EP1331393B1 - Solenoid pump with hydraulic transmission - Google Patents

Abstract

Hydraulic drive system has a cylinder bushing (40) connected to a dosing piston pump (3) directly on its housing. A hydraulic working piston (1) slides into the bushing forming a component body. Preferred Features: Oil pumped through the dosing piston pump is guided in a closed air-tight circulation. The circulation for the oil drives the working piston in a double-acting function. The movement of the working piston is controlled by the magnetic strength of a magnetic coil (7). Recoil of the working piston is regulated and/or blocked by controlling the oil volume stream using corresponding adjusting parts (11).

Description

The invention relates to a hydraulic drive system with a Schwingankerkolbenpumpe according to the preamble of patent claim 1.

In such a rocking piston pump, a magnet surrounds a pump housing and generates an axial magnetic field which moves a sealingly displaceably mounted in the pump housing piston in a working space. The forward drive of the piston is effected by the applied magnetic field, while the return is effected by a corresponding return spring which acts on the piston.

With this known piston pump according to the Schwingankerprinzip results in the advantage of a relatively small structure, so that this known pump can be used for example as a fuel delivery pump.
However, it is not known that this pump is designed as a hydraulic drive system, so that the pump acts as an actuator with a working piston, for example.

By the same principle works in the rest of the DE 195 42 914 C2 , which works as a metering pump with an effective as a suction piston, against the force of a compression spring by exciting an electromagnet surrounding it centric movable anchor.

Even with this known metering pump, the connection to a hydraulically driven working piston is missing.

With the US 4,458,487 A there is disclosed an electromagnetic actuator utilizing a fluid pressure generated by an electromagnetic pump. A control member is provided in the pump that is removable in response to fluid pressure when the fluid is forced into a second chamber from a first chamber. The removable control part can operate a valve part or the like, which with this in an open-loop or a Proportional control associated with a long stroke in a Proven way.

With the US 4,201,522 A For example, there is disclosed a pump including a boost pressure increasing device including a cylinder connected between the suction side and the exhaust side of the pump. A slidable and reciprocable piston mating with the cylinder and a passageway communicates between the suction and discharge side sides divided by the piston. An adjustable spring biases the piston against the outlet side and a valve mechanism separates the outflow of the fluid from the outlet side to the suction side, the outflow occurring in response to movement of the piston to the suction side.

With the EP 0 065 011 A discloses a hydraulic valve drive, wherein the hydraulic pressure is generated by an electromagnetic pump. The drive includes an actuator for the simultaneous drive of a plurality of such valves. The device opens and closes a plurality of valves connected in series with a main passage via a single valve drive device and can drive a freely selectable proportional valve to achieve a safe pumping function.

The disadvantages of the above-mentioned inventions is that they have no modular structure in the sense of the present application (self-contained system structure of pump part and working cylinder part) and thus a simple replacement of cylinder housings is not guaranteed. Furthermore, in the present application, the use of a spring-loaded piston (see Item 52, Item 53) prevents harmful formation of air in the intake space (19).

Furthermore, the two cited references in the rest position of the working piston to a continuous flow of the hydraulic fluid, which represents a lower efficiency for the overall system according to the present application.

The invention is therefore the object of developing a hydraulic drive system such that an exchange of components is ensured due to a modular design.

To solve the problem, the invention is characterized by the features of claim 1.

In the following description of the invention, various embodiments are described as essential to the invention.

In a first embodiment, a backflow system is described, which is arranged between the pump piston of the pump system and the working piston of the hydraulic drive system. At the same time a specific valve control is claimed as essential to the invention.

In a second embodiment, a magnetically moved valve is described with a second coil instead of a mechanically moving valve, which essentially consists of a magnetically movable control piston.

In the third embodiment, a magnetically movable spool will be described.

• Variante Schiebekolben
• Das Kolbenteil ist als Schiebekolben in Funktion eines Wegeventils ausführbar. Dabei können die Kanäle in Förder- und Rückströmrichtung vertauscht werden, so dass der Arbeitskolben hydraulisch doppelwirkend betätigt werden kann.

Below some variants of the invention are described in short form:

• Variant sliding piston
• The piston part is executable as a sliding piston in function of a directional control valve. In this case, the channels can be reversed in the conveying and return flow, so that the working piston can be hydraulically operated double acting.

Flow rate and pressure variation

One of the possible variants and advantage of the system is, through different dimensions of the armature piston flow and pressure to vary. The design allows a very simple replacement of the magnetic coil body without interfering with the closed drive part. By using different coils, adapted electrical voltage and power requirements to the drive can be achieved.

Design variation of working piston

A variety of variants of the cylinder and working piston part in their dimension allows forces and speeds to adapt to the requirements.

Modular structure of the overall system

The entire system can be modular. Both pump part and working cylinder part are self-contained units and can be connected together in a modular system.

The presented here linear drive can be used separately as a non-claimed pump.

The scope extends to all applications where linear motion is required and any lifting and force requirement is to be covered.

Additions:

The suction can include an expansion element (spring-loaded piston, diaphragm, etc.), which applies a constant static pressure and thus on the one hand prevents harmful air formation in the suction and on the other hand takes into account the expansion behavior.

The subject of the present invention results not only from the subject matter of the individual claims, but also from the combination of the individual claims with each other.

In the following the invention will be explained in more detail with reference to drawings showing only one embodiment. Here are from the drawings and their description further features essential to the invention and advantages of the invention.

Figur 1:

Schnitt durch eine erste Ausführungsform eines hydraulischen Antriebssystems,

Figur 2:

Stirnansicht auf die Anordnung nach Figur 1,

Figur 3:

ein Teilschnitt aus der Anordnung der Figur 1 mit einer Abwandlung bei der Überleitung des Druckölstroms in das Antriebssystem,

Figur 4:

eine weitere Variante gegenüber Figur 3 mit einem magnetisch bewegbaren Steuerschieber.

Figur 5:

eine weitere Variante gegenüber Figur 3 mit einem magnetisch bewegbaren Steuerschieber und abgeänderten Pumpenkolben.

Show it:

FIG. 1:

Section through a first embodiment of a hydraulic drive system,

FIG. 2:

End view of the arrangement according to FIG. 1 .

FIG. 3:

a partial section of the arrangement of FIG. 1 with a modification in the transfer of the pressure oil flow into the drive system,

FIG. 4:

another variant opposite FIG. 3 with a magnetically movable spool.

FIG. 5:

another variant opposite FIG. 3 with a magnetically movable spool and modified pump piston.

In FIG. 1 In general, a rocking armature piston pump is shown, the pump housing is referred to as a tubular body 3. The magnetic drive takes place via a magnetic coil 7, which is radially on the outer circumference of the Tube body 3 is arranged. The tubular body is interrupted approximately in the middle region of the magnetic coil 7 by a non-magnetic central part 8.

On one side of the tubular body 3, a spring-loaded inlet valve 4 is arranged, which sucks the pressure oil from a suction chamber 19 arranged at the rear end side.

The suction chamber 19 consists essentially of a closure ring 51, which forms the suction chamber 19 inside, wherein for biasing the pressure oil in the suction chamber 19, a displaceable pressure piston 52 is arranged, which is displaced under the force of a spring 53 against the suction 19. In this way, it is always ensured that the pressure oil from the suction chamber 19 is biased in the direction of arrow 66 and flows over an associated inlet bore 29 to the inlet valve 4.

The inlet valve and an associated transverse bore 25 are hereby mounted in the rest in a fixed bearing part 17 in the tubular body 3. The pressure oil flowing in via the inlet valve 4 flows into the working space 18 behind the piston 6. This piston consists essentially of a front piston head and a firmly attached thereto piston rod 27 which carries at its rear end a transverse bore which is aligned in the position shown with a housing-fixed transverse bore 25 in the bearing part 17.

The piston head of the piston 6 is biased by means of a return spring 9 in the drawn rest position and acts in the working position against a fixed housing stop 31, which is part of a likewise housing-fixed bearing part 30.

With a corresponding magnetic loading of the magnetic coil 7, therefore, the piston 6 in the indicated arrow direction 67 in the piston chamber 20 moves and compresses the pressure oil located there against a pressure valve 5, which is opened accordingly.

The pressure oil enters the valve bore 33 of the pressure valve 5, overcomes the valve spring and reaches the rear of a piston 11, which serves as a control piston.

It is important that the control piston 11 radially outwardly forms a liquid-conducting gap 22, so that the pressure oil flows through this gap 22 axially forward into the arranged in front of the piston 11 piston chamber 21.

The piston 11 is in this case held by a return spring 15 in its closed position and is moved with appropriate action with a pressure surge in the axial direction forward against the force of the return spring 15.

This piston 11 is fixedly connected as a unit with a pipe section 12, which engages in an associated guide bore 68.

Furthermore, the piston 11 carries on its front side an axially forward approach with a return flow 13, which is associated with a counterbore 23 in the tubular body 3.

The piston 11 together with the front-side front projection and the rear pipe section 12 is completely penetrated by an axial bore.

Upon impact of a pressure surge from the pressure valve 5 on the back of the piston 11, this is thus moved axially to the left against the force of the return spring 15 and the front, frontal approach with the axial Through hole so that it dips sealingly into the housing-fixed counterbore 23 and is sealed there.

Thus, no return flow in the suction via the axial channel and the adjoining transverse bore 32 and 25, and 26 can be done.

Rather, the pressure oil flows through the transverse bore 69 into the connecting piece 34 into the cylinder liner 40 of the hydraulic drive system.

The pressure oil is conveyed by the connecting piece 34 in the direction of arrow 43 into the rear cylinder chamber 43 and acts there on the back of the piston part 41, which is sealingly guided in the cylinder chamber 39.

Thus, the entire working piston 1 is moved in the direction of arrow 70 to the outside and acts on a non-illustrated return spring. 2

From the cylinder chamber 39, the displaced pressure oil is conveyed via the transverse bore 71 in the longitudinal channel 38 and flows there in the direction of arrow 44 back in the pump housing 40th

About the connector 37, the returning pressure oil enters the return flow channel 36 in the tubular body 3 of the pump housing and flows directly into the suction 19th

In addition to the above-mentioned large return flow channel, there is still the small return flow channel, which essentially results from the transverse bore 32 and the subsequent return flow channel 24 in the pump housing of the pump.

Namely, when stopped piston pump, the working piston 1 in the opposite direction to the arrow 70 runs back, the pressure oil located in the working space 42 must flow in the opposite direction to the arrow 43 through the local channel and the connector 34 into the plenum 19 back. This is achieved in that this pressure oil now flows over the transverse bore 69 in the front piston chamber 21, where it enters the end face of the return flow 13 on the piston 11, flows through the piston in the axial direction and enters the transverse bore 32 at the rear.

From there, the oil flows back via the said return flow channel 24 into the storage room. In this case, however, a further valve control is provided, which only allows a backflow when, on the one hand, the piston 11 is in the drawn rest position and on the other hand, the piston 6 is also in the rest position.

For this case, namely, the housing-fixed transverse bore 25 connects the piston rod 27 arranged in the movable piston 6, so that the oil enters via the arranged in the piston rod 27 transverse bore in the housing-fixed longitudinal bore 26 and flows from there into the storage room 19.

This would be the case even if the piston 11 with the tube piece 12 arranged therein on the working side would have no device for regulating the blocking time for the reflux of the oil via this return path. In this case, the oil reflux during the bottom dead center of the piston 6 and the piston rod 27 would be so large that at least a portion of the currently subsidized oil would flow back through this path, and thus would counterproductive effect for the advance of the working piston. This results from the vibration system consisting of the mass of the piston 6 with its individual parts, the spring force of the return spring 9 and the magnetic force of the magnetic coil 7, which performs the drive work.

To prevent this, a device is provided according to the invention, which provides a certain, by appropriate dimensioning of the parameters involved, spring force and effective flow of the oil, adjustable dead time for the release of the return line. Thus, taking into account the static and dynamic characteristics of the system, it is possible to control, if at all, and if so, how much oil can flow back through the return lines. Preferably, it is provided that no oil during the bottom dead center of the piston 6 flows through the transverse bore 25, since this would affect the feed of the working cylinder 1. This would be excited to swing. However, should a vibration behavior be desired, then the reflux can of course be regulated so that the working piston 1 undergoes at least one superimposed vibration in its drive movement.

The regulation of this dead time is now realized in the present invention in a preferred embodiment by the execution of the piston 11 with the associated components and functions.

In order to realize a corresponding dead time control in the return line of the oil, an actuator has been developed according to the invention, which is designed in the form of a piston 11 with valve function. A large part of the per stroke of the pump piston 6 to be conveyed oils is conveyed through the disposed in the piston 11 through hole 12 (pipe section), which due to the effective cross section, the oil by the significantly lower resistance to the gap 22 towards the working piston first examined. Only when the piston 11 is immersed with its return flow opening 13 in the counterbore 23, oil will continue to flow through the gap 22 in the space 21 and from there into the connecting piece 34 back to the working piston.

The main line for the return flow, the pipe section 12 is thus ineffective. About this connection can not flow until the return flow opening 13 is released again. This release can now be regulated by influencing the respective parameters. Thus, it can be determined exactly when the pipe section 12 is switched again oil-tight.

Furthermore, by appropriate parameterization and the displacement of the individual pistons 6, 11, 1 are affected, so that they do not perform the full stroke, for example, and thus not collide with the enstprechenden end faces with the associated surfaces. As a result, an enormous noise reduction is possible, and to the extent that the entire hydraulic drive system works almost noiselessly.

Generally, it is also stated that the regulation of the dead time for the backflow of the oil does not necessarily have to be effected by a so-called control piston / cylinder, as here the piston 11. There are also various other options. So z. B. in another embodiment, the control cylinder 57 in the FIG. 4 described, who also works in this #weise. The execution in the FIG. 3 shows a solenoid-operated control piston 56, which also performs this function. Further, corresponding embodiments are thus within the scope of the invention.

It should also be noted that in order to move the piston 6 at all magnetically, it is provided on the outer circumference with a magnetic ring 28 which cooperates with the magnetic field of the magnetic coil 7.

The magnetic ring 28 may also form a unitary body together with the piston head and the piston rod.

There is another operating case, in which it is provided that the piston 6 remains against the force of the spring 9 in its shifted to the left position when it is accordingly acted upon by the magnetic coil 7. In order to avoid a backflow for this operating case, it is provided that then the transverse bore in the piston rod 27 is no longer aligned with the housing-fixed transverse bore 25 in the bearing part 17, and thus the return flow is shut off.

In the drawing, it is merely stated that the front, hydraulic drive system 35 is connected to the working piston 1 via said connecting pieces 37 and 34 releasably connected to the tubular body 3 of the pump housing.

The modular structure (pluggability) of the two parts is preferred because it allows easy replacement of the front drive system 35. This allows different working piston 1 can be used with different strokes.

The connection of the two parts takes place in the rest by an attached on the front side of the cylinder liner 40 screw 49 which is screwed into an associated threaded bushing 50 on the pump housing of the tubular body 3.

The front working piston 1 is otherwise firmly connected to a piston neck 45 which is sealingly guided in the cylinder liner 40.

The piston boss 45 forms a reduced diameter neck by providing a vent bore 46. This vent hole opens into the atmosphere. The stop of reduced diameter cooperates with a housing-fixed stop 47 in the cylinder liner 40. Incidentally, the working piston 1 is sealingly guided in the longitudinal direction in a sealing manner in a front-side guide part 48 of the cylinder head 40.

It is important that in the inventive pump when sucking always a constant volume is present, because by the bias voltage with a pressure piston 52 of the suction chamber 19 and the hydraulic oil located there is always kept under a certain bias. There is no moving volume, and the oil is not removed from a free tank but kept locked up.

Regardless of this constant volume in the suction chamber 19, which is held under spring bias, the working piston 1 can move according to the operation of the metering and pump different fluids displace.

The FIG. 2 shows generally the front view of the arrangement, where it can be seen that the magnetic coil 7 centrally forms a Innenbohrugn 54 which is slid over the tubular body 3 of the pump system.

The FIGS. 3 and 4 now show modifications of the control valve system FIG. 1 , Here is how the in FIG. 1 shown piston 11 can be replaced by other controls.

The FIG. 3 in this case shows a magnetically driven control piston 56 which is acted upon by its own magnetic coil 55. In this case, a magnetic separation 65 is again arranged in the pump housing in order to avoid a short circuit of the magnetic field.

Accordingly, the control of the solenoid 55 so that the control piston 56 is moved in the axial direction against the force of the return spring 15 back and forth.
The control piston 56 then abuts against a housing-fixed end face 14.

For the sake of clarity is still as another variant of the return control in the FIG. 1 already described pipe section 12 shown with the axial through hole, which sealingly - depending on the displacement position of the control piston 56 - dips into an associated blind bore 23 in the housing-fixed part and thus closes the axial through hole.

Alternatively, however, an axial through hole 72 is provided in the control piston 56, which is associated with an associated, spring-loaded valve 73.

This valve opens into a through hole 74 and this in turn into the front piston chamber 20 of the pump.

If the piston of the pump, which is not shown in more detail, demands pressure oil in the direction of the arrow to the left, this pressure oil passes through the through-bore 74 and overcomes the valve 73 through the through-bore 72 in the control piston 56 and passes via the connecting pin 34 into the drive system 35.

At the same time the return flow is closed with the pipe section 12, because the front, end-side end is immersed in the blind bore 23.

In the rest position of the control piston 56, the reverse case applies. The valve 73 is closed, and there is a backflow over the Connector 34 and the now open axial bore in the pipe section 12 and the transverse bore 32 into the suction 19th

The valve holes complementary to each other in the transverse bearing bores 25 in the housing-fixed bearing part 18 and the associated transverse bore in the piston rod 27 is then no longer necessary.

The FIG. 4 shows a further variant of a corresponding piston control, wherein also a magnetically movable spool 57 is used, which is driven by a magnetic coil 55.

Before the piston chamber 20, the bearing member 30 is arranged, which has the valve bore 33 through which the pressure oil generated by the piston, not shown, in the direction of arrow overcomes the pressure valve 5.

This pressure oil first enters the working space 75 in front of the spool 57, wherein the spool is held by a return spring 58 in its left end stop.

If, however, the spool 57 is activated by the solenoid, then it takes its first control position. In this position, the pressure oil in the working space 55 flows via the center channel 59 and an associated transverse bore into a housing-side transverse bore 76 adjoining it, from where the pressure oil flows in the direction of the arrow 77 into the drive system 35.

In this way, the pressure oil is fed into the drive system 35.

The return flow of the oil from the drive system via the connecting piece 37, which is connected via transverse bores with the return flow channel 36. This is again fluid-conducting with a Cross channel 60 connected, which is fixed to the housing. This housing-fixed transverse channel 60 is a corresponding - arranged in the spool 57 - transverse bore 61 opposite, so that in the activated position of the spool 57, a return flow through the transverse bore 61 into the spool 57 into and over the centrally disposed transverse channel 62 in the spool 57 in a in the pump housing fixed to the housing arranged longitudinal channel 78 flows back into the suction chamber 19.

The advantage of this design is that the valve control described in the exemplary embodiment in conjunction with the piston rod 27 can be dispensed with and the entire control of the return flow already takes place in the region of the control slide 57.

Incidentally, this is also the advantage of the embodiment FIG. 3 ,

The other displacement position of the spool 57 allows a comparison of the housing-fixed transverse bore 64 to an associated, arranged in the spool, transverse bore 63rd

Thus, when the spool 57 is in its left stop position, thus comes the transverse bore 64 in accordance with the transverse channel 63 and the pressure oil flows in the axial direction to the left (arrow 79), wherein the working piston 1 performs a backward movement.

Depending on the position of the spool 57 can thus be supplied to the working piston 1 on its front or its back with pressure oil.

It is incidentally according to the embodiment FIG. 1 added that arranged in the pipe section 12 of the piston 11 bore is referred to as a guide bore 68.

With the integrated pump and piston system in a piece of pipe a simple space-saving and therefore inexpensive drive system has been created. The easy interchangeability of the solenoid allows to quickly meet other performance specifications.

The FIG. 5 shows a further variant of the present invention, which compared to the embodiment in FIG. 3 equipped with a magnetically movable spool and modified pump piston.

In this embodiment, with spool 57 is the anchor part with piston 27, in contrast to previously mentioned embodiments in the suction chamber 19 and conveys the oil via the inlet valve 4 in the pressure chamber 20 and from there via the Druckvenitl 5 via the spool 57 in a working cylinder. The special feature of this embodiment is that while the pressure chamber 20, the inlet valve 4, the pressure valve 5 and the return flow channel 24 can be integrated in one component, and thus consuming return flow channels in the tubular body 3 can be omitted.

In summary, it is noted that the system comprises in a first embodiment, four pistons, which are responsible for the oil supply and power transmission. These are the piston 52, which is responsible for the permanent pressurization of the system, and thus ensures that the closed oil system works almost air entrapment, the piston 6, which is responsible for the compression and promotion of the oil, the piston 11, the is responsible for controlling the flow of oil, and finally the working piston 1 with its effective piston part 41 for the effective linear movement to be generated.

Due to the fact that the entire system is formed in each embodiment as a closed oil system, there is the advantage in the present technical teaching that virtually no blistering and thus inevitably associated problems are prevented by air pockets in the oil. Thus prevents the system structure as a double-acting cylinder 1 the usual manner occurring problems due to air entrapment, for example in the form of blistering due to free flow of the returning oil into the tank or suction of the system. Thus, there is the advantage that the system has a permanent frictional connection, whereby a continuous linear movement of the working piston is ensured, and are not caused by air inclusions fluctuations in the delivery volume, which cause abrupt movement states.

Made possible by the technical teaching of the present invention, a targeted, adjustable in their speed provision of the working piston. The adjustment is carried out by dimensioning the pipe cross-section of the oil. By influencing the cross section is controlled according to the refluxing volume flow, which can ultimately affect the return speed.

The training as a double-acting cylinder is done by means of two appropriately controllable oil passages in the system designed as a pipe. This means that the piston part 41 of the working piston 1 is surrounded by oil on both sides. The oil in the front / outer part of the cylinder 39 is, caused by the outward movement of the piston member 41, pressed by the transverse bore 71 in the return system and so immediately fed back to the suction chamber 19, whereby the oil circuit is closed air-free. When returning the working piston 1, the oil flow takes place in the reverse direction. However, according to the technical teaching, there is the possibility of influencing the volume flow to control by the reset speed in the desired manner.

An influence on the feed of the working piston 1 is also provided according to the technical teaching of the present invention. These can be done by adjusting the magnetic coil force on the piston 6 promoting the oil. The control is carried out in such a way that the maximum feed rate at 100% delivery stroke takes place, and a reduction of the delivery to corresponding less than 100% accordingly also a reduced feed movement result, which also reduces their speed due to the known relationships.

The reduction of the delivery stroke takes place through the use of a correspondingly weaker selected magnetic coil 7, which is able to move the piston 6 only partially along its maximum working travel.

The already extensively described control of the oil flow can now take place in various embodiments of the present invention in various ways. Once, as just listed again, by means of the oil pressure itself controlled piston 11 in cooperation with the corresponding valves, inlet 4 and outlet 5, which are designed here as check valves. In addition, the restoring spring 15 and the position of the piston 6 conveying the oil act on it, so that the return speed can only be controlled by influencing the position of the piston 6.

However, the control of the piston can also be done by means of spring force and / or magnetic force.

Once again, the control by means of a two-way valve, referred to here as a spool valve 57, and the check valves 4, 5 is performed. This spool causes the oil supply to feed, lock and return the working piston 1. The spool can be operated by means of oil pressure and / or spring force and / or magnetic force to exert the desired control function.

drawing Legend

1

working piston

2

Return spring

3

Tubular body (pump)

4

intake valve

5

pressure valve

6

piston

7

solenoid

8th

midsection

9

Return spring

10

pipe section

11

piston

12

pipe section

13

return flow

14

face

15

Return spring

16

17

bearing part

18

working space

19

suction

20

Piston chamber (front)

21

Piston chamber (rear)

22

Gap (piston 11)

23

counterbore

24

backflow

25

cross hole

26

longitudinal bore

27

piston rod

28

magnetic ring

29

inlet bore

30

bearing part

31

Stop (bearing part 30)

32

cross hole

33

valve bore

34

joint

35

drive system

36

backflow

37

joint

38

longitudinal channel

39

cylinder space

40

cylinder liner

41

piston part

42

cylinder space

43

arrow

44

arrow

45

piston extension

46

vent hole

47

attack

48

guide part

49

screw

50

threaded bushing

51

lock ring

52

pressure piston

53

feather

54

internal bore

55

solenoid

56

spool

57

spool

58

Return spring

59

center channel

60

Querkanal

61

cross hole

62

Querkanal

63

Querkanal

64

cross hole

65

magn. separation

66

arrow

67

arrow

68

guide bore

69

cross hole

70

arrow

71

cross hole

72

Through Hole

73

Valve

74

Through Hole

75

working space

76

cross hole

77

arrow

78

longitudinal channel

79

arrow

Claims (12)

1. Hydraulic drive system having an oscillating armature piston pump with magnetic drive, wherein adjoining a metering piston pump (3) on the housing thereof directly sealing and axially oriented a cylinder sleeve (40) is connected, in which at least one hydraulically movable working piston (1) is displaceable, so that together they form a continuous structural part member and for pretensioning the hydraulic fluid in the intake chamber (19) a displaceable pressure piston (52) is arranged, which is displaced under the force of a spring (53) towards the intake chamber (19), characterised in that the hydraulic drive system (35) is detachably connected to the tubular member (3) of the pump housing via connecting pieces (37) and (34).
2. Hydraulic drive system according to claim 1, characterised in that the magnetic coil (7; 55) is arranged in easily exchangeable manner on the outer circumference of the pump housing.
3. Hydraulic drive system according to one of claims 1 or 2, characterised in that the oil pumped by the metering piston pump (3) is carried in a closed, air-free circuit.
4. Hydraulic drive system according to any of claims 1 to 3, characterised in that the circuit for the oil drives the working piston (1) in a double-action function.
5. Hydraulic drive system according to any of claims 1 to 4, characterised in that the advancement of the working piston (1) can be controlled on the basis of the magnetic strength of the magnetic coil (7).
6. Hydraulic drive system according to any of claims 1 to 5, characterised in that the resetting of the working piston (1) by control of the oil volume flow rate can be regulated and/or blocked on the basis of corresponding controlling elements (11; 56; 57).
7. Hydraulic drive system according to any of claims 1 to 6, characterised in that the controlling elements (11; 56; 57) are actuated by means of magnet and/or oil pressure and/or spring force.
8. Hydraulic drive system according to any of claims 1 to 7, characterised in that the stroke of each conveying or control element (6; 11 ; 56 ; 57) in the system can be set by appropriate parametrisation of the effective components in such a way that it does not strike by the end face against the associated component.
9. Hydraulic drive system according to any of claims 1 to 8, characterised in that the feed and return lines for the oil are carried in part in the walls of the tubular member (3) and of the working cylinder (40).
10. Hydraulic drive system according to any of claims 1 to 9, characterised in that the pressure liquid is delivered by the oscillating armature piston pump (3) directly in the axial direction and is fed conveying liquid into the pump housing (40) of the hydraulic drive system.
11. Hydraulic drive system according to any of claims 1 to 10, characterised in that the oscillating armature piston pump is constructed in modular fashion.
12. Hydraulic drive system according to any of claims 1 to 11, characterised in that it is possible in simple manner to transmit different drive powers for the pump piston or to exchange defective coils, without it being necessary for the system to be completely dismantled.

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