GB2450331A - I.c. engine crankshaft drive system having a pair of crankshafts per piston - Google Patents

Abstract

The crankshaft drive system has two crankshafts 2 with a gear 6 on each that causes the two crankshafts 2 to rotate in opposite directions. The piston drive system eliminates all side thrust on the piston 1. The piston 1 is connected to each crankshaft 2 by means of a normal connecting rod 4 and a short connecting rod 5 supported by a part 3 which is concentric with the crankshaft 2 to give a maximum torque arm close to maximum pressure on the power stroke. The main purpose of the crankshaft system is to have a more economical engine, to use less fuel per kilometre travelled.

Description

Crankshaft drive A background history of engines and patented engines

is described below.

An engine or part of an engine patent application is normally complex and many essential features may be required to make the concept work successfully, such as the two crankshafts and many other parts of the concept mechanism.

Nearly all of the reciprocating piston engines have used the standard crank mechanism.

The normal petrol or diesel engine has maximum cylinder pressure on the power stroke at between 100 to 20 after top dead centre.

The maximum torque arm of a normal crankshaft occurs at about 600 after top dead centre, where the temperature and pressure of gases are now much lower.

The normal connecting rod of an engine at 900 from top or bottom dead centre has the maximum angle to the vertical, as the connecting rod drives the piston to top dead centre the connecting rod is now vertical. The piston is driven by the crankshaft and the now vertical angle of the connecting rod, adding the primary and secondary forces, causing a very high crankshaft force at top dead centre on the exhaust stroke The torque of the normal crankshaft is not very good after mid power stroke is passed.

The crankshaft has positive and negative torque forces after mid power stroke.

The concept crankshaft system has a high torque radius, with each cylinder at near maximum pressure position on the power stroke.

* The concept has improved torque than that of a normal crankshaft both before and after the mid stroke.

* The concept can be used for four and two stroke petrol or diesel engines.

* There is a straight line drive to each piston giving no side loads.

* There is a longer time for Itill combustion, and for the induction stroke.

The object of the concept crankshaft drive is to have an engine that is much more efficient than existing engines. The higher torque arm of the crankshaft at near maximum cylinder pressure than normal allows an engine to have a large torque output.

The torque of the crankshaft drive should on average be much higher than a normal crankshaft. Two cranksha.fts are essential to avoid excessive piston wear and side loads.

There is a need for a much more efficient engine drive to give an engine more miles to each Litre of fuel used. Fuel for vehicles is bound to get more expensive in the future before an alternative drive for vehicles is evolved. An engine that can travel further on each Litre of fuel will lower the cost of travel.

The aim of the concept crankshaft drive is to lower the cost of driving a vehicle.

The concept crankshaft system has lower acceleration forces than is normal.

The two crankshafts are essential to avoid high friction and wear of the pistons.

The high torque output will give fuel economy, and good dnvability This drive can be the basis of a racing engine. 2.

A brief description of the crank drive concept now follows Driving each piston assembly is two normal connecting rods and two short connecting rods. Below each piston is a pair of Crankshafts. On each crankshaft is a concentric crank system that is driven by a normal connecting rod. Below each piston the two crankshafts are geared together such that the crankshaft tops rotate towards each other. The concentric parts driven by the normal connecting rods, drives the two short connecting rods that drives the actual crankshafts. The drive system almost eliminates top dead centre, and gives fill torque very close to top dead centre, and gives good torque after mid stroke is passed on each power stroke. The drive advantages greatly exceed the disadvantages.

Twin crankshafis are essential to avoid excessive connecting rod forces on each piston.

A more detailed description now follows with the help of the following drawings Fig I Shows the concept crankshaft at maximum torque on the power stroke.

Fig 2 Shows the concept crankshaft drive details Fig 3 Shows the crank concept at near BDC The drawings are diagrammatic and are not to scale.

The terms TDC and BDC are top dead centre and bottom dead centre respectively.

Cl L is the centre of a piston or any other engine part The crankshaft drive concept allows a very high torque output from an engine running on diesel, petrol, being a four stroke or a two stroke The crankshaft higher torque arm is at cylinder near maximum pressure on the power stroke, and there is also good torque arm throughout the power stroke.

The action of a single piston 1 drive is described below (other piston drives are the same).

The piston I has twin crankshafts 2 below it, each crankshaft has concentric bearings on which run concentric parts 3 that support a connecting rod 4 and a short connecting rod 5 that drives each real crankshaft 2. The crankshafts are connected by two gears 6.

The object of the drive to the crankshafts is to have a very high torque from them. The twin crankshafts give the driven piston no side loads. Twin crankshafts are used because the drive system for a single crankshaft would give excessive piston loads and wear.

As each crank throw rotates from TDC towards mid stroke the mechanism gives a higher torque radius than normal at high cylinder pressure. The crankshaft torque output after mid stroke is much higher than is normal. The object of the concept crank system is to have a much more efficient engine with good power and improved fuel economy. The crankshafts tops rotate towards each other. The higher torque arm than normal and the toggle affect at near maximum cylinder pressure will increase efficiency, as will good torque at all parts of the power stroke. The drive system can be used for racing engines.

The object is to get more kilometres from each litre of fuel The normal engine exhaust system wastes up to 3O% of engine potential power.

The concept drive system will waste less power in the exhaust.

When the piston is at TDC the two short connecting rods are at a fill crankshaft torque angle, slightly lower than this position the normal connecting rods 4 and the concentric arms 3 forms toggles, giving a very high torque at the two crankshafts. As the crankshafts move the piston further off TDC, the crankshaft torque arm is still at a maximum, giving a very high torque.

The concentric parts drive the two short connecting rods that drive the crankshafts, giving a high torque arm on the power stroke. The compression and power stroke for a normal diesel engine gives very high piston side loads and friction. The concept drive has no piston side loads, and the piston rings stay true to the bore, the piston sealing is improved Induction The inlet valves normally open before TDC and induction takes place, to beyond the piston BDC position. A straight -line piston drive allows induction above and below the pistons if a sealed area below each piston is used. The concept crankshaft drive gives more time for induction and for initial and final combustion than is normal.

A specific embodiment of the concept will now be described by way of example See Figs I to 3 The crankshaft drive concept is used to replace a normal crankshaft on a petrol or diesel four-stroke or two -stroke engine.

The higher torque arm than is normal occurs near to TDC, and a higher torque will be available over the complete power stroke.

The pistons have a drive that eliminates all side thrust and giving lower friction, and improved piston sealing. The higher engine torque than normal, allows a lower amount of fuel to be used at a given distance travelled.

The straight-line piston drive, allows induction of air from above and below the pistons giving a very high volumetric efficiency, and giving a high power output.

The petrol or diesel engines can be four stroke or two stroke types, both types of engine use the normal four-stroke type lubrication. The exhaust gas extraction from each cylinder can be more complete than is normal. The exhaust valves will be cooler than is normal, (if cooled by exhaust purging air). Under piston induction is not drawn.

The drive system has a higher torque output than normal, acting as a normal four stroke engine, and should have improved economy for diesel or petrol engines.

Engines that have the ability to use fuel more efficiently will lower the cost of travel.

The crankshaft details are shown on Figs 1, 2 and 3. A piston and crankshaft near TDC is shown on Fig 1, on Fig 2, the bearing arrangement for the connecting rods and the short connecting rods is shown, and Fig 3 shows a piston and crankshaft near BDC The concentric parts run on roller bearings to give low friction

Claims (1)

1. Claims Crankshaft drive (1) Each piston of an engine is driven by two

   crankshafts that are gear driven together such that the top surfaces move towards each other, the two crankshafts have concentric parts that are driven by connecting rods, the driven concentric parts drives the two crankshafts by short connecting rods, this arrangement gives a high torque radius at a high cylinder pressure, the arrangement gives a high torque radius throughout each power stroke, when each piston is near top dead centre on each power stroke, the two concentric parts and the two connecting rods forms two toggles, and gives a high torque to the two crankshafts due to the high cylinder pressure, the two crankshafts are essential to avoid high loading and wear of each piston, each piston has a straight line drive that gives lower inertia loads to the crankshafts, compared with a normal crankshaft drive, the straight line piston drive improves the piston sealing and gives a longer piston seal life, and reduces piston wear, the straight line piston drive allows induction from above and below the pistons, if below each piston a sealed area is used. * .

   *10 (2) The crankshaft drive described in claim (1), can be used for petrol or diesel engines, being four stroke or two stroke types of engine.

   se. (3) The crankshaft drive described in claims (!) and (2) can be used as the basis of a racing engine.

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