WO2008043080A2

WO2008043080A2 - Mechanisms for conversion between reciprocating linear motion and rotational motion

Info

Publication number: WO2008043080A2
Application number: PCT/US2007/080612
Authority: WO
Inventors: Bradley L. Raether
Original assignee: Wavetech Engines, Inc.
Priority date: 2006-10-07
Filing date: 2007-10-05
Publication date: 2008-04-10
Also published as: BRPI0719946A2; US7360521B2; JP2010506090A; AU2007303049A1; AU2007303049B2; EP2069622A4; WO2008043080A3; US20070079791A1; MX2009003524A; CN102748133A; EP2069622A2; CN101523084A; CN101523084B; KR20090077818A; WO2008043080B1; JP5090456B2; CA2664556A1

Abstract

Mechanisms for conversion between reciprocating linear motion and rotational motion include a wave-shaped track and structure that reciprocates and rotates as it follows the wave-shaped track.

Description

MECHANISMS FOR CONVERSION BETWEEN RECIPROCATING LINEAR MOTION AND ROTATIONAL MOTION

Background The present disclosure relates to mechanisms for conversion between reciprocating linear motion and rotational motion.

Mechanisms for conversion between reciprocating linear motion and rotational motion may be used in a variety of mechanical systems. A common application for such mechanisms is an internal combustion engine wherein the reciprocating linear motion of a piston is converted to the rotational motion of a crankshaft. Although the illustrated embodiment of the present disclosure is that of an internal combustion engine, the present disclosure is not limited to such applications, and the mechanisms for conversion between reciprocating linear motion and rotational motion disclosed herein may be used in a variety of applications. Summary

The present disclosure relates to mechanisms for conversion between reciprocating linear motion and rotational motion that include a wave-shaped track and a reciprocating and rotating structure that follows the wave-shaped track.

Brief Description of the Drawings FIG. 1 is a partial cross-sectional side view of a four cylinder internal combustion engine including a mechanism for converting the reciprocating linear motion of the pistons to the rotational motion of an output shaft.

FIG. 2 is a side view of a piston, connecting rod, retaining nut, and washers of the engine of Fig. 1 FIG. 3 is a somewhat schematic view of the connecting rod and piston of Fig.

2 generally taken along 3 — 3 of FIG. 2. FIG. 4 is a top view of an interchanger unit according to the present disclosure.

FIG. 5 is a side view of the interchanger unit of Fig. 4.

FIG. 6 is a schematic illustration of rollers of an interchanger unit according to the present disclosure illustrating movement within a track.

FIG. 7 is a side view of a piston, connecting rod, and interchanger unit according to the present disclosure.

FIG. 8 is an exploded view of a connecting rod and interchanger unit according to the present disclosure. FIG. 9 is a partial cross-sectional view of an interchanger unit according to the present disclosure.

FIG. 10 is a top view of the thrust-bearing retainer and its associated screws of Fig. 9.

FIG. 11 is a side view of a rotating carrier unit according to the present disclosure.

FIG. 12 is a top view of the upper carrier bearing support of the rotating carrier unit illustrated in Fig. 11.

FIG. 13 is an exploded view of the rotating carrier taken of FIG. 11.

FIG. 14 is a top view of the rotating carrier of FIG. 11. FIG. 15 is a top view a rotating carrier unit and an interchanger unit according to the present disclosure.

FIG. 16 is a side view of a piston, a connecting rod, an interchanger unit, and rotating carrier unit according to the present disclosure shown with the piston corresponding to a top dead center position. FIG. 17 is another side view of the piston, connecting rod, interchanger unit, and rotating carrier unit of Fig. 16 shown with the piston corresponding to a bottom dead center position.

FIG. 18 is an exploded view of structure defining upper and lower wave races and a spacer according to the present disclosure.

FIG. 19 is another exploded view of the structure defining the upper and lower wave races and the spacer of Fig. 18.

FIG. 20 is a top view of the structure defining the lower wave race of Fig. 18.

FIG. 21 is bottom view of the structure defining the upper wave race of Fig. 18.

FIG. 22 is an exploded side view of an interchanger block, structure defining wave races and a spacer according to the present disclosure.

FIG. 23 is a side view of the interchanger block, structure defining wave races and spacer of Fig. 22 shown in an assembled condition. FIG. 24 is a top view of the spacer Fig. 18.

FIG. 25 is top view an interchanger unit and a lower wave race according to the present disclosure.

FIG. 26 is a side view of a piston, connecting rod, and interchanger unit according to the repent disclosure shown with the interchanger unit positioned in a wave-shaped track.

FIG. 27 is a side view of the piston, connecting rod, interchanger unit, and wave-shaped track of Fig. 26 shown further with a rotating carrier unit and a stabilizer unit according to the present disclosure.

FIG. 28 is a schematic cross-sectional view of the connecting rod and stabilizer unit of Fig. 27. FIG. 29 is a side view of a rotating carrier unit positioned within structure defining a wave-shaped track, and a stabilizer unit according to the present disclosure..

FIG. 30 is a side view of an interchanger unit and rotating carrier unit including a reciprocator system according to the present disclosure.

FIG. 31 is a somewhat schematic representation of an engine cylinder and a mechanism for conversion between linear reciprocating motion and rotational motion according to the present disclosure shown with the piston in a top dead center position prior to an intake stroke. FIG. 32 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston during an intake stroke.

FIG. 33 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston in a bottom dead center position.

FIG. 34 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston during a compression stroke.

FIG. 35 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston in a top dead center position prior to combustion, or power, stroke.

FIG. 36 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston during a combustion stroke.

FIG. 37 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston in a bottom dead center position prior to an exhaust stroke.

FIG. 38 is a somewhat schematic representation of the structure of Fig. 31 shown with the piston during an exhaust stroke. Detailed Description

A nonexclusive example of an engine that incorporates a mechanism for conversion between reciprocating linear motion and rotational motion according to the present disclosure is illustrated in Fig. 1. The engine includes a block 10, which includes a cylinder block 12, an interchanger block 16, and a lower block 104. The engine further includes bores defined by cylinders 20, a cylinder head 22, intake means 24, ignition means 28, exhaust means 26, pistons 30, wave races 70 (upper) and 74 (lower), Interchanger units 60, rotating carriers 50, driver and driven gears 82 and 88, output shaft 90, lubrication means 112 and various working and support bearings 52, 56 and 100.

In the illustrated non-exclusive embodiment, the rotating assembly as shown in FIG. 27, is composed of three main components functioning together, an interchanger unit 60, as shown in FIGS. 4, 5, and 7, having track rollers 62, which ride between two wave-shaped races 70 and 74 that are part of a stationary mounted cylindrical unit as shown in FIG. 23. The wave-shaped races may be described as defining a wave-shaped track. The third component is a rotating carrier unit 50, mounted on bearings 52 and 56, with the top bearing 52, mounted on a support 54, that also adds stability to the carrier, as shown in FIG. 11 , in which the interchanger 60 rides up and down in to keep the interchanger 60 centered by means of centering rollers 66 riding on the carrier tracks 50c and 5Od as seen in FIGS. 13, 14 and 15, to maintain correct orientation of the track rollers 62 on the races 70 and 74. The carrier 50, also transfers the converted rotational motion from the interchanger 60, by means of the power transfer rollers 64, riding on the carrier tracks 50a and 50b as shown in FIGS. 11 , 14 and 15, to the output shaft (crankshaft) 90, via gears 82 and 88 as shown in FIGS. 1 , 11 , 13, 27 and 31 through 38. Referring to FIGS. 31 through 38, are illustrations of the engine through the four cycles of an Otto cycle or Diesel cycle engine from beginning to end starting with the piston 30, ready to begin the intake cycle, then continuing through the compression cycle, combustion cycle and ending with the exhaust cycle. In FIGS. 31 through 38 it shows the movement of the track rollers 62 as they traverse up and down the slopes 74a, 74b, 74c, 74d and 70a, 70b, 70c, 70c of the wave races 74 and 70, as also shown in FIGS. 18, 19, 20 and 21.

The interchanger 60 is so named because it converts reciprocating motion into rotational motion during the combustion cycle and then converts rotational motion to reciprocating motion during the intake, compression and exhaust cycles. The conversion from reciprocating motion to rotational motion is accomplished during the combustion stroke when the rollers 62, are forced at the same time down the declining slopes of the wave races causing a downward spiraling motion. Because the faces of the slopes in the illustrated embodiment are of a 45 degree decline (after a short radius at the top), the downward pressure from the piston 30, is converted to rotational motion at a one to one ratio. This means that for every inch the piston 30, moves down, the portion of the interchanger unit in contact with the wave-shaped track will rotate an inch therefore converting the reciprocating motion of the piston 30, into rotational motion at a 90 degree angle to the axis of the interchanger and therefore achieve an optimal transfer of energy. The rotating carrier as seen in FIG. 12 then transfers the converted rotational motion to the output shaft 90, through the driver and driven gears 82 and 88, when the power transfer rollers 64, and the optional interchange centering rollers 66, as seen in FIGS. 6, 7 and 8, ride up and down the races 50a, 50b, 50c and 5Od, of the carrier 50, while under the pressure created by the interchanger 60, as they follow the contours of the races 70 and 74. The piston 30, is returned to the cylinder top (top dead center) and through the remaining three strokes of the combustion cycle either by centrifugal force from the flywheel 94, as seen in FIG. 1 , attached to the crankshaft 90, or the power from other pistons connected to the same crankshaft 90. A flywheel 94 is also used to ensure smooth rotation.

To help insure the performance and service life of the engine, the piston 30, may be held from spinning inside the cylinder 20, by means of a stabilizer unit 34, as seen in FIGS. 27 and 28. The stabilizer unit 34 may keep the piston from spinning by means of one or more rollers that stay in contact with one or more sides of the connecting rod 32 (which may also be referred to as an input shaft), as shown in FIGS. 2 and 3. The piston 30 and connecting rod 32 may be able to be restrained from spinning because they may be attached to the interchanger 60, by means of thrust bearings 35, as seen in FIGS. 8 and 9. Also referring to FIGS. 2, 8, and 9, the retaining nut 43, and washers 41 and 42, thrust bearing retainer 37, and screws 39, as seen in FIGS. 9 and 10, also retain shock dampeners 35a and 35b, that help shield the thrust bearings 35, from shock created from combustion to the piston 30, or inertia during higher speeds of the engine as the track rollers 62, reach the top and bottom radiuses of the races 70 and 74

Referring to FIG. 6, the track rollers may be mounted in such a manner as to keep them in contact with each other. This contact is for the purpose of keeping them always spinning at the correct speed and direction as they ride on the races 70 and 74. The spacer 72, as seen in FIGS. 23 and 24 keeps the races 70 and 74, at the correct distance from each other to maintain close tolerance to the track rollers 62, but as the track rollers 62, follow the contours of the races 70 and 74, contact may fluctuate between the races, so to keep the track rollers 62, from skidding on the races or have to change in rotational direction, they may be always kept spinning the correct direction and speed by always being in contact with the other roller. A pair of track rollers 62, always being in contact with each other may also allow the load subjected to one roller to be shared by both, therefore reducing the load that any one roller will have to bear on its own which will extend the service life of both rollers. The track rollers 62, and races 70 and 74 may be substituted for other means of accomplishing the same functions such as gears, magnets, hydraulics, pressurized air or any other means that will facilitate a similar type working relationship that will yield the same results. In the example of gears being used, the races may be geared as well so as to mesh with the geared rollers, similar to a rack and pinion configuration. The rotating assembly may also be configured such that the interchanger and carrier are mounted stationary with the races rotating around them or any other configuration that yields the same results.

Referring to FIG. 29, the races 70 and 74, are shown mounted on shock absorbing dampeners 132. These dampeners may be installed to absorb and release shock created from combustion above the piston 30, or inertia during higher speeds of the engine as the track rollers 62, reach the top and bottom radii (also described as the crests or troughs of the wave-shaped track) of the races 70 and 74. These dampeners 132, may be made of high density rubber or polyurethane type materials that offer a higher load-bearing capacity than rubber with more resistance to oils and chemicals found on the inside of an engine. This same rubber or polyurethane type materials may also be used in the shock dampeners 35a and 35b as seen in FIG. 8. Springs, conical washers, fluid, air or any other means may be substituted for the rubber or polyurethane dampeners 35a, 35b and 132. Referring to FIG. 30, an optional reciprocator system is shown installed in the carrier 50, which is operated by centrifugal force. As the speed (RPM's) of the engine increases, the inclined centrifugal weights 140, may overcome the resistance of the centrifugal weight springs 142, allowing the weights to move outward from the center of the carrier 50. The resulting movement may thus cause the reciprocator spring inclines 144, to move up creating more pressure on the reciprocator springs 146, therefore creating a speed sensitive mechanical means of absorbing the increasing amount of energy at the end of each stroke created by inertia as the speed (RPM's) of the engine increases, then releasing that energy back after the track rollers 62, pass the upper and lower radiuses of the races 70 and 74, therefore helping facilitate the reciprocating motion of the piston 30, connecting rod 32, and interchanger unit 60, for the purpose of increasing the performance, service life and dependability of the engine by reducing stress to the track rollers 62, interchanger unit 60, and races 70 and 74. This mechanical reciprocator system may be substituted for a different type of system that utilizes pressurized fluids, compressed air, magnets or other suitable means to accomplish the same speed sensitive absorbing and releasing of energy process.

The materials that may be used in the overall construction of the engine may be aluminum, steel, rubber, plastics, automotive type gaskets and most any other materials commonly used in the manufacture of engines. Some exotic materials such as ceramics or specialty metals may be used in key areas such as the combustion chambers, rotating assemblies etc. The materials to be used in the rotating assembly will generally be of high-grade steel or similar materials because they are subjected to high pressures and impact. A softer surface may be applied to the tracks 70 and 74, such as high-density rubber or polyurethane type materials to help reduce shock loads to the track rollers 62.

Many other parts and functions of this engine and overall construction were not discussed in detail or discussed very little in this description due to the nature of many parts, designs, functions and construction of this engine may not differ or may differ very little from designs, and technology already well known and used for many years and therefore considered common knowledge and standard practice in the field of reciprocating engines. Some of these functions include but are not limited to fuel delivery system, lubrication means, ignition system, cooling system, compression ratios, combustion chamber sealing, high performance modifications, supercharging, turbocharging, previous designs, manufacturing procedures, materials of manufacture, maintenance, means for attaching the engine to machinery or transmission, etc. By remaining close to the current engine designs, materials of manufacture and manufacturing procedures of today allows this engine to be reproduced more readily and also makes it much easier for consumers to understand, maintain and operate by being nearly the same as the engines they are already familiar with.

Although the illustrated embodiment of the present disclosure is that of an internal combustion engine, the present disclosure is not limited to such applications, and the mechanisms for conversion between reciprocating linear motion and rotational motion disclosed herein may be used in a variety of applications.

The following numbered paragraphs represent non-exclusive examples of descriptions of mechanisms according to the present disclosure.

1. A mechanism for facilitating conversion between reciprocating linear motion and rotational motion, comprising: a continuous wave-shaped track defined by a first race and a second race opposing and spaced from the first race, the wave- shaped track circumscribing a circular profile and generally defining a cylindrical volume having a central axis; a carrier unit positioned at least partially within the cylindrical volume and configured to rotate about the central axis; and an interchanger unit extending at least partially through and in contact with the carrier unit and configured to rotate with the carrier unit and to reciprocate within the cylindrical volume, the interchanger unit including: a first roller positioned proximal to a first end of the interchanger unit and in rolling contact with the first race of the wave-shaped track; and a second roller adjacent the first roller and in rolling contact with the second race of the wave-shaped track.

2. The mechanism of paragraph 1 , wherein the first and second rollers are in rolling contact with each other.

3. The mechanism of paragraph 1 , wherein the wave-shaped track includes generally linear portions. 4. The mechanism of paragraph 1 , wherein the carrier unit includes a third race extending generally longitudinal relative to the central axis; and wherein the interchanger unit further includes a third roller positioned radially inward from the first and second rollers and in rolling contact with the third race.

5. The mechanism of paragraph 4, wherein the carrier unit further includes a fourth race opposing and spaced from the third race; and wherein the interchanger unit further includes a fourth roller positioned radially inward from the first and second rollers and in rolling contact with the fourth race.

6. The mechanism of paragraph 5, wherein the third and fourth rollers are in rolling contact with each other. 7. The mechanism of paragraph 1 , wherein the interchanger unit further includes: a third roller positioned proximal to a second end of the interchanger unit, the third roller in rolling contact with the first race; and a fourth roller adjacent the third roller and in rolling contact with the second race. 8. The mechanism of paragraph 7, wherein the first and second rollers are in rolling contact with each other and the third and fourth rollers are in rolling contact with each other.

9. The mechanism of paragraph 7, wherein the carrier unit includes: a third race and a fourth race opposing and spaced from the third race, the third and fourth races extending generally longitudinal relative to the central axis; and a fifth race and a sixth race opposing and spaced from the fifth race, the fifth and sixth races extending generally longitudinal relative to the central axis; and wherein the interchanger unit further includes: a fifth roller positioned radially inward from the first and second rollers and in rolling contact with the third race; a sixth roller positioned radially inward from the first and second rollers and in rolling contact with the fourth race; a seventh roller positioned radially inward from the third and fourth rollers and in rolling contact with the fifth race; and an eighth roller positioned radially inward from the third and fourth rollers and in rolling contact with the sixth race.

10. The mechanism of paragraph 9, wherein the first and second rollers are in rolling contact with each other, the third and fourth rollers are in rolling contact with each other, the fifth and sixth rollers are in rolling contact with each other, and the seventh and eighth rollers are in rolling contact with each other.

11. The mechanism of paragraph 9, wherein the first and second rollers are in rolling contact with each other and the third and fourth rollers are in rolling contact with each other. 12. The mechanism of paragraph 9, wherein the fifth and sixth rollers are in rolling contact with each other and the seventh and eighth rollers are in rolling contact with each other.

13. The mechanism of paragraph 1 , further comprising: an input shaft connected to the interchanger unit and extending generally co-axial to the central axis and configured to reciprocate with the interchanger unit; and a stabilizer unit fixed relative to the wave-shaped track and configured to stabilize the input shaft when it reciprocates.

14. The mechanism of paragraph 13, wherein the interchanger unit is rotatably connected to the input shaft; and wherein the stabilizer unit is configured to prevent the input shaft from rotating when the interchanger unit rotates.

15. The mechanism of paragraph 14, wherein the input shaft includes at least one surface defining a third race; and wherein the stabilizer unit includes a roller in rolling contact with the third race. 16. The mechanism of paragraph 1 , wherein the carrier unit includes a reciprocator system configured to help facilitate the change in reciprocating axial direction of the interchanger unit when the first and second rollers reach a crest or a trough of the wave-shaped track.

17. The mechanism of paragraph 16, wherein the reciprocator system includes that one or more spring positions to engage the interchanger unit when the first and second rollers reach a crest or a trough of the wave-shaped track.

18. The mechanism of paragraph 1 , further comprising: an input shaft connected to the interchanger unit so that the interchanger unit can rotate relative to the input shaft, wherein the input shaft extends generally co-axial to the central axis and is configured to reciprocate with the interchanger unit. 19. The mechanism of paragraph 18, wherein the interchanger unit includes bearing structure within which the input shaft is configured to rotate.

20. The mechanism of paragraph 1 , further comprising: an input shaft connected to the interchanger unit and extending generally co-axial to the central axis and configured to reciprocate with the interchanger unit, wherein the carrier unit is generally cylindrical in shape and includes a first passage for the input shaft to extend through and a second passage for the interchanger unit to extend through.

21. An engine comprising: the mechanism of paragraph 1 ; a piston positioned within a cylinder and configured to translate linearly therein in response to a force, wherein the piston is connected to the interchanger unit; and an output shaft connected to the carrier unit for providing rotational motion to an external device.

22. The engine of paragraph 21 , wherein the engine is an internal combustion engine.

23. A mechanism for facilitating conversion between reciprocating linear motion and rotational motion, comprising: a continuous wave-shaped track defined by a first side and a second side opposing and spaced from the first side, the wave- shaped track circumscribing a circular profile and generally defining a cylindrical volume having a central axis; a carrier unit positioned at least partially within the cylindrical volume and configured to rotate about the central axis; and an interchanger unit extending at least partially through and in contact with the carrier unit and configured to rotate with the carrier unit and to reciprocate within the cylindrical volume, the interchanger unit including: a first rotating element positioned proximal to a first end of the interchanger unit and in contact with the first side of the wave-shaped track; and a second rotating element adjacent the first rotating element and in contact with the second side of the wave-shaped track. 24. The mechanism of paragraph 23, wherein the first and second sides of the wave-shaped track include teeth, and wherein the first and second rotating elements include teeth that engage the teeth of the first and second sides of the wave-shaped track. 25. A mechanism for conversion between reciprocating linear motion and rotational motion, comprising: a first surface extending circumferentially around a cylindrical region, wherein the cylindrical region has a central axis and the first surface axially undulates as it extends around the cylindrical region; a second surface extending circumferentially around the cylindrical region, wherein the second surface opposes the first surface and axially undulates as it extends around the cylindrical region; a reciprocating element configured to move axially within the cylindrical region, wherein the reciprocating element includes first and second rollers configured to roll along the first and second surfaces, respectively, when the reciprocating element axially moves within the cylindrical region, and wherein the reciprocating element is configured to rotate about the axis when the first and second rollers roll along the first and second surfaces; and a rotating unit configured to rotate about the axis of the cylindrical region, wherein the rotating unit is engaged with the reciprocating unit and the rotating unit is further configured to rotate about the axis when the reciprocating element rotates about the axis. The disclosure set forth above encompasses multiple distinct inventions with independent utility. While each of these inventions has been disclosed in a preferred form or method, the specific alternatives, embodiments, and/or methods thereof as disclosed and illustrated herein are not to be considered in a limiting sense, as numerous variations are possible. The present disclosure includes all novel and non- obvious combinations and subcombinations of the various elements, features, functions, properties, methods and/or steps disclosed herein. Similarly, where any disclosure above or claim below recites "a" or "a first" element, step of a method, or the equivalent thereof, such disclosure or claim should be understood to include one or more such elements or steps, neither requiring nor excluding two or more such elements or steps.

Inventions embodied in various combinations and subcombinations of features, functions, elements, properties, steps and/or methods may be claimed through presentation of new claims in a related application. Such new claims, whether they are directed to a different invention or directed to the same invention, whether different, broader, narrower, or equal in scope to the original claims, are also regarded as included within the subject matter of the present disclosure.

Claims

Claims:

1. A mechanism for facilitating conversion between reciprocating linear motion and rotational motion, comprising: a continuous wave-shaped track defined by a first race and a second race opposing and spaced from the first race, the wave-shaped track circumscribing a circular profile and generally defining a cylindrical volume having a central axis; a carrier unit positioned at least partially within the cylindrical volume and configured to rotate about the central axis; and an interchanger unit extending at least partially through and in contact with the carrier unit and configured to rotate with the carrier unit and to reciprocate within the cylindrical volume, the interchanger unit including: a first roller positioned proximal to a first end of the interchanger unit and in rolling contact with the first race of the wave-shaped track; and a second roller adjacent the first roller and in rolling contact with the second race of the wave-shaped track.

2. The mechanism of claim 1 , wherein the first and second rollers are in rolling contact with each other.

3. The mechanism of claim 1 , wherein the wave-shaped track includes generally linear portions.

4. The mechanism of claim 1 , wherein the carrier unit includes a third race extending generally longitudinal relative to the central axis; and wherein the interchanger unit further includes a third roller positioned radially inward from the first and second rollers and in rolling contact with the third race.

5. The mechanism of claim 4, wherein the carrier unit further includes a fourth race opposing and spaced from the third race; and wherein the interchanger unit further includes a fourth roller positioned radially inward from the first and second rollers and in rolling contact with the fourth race.

6. The mechanism of claim 5, wherein the third and fourth rollers are in rolling contact with each other.

7. The mechanism of claim 1 , wherein the interchanger unit further includes: a third roller positioned proximal to a second end of the interchanger unit, the third roller in rolling contact with the first race; and a fourth roller adjacent the third roller and in rolling contact with the second race.

8. The mechanism of claim 7, wherein the first and second rollers are in rolling contact with each other and the third and fourth rollers are in rolling contact with each other.

9. The mechanism of claim 7, wherein the carrier unit includes: a third race and a fourth race opposing and spaced from the third race, the third and fourth races extending generally longitudinal relative to the central axis; and a fifth race and a sixth race opposing and spaced from the fifth race, the fifth and sixth races extending generally longitudinal relative to the central axis; and wherein the interchanger unit further includes: a fifth roller positioned radially inward from the first and second rollers and in rolling contact with the third race; a sixth roller positioned radially inward from the first and second rollers and in rolling contact with the fourth race; a seventh roller positioned radially inward from the third and fourth rollers and in rolling contact with the fifth race; and an eighth roller positioned radially inward from the third and fourth rollers and in rolling contact with the sixth race.

10. The mechanism of claim 9, wherein the first and second rollers are in rolling contact with each other, the third and fourth rollers are in rolling contact with each other, the fifth and sixth rollers are in rolling contact with each other, and the seventh and eighth rollers are in rolling contact with each other.

11. The mechanism of claim 9, wherein the first and second rollers are in rolling contact with each other and the third and fourth rollers are in rolling contact with each other.

12. The mechanism of claim 9, wherein the fifth and sixth rollers are in rolling contact with each other and the seventh and eighth rollers are in rolling contact with each other.

13. The mechanism of claim 1 , further comprising: an input shaft connected to the interchanger unit and extending generally coaxial to the central axis and configured to reciprocate with the interchanger unit; and a stabilizer unit fixed relative to the wave-shaped track and configured to stabilize the input shaft when it reciprocates.

14. The mechanism of claim 13, wherein the interchanger unit is rotatably connected to the input shaft; and wherein the stabilizer unit is configured to prevent the input shaft from rotating when the interchanger unit rotates.

15. The mechanism of claim 14, wherein the input shaft includes at least one surface defining a third race; and wherein the stabilizer unit includes a roller in rolling contact with the third race.

16. The mechanism of claim 1 , wherein the carrier unit includes a reciprocator system configured to help facilitate the change in reciprocating axial direction of the interchanger unit when the first and second rollers reach a crest or a trough of the wave-shaped track.

17. The mechanism of claim 16, wherein the reciprocator system includes that one or more spring positions to engage the interchanger unit when the first and second rollers reach a crest or a trough of the wave-shaped track.

18. The mechanism of claim 1 , further comprising: an input shaft connected to the interchanger unit so that the interchanger unit can rotate relative to the input shaft, wherein the input shaft extends generally coaxial to the central axis and is configured to reciprocate with the interchanger unit.

19. The mechanism of claim 18, wherein the interchanger unit includes bearing structure within which the input shaft is configured to rotate.

20. The mechanism of claim 1 , further comprising: an input shaft connected to the interchanger unit and extending generally co- axial to the central axis and configured to reciprocate with the interchanger unit, wherein the carrier unit is generally cylindrical in shape and includes a first passage for the input shaft to extend through and a second passage for the interchanger unit to extend through.

21. An engine comprising: the mechanism of claim 1 ; a piston positioned within a cylinder and configured to translate linearly therein in response to a force, wherein the piston is connected to the interchanger unit; and an output shaft connected to the carrier unit for providing rotational motion to an external device.

22. The engine of claim 21 , wherein the engine is an internal combustion engine.

23. A mechanism for facilitating conversion between reciprocating linear motion and rotational motion, comprising: a continuous wave-shaped track defined by a first side and a second side opposing and spaced from the first side, the wave-shaped track circumscribing a circular profile and generally defining a cylindrical volume having a central axis; a carrier unit positioned at least partially within the cylindrical volume and configured to rotate about the central axis; and an interchanger unit extending at least partially through and in contact with the carrier unit and configured to rotate with the carrier unit and to reciprocate within the cylindrical volume, the interchanger unit including: a first rotating element positioned proximal to a first end of the interchanger unit and in contact with the first side of the wave-shaped track; and a second rotating element adjacent the first rotating element and in contact with the second side of the wave-shaped track.

24. The mechanism of claim 23, wherein the first and second sides of the wave-shaped track include teeth, and wherein the first and second rotating elements include teeth that engage the teeth of the first and second sides of the wave-shaped track.

25. A mechanism for conversion between reciprocating linear motion and rotational motion, comprising: a first surface extending circumferentially around a cylindrical region, wherein the cylindrical region has a central axis and the first surface axially undulates as it extends around the cylindrical region; a second surface extending circumferentially around the cylindrical region, wherein the second surface opposes the first surface and axially undulates as it extends around the cylindrical region; a reciprocating element configured to move axially within the cylindrical region, wherein the reciprocating element includes first and second rollers configured to roll along the first and second surfaces, respectively, when the reciprocating element axially moves within the cylindrical region, and wherein the reciprocating element is configured to rotate about the axis when the first and second rollers roll along the first and second surfaces; and a rotating unit configured to rotate about the axis of the cylindrical region, wherein the rotating unit is engaged with the reciprocating unit and the rotating unit is further configured to rotate about the axis when the reciprocating element rotates about the axis.