DE102010044716A1 - Balance shaft generator for e.g. four cylinder internal combustion engine of motor vehicle, has magnets whose rotational movement is inhibited during loading of induction coil, where force components are produced perpendicular to shaft - Google Patents

Abstract

The generator has a balance shaft comprising magnets (3) e.g. permanent magnet or electro magnet, and an induction coil (7) actively-connected with the magnets in the surrounding of the balance shaft, so that rotational movement of the magnets is inhibited during loading of the induction coil. Force components are produced perpendicular to the balance shaft. A rotor (2) is attached to the balance shaft, and extends perpendicular to the balance shaft. A stator (6) is arranged concentrically around an axis of the balance shaft, where the rotor has a single pole. An independent claim is also included for a method for compensating vibration of a reciprocating engine.

Description

The present invention relates to a balance shaft device for a reciprocating engine with a balance shaft. Moreover, the present invention relates to a method of compensating for crankshaft vibration by coupling a crankshaft to a balancer shaft.

In reciprocating engines, especially internal combustion engines (gas, petrol, diesel) occur depending on the number of cylinders due to the design of free mass forces. In order to reduce these forces, if necessary to eliminate, balancing shafts are used. Balancing shafts have, relative to the axis of rotation, eccentrically arranged weights, whereby a corresponding imbalance is generated. Driven by the crank drive of the engine, balance shafts generate the required inertial forces to counteract those of the crank mechanism. However, driving the balance shaft (s) requires energy that results in an increase in consumption (gas, gasoline, diesel). The speed of the balancer shaft is drive-related in a fixed relationship to the engine speed.

Conventional balance shafts are used across manufacturers. The constant development of motor vehicles in terms of comfort and efficiency has produced a wealth of detailed solutions and concepts over the years. All have in common, however, that an eccentric mass generates a counterforce to the crankshaft vibration upon rotation of the shaft.

The document 10 2007 043 610 A1 describes an internal combustion engine with a crankshaft, in particular for a vehicle, in which at least one imbalance weight is provided for mass balance. It is envisaged that the imbalance weight is located on a rotatably coupled to the crankshaft unit.

The object of the present invention is thus to reduce the consumption of a reciprocating engine and to propose a corresponding balance shaft device or a method for compensating a crankshaft oscillation.

According to the invention this object is achieved by a balance shaft device for a reciprocating engine with a balancer shaft, wherein the balancer shaft has a magnet, and in the vicinity of the balancer shaft, an induction element is arranged in operative connection with the magnet, so that when loaded the induction element rotatory running with the balance shaft Movement of the magnet is inhibited, whereby a force component is generated perpendicular to the balance shaft.

In addition, the invention provides a method for compensating a crankshaft vibration by coupling a crankshaft with a balancer shaft, act on the equipped with at least one magnet balancer shaft magnetic forces, which generate forces on the balancer shaft, which counteract the crankshaft vibrations.

Advantageously, a force is generated by the equipped with a magnet balancing shaft on the basis of Lenz's rule, which acts on the balance shaft and thus can counteract a mass force. Thereby, the mass of the balance shaft can be reduced, whereby finally a reduction of consumption is achieved.

Preferably, the magnet is a permanent magnet or electromagnet and is part of a rotor together with the balancer shaft. The runner may have only a single pole. The induction element in turn may be part of a stator with a plurality of such induction elements. Advantageously, the plurality of induction elements are each loaded with adjustable load. For energy generation, the rotor and the stator can be components of a generator.

In a preferred embodiment, a reciprocating engine is provided with such a balance shaft device and a crankshaft that is vibration compensated with the balance shaft device. Specifically, a four-cylinder internal combustion engine can be provided with two balancing shaft devices of the type associated with a crankshaft, each rotor being centered on its balancing shaft and the two balancing shafts rotating oppositely at twice the speed of the crankshaft. In addition, a 6-cylinder internal combustion engine with said drive shaft device can be provided, wherein at each end of the balance shaft, a rotor is arranged, and the orientations of the rotor are rotated relative to the shaft axis to each other by 180 °.

The present invention will now be explained in more detail with reference to the accompanying drawings, in which:

1 a cross section through a balance shaft generator according to the present invention;

2 a longitudinal section through the balance shaft generator and

3 the balance shaft generator of 1 in several rotational positions.

The present invention is based on the idea that the counterforce to a crankshaft in a balance shaft can be generated by a magnetic or electromagnetic braking force (Lorentz).

In particular, the counterforce can also be generated by a generator with asymmetric rotor.

In 1 is a cross section of such a generator and in 2 a corresponding longitudinal section shown. Only in 2 is the actual balancing shaft 1 shown. On the balance shaft 1 is rotatably a runner 2 applied. It extends substantially perpendicular to the balance shaft 1 , At one end he has a magnet 3 , which is designed here as an electromagnet. With respect to the balance shaft axis 4 the magnet 3 opposite end of the runner 2 this has a balancing mass 5 , which is essentially the mass of the magnet 3 balances.

Concentric around the balance shaft axis 4 is a stator 6 arranged. He has eight induction coils here 7 which are regularly distributed around the circumference.

Through the asymmetric rotor or rotor 2 with, for example, only one pole, the braking force (Lorentz) in the generator is not from the opposite side of the rotor 2 converted into a pure torque, but is based fully on the balance shaft and thus generates not only a torque but also a counterforce on the balance shaft to the crankshaft. This can be determined by 3 better explain. There is the generator of 1 shown in eight different rotational positions. In the picture to the left of 3 the runner is like in 1 perpendicular, being his magnet 3 directly to an induction element of the stator 6 ie an induction coil 7 , faces. By passing the magnet 3 at the induction coil 7 a voltage is induced in this. Is the coil 7 provided with an electrical load, so flows a corresponding current, reducing the movement of the rotor 2 inhibited, ie braked, is. It is now assumed that the runner 2 moves in a clockwise direction like the other pictures of 3 to imply it. By braking the rotated rotor 2 in the place of the magnet 3 there is a counterforce 8th on the balance shaft 1 , The drag 8th acts perpendicular to the balance shaft 1 , Thus, it has the same directional component as a correspondingly arranged eccentric mass of a conventional balance shaft. The other pictures of 3 show that through each induction coil 7 of the stator 6 another direction of balancing power 8th can be achieved. This means that the direction of a drag force by the appropriate placement of an induction coil 7 can be adjusted. The strength of the counterforce 8th can be influenced by the fact that the induction coils 7 be electrically loaded depending on the desired effect. At low ohmic load, a high current flow, whereby the braking force and thus the counterforce 8th is high. Optionally, the loads of the individual induction coils can also be controlled dynamically, so that the balancing force 8th vary temporally and locally.

Alone for the generation of a compensatory power 8th it is not necessary to use the stator 6 with the runner 2 to operate as a generator. The use of a generator driven by the crank mechanism or of a plurality of generators with eccentrically arranged windings (exciter, stator), however, makes it possible to use a portion of the energy which is used to generate the compensating forces, which in turn act against the inertia forces of the crank mechanism To convert energy (electricity). By generating electric current according to this eccentric principle occur, as described, due to the Lorentz force, forces that are similar to those of a conventional balance shaft. This causes the compensation forces to be generated due to the generation of electricity. A conventional balance shaft, on the other hand, needs energy to generate the balancing forces.

By using a generator according to the described principle of action, the conventional balance shaft can be omitted or supplemented. In contrast to the conventional balance shaft, the cause of the compensating forces generated is due to the inhibition of the movement by induction (generator principle), which in addition to the power generation also allows load-dependent control. The required compensating forces can thus be optionally adapted or generated and, unlike those of a conventional balancer shaft, are not dependent on the rotational speed alone. The strength of the generated electric current increases in proportion to the generated equalizing forces.

With one or more such generators on the balancing shafts or the alternator of a motor vehicle can be relieved or possibly omitted, which is reflected in an under-consumption of fuel. The alignment of several of these generators on a drive axle allows not only the generation of higher currents and thus higher compensation forces, the generation of balancing forces in any direction in three-dimensional space.

In principle, mechanical compensation devices such as the known type with eccentric masses can be replaced by generators with asymmetric rotors. Thus, for example, a classic 4-cylinder Lanchester compensation can be realized by two balancing shafts with equal forces, with the balancer shafts rotate opposite with double crankshaft speed and each shaft has centered on a same generator with asymmetric rotor. Alternatively, two identical generators can be provided with the same distance from the center per shaft.

In addition, a 6-cylinder Kubeltriebausgleich can be realized by a shaft, the shaft rotates at crankshaft speed and act at the end of two opposing forces. In this case, each end has a same generator with asymmetric rotor, in which the rotor positions are rotated by 180 ° to each other.

LIST OF REFERENCE NUMBERS

1

balancer shaft

2

runner

3

magnet

4

Balancer shaft axis

5

Leveling compound

6

stator

7

inductors

8th

counterforce

Claims (10)

Balance shaft device for a reciprocating engine with - a balance shaft ( 1 ), characterized in that - the balance shaft ( 1 ) a magnet ( 3 ), - in the vicinity of the balance shaft ( 1 ) an induction element ( 7 ) in operative connection with the magnet ( 3 ) is arranged so that - under load of the induction element ( 7 ) one with the balance shaft ( 1 ) carried out rotational movement of the magnet ( 3 ) is inhibited, whereby a force component perpendicular to the balance shaft ( 1 ) is producible. Balancing shaft device according to claim 1, characterized in that the magnet ( 3 ) is a permanent magnet or an electromagnet and together with the balance shaft ( 1 ) Part of a runner ( 2 ). Balance shaft device according to claim 2, characterized in that the runner ( 2 ) has only a single pole. Balance shaft device according to one of the preceding claims, characterized in that the induction element ( 7 ) Part of a stator ( 6 ) with a plurality of such induction elements. Balance shaft device according to claim 4, characterized in that the plurality of induction elements ( 7 ) are each loaded with adjustable load. Balance shaft device according to claim 4 or 5, characterized in that runners ( 2 ) and the stator ( 6 ) Are components of a generator. A reciprocating engine having a balance shaft device according to any one of the preceding claims and a crankshaft which is vibration compensated with the balance shaft device. A reciprocating engine according to claim 7, which is designed as a 4-cylinder internal combustion engine with two crankshaft associated balance shaft devices according to one of claims 2 to 6, wherein each runner ( 2 ) each centered on its balance shaft ( 1 ), and the two balance shafts ( 1 ) turn in opposite directions at twice the speed of the crankshaft. A reciprocating engine according to claim 7, which is designed as a 6-cylinder internal combustion engine with a drive shaft device according to one of claims 2 to 6, wherein at each end of the balancer shaft ( 1 ) one runner each ( 2 ), and the orientations of the runners ( 2 ) are rotated relative to each other with respect to the shaft axis by 180 °. Method for compensating a crankshaft oscillation by - coupling a crankshaft with a balancing shaft ( 1 ), characterized in that - at least one magnet ( 3 ) equipped balance shaft ( 1 ) Attack magnetic forces acting on the balance shaft ( 1 ) Generate forces that counteract the crankshaft vibrations.

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