DD257952A3 - COUNTER ASSEMBLY AND SIZES ON CRANK SHAFTS - Google Patents

Abstract

The invention relates to an opposing mass arrangement and sizes for crankshafts of power and working machines, with the optimum operating conditions for the crankshaft bearings are created in conjunction with appropriately sized countermeasures. The invention is characterized in that each arranged on a crankshaft countermeasures of different sizes, both counterweights are not equal to zero, are executed, the centers of gravity of the countermeasures are axially displaced relative to the crank webs such that the ratio of the distance between retracted counterweight and bearing center to the distance between the drawn countermeasures a / b per Kroepfung between 0.6 and 1 entrains. Fig. 1

Description

Field of application of the invention

The invention relates to an opposing mass arrangement and sizes for crankshafts of power and working machines, with the optimum operating conditions for the crankshaft bearings are created in conjunction with appropriately sized countermeasures.

The countermeasures serve the mass balance and for certain cylinder numbers in addition to torque compensation.

Characteristic of the known state of the art

It is known from DE-OS 3151091 an arrangement of countermeasures in a crankshaft for an internal combustion engine with 12 cylinders in V-arrangement, in which the counter-masses are arranged in such a radial direction on the crankshaft, that each of the forces acting on each bearing inertial forces on a Minimized, thereby preventing the load acting on the bearings is excessively large, thus creating the opportunity to maintain oil films of suitable strength on the bearing surfaces.

The disadvantage of this solution is that it can only be used for 12-cylinder V engines. Furthermore, this solution does not allow to ensure an optimal bearing force curve for each individual crankshaft base stock. Furthermore, from DE-OS 2522591 a machine crankshaft with improved dynamic balance with multiple cranked crank arms, in which one or more of these crank arms individually by a relatively small angle in such a direction and by such an amount relative to the angular positions that they at a Equation with equal angular intervals in the orthogonal projection would take on a plane transverse to the geometric axis of rotation of the shaft, are offset, thereby the Auswuchtgräd is improved. A disadvantage of this solution is that not the operating conditions of the sliding bearings are improved, but only the external mass force effects and they can only be applied to crankshafts, which have a free moment of inertia (from 5 cylinders).

Object of the invention

The aim of the invention is to provide for a crankshaft counter-mass arrangement and size, with the help of the entire basic storage, but at least for the most highly stressed base camp of the crankshaft, optimal operating conditions are created.

Essence of the invention

The object of the invention is ₍ an opposing mass arrangement and large to create crankshafts, with the for the entire

Crankshaft bearing the best Betr stenicnerheit, realized by the lubricating layer thickness, the pressure and the tribotechnisch most favorable form of Wellenveriagerungsbahn the most vulnerable base camp is achieved, the vibration behavior of the crankshaft and thus the engine is maintained or improved.

According to the invention, this object is achieved in that each arranged on a crankshaft counterweights of different sizes, both counterweights are not equal to zero executed and unsymmetrical crankshaft symmetrically to the crankshaft plane counterweights symmetrically, symmetrical crankshaft counterweights are arranged, the focus of the Countermeasures against the crank webs are axially displaced so that the ratio of the distance between retracted counterweight and bearing center to the distance between the retracted countermeasures a / b per crank is between 0.6 and 1.

The countermeasures of the crankshaft are fed in each case via the left or right Hubzapfenebene up to the connecting rod, the free passage of the connecting rod is ensured.

The entire basic storage has the greatest possible operational reliability, realized by the lubricating layer thickness, the pressure and the tribotechnisch most favorable form of the wave displacement of the most vulnerable base camp, the size

the countermeasures are different at the two crank webs of a crank for different numbers of cylinders and ignition sequences and the centers of gravity of the counter masses against the crank webs axially displaced. In engines and engines with odd cylinder number is an asymmetric to the heavy plane of the engine counterweight arrangement with respect to the size and center of gravity.

embodiment

The invention will be explained in more detail with reference to an embodiment. Show it:

Figure 1: counter mass arrangement for a crankshaft for an internal combustion engine with the ignition sequence 1 -2-3 Figure 2: counter mass arrangement with a firing order 1-3-2

Starting from the usual countermeasure arrangements and sizes, both the countermass size and its position are changed so that, taking into account the different load characteristics of the individual crankshaft bearings best possible operating conditions for each slide bearing arise.

The evaluation criteria used are the hydrodynamic variables which allow statements on wear and material fatigue.

The advantage over previous solutions is the bearing force curve designed for each crankshaft base bearing. This manifests itself particularly in the larger achievable lubrication gap values or layer thicknesses and more favorable shapes of the shaft displacement paths compared to previously known solutions, including better possibilities of arranging the oil supply and oil forwarding bores.

The crankshaft has 6 counterweights, which are mounted in pairs and offset by 180 ° to the crank pin. The countermeasures are drawn in relation to the left or right Hubzapfenlagerebene up to the connecting rod, but without jeopardizing the free passage of the connecting rod.

In Figures 1 and 2, the counter-mass arrangements for the Zuendfolgen 1-2-3 and 1-3-2 are shown at a Zuendabstand of 240 ⁰ KW.

The countermass sizes listed in the table result in a degree of balance (compensation for the tilting moment around the Y-axis) of 20%. This degree of torque compensation, in conjunction with a matched engine mount also leads to a favorable vibration behavior of the engine.

Ignition sequence Countermass size 1-2-3 1-3-2

m 0.44 m +0.17 m

m ³² m ¹¹ 0.56 m ^red + 0.08 ^{m osz}

m ³¹ m ¹² 0,50m ^red + 0,16m ^osz

m ²² m ²¹ 0.50 m ^red +0.09 m ^osz

m ²¹ m ²² 0.56 m ^red + 0.10 ^{m osz}

m ¹² m ³¹ 0.44 m ^red +0.07 m ^osz

11 32 red osz

Claims (1)

Counter mass arrangement and size of crankshafts with at least two crank pins or crank arms for power and working machines offset with the direction of the crank pins or crank arms mounted countermeasures each drawn on the left or right Hubzapfenlagerebene to the limit of the free Pleueldunlaufes, characterized that each arranged on a crankshaft counterweights of different sizes, both counterweights are not equal to zero, are executed, the centers of gravity of the counterweights to the crank webs are axially displaced so that the ratio of the distance between retracted counterweight and bearing center to the distance between the countermeasures retracted a / b per crank is between 0.6 and 1. For this 1 page drawings