Piston device

Abstract

A piston device comprises: a piston; a rotatable element having a first meshing profile and rotatable about an axis, and a mechanism comprising: a first connecting member connected to the piston; a second connecting member pivotable about a fixed point and pivotally connected to the first connecting member; and a second meshing profile connected to the first and / or second connecting member, the second meshing profile being configured to mechanically engage and disengage with the first meshing profile of the rotatable element.

Description

Technical Field

[0001] The invention relates to a piston device and an internal combustion engine comprising such a device. Background Art

[0002] Most engines that use fluid expansion to drive pistons use connecting rods to connect the crankshaft to the pistons, converting the reciprocating motion of the pistons into rotational motion. WO 2015 / 107330A2 discloses an alternative arrangement for transmitting power from the pistons to the rotating shaft, in which the pistons are connected to the rails via a follower. However, the power transmission from the pistons to the rotating shaft can also be improved. Summary of the invention

[0003] A first aspect of the present invention provides a piston device.

[0004] By such an arrangement, the piston and the rotatable element can be coupled to a greater extent during the piston's drive stroke, which means that a greater proportion of the power from the piston can be transferred to the rotatable element. Overall, this can lead to higher power conversion efficiency.

[0005] The second meshing profile may comprise a plurality of second teeth.Such an arrangement may reduce wear on the second meshing profile.

[0006] At least two teeth may be of different sizes.With such an arrangement, the surfaces may be configured such that each surface engages the second engagement profile at an optimal angle.

[0007] Similarly, the first meshing profile may include a plurality of first teeth. The plurality of second teeth may reduce wear on each tooth.

[0008] The first and second meshing profiles may form a rack and sector gear arrangement.

[0009] When the first and second engagement profiles are engaged, the engagement may be at a point between the fixed point and the axis of rotation of the rotatable element.Such an arrangement may allow the second connector to be placed in compression so as to keep the two engagement profiles more securely engaged.

[0010] When the first and second engagement profiles are engaged, the second connection member can rotate about the fixed point in a first angular direction, while the rotatable element can rotate about the axis in a second angular direction, the first angular direction being opposite to the second angular direction. With such an arrangement, the two engagement profiles can move in an arc of a circle, which engages only at a desired point in the piston cycle, thereby achieving an improved engagement of the two profiles.

[0011] The piston arrangement may further comprise a track arranged to rotate about a track axis, the piston being coupled to the track, wherein the track and the rotatable element are coupled in rotation. With such an arrangement, the track provides a more customizable way of moving the piston during a stroke other than a drive stroke.

[0012] The piston may be connected to the track via a follower connected to the first and / or second connection, the follower being arranged to run along the surface of the track. Using the first connection to couple the track to the piston means that no additional specific components are required to couple the piston to the track, and therefore, such an arrangement may reduce weight.

[0013] The follower may be arranged to be coupled to the first and second connectors at a pivot joint between the first and second connectors. Alternatively, the follower may be connected to the second connector at a point away from the pivot connection between the first and second connectors.

[0014] The piston device may further comprise a further plurality of followers, each follower being arranged to run along the surface of the track, and / or comprising a plurality of concentric tracks. Providing a plurality of followers and a plurality of tracks may reduce wear on each track and each follower.

[0015] The piston arrangement may have a single follower disposed between radially outer and inner tracks, or may have a single track having radially outer and inner surfaces, and two or more followers, at least one of which runs along each surface of the track.

[0016] The track may be provided as an elongated protrusion formed from a plate, the plate being substantially flat in a plane perpendicular to the axis of the track. Thus, the track can be formed in a resilient / tough manner. Alternatively, the track may be formed as a channel recessed into the plate.

[0017] The track can be shaped so that the motion of a piston coupled to the track is substantially anharmonic. This can allow the motion of the piston to be more customizable.

[0018] For each rotation of the rotatable element, the piston can reciprocate twice. This allows the piston device to be used in a four-stroke engine.

[0019] The piston may be a first piston, and the piston device may further include a second piston movable in a corresponding cylinder, another first connecting member connected to the second piston, and another second connecting member pivotable about a second fixed point, wherein the rotatable element is configured to mechanically engage and disengage with each of the first connecting members.

[0020] The second piston and the first piston can be arranged relative to each other. Through such arrangement, a balanced piston device can be formed.

[0021] A second aspect of the present invention provides an internal combustion engine, comprising the piston device provided in the first aspect.

[0022] A third aspect of the present invention provides a piston device, comprising:

[0023] piston;

[0024] a rotating element rotatable about an axis and comprising a track; and

[0025] Institutions, including:

[0026] a first connector connected to the piston;

[0027] A second connector pivotable about a fixed point and pivotally connected to the first connector; and

[0028] A first follower is arranged to follow the track, the follower being coupled to the second connector.

[0029] In such an arrangement, the rotatable element of the piston device may have no elements that engage or disengage with the connector. Force may be transmitted to the rotatable element by a follower that engages with the track throughout the rotation.

[0030] The third aspect of the present invention may include any features of the first aspect of the present invention as required. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Embodiments of the present invention will now be described with reference to the accompanying drawings, in which:

[0032] Figure 1 An engine is shown;

[0033] Figure 2 The engine is shown with various components omitted;

[0034] Figure 3 A first piston arrangement is shown;

[0035] Figure 4 A second piston arrangement is shown;

[0036] Figure 5 A third piston arrangement is shown;

[0037] Figure 6 A fourth piston arrangement is shown;

[0038] Figure 7 A fifth piston arrangement is shown; and

[0039] Figure 8 A sixth piston arrangement is shown. DETAILED DESCRIPTION

[0040] Figure 1 An internal combustion engine 10 is shown including a cylinder block assembly 12 and two head assemblies 14. The cylinder block assembly 12 includes a plurality of housing members or plates having different shapes that form the cylinder block assembly 12 when combined.

[0041] Figure 2 The engine 10 is shown with the head assembly 14 removed. The head assembly includes cylinder bores, each of which has a corresponding cylinder liner disposed therein, and each of which has a corresponding piston disposed therein. In this view, the piston 18 can be seen extending from the cylinder block 12. The engine 10 has a total of four pistons, which are coupled to two rails in an opposing arrangement (the rails are located at Figure 2 ). Thus, the engine 10 includes four piston assemblies, and the structure and function of the first piston assembly will be described in detail, it being understood that the second, third and fourth piston assemblies are similar in structure and function to the first piston assembly. Figure 2 Four pistons 18 are shown in FIG. 1 , but it will be appreciated that any other number of pistons may be used, such as two pistons or eight pistons.

[0042] Figure 3 A piston arrangement according to the invention is shown. Figure 3 , a piston 118 is shown reciprocating in a cylinder. The piston 118 is coupled to a first link 120 via a pivot pin 119. At the other end of the first link 120, the elongated link 120 is connected to a second link 130 via a second pivot pin 121. The second link 130 is pivotally fixed at point 132 to form a mechanism with the first link 120 and the piston 118.

[0043] Point 132 is fixed relative to the cylinder in which piston 118 reciprocates. It will be appreciated that the engine may be in motion, for example within a vehicle, but there will be no relative motion between point 132 and the cylinder.

[0044] The first connection 120 further comprises an engagement profile 122 for engaging with a second engagement profile 124 coupled to a rotatable element 123 rotatable about the axis A1 .

[0045] There is no relative motion between point 132 and axis A1.

[0046] The first engagement profile 122 includes a plurality of engagement surfaces 122A and a main engagement surface 122B. As can be seen, the engagement surfaces 122A are separated by different pitches and have different sizes and inclinations relative to the first connector 120. This change in the nature of the engagement profile allows the first engagement profile 122 and the second engagement profile 124 to remain engaged as the mechanism formed by the piston 118, the first connector 120 and the second connector 130 moves during the piston drive stroke. It can also be seen that the main first engagement surface 122B is located at the very end of the first connector 120 so that engagement and power transfer with the main second engagement profile 124A can occur at an early stage within the drive or expansion stroke of the piston.

[0047] The rotatable element 123 comprises a second engagement profile 124 comprising a plurality of second engagement surfaces 124A for engaging with corresponding engagement surfaces 122A of the first engagement profile. The engagement profile 124 also comprises a second main engagement surface 124B which will engage with the main engagement surface 122B of the first engagement profile. It can be seen that the second engagement profile 122 extends around approximately 25% of the circumference of the rotatable element 123.

[0048] Although the illustrated meshing profiles each have multiple engagement surfaces, a single engagement surface on the first connector 120 and a single engagement surface on the rotatable element 123 may be sufficient to provide power transfer, such as a single tooth and groove arrangement.

[0049] The piston device also includes a track 126 and a follower 128 configured to roll along the track 126. A sliding follower can also be used, which will slide along the track 126. The follower 128 is connected to the first connecting member 120, and the action of the track 126 and the follower 128 can move the piston 118 in the return stroke, and the track 126 can be formed in any way and set to different shapes to provide different speeds for different strokes of the cycle. For example, through the track and follower arrangement, a basic non-harmonic motion of the piston can be achieved.

[0050] Figure 4 Shows Figure 3 A further improved scheme of the piston device shown in FIG. 1 . In this arrangement, similar parts are marked with corresponding reference numerals, and for the sake of brevity, the description of unchanged parts will not be repeated here.

[0051] The rotatable element 223 rotating about the axis A2 is made integral with the meshing profile 224. However, Figure 3 The rotatable element 123 can also be used here.

[0052] The second connector 230 has been modified to have a third meshing profile 225. The third meshing profile 225 is substantially identical to the first meshing profile 222 at a point where both the third meshing profile 225 and the first meshing profile 222 will engage with the first meshing profile 224. Thus, the force applied to the rotatable element 223 can be distributed over the second meshing profile 222 and the third meshing profile 225.

[0053] Although connection 219 is shown as a pin joint connection, it is equally possible that the joint can translate in a direction perpendicular to the direction of piston movement while being non-rotatable.

[0054] refer to Figure 5 ,exist Figure 4 The arrangement shown is modified so that only the third engagement profile 325 engages with the rotatable element 323 rotatable about the axis A3. The second connection 330 is formed of three separate components. The first component 330A extends from the pivot point 332 to the pin joint for connection to the first connection 320; the second component 330B extends between the pivot point 332 and the third engagement profile 325; the third component 330c extends between the engagement profile 325 and the point connection 321 between the first connection 320 and the second connection 330. In order to reduce weight, spaces are hollowed out between the first, second and third components 330A, 330B, 330C. The pivot point 332 of the second connection 330 is separated from the piston by approximately 45°, which angle is measured at the axis A3. By bringing the pivot point 332 closer to the piston 318, a larger lever arm is provided at the point where the driving stroke of the piston 318 begins.

[0055] from Figure 5 It can be seen that the first engagement portion 324 of the rotatable element 323 has changed so as to engage with the third engagement portion 325 .

[0056] exist Figure 6 In the arrangement shown, the shape of the second link 430 has been altered so that it has a central block containing the third joint 425, with the first member 430A extending from the central portion to the pivot point 432 and the second member 430B extending from the central portion to the pin joint 421. It should also be noted that the follower 428 is provided on the second member 430, opposite the first link 420.

[0057] The shape of the first engagement portion 425 has been changed so that it can mate with the second engagement portion 424, which is essentially a cylindrical bearing.

[0058] The first engaging portion 425 may function as a roller, and the second engaging portion 424 may function as a track.

[0059] In any of the above embodiments, the follower may be in the form of one or more rollers disposed on a pivot pin between the first and second connectors. The follower may be a single roller disposed between two tracks (i.e., a radially inner track and a radially outer track), or two rollers, one engaging the radially inner surface of the track and one engaging the radially outer track.

[0060] For example, Figure 7 A piston arrangement is shown having a first link 520 pivotally connected to a second link 530 at a pivot point 521 and a follower 528 arranged at the pivot point 521, the follower being arranged to follow a track 526. The follower 528 may be a wheel or roller mounted on a pivot pin that also extends through the first link 520 and the second link 530.

[0061] The second connecting piece 530 also has an engagement profile 525 for engaging an engagement profile 524 which is rotationally connected to a track 526 for rotation about the axis A5.

[0062] The second link 530 can pivot about a fixed pivot point 532 and can be lightened due to the hole 531 .

[0063] Figure 8 A piston arrangement is shown without an engagement profile on the first or second connecting member or on the rotatable element. Figure 8 In the arrangement shown, force transmission between the rotatable element and the piston 618 occurs via the followers 628 , 628 a and the track 626 .

[0064] The first follower 628 is disposed at the pivot joint 621 between the first link 620 and the second link 630, and the second follower 628A is disposed on the second link 630 and is mounted by extending the pivot pin 629 through the second link 630. It is worth noting that the pivot pin 629 does not extend through the first link 620.

[0065] The piston device has a single track 626, with first and second followers 628, 628a disposed on either side of the track. Although the present invention has been described above in conjunction with one or more preferred embodiments, it will be appreciated that various changes or modifications may be made to the present invention without departing from the scope of the invention as defined in the appended claims.

Claims

1. A piston device, comprising: A piston that can reciprocate in a cylinder; a rotatable element rotatable about an axis and having a first engagement profile; and An institution comprising: a first connector connected to the piston; a second link pivotable about a fixed point fixed relative to the cylinder and pivotally connected to the first link; and A second engagement profile connected to the first and / or second connection member, the second engagement profile being configured to mechanically engage and disengage with the first engagement profile of the rotatable element.

2. The piston arrangement of claim 1, wherein the second engagement profile comprises a second plurality of teeth.

3. The piston device of claim 2, wherein at least two of the second teeth have different sizes.

4. The piston device according to claim 2 or 3, wherein the plurality of second teeth are arranged as a rack. The piston arrangement of claim 1 , wherein the first engagement profile comprises a first plurality of teeth.

6. The piston device of claim 1, wherein the rotatable element is a sector gear.

7. The piston device according to claim 1, wherein: The first and second engagement profiles engage at a point between the fixing point and the axis.

8. The piston device according to claim 1, wherein: When the first and second engagement profiles are engaged, the second connection piece rotates about the fixed point in a first angular direction and the rotatable element rotates about the axis in a second angular direction, the first angular direction being opposite to the second angular direction.

9. The piston device of claim 1 , further comprising a track arranged to rotate about a track axis, the piston being coupled to the track, Wherein the track and the rotatable element are rotationally coupled.

10. The piston device according to claim 9, wherein: The piston is connected to the track via a follower connected to the first and / or second connection, the follower being arranged to run along the surface of the track.

11. The piston device of claim 10, wherein the follower is coupled to the first and second links at a pivot connection between the first and second links.

12. A piston device according to claim 9, 10 or 11, characterized in that The shape of the track is such that the motion of a piston coupled to the track is substantially anharmonic.

13. The piston device according to claim 1, wherein: The piston reciprocates twice for each rotation of the rotatable element.

14. A piston device according to claim 1, wherein the piston is a first piston, and the piston device also includes a second piston, another first connecting member connected to the second piston, and another second connecting member that can pivot around a second fixed point and is pivotally connected to the other first connecting member, wherein the rotatable element is configured to mechanically engage and disengage with each of the first connecting members.

15. The piston device according to claim 14, wherein the second piston and the first piston are arranged opposite to each other.

16. An internal combustion engine comprising the piston device according to claim 1.

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