CA2074754C - Power transmission mechanism - Google Patents

Abstract

A power transmission mechanism for interconverting reciprocating motion and rotational motion includes a cylinder which receives a double-head piston therein. The double-head piston has a block extending inward from an inner surface of each of two piston heads thereof, defining a space between the two blocks. A crankshaft penetrates transversely through the cylinder between the piston heads, with a crank portion thereof fittingly located in the space between the two blocks.

Description

2074 7~

3 The present invention relates to a power transmission 4 ~echanism to interconvert the reciprocating motion of a piston and the rotational motion of a crankshaft.
6 A conventional power tr~n i~sion mechanism, e.g., an 7 internal combustion engine generally has a cylinder with a 8 piston connected to a crank via a connecting rod. However, 9 the connecting rod wobbles in a plane, yet the piston is linearly guided by the cylinder wall, which renders a non-11 uniform frictional force between the piston rings and the 12 cylinder wall, thereby reducing the lives of the elements.
13 Furthermore, the piston has to connect the crank via a 14 connecting rod, which is a bulky mechanism having a low-power transmission efficiency.
16 The present invention provides an improved power 17 transmission mechanism which is compact and more efficient 18 in power tr~n! ission.
19 SUMMARY OF THE ~Nv~NllON
According to the present invention, a power 21 tr~n~ ion me~h~nism includes a cylinder which receives a 22 double-head piston therein. The double-head piston has a 23 block ext~n~;ng inward from an inner surface of each of the 24 two piston heads thereof, defining a space between the two blocks. A crankshaft penetrates transversely through the 26 cylinder between the piston heads, with a crank portion 27 thereof fittingly located in the space between the two 28 blocks. By such an arrangement, the reciprocating motion of 207ll 7~

l the piston and the rotary motion of the crankshaft are 2 interconvertable.
3 Other advantages and novel features of the invention 4 will become more apparent from the following detailed description when taken in conjunction with the accompanying 6 drawings.

8 Fig. 1 is an exploded view of a power transmission 9 me~hAn; in accordance with the present invention;
Fig. 2 is a schematic perspective view of the power 11 transmission mechanism with a portion thereof cutaway to 12 show the structure thereof; and 13 Fig. 3a through 3d are schematic views taken along line 14 3-3 in Fig. 2, which respectively show intake, compression, power, and exhaust strokes of the power transmission 16 mechanism which functions as an internal combustion engine 17 in this case.
18 DETATT~n DESCRIPTION OF THE PREFERRED EMBODIMENTS
19 Referring to the drawings and initially to Figs. 1 and 2, a power transmission mechanism for interconverting 21 reciprocating motion and rotational motion in accordance 22 with the presant invention generally includes a cylinder 10 23 which receives a double-head piston 12 therein. The double-24 head piston 12 has a block 14 ext~nding inward from an inner surface of each of two piston heads 16 thereof, defining a 26 space between the two blocks 14. In this embodiment, the 27 piston heads 16 are connected by four posts 13 to form an 28 integral unit. A crankshaft 20 penetrates transversely 2 ~ 7 4 7 J ~

1 through the cylinder 10 between the piston heads 16 with a 2 crank portion 22 having a diameter substantially equal to 3 the distance between the two blocks 14, thereby being 4 fittingly located in the space between the two blocks 14.
The transverse length of each block 14 is equal to the 6 diameter of the cylinder 10 to assure that the crank portion 7 22 always contacts the two blocks 14, i.e., during 8 operation, the crank portion is guided in the space between 9 the two blocks 14.
For illustration, the following example shown in Figs.
11 3a through 3d is an application of the power transmission 12 mechanism acting as an internal combustion engine. The 13 cylinder 10 has two bores 24 and 26 for respectively 14 installing an intake valve 25 and an exhaust valve 27 in which the controlling of ignition thereof is conventional 16 and as such further description is not required. Optionally, 17 the cylinder 10 may have intake and exhaust valves provided 18 on both end walls thereof to form a double-action piston.
19 In operation, the piston 12 in Figs. 3a through 3d is respectively shown in its intake stroke, compression stroke, 21 power stroke, and exhaust stroke. As clearly shown in these 22 figures, upon combustion of a gas mixture in the cylinder, 23 the piston's linear and reciprocal motion in the cylinder 10 24 is converted into rotary motion of the crank of the cr~nkch~ft.
26 At least one piston ring 18 (in this embodiment only 27 one piston ring is shown) is provided to each piston head 28 for sealing and lubrication.

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1 It is appreciated that the invention has alternative 2 uses as a power transmission mechanism such as a compressor 3 in which rotary motion of the crankshaft is converted into 4 reciprocating motion of the piston to pressurize the working fluid.
6 Although the invention has been explained in relation 7 to its preferred embodiment, it is to be understood that 8 many other possible modifications and variations can be made 9 without departing from the spirit and scope of the invention as hereinafter claimed.

Claims

CLAIMS:
A power transmission mechanism for interconverting reciprocating motion and rotational motion comprising a cylinder which receives a piston with two piston heads therein, a block extending inward from an inner surface of each of said piston heads, defining a space between said blocks, each said block having a length equal to the diameter of said cylinder, a crankshaft penetrating transversely through said cylinder between said piston heads, with a crank portion thereof fittingly located in said space between said blocks.