WO1996035864A1

WO1996035864A1 - Crank mechanism of variable crank throw

Info

Publication number: WO1996035864A1
Application number: PCT/PL1996/000008
Authority: WO
Inventors: Antoni Wierzbicki
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-05-09
Filing date: 1996-04-17
Publication date: 1996-11-14
Anticipated expiration: 1997-11-09
Also published as: PL308560A1

Abstract

Invention raises efficiency of crank mechanism. It is characterized that between crank pin (1) of crankshaft and big end (2) of connecting rod (3) are placed one inside the other both eccentric sleeves (4 and 5) ending with gears. On eccentric sleeves (4 and 5) cradle (9) is mounted, on which idle wheels are seated.

Description

CRANK MECHANISM OF VARIABLE CRANK THROW

The object of this invention is the crank mechanism of variable crank throw in particular for internal fuel piston engine as well as a piston compressor.

There are known from Polish patent description No.144411 crank mechanisms of variable crank throw equipped with piston which is connected to the connecting-rod by means of piston pin and with crankshaft comprised of eccentric sleeve as an indirect component between crank pin of crankshaft and connecting rod big end. Internal opening axis of sleeve is displaced in relation to external axis of cylindrical in size of eccentric. Eccentric sleeve is joint driving mechanism guaranteed angular speed of eccentric sleeve. Eccentric sleeve is joint driving mechanism to assure angular speed of eccentric sleeve relative to crank pin of crankshaft and mechanism controlling angular position of eccentric sleeve to specified angle with respect to crank throw of crankshaft.

The essence of this invention is construction of crank mechanism of variable crank throw characterized so that between crank pin of crankshaft and connecting rod big end are located one inside the other double arrangement of eccentric sleeve ending with gears. On the eccentric sleeves cradle is seated on which are idle wheels on the upper part of cradle and idle wheel axis is perpendicular to wheels axis of eccentric sleeves. In variation, eccentric sleeve wheels and idle wheels are cylindrical and common idle wheels shaft is rotating in the upper part of cradle and parallel to eccentric sleeve wheels axis. Driving wheel frontal surface of eccentric sleeve has passage, in which slide is driven seated in corresponding crank surface. In variations, crank frontal surface has passage in which is driven slide seated in corresponding driving wheel surface. Crank mechanism has two crankshafts situated parallel comparative to each other, symmetrical against cylinder axis.

Qualities of crank mechanism according to the invention are: shortened piston stroke for engine and its prolonged for compressor this raises efficiency of crank mechanism. Using a two crankshaft engine eliminates piston power influence on the cylinder walls that causes increased static power on crank, therefore improves efficiency.

These two solutions together, i.e. double eccentrics and two crankshafts increase efficiency of fuel engine from η₀ = 0,28 to η₀ = 0,46 which means 40% less fuel consumption and the same less pollution.

The object of this invention is shown on the drawing, where: Fig.l presents longitudinal section of crank mechanism components with cone shaped wheels interrelated to eccentric drive; Fig. 2 presents longitudinal section of crank mechanism components with cylindrical wheels, interrelated to eccentric drive; Fig.3 is crossection of crank mechanism with two crankshafts; Fig. 4 presents view of driven slide passage: Fig. 5 is movement curve for engine, and Fig.6 - for compressor. As presented in Fig.l between crank pin 1 of crankshaft and big end 2 of connecting rod 3 are located one in the other two off centre mounted sleeves 4 and 5, ending with gears. Wheels 6 and 7 of sleeves 4 and 5 and idle wheels are cone shaped wheels. Idle wheel is rotating in the upper part of cradle 9, fasten swing on sleeves 4 and 5. Axis of idle wheel 9 is perpendicular to the axis of wheels 6 and 7 of eccentric sleeves 4 and 5. In invention variation, wheels 6a and 7a of sleeves 4 and 5 and idle wheels 8a and 8b seated together on common shaft 10 are cylindrical wheels. Shaft 10 is rotating in the upper part of cradle 9 and parallel to the axis of wheel 6a and 7a of eccentric sleeves 4 and 5. On the frontal surface drive wheel 6 of eccentric sleeve 4 has passage with driving slide 11 seated in its crank surface 12 of crankshaft. In invention variation, and crank frontal surface 12a has passage, in which driving slide 11a is located, seated in frontal surface of driving wheel 6a. Crank mechanism in the variation for fuel engines has two crankshafts 13 and 14, situated parallel relative to each other and symmetrical relative to cylinder axis 15.

Crank drive 12 of crankshaft is transmitted directly to the external eccentric sleeve 4 with driving slide 11 and simultaneously with gears 6,7 and 8 to the external eccentric sleeve 5, causing this type of revolutions opposite to crankshaft revolutions. During the motion idle wheel 8 mates displacing and swinging with connecting rod shank 3, which causes rotating motion - but also moves backward 80 and forward oscillatory relative to the main shaft driving simultaneously through idle wheel 8 internal eccentric opposite relative to main shaft. Rotary movement of internal eccentric sleeve is variable movement and depends on actual radius of sleeve eccentric 5. Next to a such solution, big end of connecting rod is moving 85 according to curve, that is resulting of superposition of swinging movement of external eccentric sleeves 4 variable rotary opposite motion of internal eccentric sleeve 5 and circumference movement of crank pin 1 of crankshaft. Movement curve of crank pin opening axis 2 of connecting rod 3 describes equation:

90 p2 = (rsinφ + ejsinψ + e₂sinξ)2+(rcosφ - ejcosψ - e₂Cθsξ)2

p - actual crank pin axis radius of connecting rod big end r - crank throw 5 ei - eccentricity of internal sleeve e2 - eccentricity of external sleeve φ - angle of crank rotation ψ- angle of eccentricity of internal sleeve ξ - angle of eccentricity of external sleeve 0

Angles ψ and ξ can be used within described range to form movement curve.

Additional regulating can be obtained by means of angle α = (0 ÷ π) shifting driving slide 11. Movement curve also depends on meshing position of eccentric and idle wheel. For example, this meshing for engine and compressor theoretically differs itself at an angle π.

Claims

1. Crank mechanism of various crank throw, is characterized by the following features: between crank pin (1) of crankshaft and big end (2) of connecting rod (3) are situated one in the other two eccentric sleeves (4 and 5}, ending with gears and on eccentric sleeves (4 and 5) cradle 9 is mounted on which idle wheels are seated.

2. Crank mechanism as claimed in claim 1, is characterized by the following features: wheels (6 and 7) of sleeves (4 and 5) as well as idle wheel (8) are cone shaped wheels and wheel (8) is mounted in the upper part of cradle (9) and axis of that wheel is perpendicular to the axis of wheels (6 and 7) of eccentric sleeves (4 and 5)

3. Crank mechanism as claimed in claim 1, is characterized by the following features: the wheels (6a and_7a) of sleeve 4 and 5 and idle wheels (8a, 8b and 8c) are cylindrical wheels, and common shaft (10) of idle wheels (8a and 8b) is rotating in the upper part of cradle (9) and parallel to axis of wheels (6a and 7a) of eccentric sleeves (4 and 5).

4. Crank mechanism as claimed in claim 2, is characterized by the following features: driving wheel (6) of eccentric sleeve (4) on its frontal surface has passage with driving slide (11) , seated in corresponding surface of crank (12).

5. Crank mechanism as claimed in claim 3, is characterized by the following features: frontal surface of crank (12a) has passage with driving shde (11a), seated in corresponding surface of driving wheel (6a).

6. Crank mechanism as claimed in claim 1, is characterized by the following features: it has two crank shafts (13 and 14) situated parallel relative to itself and symmetric relative to cylinder axis 15.