AU2011100646A4 - Cylindrical Cam Piston Engine - Google Patents

Abstract

Abstract This invention discloses a type of piston engines which the piston is substituted by cylindrical can. The main shaft of a traditional piston engine is a crank shaft. Piston is perpendicular to the main shaft. The reciprocating motion of the piston rotates the crankshaft via a connecting rod. The difference between the traditional piston engines and this invention is that the cam piston of this invention is on the same axis as the main shaft. Cam groove, roller and roller shaft guide the reciprocating motion of the cam piston and this motion rotates the main shaft through an axle arm. Moreover, the valve of mechanism traditional piston engine is replaced by admission and exhaust valve and valve cam of this invention. The cylinder body (outer cylinder wall) and valve sleeve (inner cylinder wall) form ring cylinder of the invention. Co m G) 4 C) Ln %D C> w co FX) w Ln ru w C:> Ln ru co ru 4 co ro %D w ro Ln C:) m N ro ci ro

Description

description Cylindrical Cam Piston Engine This invention is a type of Piston Engine. This invention does not change the basic structure and principle of traditional piston engines. Main changes are done to the piston structure, the way piston rotates the main shaft and the replacement for the valve body of traditional piston engine with admission and exhaust valve and valve cam. The main shaft of a traditional piston engine is a crankshaft. Piston is perpendicular to the main shaft. The reciprocating motion of the piston rotates the crankshaft via a connecting rod. For this invention (hereinafter called The Engine), cylindrical cam is used to serve as piston. The cam piston is on the same axis as the main shaft. Cam groove, roller and roller pin shaft guide the reciprocating motion of the cam piston and this motion rotates the main shaft through an axle arm. The setup of a cylindrical cam serving as a piston simplifies the structure of The Engine, reduces the number of components and the size of The Engine. The following Figures further explain the structure and principle of The Engine. Figure 1 Main view of The Engine Figure 2 Expanded view of the surface of cylindrical cam piston Figure 3 Expanded view of cylindrical surface of valve cam Figure 4 Diagram showing the sealing principle of double sealing ring Figure 5 Expanded view of cylinder surface of admission and exhaust valve Figure 6 Diagram showing the distribution of oil grooves of main shaft cylinder surface Figure 7 Vertical-sectional view of fuel channel Figure 8 Sectional view of the end piece of valve sleeve Figure 9 Sectional view along the axle arm Figure 10 Structural diagram of another driving mode of admission and exhaust valve Figure 11 Sectional view of roller shaft along the valve (Figure 10) Figure 12 Sectional view along air inlet (Figure 10) In the Figure: cylindrical cam piston[1], cam groove[2}, cylinder [3], cylinder head [4], spark plug[5], admission and exhaust valve[6}, end cap[7], valve camt8], air inlet[9], oil outlet[10], piston roller shaft[11], Piston roller[12], main shaft[13], oil groove[14], valve sleeve[15], air opening[16], double sealed ring groove[17], air outlet[18], exhaust ring groove[19], valve roller shaft[20], valve roller[211, bearing housing[22], bearing[23], main shaft pin[241, axis pin groove[25], oil inlet[26], exhaust channel[27], venthole[28, air inlet ring groove[29], sealed ring groove[30], piston cover[31], inner piston ring spacer[321, inner piston ring groove[33], inner piston ring housing[34], valve sleeve end piece [35], oil return hole[36], axle arm[37], water jacket[38], piston ring groove[39], air admission channel[40], double sealed ring[41], double sealed ring gap[42], inner piston groove[43], roller shaft oil channel[44], cam rail[45], cam sleeve[46J, cam sleeve ventholet47] and U- shaped tube[48]. Figure 1 is the main view of the Engine. From the Figure: the main shaft[13] is the central axis of cam pistont1], admission and exhaust valve[6], valve cam[8l and bearing[231. The main shaft[13] is located on the central axis line of cylinder[3}, valve sleeve[15], cylinder head[4], end cap[7] and bearing base[22}. The main shaft can rotate freely. The cylinder, cylinder head and piston cap can be linked and fixed on the fuel tank (not shown in the Figure; located on the dash line in Figure 9) with bolts. The cylinder consists of cylinder body, valve sleeve and cylinder head. The cylinder body is the outer cylinder wall. Valve sleeve is the inner cylinder wall. The valve sleeve is fixed on the cylinder head or integrated with it. The cylindrical cam piston separates the cylinder into two changeable ring cylinders of the same volume. -- -- - - - -- - - - - -- 1 -- - .description From Figure 1 and Figure 9: there is an axial inner piston groode[43] on the inner wall of the cam piston. The axle arm[37] of the main shaft is embedded on the inner piston groove and can make axial slide. Piston roller[12] is embedded inside the cam groove[2]. Piston roller shaft[11} is fixed on the cylinder body. Roller can rotate freely on roller shaft. When The Engine starts, flywheel drives main shaft and axle arm and rotates cylindrical cam. Roller and cam groove guide and reciprocate cylindrical cam which also functions as a piston. When the Engine is running, cam piston reciprocates and the volumes of the two cylinders keep changing: when one cylinder increases in volume, the other decreases in volume and vice versa. Cam piston rotates under the action of roller and cam groove, and axle arm and inner cam groove, which then leads to the rotation of main shaft. To accord with the requirement of four-stroke and achieve balance in motion, there are two symmetrical, undulating curve grooves(cam groove). Two sets of roller and roller pin shaft are setup on cylinder body accordingly as shown in Figure I and 2. Figure 2 shows an expanded view of the surface of cylindrical cam piston. From the Figure: the two sets of roller and roller pin shaft are 180 degree apart from each other. The path of roller(cam groove) is circular envelope. The central path of the circle can be any symmetric smooth curve which consists of circular arc, elliptic arc or parabolic arc, etc. The piston can be one-wave, two-wave or four-wave cylindrical cam of symmetrical, smooth and curved groove. In this example, the path of the cam groove of the cylindrical cam piston consists of circular arcs. In this example, the cam piston has two-wave groove. When main shaft rotates one loop, cam piston goes to and fro two times, i.e. four strokes. Hence, this invention can be designed as a four-stroke engine. From Figure 1: there are air opening[16], air outlet[18] and valve sleeve end piece[35] on the valve sleeve. The dashed lines in Figure 5 indicate the air opening and air outlet: they are not full circles in 360 degrees. Figure 8 shows the shape of the valve sleeve end piece. The end piece is fixed on the valve sleeve and has a larger opening. There are axle arm, main shaft pin[24], oil groove[14] and air admission channel[40] on the main shaft. Figure 6 shows the distribution of oil grooves on the cylindrical surface of the main shaft. From Figure 6, air admission channel and oil groove are arranged alternatively on the main shaft surface. Admission and exhaust valve can slide and is located in between the main shaft and valve sleeve. There are sealed ring groove[30], air inlet ring groove[29], double sealed ring groovef17] and exhaust ring groove[19] on the admission and exhaust valve as show in Figure 5. From Figure 1 to 6: there is an axial axis pin groove[25] on admission and exhaust valve. Main shaft pin is embedded in the axis pin groove and can slide. Valve cam[8] is fixed on the admission and exhaust valve. The two sides of valve cam form two chambers of changeable volumes. The widths of the chambers are a bit larger than the distance that the valve cam moves. One of the chambers is related to burning of gas and is called the gas chamber. The other chamber is called the oil chamber. There is a set of roller and shaft on the valve cam. Valve roller shaft[20] is fixed on the end cap. Valve roller[21] is embedded in the valve cam groove. When the main shaft rotates, the admission and exhaust valve rotates accordingly and also slides axially. To accord with the 4 strokes of the cam piston, the intake and exhaust of the admission and exhaust valve is controlled by valve cam. Figure 3 is an expanded view of the cylindrical surface of valve cam (the path of cam groove of the valve cam is indicated by arc lines in this example). From Figure 1 and 3: in the 360 degrees of the cylindrical surface, 90 degrees of crest and 90 degrees of trough of the cam groove are situated in positions where intake stroke or exhaust stroke occur. The other 180 degrees of cam groove is flat and is where compression stroke and power stroke occur. Viewing from the right side, if the main shaft is rotating clockwise, then from Figure 1, the right cylinder is located at the starting position of exhaust stroke and the left cylinder is located at the starting position of intake - - - - - - -- 2 - - - - - - description stroke. In the meantime, air opening is facing the double sealed ring groove. Double sealed ring[41] shuts the air opening. From Figure 1 (regarding the right cylinder): when the main shaft rotates, cam piston moves towards the right, valve cam and admission and exhaust valve move towards left, exhaust ring groove and air opening overlaps and begin to exhaust. When the main shaft rotates 45 degrees, admission and exhaust valve reach the left end and the overlap area is maximized. The main shaft continues to rotate. admission and exhaust valve move towards right from the left end and overlap area is decreasing. When it reaches 90 degrees, the air opening is closed and the exhaust stroke is done. The main shaft keeps rotating. Cam piston moves towards left. Admission and exhaust valve moves towards right. Air inlet ring groove and admission and exhaust valve overlap and intake stroke starts. When the main shaft rotates 135 degrees, the admission and exhaust valve reaches the right end. The overlap area is maximized. The main shaft continues to rotate. The admission and exhaust valve move towards left from the right end. The overlap area is decreasing. When it reaches 180 degrees, the air opening is closed and the intake stroke ends. The main shaft keeps rotating. The valve cam groove is flat from 180 degrees to 360 degrees. Therefore, valve cam does not move the admission and exhaust valve axially and the air opening is closed. From 180 degrees to 270 degrees, cam piston moves towards right. Compression stroke is in progress. From 270 degrees to 360 degrees, cam piston is undergoing the power stroke and moving towards the left. Another cycle of the four strokes begins afterwards. Figure 4 shows the working principle of double sealed ring. As mentioned above, the double sealed ring on the double sealed ring groove controls the opening or closure of air opening. From Figure 1 and 4: double sealed ring is slightly wider than the air opening. There is a double sealed ring gap[42) between the sealed rings. Under normal pressure, the tight contact between the cylindrical surface and the valve sleeve[15] forms the seal by elastic force. During compression stroke and power stroke, pressurized air passing through the sealed ring gap forces the double sealed ring to stick to the side of double sealed ring groove and the valve sleeve, forming the seal and making it function as valve. From Figure 1 and 7: the way for air admission and exhaust of The Engine is from air inlet[9] on the end cap. The air then enters gas chamber. It passes through air admission channel[40], venthole[28], air inlet ring groove[29] and air opening to the cylinder. After combustion, air goes through air opening, exhaust ring groove, air outlet and exits from exhaust channel[27]. From Figure 1: the sealed components of The Engine include cam piston, cylinder, the seal between cam piston and valve sleeve, the seal between admission and exhaust valve and valve sleeve and the seal of double sealed ring (which also function as a valve as mentioned above). The seal between cam piston and cylinder wall is an external seal which is the same sealing method as of traditional piston engines. The seal between cam piston and valve sleeve is an internal seal. For easy installation and uninstallation, an inner piston ring housing[34] is set there. Inner piston ring groove{33] is separated by inner piston ring spacer[32]. Inner piston ring base is fixed on the piston cover[31]. Between the admission and exhaust valve and the valve sleeve, exhaust ring groove[19] and air inlet ring groove[29] are sealed by sealed ring of sealed ring groove[30] and double sealed ring of double sealed ring groove. The lubrication cycle of The Engine is as follows: oil of oil tank enters oil chamber from oil inlet[26]. It enters the inside of valve sleeve through axis pin groove[25] and oil groove[14] and then enters the inside of cam piston through the opening on valve sleeve end piece[35]. Oil from the inside of the cam piston pass through oil outlet[10] and gets back to oil tank via oil return hole[36]. Oil lubricates along its path. The roller (including piston and valve cam) is lubricated by the oil squeezed into roller shaft oil channel[44] in the gap between the roller shaft and the bottom surface of cam groove when the cam rotates, or by oil pump which makes oil move from roller shaft (direction of the dashed line on roller shaft in Figure 9) to roller shaft oil channel via oil tube. A small -------------- - -- - 3 description amount of oil which infiltrated to the gas chamber from oil chamber can be collected by U-shaped tube[48] and gets back to oil tank. There are two cooling method for The Engine. From Figure 1: cylinder body and cylinder head are cooled down by circulating water in the water jacket[38] on them. Valve sleeve is cooled down by oil. Besides functioning as lubricant, large amount of oil which passes through oil groove and enters valve sleeve also functions as coolant. Figure 10 is a structural diagram showing another driving mode of the admission and exhaust valve of The Engine. As mentioned above, the movement of admission and exhaust valve and cam piston is reciprocation and rotation. However, admission and exhaust valve needs only reciprocation. To do that, parts of the structure involved are modified. Comparing Figure 10 with Figure 1: cam sleevet46] is added outside the valve cam. Main shaft pin[24] is eliminated. Axis pin groove[25] is changed to oil inlet[26]. These make the outside part of the valve sleeve turn to two axial cam rail[45] (as shown in Figure 10 and 11). There is cam sleeve venthole[471 on the cam sleeve (as shown in Figure i2). After modification, valve cam sleeve is fixed on the main shaft. Valve roller shaft is fixed on the cam sleeve. The valve cam with two holes can slide on the rail but remain fixed on admission and exhaust valve. From Figure 10: admission and exhaust valve and valve cam cannot rotate. When main shaft rotates cam sleeve, valve roller moves valve cam, reciprocating it and the admission and exhaust valve axially. When the main shaft rotates anti-clockwise, the engine works similarly as above. From above, we know how cylindrical cam becomes the piston of The Engine, how reciprocating motion of the cam piston transform into circular motion of main shaft, how The Engine carries out the four strokes of exhaust, intake, compression and combustion. In addition, we know how the friction surface of The Engine is lubricated, the internal and external sealing, water and oil cooling, etc. Furthermore, we know for each 360 degrees the main shaft of The Engine rotates, work is done by two the cylinders beside cam piston once, i.e. work is done twice for each loop of rotation. For traditional piston engines, work is done for each 720 degrees of rotation per cylinder. That means traditional piston engine with four cylinders is equivalent to The Engine with two-wave cam groove piston. The piston reciprocating motion of traditional piston engines is the rotation of crankshaft which is driven by piston pin, connecting rod and crank. For The Engine, cam groove, roller and roller shaft rotate the main shaft. The two sets of rollers and roller shafts of The Engine function as the four sets of connecting rods and crankshaft. Therefore, The Engine has the advantages of compact structure, few components and small size. 4-_

Claims (6)

1. A Cylindrical Cam Piston engine, the piston is cylindrical cam, its characteristic is that cylindrical cam piston[1], cylinder[3], admission and exhaust valve[6], valve sleeve[15], and valve cam[8] are on the same axis as the main shaft[13].

2. According to the description of the engine of claim 1, the characteristic of the engine is that the central path of cam groove[2] of cam piston is consisted of symmetric smooth curve, such as circular curve, elliptic curve or parabolic curve, etc, inner piston groove[43] is axially parallel with the main shaft.

3. According to the description of the engine of claim 1, the characteristic of the engine is that there are air inlet ring groove[29], exhaust ring groove[19] and sealed ring groove[30](double sealed ring groove included) on the admission and exhaust valve.

4. According to the description of the engine of claim 1, the characteristic of the engine is that cylinder body and valve sleeve form the ring cylinder of the engine, there are air opening{16] and air outlet[18] on the valve sleeve.

5. According to the description of the engine of claim 1, the characteristic of the engine is that admission and exhaust valve and valve cam are connected.

6. According to the description of the engine of claim 1, the characteristic of the engine is that there is axle arm{37] on the main shaft.