Double crankshaft reciprocating engine

1 . A double crankshaft reciprocating engine, comprising:

a plurality of cylinder assemblies, each cylinder assembly comprising:

a cylinder, which is provided with cylinder air inlets and an intake valve at the top;

a piston, which is mounted in the cylinder, the piston and an inner wall of the cylinder located above the piston form a combustion chamber; the piston is provided with first vent holes and a first exhaust valve for controlling the on-off of the first vent holes; and

a displacer, which is mounted in the cylinder and located below the piston, a cylindrical space between the displacer and the piston is a compression chamber; the displacer is provided with second vent holes and a second exhaust valve for controlling the on-off of the second vent holes; and

a double crankshaft transmission system, comprising:

two crankshafts provided in parallel, each crankshaft comprises a plurality of cranks, a plurality of the corresponding cranks of the two crankshafts constitute a plurality of crank pairs, and each of the crank pairs is mirror symmetric with respect to a YZ plane;

a pair of transmission gears which are mounted on the front ends of the two crankshafts and mesh with each other;

wherein a midpoint of a connecting line of centers of the pair of transmission gears is defined as the origin O of an XYZ coordinate system, the connecting line of centers is defined as an X-axis direction, a direction parallel to the axis of the transmission gears is defined as a Y-axis direction, and a vertical direction is defined as a Z-axis direction,

a plurality of displacer rods, each displacer rod is a hollow rod that extends in the Z-axis direction and is connected to the displacer at a top end and extends out of a bottom end of the cylinder at a bottom end;

a plurality of piston rods, each piston rod extends in the Z-axis direction and has a top end connected to the piston and a bottom end passing through the displacer and the displacer rod and extends beyond the bottom end of the displacer rod;

a plurality pairs of push rods, upper ends of each pair of the push rods are rotatably connected to the bottom end of the displacer rod respectively; and

a plurality of pairs of connecting rods, lower ends of each pair of the connecting rods are rotatably connected to the bottom ends of the piston rods respectively, and the lower ends of each pair of the push rods and the upper ends of each pair of the connecting rods are rotatably connected to the same crank pair respectively, so that each pair of the connecting rods and each pair of the push rods form a rhombic structure.

2 . A double crankshaft reciprocating engine according to claim 1 , wherein

the bottom ends of the displacer rod and the piston rod are in an inverted “T” shape, and respectively have a cross beam extending in the X-axis direction,

the cross beam is provided with a first shaft hole at each end,

each connecting rod and each push rod are provided with a second shaft hole at each end,

the piston rod and the displacer rod are connected to the connecting rod and the push rod by means of pins which link the first shaft hole and the second shaft hole; and

the piston rod and the displacer rod are pivotally connected to the connecting rod and the push rod by means of pins which link the first shaft hole and the second shaft hole.

3 . A double crankshaft reciprocating engine according to claim 2 , wherein

each of the cranks is provided with a crank pin, and

the connecting rods and the push rods are pivotally connected to the crank pair by means of the second shaft hole cooperating with the crank pins of the crank pair.

4 . A double crankshafts reciprocating engine according to claim 1 , wherein

the first exhaust valve is rotatably mounted in the piston and provided with first exhaust valve holes,

the first exhaust valve is connected to an exhaust valve drive mechanism mounted on the piston to realize the opening and closing of the first exhaust valve by means of rotating the first exhaust valve,

when the first exhaust valve is closed, the first vent holes and the first exhaust valve holes are offset and not communicated,

when the first exhaust valve is open, the first vent holes are aligned and communicated with the first exhaust valve holes, and

the structural form and working principle of the second exhaust valve are the same as those of the first exhaust valve.

5 . A double crankshaft reciprocating engine according to claim 4 , wherein the exhaust valve drive mechanism comprises;

an exhaust valve rack, an exhaust valve gear, and a pneumatic device, wherein the exhaust valve gear and the first exhaust valve are coaxially and rotatably mounted on the piston,

the exhaust valve rack engages with the exhaust valve gear at one end and is fixedly connected to the pneumatic device at the other end, and

the pneumatic device is actuated by a high-pressure gas in the compression chamber.

6 . A double crankshaft reciprocating engine according to claim 5 , wherein the pneumatic device comprises:

a gas reservoir, a pressure control valve and an actuator cylinder, wherein

an inlet of the gas reservoir is fluidly communicated with the compression chamber through a one-way intake valve,

an outlet of the gas reservoir is fluidly communicated with the actuator cylinder through the pressure control valve,

the pressure control valve is a pressure controlled two-position two-way valve, and

a piston of the actuator cylinder is connected to the rod portion of the control rack.

7 . A double crankshaft reciprocating engine according to claim 1 , wherein

the intake valve is rotatably mounted in the cylinder air inlets and provided with intake valve holes,

the intake valve is connected to an intake valve drive mechanism mounted outside the top of the cylinder to realize the opening and closing of the intake valve by rotating the intake valve,

when the intake valve is closed, the cylinder air inlets and the intake valve holes are offset and not communicated, and

when the intake valve is open, the cylinder air inlets are aligned and communicated with the intake valve holes.

8 . A double crankshaft reciprocating engine according to claim 7 , wherein

the intake valve drive mechanism comprises an intake valve rack, an intake valve gear and a hydraulic unit, wherein

the intake valve gear and the intake valve are coaxially and rotatably mounted in the cylinder air inlets, and

the intake valve rack engages with the intake valve gear at one end and is fixedly connected with the hydraulic unit at the other end.