Vibration damper with a generator connection

Abstract

Vibration damper (1) comprising a cylinder (3) in which a piston rod (5) with a piston (7) is axially movably guided as a displacer, wherein both working chambers (9; 11) of the cylinder (3) are completely filled with a pressure medium, so that a displacer movement conveys pressure medium through lines (13; 15) to a generator (17), drives it and the displacer movement is converted into electrical energy, wherein the vibration damper (1) has an elastic element (27) that compensates pressure peaks from the displacer movement to the generator (17), characterized in that the elastic element is designed as a torsional damper (27) for the generator (17).

Description

[0001] The invention relates to a vibration damper with a generator connection according to the preamble of patent claim 1.

[0002] DE 10 2009 056 874 A1 discloses a vibration damper for a vehicle whose hydraulic cylinder is connected to a generator that converts a stroke of the vibration damper at least partially into electrical energy. In normal use, a vibration damper is exposed to a wide variety of excitations, which can lead to load peaks on the generator. These load peaks can manifest themselves, for example, as noise or even lead to damage to the system.

[0003] As a solution, DE 10 2009 056 874 A1 proposes a reservoir filled with a pressure medium to cushion the pressure peaks. However, such a reservoir can result in additional costs associated with one of the piping systems inside and / or outside the vibration damper.

[0004] From DE 10 2008 063 653 A1 a vibration damper is known whose generator is protected from overload by a damping valve connected in parallel.

[0005] The application and design of a torsional vibration damper, e.g. between a drive motor and a driven unit, are known from EP 2 199 643 A1, US 2007 / 0 295 569 A1, WO 2007 / 000 152 A1 or DE 10 2009 005 740 A1.

[0006] The object of the present invention is to find an alternative solution to the problem of pressure peaks occurring within the vibration damper.

[0007] According to the invention, this problem is solved by embodying the elastic element as a torsional damper for the generator. Instead of a hydraulic accumulator, which requires considerable space, a purely mechanical torsional damper is used.

[0008] In a further advantageous embodiment, the torsional damper has an input element and an output element, with at least one spring element arranged between the two elements. Practically any spring can be used as the spring element, although coil springs have proven particularly advantageous due to their comparatively large spring travel, while elastomer springs have proven particularly advantageous due to their simple design and high load limit.

[0009] According to an advantageous subclaim, the torsion damper comprises a vibration damper. This vibration damper counteracts the operating movement of the torsion damper and forces it to perform a release function.

[0010] A friction damper has proven to be particularly simple and completely sufficient for the application as a vibration damper for the torsion damper.

[0011] To achieve a compact design, the torsion damper is arranged between a turbine driven by the displacement engine and an electric motor as part of the generator. With this arrangement, it is conceivable that a generally known turbine as a structural unit, the torsion damper as a structural unit, and the electric motor as a structural unit are arranged in series. If the installation space conditions make it necessary, the torsion damper can also be arranged between the input and output sides of the turbine.

[0012] In a further design, the turbine, the torsion damper and the electric machine are arranged in a common housing.

[0013] The invention will be explained in more detail with reference to the following description of the figures. Fig. 1 Schematic diagram of the vibration damper with a generator Fig. 2 - 4 torsion dampers Fig. 5 - 7 torsion dampers with a friction damper

[0014] The Fig. Figure 1 shows a schematic diagram of a vibration damper 1 of any design, i.e., a single-tube vibration damper or a twin-tube vibration damper. A piston rod 5, optionally with a piston 7 as a displacer, is guided axially movably in a cylinder 3. The cylinder 3 is completely filled with a pressure medium in its two working chambers 9; 11, so that a displacement movement conveys pressure medium through lines 13; 15 to a generator 17, which converts the displacement movement into electrical energy.

[0015] The vibration damper 1 also has an accumulator 21 in a bypass line 19 to line 15, which serves to compensate for the pressure medium volume displaced from the cylinder 3 by the piston rod 5. The accumulator 21 is preloaded, so that a pressure volume occurring during a displacement movement into the working chamber 11 is also primarily supplied to the generator 17.

[0016] The generator 17 includes a turbine 23 driven by the displaced pressure medium. The turbine 23 drives an electric motor 25, which generates electrical energy. Furthermore, the generator 17 has a torsional damper 27 as an elastic element, which smooths out pressure peaks in the pressure medium or at the turbine 23. However, the generator 17 can also function as a motor when connected to a power source.

[0017] The torsion damper 27 is functionally arranged between the turbine 23 and the electric motor 25. The torsion damper can be used as a separate unit or as a component, e.g., of the turbine. In this case, all components of the generator 17 are arranged in a common housing 29.

[0018] The Fig. 2 to 4 show a first embodiment of the torsional damper 27, which has an input element 31 leading from the turbine 23 and an output element 33 leading from the electric machine 25, wherein at least one spring element 35 is arranged between the two elements 31; 33. The output element 33 has a carrier disk 37 with axial segment-like projections 39. Elastomer bodies act as spring elements 35 in the circumferential direction. In this embodiment, the input element has three projections 39, which interact with six elastomer bodies 35. As can be seen from the Fig. 3, the elastomer bodies 35 each define in pairs an engagement area 41 for the disc-shaped input element 31, Fig. 4, which has three ribs 43 which project into the engagement area 41 and essentially fill it, as the Fig. 2. The ribs 43 have torque transmission surfaces 45, just as the projections 39 have torque transmission surfaces 47. The torque transmission surfaces 45, in turn, delimit a receiving area 49 for the projections 39 and the elastomer bodies 35. Bolts 51 serve to axially connect the input and output elements 31; 33. These bolts pass through elongated holes 53 in the output part 33 and are fixed in fastening openings 55 in the input element 31, so that the two elements 31; 33 are held together. The output part 33 has a hub flange 57 with a guide surface 59 for the input element 31.

[0019] A pressure peak in the hydraulic area of ​​the vibration damper 1 also acts on a shaft 61 ( Fig. 1) between the turbine 23 and the electric machine 25. This shaft 23 is split, with the torsion damper 27 arranged between the two shaft sections. The pressure peak acts circumferentially on the input element 31 of the torsion damper 27. The electric machine 25 has a mass inertia that counteracts the rotational movement of the shaft 61. The input torque at the input element 31 and the mass moment of inertia at the output element 33 of the torsion damper 27 ensure a relative movement between the input and output elements 31; 33, which is compensated by the elastomer elements 35.

[0020] The Fig. 5 and Fig. 6 shows a torsional damper 27 as an assembly arranged on the shaft 61 between the turbine 23 and the electric machine 25. The torsional damper 17 comprises a hub disk 63 as an input element, which has any shaft receiving profile for torque transmission. The hub disk 63 has a hub flange 65 to which cover disks 67; 69 are attached laterally. A riveted connection 71 is shown as an example. The cover disks 67; 69 and an outer surface of the hub disk define an annular space in which a drive disk 73 is mounted as an output element, displaceable in the circumferential direction. Furthermore, at least one friction disk 75 is arranged in the annular space between the drive disk 73 and a cover disk 67; 69. All disk bodies 67; 69; 73 have windows 77 for accommodating at least one coil spring as the spring element 35.This allows the drive plate 73 to rotate relative to the hub plate 63, whereby the coil springs 35 are preloaded.

[0021] This design of a torsion damper 27 features a vibration damper in the form of a friction damper. In a theoretical consideration of the torsion damper, an external excitation would lead to an infinitely long oscillating motion between the input element 61 and the output element 73. The frictional relative movement between the drive plate 73 and the at least one friction plate 75 causes the oscillating motion to subside quickly.

[0022] The execution according to Fig. 7 shows a torsion damper 27, which is constructed in the same principle as Fig.2 to 4. Coil springs 35 are used instead of elastomer bodies. Furthermore, this torsion damper 27 also features a vibration damper in the form of a friction damper. The output element 33 features a polygonal outer surface 79, so that a relative movement between the input and output elements 31; 33 results in a radial reduction in the engagement area 41. As a result, radially preloaded friction bodies 81 become effective depending on the angle of rotation. The friction bodies 81 guide the coil springs 35 and are supported radially between the input and output elements 31; 33. If the radial distance between the polygonal outer surface 79 of the output element 33 and a concentric friction surface 83 of the input element 31 changes, the frictional effect of the vibration damper also changes.

[0023] The connection areas to the shaft 61 have been omitted. Reference symbol 1 vibration damper 3 cylinders 5 Piston rod 7 pistons 9 Workspace 11 Workroom 13 Management 15 Line 17 Generator 19 Bypass line 21 storage 23 turbines 25 electric machine 27 torsion dampers 29 housings 31 Input element 33 Output element 35 spring element 37 Carrier disc 39 lead 41 Intervention area 43 rib 45 Torque transmission area 47 Torque transmission surface 49 Recording area 51 bolts 53 elongated holes 55 mounting holes 57 Hub flange 59 Guide surface 63 Hub disc 65 Hub flange 67 cover plates 69 cover plates 71 riveted joint 73 Drive plate 75 friction disc 77 windows 79 lateral surface 81 friction bodies 83 Friction surface 61 Wave

Claims

[1] Vibration damper (1), comprising a cylinder (3) in which a piston rod (5) with a piston (7) as a displacer is guided axially movably, wherein both working chambers (9; 11) of the cylinder (3) are completely filled with a pressure medium, so that a displacement movement conveys pressure medium through lines (13; 15) to a generator (17), drives this and the displacement movement is converted into electrical energy, wherein the vibration damper (1) has an elastic element (27) which compensates pressure peaks from the displacement movement to the generator (17), characterized by that the elastic element is designed as a torsion damper (27) for the generator (17). [2] Vibration damper according to claim 1, characterized by that the torsion damper (27) has an input element (31) and an output element (33), wherein at least one spring element (35) is arranged between the two elements (31; 33). [3] Vibration damper according to claim 1, characterized by that the torsion damper (27) has a vibration damper (75; 79; 81; 83). [4] Vibration damper according to claim 3, characterized by that the vibration damper (75; 79; 81; 83) of the torsion damper is designed as a friction damper. [5] Vibration damper according to claim 1, characterized by that the torsion damper (27) is arranged between a turbine (23) driven by the displacer and an electric machine (25) as parts of the generator (17). [6] Vibration damper according to claim 1, characterized by that the turbine (23), the torsion damper (27) and the electric machine (25) are arranged in a common housing (29).

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