Axial piston machine with rotation restraint mechanism

An axial piston machine acting as a thermodynamic engine, compressor, motor or pump comprising;

• a crankshaft rotatable about a crankshaft axis and carrying an crank journal having an inclined crank axis that is oblique to the crankshaft axis but aligned to intersect therewith at an acute angle A at point X,
• a cylinder cluster comprising at least two cylinders rigidly located with respect to each other, each cylinder containing a complementary piston to each reciprocate along a reciprocating axis defined by its respective cylinder and each of a cross section matched to the cross section of the cylinder, each said cylinder in fluid connection with at least one valved inlet/outlet port therefor,
• a reciprocator mounted to rotate relative to said crank journal about said inclined crank axis, said reciprocator in mechanical engagement with each piston to allow the requisite reciprocating displacement of each piston within its respective cylinder between top dead centre (TDC) and bottom dead centre (BDC) upon the crankshaft rotating relative to said cylinder cluster about the said crankshaft axis,
• at least two rotation restrainers to restrain the relative rotation between said cylinder cluster body and said reciprocator about the crankshaft axis, each of said rotation restrainers being comprised of a pair of gimbal arms linking between the reciprocator and cylinder cluster, a first of said arms being a cylinder gimbal arm pivotably connected to said cylinder cluster and pivotable thereto only about a cylinder gimbal hinge axis oblique to said crankshaft axis, a second of said arms being a reciprocator gimbal arm pivotably connected to said reciprocator and pivotable thereto only about a reciprocator gimbal hinge axis oblique to said inclined crank axis, the reciprocator gimbal arm and cylinder gimbal arm of each said pair are linked together by a gimbal arm tip link having three rotational degrees of freedom that intersect at a point T1 that is equidistant from their respective gimbal arm hinge axes and always lying on a medial plane defined as the plane passing through point X to which the line that bisects angle A is normal, the orientations of the hinge axes for each pair of gimbal arms being mutual reflections in the medial plane so that as the crankshaft rotates with respect to the cylinder cluster homo-kinetic restraint of said reciprocator is ensured.

A reciprocator restraint assembly of or for a Z-crank axial piston machine that includes a crankshaft rotatable about a crankshaft axis and carrying a crank journal having an inclined crank axis that is oblique to the crankshaft axis but aligned to intersect therewith at an acute angle A at a point X on the crankshaft, said assembly to restrain the relative rotation between a cylinder cluster body and a reciprocator said assembly comprising:

• two gimbal arms, said gimbal arms linked together by a gimbal link joint with multiple rotational degrees of freedom and that intersect at a point T, point T lying in a medial plane M being defined as the plane passing through point X to which the line that bisects angle A is normal, wherein each of said gimbal arms is pivotally mounted at an identical distance L from point T, one of said gimbal arms, hereinafter referred to as the “cylinder gimbal”, being pivotally mounted from said cylinder cluster about a cylinder gimbal pivot axis, the second of said gimbal arms, hereinafter referred to as the “reciprocator gimbal” being pivotally mounted from said reciprocator about a reciprocator gimbal pivot axis, said reciprocator gimbal pivot axis positioned equidistant from point X and point T as is the cylinder gimbal pivot axis, the orientations of the pivot axes of the two gimbal arms being mutual reflections in the medial plane M resulting in the point T lying on the medial plane M as the crankshaft rotates with respect to the cylinder cluster, and thus ensuring homo-kinetic rotational restraint between said reciprocator and said cylinder cluster.

An axial piston machine acting as a thermodynamic engine, compressor, motor or pump comprising;

• a crankshaft rotatable about a crankshaft axis and carrying an crank journal having an inclined crank axis that is oblique to the crankshaft axis but aligned to intersect therewith at an acute angle A at point X,
• a cylinder cluster comprising at least two cylinders rigidly located with respect to each other, each cylinder containing a complementary piston to each reciprocate along a reciprocating axis defined by its respective cylinder and each of a cross section matched to the cross section of the cylinder, each said cylinder in fluid connection with at least one valved inlet/outlet port therefor,
• a reciprocator mounted to rotate relative to said crank journal about said inclined crank axis, said reciprocator in mechanical engagement with each piston to allow the requisite reciprocating displacement of each piston within its respective cylinder between top dead centre (TDC) and bottom dead centre (BDC) upon the crankshaft rotating relative to said cylinder cluster about the said crankshaft axis,
• at least two rotation restrainers to restrain the relative rotation between said cylinder cluster body and said reciprocator about the crankshaft axis, each of said rotation restrainers being comprised of a pair of gimbal arms linking between the reciprocator and cylinder cluster,
• a first of said gimbals arms herein after “a cylinder gimbal arm” pivotably connected to said cylinder cluster and pivotable thereto about a cylinder gimbal hinge axis that is normal to a plane in which the crankshaft axis lies and that is set a distance from the crankshaft axis on a side thereof so that said cylinder gimbal arm projects, from said cylinder gimbal hinge axis, away from said crankshaft
• a second of said arms (herein after “reciprocator gimbal arm”) pivotably connected to said reciprocator and pivotable thereto about a reciprocator gimbal hinge axis that is normal to a plane in which the crank axis lies and that is set a distance from the crank axis on a side thereof so that said reciprocator gimbal arm projects, from said reciprocator gimbal hinge axis, away from said crank,
• the reciprocator gimbal arm and cylinder gimbal arm of each said pair linked together by a gimbal arm tip link having three rotational degrees of freedom that intersect at a point T1 that is equidistant from their respective gimbal arm hinge axes and always lying on a medial plane defined as the plane passing through point X to which the line that bisects angle A is normal, the orientations of the hinge axes for each pair of gimbal arms being mutual reflections in the medial plane so that as the crankshaft rotates with respect to the cylinder cluster homo-kinetic restraint of said reciprocator is ensured.

A Z-crank axial piston internal combustion engine comprising

• a cylinder cluster of at least two piston containing cylinders rigidly located with respect to each other, each said cylinder including at least one working fluid transfer port,
• a crankshaft rotatable relative to said cylinder cluster and carrying an angled crank about which a reciprocator can rotate that is in mechanical connection with the pistons, said angled crank having a crank axis that is oblique to the crankshaft axis but aligned to intersect therewith at an acute angle A at a point X on the crankshaft, and
• a ported member relative to which the cylinder cluster can rotate and that can seal the at least one fluid transfer port of each cylinder yet offers, at intervals, their exposure to spark plug(s) and/or working fluid delivery and removal facilities,
• an indexing drive to transmit rotation between said cylinder cluster and said crank shaft to, in use, rotate said cylinder cluster relative said ported member about said crankshaft axis at a rotational rate timed to coincide with the desired range of movement of the piston in each cylinder between TDC and BDC, and two gimbal arms, said gimbal arms linked together by a gimbal link joint with multiple rotational degrees of freedom and that intersect at a point T, point T lying in a medial plane M being defined as the plane passing through point X to which the line that bisects angle A is normal, wherein each of said gimbal arms is pivotally mounted at an identical distance L from point T, one of said gimbal arms, hereinafter referred to as the “cylinder gimbal”, being pivotally mounted from said cylinder cluster about a cylinder gimbal pivot axis, the second of said gimbal arms, hereinafter referred to as the “reciprocator gimbal” being pivotally mounted from said reciprocator about a reciprocator gimbal pivot axis, said reciprocator gimbal pivot axis positioned equidistant from point X and point T as is the cylinder gimbal pivot axis, the orientations of the pivot axes of the two gimbal arms being mutual reflections in the medial plane M resulting in the point T lying on the medial plane M as the crankshaft rotates with respect to the cylinder cluster, and thus ensuring homo-kinetic rotational restraint between said reciprocator and said cylinder cluster.