EP1260715A1 - Positioning unit actuated by pressurised fluid - Google Patents

Abstract

The actuator device has a pressurized medium delivery device (20) that takes up a volume of medium during a first partial stroke of a working piston (2) in a second pressurized medium chamber (D2) and delivers a volume of the medium during a second partial stroke of the piston, whereby the delivered or taken up quantities are dependent on the amplitudes of each partial stroke. Independent claims are also included for the following: a unit containing an inventive device for fitting in a rotary system of a helicopter's main rotor and a helicopter rotor blade controller.

Description

The invention relates to a pressure medium actuable Actuator arrangement in particular for use in a helicopter rotor blade control according to the generic term of Main claim.

Such an actuator arrangement is particularly suitable for use in a single blade control for helicopter rotor blades, a higher harmonic rotor blade control or also in a system for active structure excitation.

Such actuator systems have very high requirements in terms of weight, installation space and power requirements. However, high forces must be transferred can, while maintaining a high positioning accuracy got to. In particular with a rotor head in which each rotor blade at least one of your own actuators is assigned ensure that a neutral position once adjusted does not change during operation. Because there are leaks in one never completely prevent hydraulic pressure medium system measures must be taken to ensure compliance with the Ensure neutral position. See previous approaches an electro-hydraulic control circuit. With this the position of the actuator is constantly measured and with compared to a target position. In the event of a target deviation becomes a control signal for controlling a leakage compensation valve issued, which is a pressure medium compensation volume feeds or discharges. Such a control system is extremely complex, however. For warranty The security of electronic systems must be high Effort.

In DE G 89 09 165.5 is a pressure fluid operated Actuator arrangement for rotor blades shown, in which a Working piston guided in an actuating cylinder on both sides is pressurized and by pressure medium volume flows, the pressure medium spaces arranged on both sides of the piston can be fed or removed, axially movable is. To generate the pressure medium volume flows a displacement body arrangement is provided, which with a adjustable control cam system with several adjustable Control elements cooperates. When the Rotors, the displacement bodies perform harmonious lifting movements for the generation of pressure medium volume flows. The Pressure medium volume flows are via a line system Supplied. The cam elements of the cam system are in accordance with the rotor blade arrangement angularly displacers scanned, which are assigned to the respective rotor blades are. Accordingly, not every actuator is an independent one Tax system assigned. Leaks at the actuators different rotor blades have different values can, therefore, can not easily from the central Encoder system can be compensated.

The invention has for its object to be a pressure fluid operated Actuator arrangement specify the one time adjusted neutral position during operation with high Adheres to accuracy.

According to the invention, this object is achieved by one, too the characteristics of the characterizing part of the main claim having, pressure fluid actuated actuator arrangement solved. Advantageous configurations and uses of the Invention, are given by the subclaims.

A back and forth movement between a first end position and a second end position of the guided in the actuator cylinder Working piston consists of a first and a first second partial stroke movement together. One corresponds to Moving back and forth from neutral the first end position and back a first partial stroke movement and a reciprocation from the neutral position in Direction of the second end position and back of a second partial stroke movement. The working piston is supported from two sides Pressurized, with each side a pressure medium space assigned. The first pressure medium space points in the first End position a minimal volume and the second pressure medium space in the second end position.

According to the invention is now a pressure medium delivery device provided that in the first partial stroke movement of the Working piston the second pressure medium volume a pressure medium takes and that in the second partial stroke movement volume of the working piston to the second pressure medium space supplies. The pressure medium delivery device the second pressure medium space supplied or removed Pressure medium volumes are dimensioned so that the same volumes are supplied or removed as long as the harmonious lifting movement of the working piston around the neutral position done around. If a leak occurs, the one Emigration of the working piston from the neutral position to As a result, it follows that the amplitude of a partial stroke movement is increased while the amplitude of the other Partial stroke movement is reduced. The amounts of the funded Volumes depend on the amplitudes of the partial stroke movements. The difference in amplitude between the partial stroke movements has the consequence that the second pressure medium space at Piston emigrated from the neutral position a period of pressure medium is added or removed. This ensures that the correct neutral position is taken up again by the actuator.

Is the pressure medium delivery mechanism mechanically through Transmission means coupled to the working piston, can the power consumed by the pressure medium delivery device tapped directly from the movement of the working piston become. It is not another tax or utility facility necessary for the pressure medium delivery device. The actuator arrangement with the pressure medium delivery device can then be used as a quasi self-sufficient unit be used which are very good for installation in a rotating System of a helicopter main rotor is suitable. at a helicopter rotor blade control for several, evenly rotor blades arranged on the circumference of a rotor hub, is advantageously each rotor blade at least one Assigned actuator arrangement according to the invention. Each of the Actuator arrangements maintain their neutral position once set with high accuracy, which is why a combination with an encoder system in the form of a hydraulic displacement control, which are arranged in the rotor head of the helicopter is particularly advantageous. Regarding the construction and the interconnection of the hydraulic displacement control reference is made to DE G 89 09 165 mentioned at the beginning, the content of which is disclosed in the disclosure of the present application to be recorded with.

Between the piston rod arrangement of the working piston and the rotor blades of the rotor head are transmission means provided so that the setting angle movement controlled can be.

Fig. 1

eine schematische Darstellung einer ersten Ausgestaltung einer erfindungsgemäßen Stelleranordnung,

Fig. 2

einen zeitlichen Verlauf einer Stellerbewegung und der zugeordneten Druckmittelvolumenströme der Druckmittelfördereinrichtung in Neutralstellung,

Fig. 3

einen zeitlichen Verlauf einer Stellerbewegung und der zugeordneten Druckmittelvolumenströme der Druckmittelfördereinrichtung bei einer Abweichung von der Neutralstellung und

Fig. 4

eine schematische Darstellung einer zweiten Ausgestaltung einer erfindungsgemäßen Stelleranordnung.

Further advantageous embodiments of the invention are explained with reference to the accompanying drawings. Show:

Fig. 1

1 shows a schematic representation of a first embodiment of an actuator arrangement according to the invention,

Fig. 2

a time course of an actuator movement and the associated pressure medium volume flows of the pressure medium delivery device in the neutral position,

Fig. 3

a time course of an actuator movement and the associated pressure medium volume flows of the pressure medium delivery device in the event of a deviation from the neutral position and

Fig. 4

is a schematic representation of a second embodiment of an actuator arrangement according to the invention.

In Fig. 1, 2 denotes a working piston guided in an actuator cylinder 4. The working piston 2 separates a first pressure medium chamber D1 from a second pressure medium chamber D2 in the actuator cylinder 4. The pressure medium chamber D2 is connected via a line 6 to a controllable, hydraulic sensor system 8. The hydraulic transmitter system 8 can consist of a controllable pump or, advantageously, of a hydraulic displacement control, as is disclosed in DE-G 89 09 165. The first pressure medium chamber D1 is connected via a line 10 to a pressure medium source 12 with at least approximately constant pressure, which can be designed, for example, as a pressure-controlled pump. This produces a hydraulic preload so that the actuator arrangement can absorb forces in two directions, although only the second pressure medium space D2 is actively controlled. As a result of a positive volume flow Q _P from the transmitter system 8 to the pressure medium chamber D2, the working piston 2 executes a movement to the right with the piston rod 14. A negative volume flow Q _P causes the working piston 2 and the piston rod 14 to move to the left. The volume compensation of the pressure medium space D1 takes place via the line 10 to the pressure medium source 12.

In Fig. 1, the working piston 2 is in its neutral position shown, in which the deflection x is 0. The neutral position is the middle between a first one End position 16 and a second end position 18 between those of the Piston is axially movable. In the first end position 16 points the first pressure medium space D1 has a minimal volume on and in the second end position 18, the pressure medium space D2 minimal volume.

To explain the invention is a reciprocation from the neutral position towards the first End position 16 and back as a first partial stroke movement and a back and forth movement from the neutral position towards the second end position 18 as a second partial stroke movement designated.

Occur in the connected to the pressure medium space D2 Pressure medium system leaks out of the system , this led to an unwanted emigration of the working piston 2 to the left. To avoid this is a Pressure medium delivery device 20 is provided, which at the first partial stroke movement of the working piston 2 the second Pressure medium space D2 takes a pressure medium volume and the in the second partial stroke movement of the working piston 2 supplies a pressure medium volume to the second pressure medium space D2. As long as the working piston 2 has a harmonious movement executes the neutral position, they are the pressure medium room D2 supplied or withdrawn volumes over a Period of movement of the working piston 2 compensated. If the working piston is in relation to the neutral position, during a period too far to the right, the first partial stroke movement carried out with an increased amplitude, while the second partial stroke movement with a reduced one Amplitude is executed. As a consequence, that the pressure medium delivery device 20, over the full Seen period, the pressure medium space D2 a compensation volume extracts. As a result, the center position of the piston corrected in the direction of the neutral position.

In the embodiment shown in FIG. 1, a pressure medium volume Q _{D1 is also} supplied to the first pressure medium chamber _D1 during the first partial stroke movement of the working piston 2 and a pressure medium volume is withdrawn from the first pressure medium chamber _D1 during the second partial stroke movement, with a deviation from the neutral position in turn over a period a compensation volume is promoted, which corrects the central position of the piston in the direction of the neutral position.

The pressure medium delivery device 20 comprises a first one Delivery cylinder 22 and a second delivery cylinder 24. A working volume V1 of the first delivery cylinder 22 is through a line 26 to the second pressure medium space D2 connected. A one-way valve is arranged in line 26, permeable towards the first feed cylinder 22 is. The working volume V1 of the first delivery cylinder 22 is through a line 29 also with the first Pressure medium chamber D1 connected. In line 29 is a biased one-way valve 30 arranged in the direction away from the first delivery cylinder 22, towards the pressure medium space D1 is permeable.

A working volume V2 of the second delivery cylinder 24 is through a line 32 to the first pressure medium space D1 connected. A one-way valve 34 is arranged in line 32, that towards the second feed cylinder 24 is permeable. Line 36 connects the work volume V2 of the second delivery cylinder 24 with the second Pressure medium room D2. In line 36 is a biased one One-way valve 38 arranged in the direction away from the second delivery cylinder 24 permeable to the pressure medium chamber D2 is. The preload of the preloaded one-way valves 30, 38 is so large that it is not due to the in the Pressure medium spaces D1, D2 prevailing pressure levels can be.

The feed cylinders 22, 24 each have a piston 40, 42 on. The end faces 44, 46 of these pistons 40, 42 are with the prevailing in the feed cylinders 22, 24 Pressurized. The amount of end faces 44, 46 is significantly less than the amount of the end face 48 of the working piston 2. An advantageous value for the The amount of end faces 44, 46 is 3% of the amount of End face 48. This makes it possible via the plunger 50, 52, which are connected to the pistons 40, 42 at low actuation forces to build up high pressures that Overcome the preload of the preloaded one-way valves 30, 38. According to the size ratio of the end faces are also the equalizing volume flows from the delivery cylinders 22, 24 small compared to those generated by the encoder system 8 Volume flows. Correcting a deviation of the working piston from the neutral position is therefore very sensitive and exactly.

During the first partial stroke movement, i.e. during one Movement of the working piston 2 from the neutral position the piston is in the direction of the first end position 16 40 of the first feed cylinder 22 to the movement of the Working piston 2 coupled. The plunger 50 is located here its left end on the axial stop surface 54 of the Driver 56 on. The driver 56 is from the Piston 40 acting pressure against the axial stop surface 54 pressed.

During the piston 40 of the first delivery cylinder 22nd thus follows the first partial stroke movement of the working piston, is the piston 42 of the second feed cylinder 24 of the Decoupled movement of the working piston. He remains in his right end position, the axial stop surface 58 of the Driver 60 is lifted, so no longer with the plunger 52 is in contact. Only when the working piston 2 again has reached its neutral position and from there to the left is moved, the plunger 52 is again on the axial stop surface 58 at.

During the second partial stroke movement is quite corresponding the piston 42 of the second feed cylinder 24 to the Movement of the working piston 2 coupled while the piston 40 of the first delivery cylinder 22 is decoupled.

The neutral position of the working piston 2 in the actuator cylinder 4 can be easily adjusted in that Adjusting means for adjusting the position between the pistons 40, 42 of the feed cylinders 22, 24 and the axial stop surfaces 54, 58 are present. This is the axial position the driver 56, 60 adjustable on the piston rod 14. Alternatively, however, the plungers 50, 52 can also be used Length changeable by a threaded connection or the like his.

An actuator arrangement provided in this way with adjusting means allows a very simple adjustment of the setting angle of the individual rotor blades of a helicopter rotor when tracking.

In FIG. 1, Q _D1 denotes the volume flow that is supplied to the first pressure medium space D1 by the pressure medium delivery device 20 and Q _D2 the pressure medium volume flow that is supplied to the pressure medium space D2 by the pressure medium delivery device 20. The course of these pressure medium volume flows Q _D1 , Q _D2 is shown in FIG. 2 over a period t / T. The time course 62 of the deflection x of the working piston 2 corresponds to a sine movement around the neutral position x = 0. From t / T = 0 to t / T = 0.5, the working piston 2 executes its first partial stroke movement. The working piston executes its second partial stroke movement from t / T = 0.5 to t / T = 1. From t / T = 0 to t / T = 0.25, a positive volume flow Q _D1 flows from the pressure medium chamber _D1 , which comes from the first delivery cylinder 22. At t / T = 0.25, the second part of the first partial stroke movement begins, in which the delivery cylinder 22 is again filled with a pressure medium volume flow -Q _D2 from the second pressure medium space _D2 . In relation to the pressure medium chamber D2, this corresponds to a negative volume flow Q _D2 .

During the first part of the second partial stroke movement from t / T = 0.5 to t / T = 0.75, the pressure medium space D2 is again supplied with a positive pressure medium volume flow Q _D2 , which comes from the second delivery cylinder 24. During the second part of the second partial stroke movement from t / T = 0.75 to t / T = 1, a pressure medium volume flow Q _{D1 is again} taken from the first pressure medium space _D1 , which serves to fill the second delivery cylinder 24.

und

gleich Null. Die den Druckmit-telräumen D1, D2 zu- bzw. abgeführten Druckmittelvolumina sind also während einer Periode ausgeglichen, so daß die Neutralstellung des Arbeitskolbens 2 erhalten bleibt.As can be seen in FIG. 2, the time integrals are

and

equals zero. The pressure medium volumes supplied to and discharged from the pressure medium spaces D1, D2 are therefore balanced during one period, so that the neutral position of the working piston 2 is maintained.

und

wieder. Diese Aus-gleichsvolumina bewirken, daß die Mittellage des Arbeitskolbens 2, die bei dem Verlauf 64 bei Δx liegt, ein Stück in Richtung der Neutralstellung (x = 0) verschoben wird.The course 64 of the deflection movement x of the working piston 2 shown in FIG. 3 is shifted by the amount Δx compared to the course 62 (FIG. 2). That is, the center position of the working piston 2, relative to the illustration in FIG. 1, has been shifted to the right by the amount Δx compared to the neutral position. The amplitude of the first partial stroke movement 66 is larger than the curve 62 by the amount Δx, while the amplitude 68 of the second partial stroke movement is smaller by the amount Δx. From the courses of the volume flows Q _D1 , Q _{D2 it} can be seen that on average a compensation volume is supplied to the pressure medium chamber D1, while a compensation volume is taken from the pressure medium chamber D2. This is also reflected in the representation of the temporal integrals

and

again. These equalizing volumes have the effect that the central position of the working piston 2, which lies at Δx in the course 64, is shifted a little in the direction of the neutral position (x = 0).

Fig. 4 shows an alternative embodiment of the invention, in which the line 29 is connected to a pressure medium reservoir. The result of this is that the pressure medium delivery device 20 supplies a pressure medium volume Q _R to the reservoir 70 during the first partial stroke movement of the working piston 2 and takes a pressure medium volume Q _R from the reservoir 70 during the second partial stroke movement of the working piston 2.

In this embodiment, the pressure medium delivery device comprises 20 a first feed cylinder 22 and one second delivery cylinder 24, a working volume V1 of the first delivery cylinder 22 through a line 26 with a in the direction of the first feed cylinder 22 permeable one-way valve 28 with the second pressure medium space D2 and through a line 29 with one in the direction away from the first Delivery cylinder 22 permeable, biased one-way valve 30 is connected to the reservoir 70.

The working volume V2 of the second delivery cylinder 24 is through a line 32 with one towards the second Delivery cylinder 24 permeable one-way valve 34 with the Reservoir 70 and through a line 36 with one in the direction permeable away from the second feed cylinder 24, biased one-way valve 38 with the second pressure medium chamber D2 connected.

With this configuration, the correction of the Middle position of the working piston by feeding or removing a Compensating volume to the second pressure medium space D2, while the volume of the first pressure medium space automatically the pressure medium source is balanced.

reference numeral

2

working piston

4

Steller cylinder

6

management

8th

encoder system

10

management

12

Pressure medium source

14

piston rod

16

first end position

18

second end position

20

Pressure fluid delivery device

22

first delivery cylinder

24

second delivery cylinder

26

management

28

one-way

29

management

30

preloaded one-way valve

32

management

34

one-way

36

management

38

preloaded one-way valve

40

piston

42

piston

44

face

46

face

48

face

50

tappet

52

tappet

54

stop surface

56

takeaway

58

stop surface

60

takeaway

62

course

64

course

66

amplitude

68

amplitude

70

reservoir

Claims (13)

Actuator arrangement that can be actuated by pressure medium, with a working piston (2) guided in an actuator cylinder (4), which separates a first pressure medium chamber (D1) from a second pressure medium chamber (D2) in the actuator cylinder (4), and as a result of pressure medium volume flows Q _P that separate the pressure medium chambers (D1), (D2) can be supplied or removed, can be moved axially between a first end position (16) and a second end position (18), the first pressure medium chamber (D1) having a minimal volume in the first end position (16) and in the second end position (18) the second pressure medium space (D2) has a minimal volume, and a neutral position (x = 0) can be assumed by the working piston (2) between the two end positions (16), (18), and movement from the neutral position in the direction of the first end position (16) and back corresponds to a first partial stroke movement and a back and forth movement from the neutral position in the direction of the second end position (18) and back one r corresponds to the second partial stroke movement, characterized in that a pressure medium delivery device (20) is provided, which takes a pressure medium volume (∫Q _D2 ) from the second pressure medium space (D2) during the first partial stroke movement of the working piston (2) and which during the second partial stroke movement of the working piston ( 2) supplies a pressure medium volume (∫Q _D2 ) to the second pressure medium chamber (D2), the pressure medium volumes supplied or withdrawn depending on the amplitude of the respective partial stroke movement. Actuator arrangement according to Claim 1, characterized in that the pressure medium delivery device (20) supplies a reservoir (70) with a pressure medium volume (∫Q _R ) during the first partial stroke movement of the working piston (2) and with the reservoir (70) during the second partial stroke movement of the working piston (2) takes a pressure medium volume (∫Q _R ). Actuator arrangement according to claim 2, characterized in that the pressure medium delivery device (20) comprises a first delivery cylinder (22) and a second delivery cylinder (24), a working volume (V1) of the first delivery cylinder (22) through a line (26) with an in Direction to the first feed cylinder (22) permeable one-way valve (28) with the second pressure medium chamber (D2) and through a line (29) with a biased one-way valve (30) permeable in the direction away from the first feed cylinder (22) with the reservoir (70 ), and wherein a working volume (V2) of the second delivery cylinder (24) is connected to the reservoir (70) by a line (32) with a one-way valve (34) which is permeable towards the second delivery cylinder (24) and by a line (36 ) is connected to the second pressure medium chamber (D2) with a prestressed one-way valve (38) which is permeable in the direction away from the second delivery cylinder (24). Actuator arrangement according to Claim 1, characterized in that the pressure medium delivery device (20) supplies a pressure medium volume (∫Q _D1 ) to the first pressure medium chamber (D1) during the first partial stroke movement of the working piston (2) and to the first pressure medium chamber (2) during the second partial stroke movement of the working piston (2) D1) takes a pressure medium volume (∫Q _D1 ). Actuator arrangement according to claim 4, characterized in that the pressure medium delivery device (20) comprises a first delivery cylinder (22) and a second delivery cylinder (24), a working volume (V1) of the first delivery cylinder (22) through a line (26) with a Direction to the first feed cylinder (22) permeable one-way valve (28) with the second pressure medium chamber (D2) and through a line (29) with a biased one-way valve (30) permeable in the direction away from the first feed cylinder (22) with first pressure medium chamber (D1 ), and a working volume (V2) of the second delivery cylinder (24) through a line (32) with a one-way valve (34) which is permeable in the direction of the second delivery cylinder (24) with the first pressure medium chamber (D1) and through a line (36 ) is connected to the second pressure medium chamber (D2) with a prestressed one-way valve (38) which is permeable in the direction away from the second delivery cylinder (24). Actuator arrangement according to one of claims 1 to 5, characterized in that transmission means (14), (56), (58) are provided which mechanically couple the pressure medium delivery device (20) to the working piston (2). Actuator arrangement according to one of the preceding claims, characterized in that the feed cylinders (22), (24) each have a piston (40), (42) which can be displaced by an actuating member (50), (52) guided to the outside, wherein during the first partial stroke movement of the working piston (2) guided in the actuator cylinder (4), the actuating member (50) of the first delivery cylinder (22) is coupled to the movement of the working piston (2) and the actuating member (52) of the second delivery cylinder (24) from the Movement of the working piston (2) is decoupled, and during the second partial stroke movement of the working piston (2) guided in the actuator cylinder (4), the actuating member (52) of the second delivery cylinder (24) is coupled to the movement of the working piston (2) and the actuating member ( 50) of the first delivery cylinder (22) is decoupled from the movement of the working piston (2). Actuator arrangement according to claim 7, characterized in that the working piston (2) of the actuator cylinder (4) is connected to a piston rod arrangement (14, 56, 60) which has axial stop surfaces (54, 58) which act on the actuating members (50, 52) are assigned to the delivery cylinder, each actuating member (50, 52) only resting against one of the axial stop surfaces (54, 58) during a partial stroke movement of the working piston (2) and being carried along by it and during the other partial stroke movement of the working piston (2) you take off. Actuator arrangement according to claim 8, characterized in that adjusting means for adjusting the position between the pistons (40), (46) of the delivery cylinders (22), (24) and the axial stop surfaces (54), (58) are provided. Actuator arrangement according to one of the preceding claims, characterized in that the first pressure medium chamber (D1) is connected by a line (10) to a pressure medium source (12) with at least approximately constant pressure, and the second pressure medium chamber (D2) by a line (6) is connected to a controllable transmitter system (8). Unit comprising an actuator arrangement according to one of the preceding claims for installation in a rotating System of a helicopter main rotor. Helicopter rotor blade control for several, rotor blades arranged evenly on the circumference of a rotor hub, each rotor blade having at least one actuator arrangement or a structural unit according to one of the preceding Claims are assigned, with a donor system in the form a hydraulic displacement control is provided, which is arranged in the rotor head of a helicopter, and wherein transmission means are provided which the piston rod arrangement of the working piston with a helicopter rotor blade couple, to control a setting angle movement of the helicopter rotor blade. Use of the setting means of an actuator arrangement according to claim 6 for adjusting the setting angle of the Rotor blades of a helicopter rotor.

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