WO2010115805A1

WO2010115805A1 - Vibration damper having a device for generating electrical energy

Info

Publication number: WO2010115805A1
Application number: PCT/EP2010/054310
Authority: WO
Inventors: Markus Renninger; Karl-Hermann Ketteler; Andreas Thies
Original assignee: Zf Friedrichshafen Ag
Priority date: 2009-04-07
Filing date: 2010-03-31
Publication date: 2010-10-14
Also published as: DE102009002260A1

Abstract

The invention relates to a vibration damper (1) comprising at least one cylindrical chamber (11) containing a fluid, in which cylindrical chamber at least one working means (12) is guided by means of a rod (13) in a longitudinally movable manner and divides the chamber (11) into two working spaces (11a, 11b), wherein damping is produced by movement of the working means (12), and wherein means for generating electrical energy are provided. According to the invention, at least one turbine (41) coupled to a generator (42) is provided as the means for generating electrical energy, which turbine can be acted on by a fluid that is displaced during the longitudinal movement of the working means (12).

Description

Vibration damper with a device for generating electrical energy

The invention relates to a vibration damper with a device for generating electrical energy according to the features of the preamble of claim 1.

Vibration dampers or shock absorbers are important components particularly in vehicle construction. They serve to prevent or damp excessive vibrations of the vehicle. The most commonly used in today's vehicle vibration damper work on the principle of hydraulic damping. In these, the necessary for the reduction of unwanted vibration damping force is generated substantially by a pressure difference on valve components of the vibration damper. The vibration energy, for example, from the vehicle body or a wheel is converted into heat energy and not used in the rule, but radiated into the environment.

In the construction of hydraulic vibration dampers, the so-called one-pipe or two-pipe design is common. In the monotube construction, a working piston is guided in a longitudinally displaceable manner by means of a piston rod in a cylindrical chamber, wherein the working piston divides the chamber into two working spaces. The working piston also has damping valves for the tensile or compressive movement ("rebound" or "pressure stage") of the working piston, release the corresponding through holes of the working piston and an overflow of the damping fluid (for example hydraulic oil) between the work areas with accordingly adjusting or possibly allow adjustable damping.

In addition, a movably arranged separating piston can be arranged in the chamber, which delimits an additional, for example filled with gas compensation chamber. The separating piston thus separates this into the working clear existing oil from the gas. Depending on whether there is a push or pull operation during operation of the vibration damper, the gas cushion separated by the separating piston is compressed or expanded and the separating piston in the working space is displaced accordingly.

In the case of the two-pipe construction, another pipe is arranged concentrically around the cylindrical chamber, wherein a compensation space for the damping fluid in the chamber is created by the hollow wall which then arises. The transition of the fluid from the chamber into the expansion chamber and vice versa is usually made possible by a damping valve located in the bottom region of the chamber.

From DE 195 31 790 A1 a vibration damper is known, in which the kinetic energy introduced in these can be used as drive energy. Here, the damping medium does not flow through throttle valves, but drives via a hydraulic motor other units, such as an air compressor, an alternator or a servo pump.

In DE 10 2006 006 482 A1 a vibration damper for a bicycle with a so-called energy recovery is described. The energy recovery unit is designed in the form of a plunger coil arrangement whose generated electrical energy is used to charge a battery.

Further, DE 102 46 837 A1 discloses a vibration damper for converting mechanical vibration energy into electrical energy, in which the mechanical vibration energy of a vibration element is converted into electrical energy with a piezoelectric actuator.

Against this background, the object underlying the invention is to present a vibration damper which can easily be used to convert a vibration damper. ment of introduced into the vibration damper kinetic energy into electrical energy allows.

This object is achieved by a vibration damper having the features of the main claim. The dependent claims represent advantageous developments of the inventive concept.

The invention relates to a vibration damper, comprising at least one fluid-containing cylindrical chamber in which at least one working means is guided longitudinally displaceable by means of a rod and divides the chamber into two working spaces, wherein by a movement of the working means a damping is generated, and in which Means are provided for generating electrical energy. To achieve the object, it is provided that at least one coupled to a generator turbine is provided as a means for generating electrical energy, which is acted upon by a fluid, which is caused by the working fluid in its longitudinal movement.

With this structure, vibration energy to be taken out of a vehicle for improving running stability, for example, is not converted into heat and radiated from the vibration damper, as in conventional vibration dampers, but converted into electric energy that can be otherwise used or cached by the vehicle. Thus, in cooperation with the connected generator, the turbine can be set in motion during an operational movement of the working means during the operation of the vibration damper. This can for example be realized in such a way that the turbine is set in motion only during the rebound stage or only during the compression stage. However, it is structurally also possible to put the turbine in motion during rebound and compression. According to a first expedient development of the vibration damper is provided that the turbine and / or the generator are arranged outside of said cylindrical chamber. If the turbine and / or the generator are arranged outside the cylindrical chamber of the vibration damper, the size of the vibration damper can be kept small and one is free with regard to the positioning of the turbine or generator.

A second expedient development provides that the turbine and / or the generator are arranged within the cylindrical chamber of the vibration damper.

With regard to the former refinement, it is provided in an even more concrete embodiment that a piston which is arranged in the cylindrical chamber of the vibration damper is used as the working means. This piston has at least one axial passage opening, which connects an upper and a middle working space with each other. Further, a valve is arranged at this passage opening, with which the passage opening can be closed. Also provided within the cylinder is a circular wall defining a lower working space from the adjacent central working space, the circular wall having at least one axial passage opening connecting the middle and lower working spaces. In addition, at least one valve is arranged on the last-mentioned passage opening, with the aid of which this passage opening can be closed. Further features are that the upper working space and the lower working space are connected via hydraulic lines to a turbine-generator unit arranged outside the cylindrical chamber, and that the lower working space is connected to a fluid accommodating equalization space.

To achieve a compact design can be provided that the turbine concentrically surrounds the generator. It is advantageous if the generator is disposed radially between the turbine and a piston base connected to the piston base. In the context of this description, the piston base is understood to mean the part of the piston which is formed radially inward and connected to the piston rod.

In addition, it contributes to a compact design, when the generator has a rotatably connected to the turbine rotor and a rotatably connected to the piston base stator.

In order to ensure that during relative movements between the turbine and the cylindrical chamber of the vibration damper, the turbine is sufficiently flowed through in at least one direction, it is provided that the piston base has at least one passage opening connecting the upper working space and the middle working space and closable by at least one valve ,

Another, very advantageous embodiment of the invention provides that around the cylindrical working space around a further chamber is concentrically arranged, and that at least a second turbine is provided with a generator whose passage opening connects the cylindrical chamber fluidly with the other, concentric chamber. In this way, the advantages of the invention can be transferred to vibration damper in two-pipe design.

Advantageously, it can be provided that the turbines or the turbine wheels are each connected to a mechanical freewheel. This ensures that the turbine wheels rotate only in one direction of rotation, which ultimately also simplifies the necessary design of the generators.

Finally, the invention provides room for a further variant of a vibration damper, in which one between a generator operation and an engine operation switchable electric machine is connected to the turbine wheel. To control the operating mode of the electric machine, an electronic control and regulating device is present, which is connected via lines to the electric machine. In addition, this control and regulating device can regulate the engine operation and also the generator operation of the electric machine for generating a variable damping force of the vibration damper. Depending on the current operating situation, the electric machine is therefore operated as a generator or as a motor, wherein a desired damping of the vibration damper is set in both modes.

In the following, three embodiments of the invention will be explained in more detail with reference to the accompanying drawings. It shows

1 is a schematic representation of a first vibration damper, in which a turbine and a generator are arranged outside of the vibration damper,

Fig. 2 is a schematic representation of a second vibration damper in a single-pipe construction, in which a turbine and a generator are arranged within the vibration damper, and

Fig. 3 is a schematic representation of a third vibration damper in two-pipe design, in which two turbines and two generators are also disposed within the vibration damper.

Accordingly, Fig. 1 shows a first embodiment of a vibration damper 1 according to the invention, which has a cylindrical chamber 1 1, which is filled with hydraulic oil. The cylindrical chamber 1 1 is sealed at the top by a lid 15 and bottom by a bottom 16. In the chamber 1 1, a working piston 12 by means of a piston rod 13 is displaceable guided (see arrow). The working piston 12 divides the chamber 1 1 in an upper working space 1 1 a and a middle working space 1 1 b. Furthermore, within the chamber 1 1 below the middle working space 1 1 b a circular wall 14 is arranged, which is fixedly connected to the cylinder 10 and a lower working space 1 1 c limited.

The upper working space 1 1 a is connected via a hydraulic line 19 a with a turbine-generator unit 17, which is arranged outside of the cylinder 10. The lower working space 1 1 c is also connected via a hydraulic line 19b to the turbine-generator unit 17. In addition, the lower working space 1 1 c is connected via a hydraulic line 19 c with an external compensation chamber 18 for receiving required hydraulic oil.

Furthermore, it can be seen that the working piston 12 is provided with an axial passage opening 120, which connects the two working spaces 1 1 a and 1 1 b with each other. The passage opening 120 can be closed or opened by means of a valve 121, and blocks off as a check valve in the direction of the middle working space 11 b. The circular wall 14 is optionally provided with two axial passage openings 140 a and 140 b, which can be opened or closed by means of two valves 141 a, 141 b. The two valves 141 a, 141 b are also designed as check valves which shut off in opposite directions. The valve 141 b is also loaded in the direction of the middle working space closing direction of a compression spring with a closing force. The valve 141 b is optional. It allows the adjustment of the damper characteristic.

The operation of the vibration damper 1 according to FIG. 1 is now the following:

When the working piston 12 is pressed down by means of the piston rod 13 (pressure stage), the valve 121 opens and oil can through the through hole 120 from the middle working space 1 1 b in the upper Working space 1 1 a get. The valve 141 a and the valve 141 b (with appropriate design up to a certain pressure) prevent backflow of the oil in the lower working space 1 1 c. The displaced volume due to the piston rod flows via the hydraulic line 19a to the turbine 41, rotates a rotor and thus generates electrical energy.

In a subsequent upward movement of the working piston 12 (rebound), however, the valve 121 closes the passage opening 120 and oil is pressed from the upper working chamber 1 1 a via the hydraulic line 19a in the turbine-generator unit 17, whereby the turbine wheel 41 and the with Rotor of the generator 42 connected to the turbine wheel 41 are rotated or driven, so that electrical energy is generated. From the turbine-generator unit 17, the oil then passes via the hydraulic line 19b in the lower working space 1 1 c and from there via the passage opening 140a in the middle working space 11 b or if necessary via the hydraulic line 19c in the compensation chamber 18th Der Hydraulic circuit is designed such that the turbine wheel 41 always turns the turbine-generator unit 17 in the same direction, whereby a hydraulic freewheel is realized.

In a variant, Fig. 1 shows that the vibration damper 1 may also be connected to an electric machine 42, which is alternately switchable between a generator operation and a motor operation. The switching between the two modes mentioned controls a control and regulating device 43, which is connected by signal technology with the electric machine 42. The electric machine 42 is connected via an unspecified shaft to the turbine wheel 41, which is acted upon and driven by a flow of hydraulic oil both during a movement of the piston 12 upward and during a piston movement downward via the hydraulic line 19a. When the electric machine 42 is operated as a motor, the turbine wheel 41 can be arranged with adjustable wing geometry as a impeller or just form an increased flow resistance for passing oil. Depending on the manner of the motor operation of the electric machine 42, the damping characteristics of the vibration damper 1 can be controlled by the control and regulation device 43.

2 shows a second exemplary embodiment of a vibration damper 2 according to the invention. The latter has a cylinder 20 filled with hydraulic oil, in which a piston with its piston base 22 and with it a generator 23 and a turbine 24 are guided so as to be longitudinally displaceable by means of a rod 27. By piston, generator 23 and turbine 24, the cylindrical chamber 21 formed in the cylinder 20 is divided into an upper working space 21 a and a middle working space 21 b. Furthermore, a displaceably arranged in the cylindrical chamber 21 separating piston 25 is present, which is sealed to a gas-filled lower working space 21 c by means of a seal 26.

If now the piston base 22 is pressed down (pressure stage), so a pressure is exerted on the separating piston 25 at the same time and this performs a downward movement, so that the gas located in the lower working chamber 21 c is compressed. A desired damping can be generated by means of a spring-loaded valve 221, which opens with appropriate dimensioning of the valve spring upon downward movement of the piston base 22, so that oil from the middle working space 21 b pass through a through hole 220 in the piston base 22 in the upper working chamber 21 a can.

During upward movement (rebound) of the piston base 22, the valve 221 acts as a check valve, whereby the befindlicher in the upper working chamber 21 a oil is forced through a radially outside of the piston base 22 arranged turbine 24 and the turbine wheel in the middle working space 21 b escape. As a result, the turbine of the turbine 24, a Generating damping force, set in rotation. Since the turbine 24 is fixed radially inwardly to the rotor 23b of a generator 23, the rotor 23b also rotates. As a result, the rotor 23b is moved relative to a radially inwardly fixed stator 23a connected to the piston base 22, whereby an electric current is generated which can be used directly in the vehicle electrical system or stored in a battery. Optionally, a mechanical freewheel can be provided on the turbine wheel, which prevents a rotational movement of the turbine 24 under a pressure load of the vibration damper 1 (not shown in detail).

In Fig. 3, a third embodiment of a vibration damper 3 according to the invention is shown. This comprises a first cylinder 30, through which a cylindrical, oil-filled chamber 31 is formed. Further, there is a unit consisting of a piston base 34, a generator 35 with a stator 35a and a rotor 35b and a turbine 36, which essentially corresponds in construction to the turbine-generator unit described in FIG. 2 and in the chamber 31 by means of a Rod 40 is guided longitudinally displaceable. The chamber 31 is characterized in an upper working space 31 a and a lower working space 31 b divided. At the bottom of the chamber 31, a bottom plate 37 is provided, which is provided with a first axial passage opening 370 and a second axial passage opening 371. In the first passage opening 370, a second turbine 38 is arranged, which is connected to the rotor of a generator 39 arranged outside the cylinders 30 and 32.

Concentric with the first cylinder 30, a second cylinder 32 is provided, whereby an at least partially filled with oil compensation chamber 33 is formed.

During a downward movement (pressure stage) of the turbine-generator unit according to FIG. 3, the oil located in the lower working space 31 b is transferred through the passage opening 370 and via the turbine 38 into the compensation chamber 33 pressed. The turbine 38 and with it the not shown rotor of the generator 39 are rotated and thus generates electrical energy.

In a subsequent upward movement (rebound) of the turbine-generator unit according to FIG. 3, however, a piston 34 disposed on the valve 341 includes an opening formed in the piston 34 axial passage opening 340, so that in the upper working space 31 a befindliches oil is forced over to get the turbine 36 at the piston base 34 in the lower working space 31 b and to set the turbine 36 on the generator 35 in rotation. As a result, a damping force is generated in this case via the turbine-generator unit. If necessary, further oil from the compensation chamber 33 via an introduced in the bottom plate 37 axial passage opening 371 after opening a valve arranged there 372 in the lower working chamber 31 b nachgeliefert. Not shown in detail mechanical freewheels on the turbines 36, 38 each secure their constant direction of rotation in opposite directions of flow of the oil.

The valves 141 b and 221 on the respective piston base 14, 22 are each loaded by a spring force of springs not further described, wherein the throughflow of the respective valve is set by the choice of the spring constant. This also makes it possible to adjust the damping properties of the respective vibration damper 1.

REFERENCE CHARACTERS

vibration

cylinder

Cylindrical chamber a Upper working space b Middle working space c Lower working space

Work equipment, working piston

piston rod

Circular wall

cover

ground

Turbine generator unit

Compensation space a Hydraulic line b Hydraulic line c Hydraulic line

cylinder

Work equipment, piston base

Generator a stator b rotor

turbine

separating piston

poetry pole

First cylinder

Cylindrical chamber a Upper working space b Lower working space

Second cylinder

Coaxial chamber

Work equipment, piston base

Generator a stator b rotor

turbine

baseplate

Second turbine

generator

pole

turbine

Electric machine, generator, engine

Control unit0 Through hole 1 Valve 0a Through hole 0b Through hole 1 a Valve 1 b Valve 0 Through hole 1 Valve 0 Through hole 1 Valve 0 First through hole 1 Second through hole 2 Valve

Claims

claims

1. Vibration damper (1, 2, 3), with at least one fluid-containing cylindrical chamber (1 1, 21, 31), in which at least one working means (12, 22, 34) by means of a rod (13, 27, 40) is longitudinally displaceable and the chamber (1 1, 21, 31) in two working spaces (1 1 a, 1 1 b, 21 a, 21 b, 31 a, 31 b) divided, wherein by a movement of the working means (12, 22 , 34) an attenuation is generated, and are provided in the means for generating electrical energy, characterized in that as means for generating electrical energy at least one to a generator (23; 35, 39, 42) coupled turbine (24; 36, 38, 41) is provided, which is acted upon by a fluid, which is caused by the working means (12, 22, 34) in its longitudinal movement.

2. Vibration damper (1) according to claim 1, characterized in that the turbine (41) and / or the generator (42) outside the chamber (1 1) are arranged.

3. Vibration damper (2, 3) according to claim 1, characterized in that the turbine (24, 36) and / or the generator (23,35) within the chamber (21, 31) are arranged.

4. Vibration damper (1) according to any one of claims 1 or 2, characterized in that as a working means a piston (12) is provided, which has at least one axial passage opening (120) having an upper and a middle working space (1 1 a, 1 1 b) with each other, that at the passage opening (120) a valve (121) is arranged, with which the passage opening (120) is closable, that within the cylinder (10) is provided a circular wall (14), the one lower working space (1 1 c) from the adjacent middle working space (1 1 b) demarcates that the circular wall (14) has at least one axial passage opening (14Oa, 14Ob), which connects the middle and the lower working space (1 1 b, 1 1 c) that at least one valve (141 a, 141 b) at the passage opening (14Oa , 14Ob), with which this passage opening (140a, 140b) is closable, that the upper working space (1 1 a) and the lower working space (1 1 c) via hydraulic lines (19 a, 19 b) with an outside of the cylindrical chamber ( 1 1) arranged turbine-generator unit (17) is connected, and that the lower working space (1 1 c) with a fluid receiving compensating space (18) is connected.

5. Vibration damper (2, 3) according to one of the preceding claims, characterized in that the turbine (24, 36) surrounds the generator (23, 35) concentrically.

6. Vibration damper (2, 3) according to claim 5, characterized in that the generator (23, 35) radially between the turbine (24, 36) and one with the rod (27, 40) connected to the piston base (22, 34) is.

7. vibration damper (2, 3) according to claim 6, characterized in that the generator (23, 35) rotatably connected to the turbine (24, 36) connected to the rotor (23b, 35b) and a rotationally fixed to the piston base (22, 34 ) connected stator (23a, 35a).

8. Vibration damper (2, 3) according to one of the preceding claims, characterized in that the piston base (22, 34) at least one of the upper working space (21 a, 31 a) and the middle working space (21 b, 31 b) connecting and by at least one valve (221; 341) closable passage opening (220; 340).

9. Vibration damper (3) according to one of the preceding claims, characterized in that around the cylindrical working space (31) around a further chamber (33) is arranged concentrically, and that at least a second turbine (38) is provided with a generator (39) whose passage opening (370) fluidly connects the cylindrical chamber (31) with the further, concentric chamber (33).

10. Vibration damper (2, 3) according to one of the preceding claims, characterized in that the turbines (24, 36, 39) are each connected to a freewheel.

1 1. Vibration damper according to one of the preceding claims, characterized in that the electric machine used (42) alternately as a generator or motor is operable, that an electronic control and regulation device (43) with the electric machine (42) is connected, which controlling the switching of the electric machine (42) between generator operation and engine operation and the engine operation and / or the generator operation of the electric machine (42) for generating a variable damping force of the vibration damper (1) can control.