LRT engine technology – changing  the heart of  the engine

Every single, functional part of the ICE from air- and fuel intakes to the exhaust have been optimized for more than 100 years.

Except for the heart of the engine.

What if the traditional rotating crankshaft has been based on the wrong idea all along? What if more than 170 million ICE engines sold every year are all based on the wrong architectural solution?

Simultaneously, both ICE engine manufacturers, energy producers and -distributors must make the transition to environmentally sustainable energy carriers, where maybe electric energy or propulsion is not applicable or optimal.

The LRT represents a radical simplification of the engine’s Crankshaft – Rod – Piston connection.

The conventional crankshaft – rod – piston sets limits for interventions to achieve variable compression ratio. The rotating and reciprocating movement of the rod makes it virtually inaccessible to mechanisms capable of changing the distance from the crank to the piston top without a quite complex system which also affects the inertia of the moving parts.
Unlike all engines today, the LRT unique construction works with linear moving connection rods. This eliminates the piston’s sideway friction against the cylinder walls, which significantly reduces the internal mechanical losses.
As the two pairs of pistons, rods and yokes always move in the same direction, a counter moving weight is required to achieve full reciprocating inertia balance. This counterweight comprises a third yoke system having the equal mass of the two first yoke systems connected to the crank midways between the other two. This third yoke is equipped with four pistons which forms two compressors and two exhaust gas expanders, further explained below (about DCE). As the system invokes true reciprocating and rotating parts only, with all internal inertia forces fully balanced, LRT provides a virtually vibration free engine.

Variable compression ratio has for decades been a recognized method of improving the efficiency of engines, especially for IC engines running at lower and varying operating loads. Several attempts have for various reasons failed. Foremost, if not for all proposals, because they were based on modifications of the conventional piston rod system. Consequently, they became too complicated, too heavy, too large and mostly, too expensive.

Changing challenges to become options by eliminating the cause of the issue, often seems better than fighting the problems. The innovation of LRT has released the design of a practical, robust and fuel-efficient VCR solution. The linear moving piston rods run through coaxial worm gears, which by turning the rods can elevate the rods up and down on the yoke’s furnished threads, thereby changing the top dead position of the piston.

The compression ratio can be adjusted automatically at run-time between 7:1 and 15.4:1, depending on the engine’s actual load. When cruising, a car engine works at an average of 15 – 25% of full effect. Within this range the compression ratio will stay at 15,4:1, and the engine efficiency remains high. The VCR mechanism is moving only when the compression rate is changed, otherwise it will remain passive.

As for VCR, the LRT is also the freedom key to design an engine where both high supercharging without a turbo device, as well as an effective double exhaust where recovered residual power of the exhaust is fed to the engine shaft, becomes realized. The latter process takes place in the upper part of the set of expansion cylinders, which common piston area has twice the size of the main piston area.
The lower part of the expansion cylinders forms a compressor, driven by the very same expansion pistons. When supercharging is needed, the expander’s regenerated energy is shared by the shaft and the compressor. However, when the load increases, the resident exhaust gas pressure from the main cylinders rise accordingly, so that even at full load, still a significant amount of recovered energy will be transferred to the engine shaft.
This method of supporting the main cylinders by pressurized charge has several advantages over the traditionally turbochargers:
• Instant response to speed and load changes. (Turbo is slow)
• Empties the main cylinders to atmosphere by discharging. (Turbo cause residual pressure in the exhaust manifold.)
• Higher level of supercharging than turbo.
• Built-in and away.
• Silent operation.
• Lower cost.

Main engine features


  •  Reduced friction
  •  Low weight
  •  Small size