RU2043522C1 - Drive of attached units of internal combustion engine - Google Patents

Abstract

FIELD: mechanical engineering. SUBSTANCE: drive of attached units has torsion shaft 2 arranged in hollow shaft of generator armature 1. One end of torsion shaft 2 is embedded in shaft of armature 1; other end is provided with splines 6 with whose help armature 1 is set in rotation from the engine drive. Next to splines 6 additional splines 7 are provided whose projections and grooves correspond respectively to those of splines on inner surface of hollow armature 1 with backlash at either side of each spline 7. At resonance mode of operation of engine, this backlash will be taken up by grooves and projections of additional splines 7, frequency response of the shaft-armature system will be considerably reduced and resonance mode of operation will disappear. EFFECT: enhanced efficiency. 3 dwg

Description

 The invention relates to mechanical engineering, in particular to engine building, and in particular to structures of drives of mounted units of internal combustion engines, mainly charging generators.

 It is known that internal combustion engines are equipped with a number of auxiliary or mounted units, driven by rotation, from a gear transmission or engine crankshaft (water, oil, fuel pump, air compressor, charging generator, etc.).

 Most drive mounted units have a relatively small mass of moving parts and do not require special protection against inertial forces arising from the operation of an internal combustion engine in unsteady non-stationary modes.

 In some cases, the drive of most of the units is carried out by a V-belt drive, which in itself has damping properties, and there will be no problems with the drive of the units.

Especially desirable is the use of V-belt transmission in the drive of a charging generator, which has an increased rotational speed, usually exceeding the rotational speed of the crankshaft and a substantial rotor mass, which is a source of increased inertial forces in the drive in case of an unsteady frequency operation of the internal combustion engine [1]
In this case, the V-belt drive (typical, for example, for most automobile engines) satisfactorily protects both the generator itself and the drive part of the engine from inertial overloads.

 For a number of reasons (including for reasons of fire safety, for example, on marine and some special engines), the use of V-belt drives in some cases may be limited.

 Moreover, to protect the rotating parts of the generator and its drive from the occurring dynamic overloads in the drive parts, it is necessary to provide for the use of various kinds of protective couplings.

 In a special class, hydraulic turbo couplings used in the drive of charging generators can be distinguished. All these devices in the drive of charging generators complicate and increase the cost of the drive design, and also increase the complexity of manufacturing and assembling an internal combustion engine.

A known design solution of the drive of the charging generator, significantly simplifying the device and its dimensions [2]
Such a known drive is a flexible torsion shaft clamped at one end of the generator armature and located in its center in a hollow coil. The other end of this shaft ends with slots entering the corresponding socket in the diesel drive.

 Torque from a working internal combustion engine is transmitted through a splined end to a flexible torsion shaft, which causes the charging generator to rotate through an existing seal. The non-uniformity of the rotational speed of the internal combustion engine, the set and release of revolutions are compensated by the corresponding twisting of the flexible torsion shaft, which protects the entire drive mechanism and the generator armature from excessive stresses. The torsion margin in the torsion shaft is selected based on the value of the armature mass and possible angular accelerations of rotation of the crankshaft of the internal combustion engine.

 A significant drawback of such a known drive is the presence of resonant zones in its operation.

 In fact, the malleable torsion shaft and the mass of the generator armature represent a known mechanical torsional vibrational system that has its own vibration frequency, which coincides with the frequency of torsional vibrations of the diesel crankshaft, and the system goes into resonant operation. In this case, the torsion stresses in the torsion shaft grow unlimitedly and the latter breaks.

 To protect against the resonant mode, the torsion shaft needs to be installed additional clutch maximum torque or clutch friction type or the like, which complicates and increases the cost of drive design.

 The objective of the invention is to preserve the simplicity and compactness of the torsion drive, to prevent the development of resonant modes of operation.

 The task of detuning from the resonant mode can be solved by performing a torsion shaft that provides its own vibration frequency higher than the frequency of torsional vibration of the engine.

 However, in this case, the armature shaft should increase its rigidity and actually cease to play the role of a damping element.

 The objective of the invention is the design of the drive using a torsion shaft with the required flexibility, not requiring the use of a special coupling in the diesel engine to protect against resonant modes of operation.

 The solution to the problem is due to the fact that in the drive mounted units of the internal combustion engine, mainly charging generators, having a torsion roller located in the hollow shaft of the generator armature, one ring of which is embedded in the shaft of the armature of the generator, and the other end is equipped with a spline connection transmitting torque from the transmission of the internal combustion engine, the torsion shaft on the side of the supply of torque to it through, for example, a spline connection has at least one more additional splines, the pits and depressions of which respectively enter the depressions and protrusions made on the inner surface of the hollow armature shaft with lateral clearance on both sides of each of the splines.

 In FIG. 1 shows a drive of mounted units of an internal combustion engine, a longitudinal section; in FIG. 2, section AA in FIG. 1; in FIG. 3 section BB in FIG. 1.

 In the anchor 1 of the charging generator, the torsion shaft 2 at one end through the cone 3 and the key connection 4 is fixed to the shaft 5 of the generator armature. The other end of the torsion shaft 2 is free and ends with slots 6, with the help of which the generator armature 1 is driven from the engine transmission. On the same free end of the torsion shaft 2, slots 7 are made, protrusions and troughs extending into the corresponding troughs and protrusions of the shaft 5 with side gaps B on both sides of each of the splines.

 Drive mounted units of an internal combustion engine operates as follows.

 Through the slots 6 from the engine transmission, the generator armature 1 is driven into rotation.

 The angular accelerations arising in the system from uneven rotation of the crankshaft of the engine, as well as from changes in the rotational speed of the crankshaft (acceleration, deceleration) are compensated by the corresponding twist of the torsion shaft 2 around its axis, thereby protecting the engine transmission parts and the generator armature from dynamic loads, which for torsion shaft 2 for engine operating conditions should be available, except for resonant modes of operation.

 When the resonant mode of operation, when the natural frequency of torsional vibrations of the torsion shaft 2 together with the armature 1 of the generator coincides with the frequency of torsional vibrations of the crankshaft of the engine, the amplitude of the angular twist of the torsion shaft 2 increases significantly. In this case, the gap B between the troughs and protrusions of the additional slots 7 will be selected, the frequency response of the shaft-armature system will be sharply changed, and the resonant mode of operation disappears. If the engine by this time departs from the resonant mode of operation, then the drive will operate in normal mode with unselected clearances B.

 If the engine continues to operate in resonant mode, the shaft-armature system will periodically select the gaps B in one or the other direction, but each time the torsion shaft 2 will be protected from excessive twists and destruction by the presence of stops in additional slots 7.

 Practice shows that the oscillatory system of the torsion shaft-armature can be set to the area of the initial set of engine speed or coast before stopping, i.e. lower idle of the crankshaft.

 From this it follows that the resonant mode of operation is a very short-term, unsteady mode, the passage of which will not cause intensive wear of the side surfaces of the gaps In the slots 7.

Claims (1)

 DRIVE OF MOUNTED UNITS OF THE INTERNAL COMBUSTION ENGINE of predominantly charging generators, having a torsion roller located in the hollow shaft of the armature of the generator, one end of which is embedded in the shaft of the armature of the generator, and the other end is provided with a spline connection transmitting torque from the transmission of the internal combustion engine, characterized in that the torsion roller has at its free end at least one more splines, the protrusions and troughs of which are designed to interact with the troughs and protrusions, respectively, on the inside nney surface of the hollow armature shaft with providing a side clearance on both sides of each of the slots.

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