可变气门驱动系统

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2135247A (en) * 1936-05-26 1938-11-01 Westinghouse Air Brake Co Compressor valve control
JP2664986B2 (ja) * 1989-04-03 1997-10-22 三菱重工業株式会社 内燃機関の動弁装置
GB9315383D0 (en) * 1993-07-24 1993-09-08 Carding Spec Canada Hydraulically actuated cylinder valve

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See references of WO9622466A2 *

Also Published As

Publication number Publication date
WO1996022466A3 (fr) 1996-09-12
WO1996022466A2 (fr) 1996-07-25
JPH10512658A (ja) 1998-12-02
GB9501118D0 (en) 1995-03-08

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