RU233027U1 - Torsional vibration damper with arc springs - Google Patents

Abstract

The utility model is intended for damping torsional vibrations of cyclic machines, in particular those arising in diesel generator units equipped with internal combustion engines, as well as in transmissions of transport vehicles and other devices. The leading part, consisting of a damper housing, made with the possibility of connection with the engine flywheel by means of a spacer, the damper housing, consisting of covers and a middle housing part, interacts through blocks of elastic elements made in the form of two rows of helical arc springs, located concentrically along the circumferences - springs of a smaller diameter inside springs of a larger diameter, as well as friction of crackers and outer surfaces of the spring coils with the driven part of the damper, made in the form of a connection of petal disks and a hub, made with the possibility of connection with the generator rotor through a clutch by means of a splined connection, the leading and driven parts of the damper are coaxial by means of plain bearings, the inner space of the housing parts is filled with consistent grease, the exit of which is prevented to the outside by means of covers and cuffs fixed to the housing covers, plates are welded to the housing parts, centered by means of pins. The use of a torsional vibration damper with arc springs will increase the service life of power transmission elements and improve the efficiency of the driven devices by reducing the level of torsional vibrations. 5 fig.

Description

The utility model relates to the field of mechanical engineering, namely to torsional vibration dampers, and can be used to dampen torsional vibrations of cyclic machines, in particular those arising in diesel generator units, transmissions of transport machines equipped with internal combustion engines, electric machines, and generators.

Power transmissions of transport machines are characterized by high dynamic loading. The main reason for the unevenness of torque is the effect of gas and inertial forces during operation of the internal combustion engine mechanisms. When the frequencies of cyclically acting forces coincide with the natural frequencies of power transmissions, resonance phenomena occur, significantly limiting the durability of units and assemblies. To prevent this, various methods and devices are being developed aimed at reducing the level of torsional vibrations and shifting resonances from the working zone of internal combustion engines.

A design of an internal combustion engine is known in which the engine, in addition to a crankshaft, a flywheel and a power take-off device, contains a disk with a hub and a set of springs, wherein a cylindrical bore with peripheral recesses is made inside the flywheel, a disk with a hub mounted on bearings is placed inside the cylindrical bore, springs are placed in the peripheral recesses and in the peripheral holes of the disk that coincide with the recesses, and the power take-off device is fixed on the hub (patent for invention RU No. 2169301).

The closest in technical essence is a two-section flywheel assembly, which includes a flywheel drive disk, a flywheel damping disk and a tightly attached toothed ring, a flywheel disk bushing connected to the flywheel disk, an installation disk fastened to the flywheel drive disk, a spring located between the flywheel drive disk, a flywheel disk bushing and a flywheel damping disk, wherein the connection of the spring and the flywheel disk bushing is a damping-spring type connection, the finishing ring is connected to the flywheel damping disk. The outrigger bearing is located between the specified flywheel disk bushing and the flywheel drive disk, its outer coating is tightly attached to the inner end of the flywheel disk bushing, and the inner coating is tightly attached to the flywheel drive disk (one of the possible examples of the implementation of which is reflected in the patent for invention RU No. 2542802). Such a device is characterized by the fact that the original flywheel of the power transmission consists of two parts, one of which remains in the initial position on the engine side and is designed to start and transmit the engine torque and is called the main mass, and the other part is located on the side of the driven part (gearbox, generator, actuator) and is designed to change the inertia of the driven part and is called the secondary mass.

Utility models DE 3721712 C2, DE 4117582 A1, DE 4117579, CN 200710192763.0, CN 200820071783.2 are known, which relate to this type of devices.

The achieved results of the above devices are preventing the occurrence of resonant oscillations. As is known, power transmissions are characterized by high dynamic loading. The main reason for the occurrence of variable torque is the effect of gas and inertial forces during the operation of the internal combustion engine mechanisms. When the frequencies of cyclically acting forces coincide with the natural frequencies of power transmissions, resonant phenomena occur, significantly limiting the durability of units and assemblies. The most susceptible form of oscillations to this type of impact is the form of oscillations with a unit between the engine flywheel and the actuator. To prevent this, specialists take measures to reduce the amplitudes of resonant oscillations in various ways, which have found their implementation in the form of the above-mentioned devices.

Although the above devices achieve significant performance, the relationship between the primary mass and the secondary mass is not perfect, and, in addition, their price is quite high.

Research has shown that the most effective ways to prevent the propagation of disturbance from an internal combustion engine are two: 1) reducing the frequency of resonant oscillations and taking it outside the operating range of the engine by reducing the rigidity of the elastic elements or by increasing the inertial mass of the driven part; 2) increasing the damping between the engine and the actuator. The solution to the problem of preventing resonant oscillations in these ways has a number of specific difficulties. Thus, when reducing the rigidity of the system, in order to maintain the ability to transmit the effective torque of the engine, it is necessary to significantly increase the travel of the springs, and reducing the frequency of oscillations by increasing the inertia of the driven part is also an irrational solution, since it implies a significant increase in the mass of the rotating elements; increasing the damping in the system reduces the amplitude of oscillations in the event of resonance, but increases it at any other frequencies of disturbance.

To dampen vibrations and eliminate resonances in the power transmission based on a scientifically substantiated choice of the optimal ratio of inertial, elastic and dissipative properties, a torsional vibration damper is proposed, containing a leading and driven part, elastic elements. The leading part consists of a damper body, made with the possibility of connecting to the engine flywheel using a spacer. The damper body, consisting of covers and a middle body part, interacts through blocks of elastic elements made in the form of two rows of helical arc springs located concentrically along the circumferences - springs of a smaller diameter inside springs of a larger diameter, and crackers, with the driven part of the damper made in the form of a connection of petal disks and a hub made with the possibility of connection with the generator rotor through a clutch by means of a splined connection, the leading and driven parts of the pine damper by means of friction bearings, the internal space of the body parts is filled with consistent grease, the exit of which to the outside is prevented by means of covers and cuffs fixed to the covers of the body, plates are welded to the body parts, centered by means of pins.

Fig. 1 shows the cross section B-B;

Fig. 2 shows a front view;

in Fig. 3 cross section B-B;

Fig. 4 shows graphs characterizing the effectiveness of the technical solution.

In the proposed design of the torsional vibration damper, the leading part, made with the possibility of connection with the flywheel 1 of the engine by means of the spacer 2, is the damper housing, consisting of covers 3, 5 and the middle housing part 4 (Fig. 1). The damper housing interacts through blocks of elastic elements and friction pairs with the driven part. The elastic elements are made in the form of two rows of helical arc springs 6 and 7, located concentrically along the circumferences - springs of a smaller diameter inside springs of a larger diameter. Friction is achieved due to the interaction of the inner surfaces of the crackers 8 (Fig. 2) and the outer surface of the spring turns. In the outer surface of the crackers 8 fixedly installed relative to the damper housing, a groove is made (Fig. 4) to ensure the movement of the disk 9 relative to the leading part of the damper when the springs are deformed. The driven part of the damper consists of a connection of petal disks 9, a hub 10 and is designed with the possibility of connection with the generator rotor through a coupling 11 by means of a splined connection. The leading and driven links of the damper are coaxial, and the centering of the driven part is carried out in the leading one by means of plain bearings 12. The internal space of the housing parts is filled with consistent grease, the exit of which is prevented by means of covers 13 and cuffs 14, fixed to housing covers 3 and 5. Small plates 15 are welded to the housing parts, centered by means of pins 16 (Fig. 3). Small plates 15, welded to housing covers 3 and 5, as well as petals of petal disks 9 are stops for spring blocks on the side of the leading and driven parts of the damper, respectively.

The proposed design operates as follows. Torque is transmitted from engine 1 to the generator rotor through elastic elements - springs 6, 7 made in the form of spring blocks, as well as through friction of the inner surfaces of crackers 8 and the outer surface of the spring coils to the driven part of the damper, through petals 9 of the hub 10 and clutch 11. Damping of variable components of torque from the engine is realized by ensuring a minimum value of the frequency of free oscillations of the dynamic system "Driver Part - Elastic Element - Driven Part", determined by the dependence

,

Where - rigidity of the torsional vibration damper;

- the reduced moment of inertia of the two-mass dynamic system under consideration.

The elastic-inertial parameters of the damper are selected in such a way that the value of the frequency of free oscillations was less than the frequency of the fundamental motor harmonic of the engine in the operating range of crankshaft rotation speeds.

The efficiency of the proposed solution is demonstrated during operation in the main modes of the power transmission, when in addition to the actual transmission of the effective torque, the driven energy consumer, such as an electric generator, transmission or other actuator, is excited by means of a disturbing variable torque on the main motor harmonics of the engine. The amplitude of oscillations is reduced due to the operation of the torsional vibration damper as a filter of the variable torque. The efficiency of oscillation damping is achieved by selecting the rigidity of the elastic elements, the friction parameters between the driven and driving parts in the contact of the crackers and the outer surface of the spring coils and taking into account the inertial parameters of the engine and the driven energy consumer. For example, the efficiency of oscillation damping using the proposed torsional vibration damper as part of the DG3500T diesel generator is confirmed by the achieved value of the attenuation coefficient of the main motor harmonic of the diesel engine at revolutions 775 rpm, which is dB (9.0 times the absolute value) and at revolutions 1800 rpm components dB (by 50.1 times in absolute value). This result is clearly illustrated in the time diagrams (Fig. 5), where the moment on the leading part of the damper (diesel flywheel) is shown at the top, and the moment on the driven part of the damper (generator rotor) is shown at the bottom.

Thus, the proposed solution allows to increase the durability of power transmission elements, to improve the efficiency of the driven devices by reducing the level of torsional vibrations.

Claims (1)

A torsional vibration damper with arc springs comprising a leading and a driven part, elastic elements, characterized in that the leading part consists of a damper housing made with the possibility of connection to the engine flywheel by means of a spacer, the damper housing consisting of covers and a middle housing part interacts through blocks of elastic elements made in the form of two rows of helical arc springs arranged concentrically around the circumferences - springs of a smaller diameter inside springs of a larger diameter, as well as friction of crackers and outer surfaces of the spring coils with the driven part of the damper made in the form of a connection of petal disks and a hub made with the possibility of connection to the generator rotor through a clutch by means of a splined connection, the leading and driven parts of the damper are coaxial by means of plain bearings, the inner space of the housing parts is filled with consistent grease, the exit of which is prevented to the outside by means of covers and cuffs fixed to the housing covers, to The body parts are welded with plates that are centered using pins.