Crankshaft Change: With a piston fixed to its connecting rod and moving parallel to the cylinder walls, the Wiseman engine has lower friction than a conventional internal combustion engine. To convert this linear movement into rotary motion, the pinion (with wedge shape counterweight) rotates counter to the carrier, which is the element transmitting the engine's torque output.
More efficient conversion of vertical piston motion into rotational shaft output is reported for the patented Wiseman Engine developed by Wiseman Technologies. Linear movement of the piston and its non-sideways displacing connecting rod is converted into rotary motion by a counter-rotating pinion and a surrounding carrier, which acts as a crankshaft to output the engine torque (see animation at www.wisemanengine.com).
Company President Randy Wiseman says the basic mechanism is more efficient than conventional internal combustion engines, where the connecting rod is displaced off the cylinder axis to produce crankshaft rotation. This improvement comes about from four different features. First is reduced friction on the piston because, without a conventional crankshaft, there are no offset forces from the connecting rod directed into the cylinder walls. The only drag is from the piston rings sealing the combustion chamber.
An animation of the Wiseman engine in action.
"The geometry of the mechanism converts pressure into rotary torque 16% more efficiently," says Wiseman. The geometry also allows more efficient gear tooth meshing and power transfer, he adds.
Another benefit, Wiseman reports, is that "as the piston moves in a perfect sine-wave displacement, it moves slower during the first half of the power stroke, producing more force per degree of crankshaft rotation." Finally, "The engine applies torque to the crankshaft earlier in the power stroke (12 degrees after top dead center) when pressure is maximum in the cylinder," he adds.
Wiseman notes previous attempts at engines directly converting linear to rotary motion "had unsupported stress points," whereas his engine has complete rotating element support. Stresses are reduced also, he adds, by careful cross section geometry selection, such as the crescent-shaped carrier opening.
CONTACT:Randy Wiseman, Wiseman Technologies; Building 9313, Suite 121, Stennis Space Center, MS 39529; Tel (228) 806-5226; e-mail: [email protected]; www.wisemanengine.com; or enter 509 at www.designnews.com/info.