GB2102066A - I.C. engine with a split crankshaft - Google Patents

Abstract

A cylinder bore 70 without a piston in a cylinder line having the pistons of the remaining cylinders connected to one or other of two crankshaft parts 71, 72 houses components necessary for operation of the engine. The components may include a clutch and gear arrangement 77 for connecting the crankshaft parts 71, 72 when fuel is supplied to all the working cylinders rather than only those associated with one or other of the crankshaft parts. An air compressor (97), Fig. 8 (not shown), or the overhead camshaft driving gear (61, 62, 106, 107), Figs. 5 and 9 (not shown), may be located in the non- working cylinder. In a V-engine, Figs. 1 to 3 (not shown), one cylinder of each bank may house a pump or motor of an hydraulic transmission for connecting the crankshaft parts. <IMAGE>

Description

SPECIFICATION A vehicle engine This invention relates to a vehicle engine.

The internal combustion engines used in vehicles usually have too high a power output for normal operation. However this output is considered necessary in order to take care of the load peaks occurring during overtaking, rapid acceleration and hill climbing. This means that the engine, during a substantial part of its operating time, will work at part load, resulting in a low efficiency and a corresponding high fuel consumption.

Various ways of reducing the fuel consumption have been proposed, of which several include means for cutting off, during part load, the fuel supply to certain cylinders, and/or disconnecting the drive inlet and/or exhaust valves at certain cylinders. This will require a complicated and sensitive control device, and can result in a mechanical system with a high risk of failures.

Besides there will always be high frictional losses in the crank mechanisms associated with the cylinder or cylinders occasionally cut out but still following the crank shaft rotation. There is also an apparent risk of an unsatisfactory running at an engine, where ignition does not occur at all cylinders, as well as an increased wear. The possibility of cutting off certain cylinders will, however, result in a lower emission content in the exhaust gases, as the remaining cylinders will operate at normal load conditions.

The object of the present invention is to provide a simple, sturdy and efficient arrangement in an internal combustion engine having a number of cylinders arranged in at least one line, and which has a fuel supply system permitting a cutting line, and which has a fuel supply permitting a cutting out of certain cylinders.

According to the present invention there is provided a vehicle engine having cylinders arranged in at least one line, and having a fuel supply system permitting certain cylinders to be brought out of, and into operation, wherein the crankshaft of the engine is divided into at least two parts, at least one cylinder in the, or each line, lacks a piston and associated connecting rod, and certain components in the transmission system of the engine are housed in the piston-less cylinder, and are connected to the parts of the crankshaft.

The components may include a releasable clutch adapted, at will, to interconnect the parts of the crankshaft, but can alternatively, or in combination therewith, include driving means for the engine cam shaft or parts thereof.

With an engine of the V-type it is possible to remove the piston from a cylinder in each line. A fluid pressure machine of a type capable of operating as a pump or as a motor may be fitted in each of these piston-less cylinders, said machines each being drivingly connected to an associated one of said parts of the crankshaft, and being further interconnected by fluid transferring conduits.

Alternatively an air compressor may be mounted in the piston-less cylinder. The compressor will be cooled bythe cooling water of the engine, and when a hydraulic machine is mounted on the cylinder the temperature of the hydraulic fluid will be maintained at a suitable level by the cooling water.

The ends of the crankshaft parts preferably carry bevel gears for engagement with means for driving the components mounted in the actual cylinder, and possibly also with spur gears forming part of a transmission to the output shaft.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 shows a standard V-engine modified in accordance with the present invention; Figure 2 schematically shows a cross-section through the engine of Figure 1; Figure 3 shows a longitudinal Section through part of the engine of Figure 1; Figure 4 schematically shows the installation of an engine in a vehicle; Figure 5 shows a longitudinal section through the engine of Figure 4; Figure 6 shows an alternative driving arrangement for an engine of the same type as shown in Figure 5; Figure 7 shows a longitudinal section through an engine, where a lamella clutch connecting the parts of the crankshaft is fitted in the piston-less cylinder; Figure 8 shows the same engine as in Figure 7 but with an air compressor fitted in the piston-less cylinder; and Figure 9 shows the same engine as in Figure 7, but with means for driving the cam shafts fitted in the piston-less cylinder, and with a transmission to the output shaft fitted between the two crankshaft parts.

Figures 4-8 show engines having the cylinders arranged in a line, but it is evident, that the arrangements shown therein may also be used with V-engines, where the piston of one cylinder in each line has been removed.

When the engine block is adapted to receive separate cylinder liners, some components for fitting into a piston-less cylinder, e.g. hydraulic machines, air compressors or clutches, are preferably formed so that in each case their external envelope surface corresponds with that of a cylinder liner. The component in question will then be directly swept by the cooling water, and will rapidly be "conditioned" to a suitable operating temperature.

Figure 1 shows, very schematically, an eight cylinder V-engine 10 of standard design. The piston and the associated connecting rod has been removed from one cylinder 11 a, b of each line, and the empty cylinder space has been used for mounting of other engine components. The crankshaft is divided into two parts in the manner to be described in connection with Figure 3.

Hereby one two-cylinder V-engine comprising cylinders 1 2a, b and one four-cylinder V-engine comprising cylinders 1 3a, b and 1 4a, b are obtained.

The engine is provided with an exhaust gas turbine driven charging compressor installation 15, and the air intake manifolds 1 6a, b are provided with fuel injection means 1 7 of known design. These are connected to a monitoring device 18, which makes it possible to direct the supply of fuel either to cylinder group 1 2a, b, or to group 1 3a, b + 14a, b, or to both groups simultaneously, so it will be possible, during each operating condition to take out approximately only the necessary power output.

Pressure fluid machines 19, or a type operating arbitrarily as a pump or as a motor, are fitted in the piston-less cylinders 11 a, b. These machines may be of arbitrary known kind, for instance of the screw, vane or swash-plate type. As they are mounted within the cylinder the pressure fluid will rapidly be heated during start-up, and will then be maintained at a suitable operating temperature.

The machines 1 9 are interconnected by conduits 20, 21 in which one or more valves 22 are fitted for governing the switching in and out of the machines, the direction of flow, the pressure of fluid etc.

Figures 2 and 3 show how the machines 1 9 are driven from the crankshaft 23. The latter is divided in two parts 23a, b adjacent cylinders 11. Each of said parts of the crankshaft is provided with a respective bevel gear 24a, b.

Each bevel gear meshes with a further bevel gear 25a, b at driving shafts of the pressure fluid machines. The cylinders 11 a, b are, as is common with V-engines, displaced in relation to each other in the longitudinal direction of the engine, and are furthermore arranged at an angle to each other.

Hereby it is possible, by a suitable selection of the external diameters of the gears 24 and 25, to prevent collision between the drives to the two pressure fluid machines 19.

An adjustment at valve 22 provides the possibility of switching out cylinders 1 2a, 1 2b.

The pressure fluid machine 1 9a is driven by crankshaft part 23a, and its inlet and outlet may be directly connected by the valve 22. The pressure fluid may possibly be drained from this machine during such operation. When the two machines 1 9a, b are interconnected, torque will be transferred from crankshaft part 23b to crankshaft part 23a by way of the hydraulic system during normal driving, as well as during engine braking.

Depending upon where the output transmission is located it is possible to arrange for only the two cylinders 1 2a, b to remain operable at low load, while cylinders 1 3a, 1 3b and 1 4a, b are switched out.

The drawing shows an eight cylinder engine, but the invention may also be used with six cylinder engines, at which it is possible to obtain two plus two operating cylinders.

Figure 4 shows the front end of a vehicle 40 provided with an internal combustion engine 41 of the invention, and adapted to transfer torque to the front wheels 42 of the vehicle by way of a clutch/transmission means 43 built into the engine, and a conventional transmission/differential 44. The engine is a six cylinder unit (Figure 5), the crankshaft of which is divided. The piston and the connecting rod have been removed from one cylinder, and are substituted by transmission elements, in the manner to be explained in connection with Figure 5.

The fuel supply system of the engine is not shown in detail, but is operable by a control device 45, which supplies either part of the engine, or both parts, with fuel (Figure 4).

Figure 5 shows a longitudinal section through the engine 41, which has six cylinders 46-51.

Cylinder 48 lacks a piston and associated connecting rod, which have been substituted by transmission elements. By this arrangement it is possible to utilize the engine block, and all main components in a standard engine to provide a compact unit, where it is easy to adjust the power output to the operational requirements and which ensures a low fuel consumption and a low emission content in the exhaust gases.

The crankshaft of the engine is divided in two parts 52a, b adjacent to cylinder 48. Each crankshaft part carries a bevel gear 54, 55, which by way of meshing gears 56, 57 drive components in a lamella coupling 53 which determine the connection of the crankshaft parts to the clutch/transmission means 43.

The control device 45 (Figure 4), which governs the supply of fuel to the two groups of cylinders 46, 47 and 49-51, respectively, will also operate the lamella coupling in the transmission 53, so that a selected group of cylinders, or both groups, will be connected to the output shaft.

It is for instance possible to arrange for cylinders 49-51, to the crankshaft part 52a of which the electric generator 58 and other auxiliaries are connected, is the part of the engine which is used during normal engine load, whereas cylinders 46 and 47 form a booster unit, which is switched in when extra power is needed.

Further bevel gears 59, 60 mesh with bevel gears 54, 55 at the crankshaft parts, and are mounted upon shafts 61,62 which drive the cam shafts 63, 64 of the associated cylinder groups.

This provides the possibility of reducing the length of the engine, which is especially advantageous with front wheel drive.

Figure 6 shows a modification of the interconnection arrangement at an engine of the type above described, but where the transmission 43a is directly connected to one of the crankshaft parts 65. The two parts 65, 66 of the crankshaft are interconnectable by a free-wheel clutch 67 arranged directly between the crankshaft parts.

Bevel gears 54a 55a here drive parallel shafts 61 a, 62a to the cam shaft transmissions, as well as auxiliaries 58a.

Figure 7 shows a middle portion of an engine having an arbitrary number of cylinders, and where the piston and its associated connecting rod of cylinder 70 has been removed and substituted by other components. The crankshaft is divided into two parts 71, 72, which in the manner above described are provided with bevel gears 73, 74. These gears mesh with further bevel gears 75, 76, which drive various components in a planetary gear/clutch device 77, which is mounted in cylinder 70.

A casing 78, integral with a ring wheel 79 and a clutch housing 80, is driven by gear 76, while a carrier 81 for planet gears 82 is driven by gear 75.

A sun wheel 83 is mounted upon a shaft 84, which carries a first clutch lamella 85 for cooperation with the clutch housing 80, and further with a second lamella 86 for co-operation with a stationary clutch housing 87.

The drawing is schematic only. In practical realisation each lamella shown will be represented by a number of lamella units, and there are of course means for operating the lamella as well as bearings and so forth, which are not shown for the sake of clarity. The compact type which is used in modern motorcycle transmissions may advantageously be used.

Depending upon how the transmission relating to the booster group is selected, this may operate at the same speed, or at a higher speed than the other cylinder group, and can also be designed for rapid heating during start-up.

As the gearing/clutch is located within the cylinder, a satisfactory cooling of the components is obtained.

Figure 8 shows a portion of an engine having an arbitrary number of cylinders, where one cylinder 90 in the line lacks piston and associated connecting rod, and where the crankshaft is divided in two parts 91 and 92. The ends of the crankshaft parts carry bevel gears 93, 94, which co-operate with a lamella clutch 95, governed in any suitable way so that it connects the two parts of the crankshaft, or holds the cylinder group to the left in the drawing inactive. The output shaft (not shown) is connectable to the right hand group of cylinders, and bevel gear 93 at the associated crankshaft part 91 also drives, by way of a further bevel gear 96, an air compressor 97 mounted in cylinder 90, and communicating with the air intake manifold of the engine by way of a conduit 98.

Figure 9 shows a further adaptation of the invention. One cylinder 100, in the line lacks its piston and the crankshaft is divided in two parts 101 and 102. Crankshaft part 101 co-operates with part 102 by way of a free-wheel clutch 103, which makes it possible for last-mentioned part to remain at standstill, while the first mentioned part rotates. Instead of a free-wheel clutch, bearing of arbitrary type may be used, while the interconnection of the crank shaft parts occurs at the transmission located below the engine.

Both crankshaft parts are provided with a bevel gearing 104, 1 05, driving respective shafts 106, 107, which, in turn, by further bevel gearings, drive the cam shafts 108,109 of the engine.

Each crankshaft part further carries a spur gear 110, 111. A connection between the crankshaft parts 101, 102 may be arranged by arbitrary transmission means. A spur gear transmission 11 5 is, as one example, shown in conjunction with crankshaft part 102 a chain transmission 11 6 is shown. The transferring element thereof may alternatively be a chain or a belt. Such arrangements are especially suitable when the engine is located transversely in the vehicle, and has oppositely directed output shafts 11 3, 114.

The embodiments according to Figures 4-9 schematically indicate engines having cylinders arranged in a single line, but it is evident that the same arrangement may be used with V-engines, in which two piston-less cylinders are obtained, and may be used for the reception of components such as clutches, shaft transmissions and/or air compressors.

Certain auxiliaries, for instance electric generators, may of course also be mounted within the "empty" cylinder, and instead of, or together with, transmission shafts to the cam shafts, transmissions to auxiliaries driven by the engine may be executed through the cylinder.

Claims (11)

1. A vehicle engine having cylinders arranged in at least one line, and having a fuel supply permitting certain cylinders to be brought out of, and into operation, wherein the crankshaft of the engine is divided into at least two parts, at least one cylinder in the, or each line, lacks a piston and associated connecting rod, and certain components in the transmission system of the engine are housed in the piston-less cylinder, and are connected to the parts of the crankshaft.

2. A vehicle engine as claimed in claim 1, wherein the components include a releasable clutch adapted, at will, to interconnect the parts of the crankshaft.

3. A vehicle engine as claimed in claim 2, wherein the clutch is adapted to permit one crankshaft part to be operated at a higher speed than the other part.

4. A vehicle engine as claimed in either of claims 1 and 2, wherein the components include driving connections to the engine cam shaft or parts thereof.

5. A vehicle engine as claimed in claim 1 and of the V-type, wherein one cylinder in each line of cylinders lacks a piston and connecting rod, and a fluid pressure machine of a type capable of operating as a pump or as a motor is fitted in each of these piston-less cylinders, said machines each being drivingly connected to an associated one of said parts of the crankshaft and being further interconnected by fluid transferring conduits.

6. A vehicle engine as claimed in claim 1, wherein the components comprise an air, compressor driven by at least one of the crankshaft parts and connected to the air intake side of the engine.

7. A vehicle engine as claimed in any one of the preceding claims, wherein the components are mounted within the cylinder so the driving fluid therein will be conditioned by the cooling water of the engine.

8. A vehicle engine as claimed in any one of the preceding claims, wherein the ends of the crankshaft parts are interconnected by a freewheel, and each part carries a bevel gear meshing with driving gears at the components.

9. A vehicle engine as claimed in any one of claims 1 to 7, wherein each of the ends of the crankshaft parts carries a bevel gear in. a gearing driving components in the associated cylinder, and further a spur gear forming part of a chain or gear transmission to the output shaft.

10. A vehicle engine as claimed in either of claims 1 and 2, wherein the components include transmission means to auxiliaries of the engine.

11. A vehicle engine substantially as hereinbefore described with reference to, and as shown in, Figures 1 to 3, or Figures 4 and 5, or Figure 6, or Figure 7 or Figure 8 or Figure 9 of the accompanying drawings.