Reciprocating fluid machines
OwnerPeter Robert Raffaele, Michael John Raffaeleinventors
Life of this patent
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Abstract
A scotch yoke type fluid device in which the pistons are decoupled from each other is provided. Each piston of the device has its own pair of sliding surfaces and its own slider. The sliding surface of each piston is disposed on the same side of a big end bearing of a crank. The main axis of the crank is movable along a path such that the pistons are neither substantially retarded nor advanced. The effective centre of mass of the crank, piston and slider remains stationary relative to the crank axis. Each piston includes a guide for constraining the piston to move along the piston axis. An intermediate member may interconnect the piston and the slides.
Claims49
A scotch yoke fluid device selected from an engine and a pump comprising:
- a crankshaft having a main axis and a big end bearing pin, the bearing pin having a bearing pin axis and being adapted to orbit the main axis during crankshaft rotation, the bearing pin sweeping a first volume centered on the main axis as it orbits the main axis;
- slider connecting means rotatably mounted on the bearing pin;
- a cylinder having a cylinder axis, the cylinder axis being perpendicular relative to the main axis;
- a piston having a piston axis and including:
- (a) a piston crown having a total cross sectional area perpendicular to the piston axis;
- (b) first guide means elongate along a first axis extending perpendicular to the piston axis;
- (c) restricting means elongate along a second axis extending parallel to the piston axis and the restricting means having a first end and a second end;
- the piston mounted for reciprocation along the cylinder axis;
- the first guide means being located only to that side of the bearing pin axis lying between the bearing pin axis and the piston crown;
- the first guide means adapted to constrain the slider connecting means for reciprocation along the first guide means during crankshaft rotation;
- a block comprising third guide means adapted to engage the restricting means, the restricting means and the third guide means adapted to cooperate to substantially prevent rotation of the piston around an axis parallel to the main axis
- wherein:
- (i) the restricting means and the third guide means are in engagement only within a second volume defined by a projection of the piston crown total cross sectional area along the piston axis towards the crankshaft;
- (ii) the restricting means is positioned to a long side of the first guide means, the first end of the restricting means is located closer than the first guide means to the piston crown, and when the piston is at TDC and at BDC the second end of the restricting means is located closer to the bearing pin axis than the first guide means is;
- and
- (iii) the restricting means is adapted to be moved in and out of the first volume such that the restricting means is completely outside the first volume when the piston is at TDC and is at least partially inside the first volume when the piston is at BDC.
Dependencies are inferred from the claim text.