HK1185647A - Engine - Google Patents

Description

Engine

Technical Field

The subject disclosure relates to an engine, and more particularly to an engine for use in a powersports equipment (powersports equipment).

Background

A number of different engine types are known, for example engines capable of using a number of fuel types, and engines having a number of different sizes, as well as engines having a different number of cylinders, can be used. The engine may also be two-stroke and four-stroke and positioned in a number of different orientations, for example the pistons may be oriented vertically, horizontally or in any other possible orientation. The subject disclosure can be applied to all types of such engines.

Disclosure of Invention

In a first embodiment, an engine includes a crankcase, a crankshaft journalled in the crankcase, a piston coupled to the crankshaft, a cylinder in which the piston reciprocates, and a head positioned above the piston and the cylinder. The crankcase is split along a plane to form a first crankcase portion and a second crankcase portion, with a fluid passage only in the first crankcase portion, the fluid passage communicating with the head to deliver fluid to the head.

In another embodiment, an engine includes a crankcase, a crankshaft journalled in the crankcase, a piston coupled to the crankshaft, a cylinder in which the piston reciprocates, a head positioned above the cylinder, and a water pump assembly mounted above a first end of the crankshaft and drivingly coupled to the crankshaft.

In another embodiment, an engine includes a crankcase, a crankshaft journalled in the crankcase and having a first end and a second end, a piston coupled to the crankshaft, a cylinder in which the piston reciprocates, a cylinder head positioned above the cylinder, an oil pump, a magneto, and a water pump assembly, the magneto including a rotor and a stator. The oil pump, water pump, and magneto are all drivingly coupled to the first end of the crankshaft.

In another embodiment, an engine includes a crankcase, a crankshaft journalled in the crankcase, a piston coupled to the crankshaft, a connecting rod reciprocating in a cylinder, and a cylinder head positioned above the piston and the cylinder. The connecting rod has a first end coupled to the crankshaft and a second end connected to the piston. The second end tapers inwardly and upwardly and the piston includes a complementary tapered coupling, the pin connecting the second end to the piston.

In another embodiment, an engine includes a crankcase, a crankshaft journalled in the crankcase, a piston coupled to the crankshaft, a connecting rod reciprocating in the cylinder, a cylinder positioned above the piston and the cylinder, and a cylinder head having a first end coupled to the crankshaft and a second end coupled to the piston. The second end tank tapers inwardly and upwardly and carries a press-fit bushing having indicia to properly align the bushing within the second end.

Drawings

The above-mentioned and other features of this invention, and the manner of attaining them, will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is an upper perspective view of the subject engine;

FIG. 2 is a top perspective view of the side of the engine opposite that shown in FIG. 1;

FIG. 3 is a bottom perspective view similar to FIG. 1;

FIG. 4 is a bottom perspective view similar to FIG. 2;

FIG. 5 shows an exploded view of various components of the engine taken from the perspective shown in FIG. 2;

FIG. 6 shows a split housing portion of the crankcase;

fig. 7 and 8 are opposite sides of the crankcase portion as shown in fig. 6.

FIG. 9 is a cross-sectional view taken through line 9-9 of FIG. 6;

FIG. 10 is a cross-sectional view taken through line 10-10 of FIG. 6;

FIG. 11 is a perspective view of the crankcase, with the crankcase partially removed to show the cooling water passages;

FIG. 11A is an enlarged view of the portion indicated in FIG. 11;

FIG. 12 is a cross-sectional view taken through line 12-12 of FIG. 6;

FIG. 13 is a perspective view of the crankshaft and connecting rod assembly;

FIG. 14 is a cross-sectional view taken through line 14-14 of FIG. 13;

FIG. 15 is an exploded view of the assembly shown in FIG. 13;

FIG. 16 is an exploded view of the connecting rod and piston assembly;

FIG. 17 is a cross-sectional view of the piston and connecting rod of FIG. 16 in an assembled configuration;

FIG. 18A is a bottom perspective view of the cylinder liner;

FIG. 18B is a top perspective view of the cylinder liner;

FIG. 19 is a cross-sectional view taken through line 19-19 of FIG. 18A;

FIG. 20A is a bottom perspective view of the cylinder head assembly;

FIG. 20B is an upper perspective view of the cylinder head assembly;

FIG. 21 is a cross-sectional view taken through line 21-21 of FIG. 20A;

FIG. 22 is a cross-sectional view taken through line 22-22 of FIG. 20A;

FIG. 23 is a cross-sectional view taken through line 23-23 of FIG. 20A;

FIG. 24 is a perspective view of a camshaft retainer;

FIG. 25 is a cross-sectional view taken through line 25-25 of FIG. 24;

fig. 26 is a perspective view showing the crankshaft and balance shaft in one of the crankcase sections in an assembled state;

FIG. 27 shows the drive train assembly between the crankshaft and the dual overhead camshaft;

FIG. 28 shows an exploded view of the oil pump assembly;

fig. 29 shows the oil pump assembly of fig. 28 in an assembled state.

Fig. 30 shows an exploded view of the water pump assembly.

Fig. 31A shows an exploded view of a water pump housing with the stator in a position to be attached to the water pump housing;

FIG. 31B shows an assembled view of the water pump housing and stator;

fig. 32 shows the rotor in a posture to be attached to the crankshaft;

FIG. 33 shows a transmission of the starter assembly;

FIG. 34 shows an alternative view of the transmission for the starter motor;

FIG. 35 is a cross-sectional view taken through line 35-35 of FIG. 4;

FIG. 36 is a cross-sectional view taken through line 36-36 of FIG. 4;

FIG. 37 is a cross-sectional view taken through line 37-37 of FIG. 1;

FIG. 38 is an enlarged cross-sectional view similar to the cross-sectional view of FIG. 37, showing the oil distribution pattern;

FIG. 39 is a cross-sectional view taken through line 39-39 of FIG. 37;

FIG. 40 shows a cross-sectional view through a cylinder liner, illustrating a fluid flow pattern;

FIG. 41 is an exploded view showing the cylinder head assembly and cylinder liner in an assembled state, and showing the fluid flow pattern;

FIG. 42 shows a perspective view of the engine to show the water distribution pattern;

FIG. 43 is a cross-sectional view taken through line 43-43 of FIG. 1;

FIG. 44 is a cross-sectional view taken through line 44-44 of FIG. 1;

FIG. 45 is a perspective view of the balance shaft;

FIG. 46 is a front view of the balance shaft of FIG. 45;

FIG. 47 shows a perspective view of the drive gear of the balance shaft;

FIG. 48 shows an exploded view of the shaft of FIG. 47;

FIG. 49 shows an outside view of a recoil gear;

FIG. 50 shows an inside view of the recoil gear;

FIG. 51 is a side view of the crankcase assembly;

FIG. 52 is a cross-sectional view taken through line 52-52 of FIG. 51; and

fig. 53 shows a detailed view of the oil scoop.

Detailed Description

As best shown in fig. 1-4, the engine of the subject disclosure is shown generally at 2 and generally includes the following components: a crankcase 4, cylinder liners 6, a head assembly 8, a valve chamber cover 10, and a crankshaft assembly 12. As shown, the crankcase 4 includes first and second portions 18, 20, a water pump assembly 24, an oil filter 26, and a starter motor 30. As shown in FIG. 5, the water pump assembly 24 includes a water pump housing 36 and a water pump cover 38 and gaskets 40 and 42 as described herein. As also shown in fig. 5, the engine 2 further includes: a cylinder liner gasket 46, a head gasket 48, and a valve chamber cover gasket 50. Referring now to fig. 6 to 12, the crankcase 4 will be described in more detail.

Referring first to fig. 6 and 8, the first crankcase section 18 includes a planar surface 60, the planar surface 60 defining a split line of the crankcase assembly along a vertical plane. It should be appreciated that the planar surface 60 defines a flange surface having a plurality of protrusions with through holes 62, as described herein. As here embodied, the first crankcase section 18 also includes a top surface 66, the top surface 66 creating a flat surface for receiving the cylinder liners 6. As described herein, the crankcase portion 18 also includes main bearings 70 and roller bearings 72 (for balancing the shaft).

It will also be understood from the specification that such directional descriptions, such as the term "vertical", are to be considered in the disclosed embodiments as references only, and that the engine split line may actually be horizontal or at some other angle.

As best shown in fig. 8 and 11A, the crankcase portion 18 also includes an oil pump mounting portion 80 defining a mounting surface 82, and the oil pump mounting portion 80 communicates with an oil conduit 84 (fig. 9). The oil conduit 84 is also in communication with an inlet or suction pipe (snorkel) 86. As shown herein, it should be appreciated that the conduit 84 and inlet 86 are cast integrally with the remainder of the crankcase portion, although it should be understood that other components, such as tubing or other such components, may be provided. As best shown in fig. 11A, an oil sump is formed to contain a portion of the oil to assist in filling the pump.

Referring now to fig. 9 and 10, the integration of the oil pump into the crankcase portion 18 will be described. As shown in fig. 9, the conduit 84 and inlet 86 are shown in cross-section, which illustrates the definition of an oil passage 100 leading into a pump inlet chamber 102. Pump outlet chamber 104 discharges through surface 110 into passage 106. As shown in fig. 10, another passageway 120 extends from surface 110 to a groove 122 surrounding an aperture 124. It should be noted that the bearing 70 (fig. 8) is machined to be positioned in the aperture 124. The last passageway 126 extends from the passageway 120 to the top surface 66, and the top surface 66 communicates with a zig-zag slot 128 (see FIG. 8).

Referring again to fig. 8, the exterior of the crankcase portion 18 is provided with a wall 130 that surrounds the bearings 70, 72 and the oil pump mount 80. The wall 130 defines a cavity 132 having a front surface 134, wherein the front surface 134 includes a recess 136 and a plurality of protrusions having threaded apertures 138. It should be appreciated that the surface 134 defines a mounting surface for the water pump assembly 24, as described further herein. As described herein, the crankcase portion 18 also includes a mounting wall 140 for the starter motor 30, as well as an access opening 142 and a mounting aperture 144.

Referring to fig. 8 and 11, a water inlet passage 150 is provided, the water inlet passage 150 extending from the mounting surface 134 and communicating with a channel 152, the channel 152 opening onto the top surface 66. Referring to fig. 8 and 12, crankcase portion 18 includes a semi-cylindrical opening 160 (fig. 8) and a passage 162. As described herein, the channel 162 opens into the cavity 132 and aligns with the aperture 124, as best shown in fig. 12.

Referring now to fig. 6 and 7, the crankcase housing portion 20 generally includes a mounting surface 200, wherein the mounting surface 200 includes a protrusion having a threaded opening 202. It should be appreciated that each of the threaded openings 202 is aligned with the opening 62 and the mating surface 200 mirrors the mating surface 60 of the crankcase portion 18. The crankcase portion 20 also includes an upper surface 206 that is planar with the upper surface 66 of the crankcase portion 18. The crankcase section 20 includes roller bearings 210 longitudinally aligned with and opposed to the bearings 70, and roller bearings 212 longitudinally aligned with and opposed to the roller bearings 72. Finally, as described herein, the crankcase portion 20 includes a semi-cylindrical opening 220, the semi-cylindrical opening 220 together with the plate cylindrical opening 160 defining a cylindrical opening for the cylinder liner 6. It should be understood from the above description that all of the crankcase oil passage and the crankcase water passage are provided in the crankcase portion 18, and that the passages are not provided in the crankcase portion 20.

Referring now to fig. 13-15, the crankshaft assembly 12 will be described in greater detail. As shown in fig. 13 and 15, the crankshaft subassembly includes a first crankshaft portion 260, a second crankshaft portion 262 coupled together by an intervening press-fit pin 264 (fig. 14 and 15). As shown in FIG. 14, the crankshaft portion 260 includes a first shaft end 266 having a diameter portion 268, a diameter portion 270, a keyway 272, and a water pump drive 274, wherein the water pump drive 274 is machined with a groove 276. The cam sprocket 278 is integrally provided between the diameter portions 268, 270, and the transmission gear 280 is provided on the shaft diameter portion 282 (fig. 15). The first crankshaft portion 260 is also provided with a counterweight portion 288 and a first offset portion 284 having an aperture 286. In a similar manner, the crankshaft portion 262 is provided with a second shaft end 290, the second shaft end 290 having a weighted portion 298 and a second offset portion 294 having an aperture 296.

As shown in fig. 15, the link 265 includes a first end 300 having an aperture 302 and a second end 304 having an aperture 306. It should be appreciated that the split bearing 310 is received in the aperture 302 and on the pin 264. As shown in fig. 15, a sleeve bushing 312 is provided that is positioned in the aperture 306, as described herein.

As best shown in fig. 14, the first end 266 includes a longitudinally extending oil passage 320, the oil passage 320 having a passage 322, a passage 324, and a passage 330, wherein the passage 322 communicates with the surface 268, the passage 324 communicates with the surface 270, and the passage 330 communicates with the orifice 286. The pin 264 includes a passage 340, the passage 340 being aligned with the passage 330 and opening into an interior volume 342 of the pin 264. The pin 264 includes an end cap 344 to close the interior volume 342. The pin 264 also includes a passage 350, the passage 350 being positioned between the offset portion 284 of the crankshaft portion 260 and the offset portion 294 of the crankshaft portion 262, it being understood that the passage 350 is aligned with the split bearing 310.

Referring again to fig. 14 and 15, sleeve bearing 312 includes a groove 360 and indicia in the form of a notch 362. As best shown in fig. 14, both the sleeve 312 and the connecting rod second end 304 are tapered such that the sleeve has a narrower top portion 364 (fig. 15) and a wider lower portion 366. In a similar manner, the link second end 304 has a narrower top portion 370 and a wider lower portion 372 (FIG. 15). The markings enable a person to see the alignment of the sleeve bearing relative to the connecting rod during assembly and, since the markings are slots, allow for ease of rotational positioning of the bushing. The indicia is a tool that can catch the notch 362 and ensure that the sleeve bearing is inserted in its proper rotational orientation.

Referring now to fig. 16 and 17, a piston 390 is shown having a plurality of piston rings 392 disposed in complementary grooves 394, as is known to those skilled in the art. The piston 390 further includes an integral bearing area 400, the integral bearing area 400 being provided with an aperture 402 for receiving a pin 404. As is also known in the art, a snap ring 406 is provided, the snap ring 406 being received in a complementary groove 408 to retain the pin 404 in place. As best shown in fig. 17, the bearing portion 400 defines a tapered surface 410, the tapered surface 410 tapering inwardly and upwardly providing a complementary receiving opening 412 to receive the second end 304 of the link 265. The reduced mass of the connecting rod 265 (through the tapered end 304) enables additional mass to be added to the piston to structurally stiffen the upper end of the piston, for example at the location shown at 414.

Referring now to fig. 18A and 18B, the cylinder liner 6 will be described in more detail. As shown, cylinder liner 6 includes an upper portion 440 and an extension 442 that defines a cylinder wall 444, as described herein. The upper portion 440 includes an upper surface 450 (fig. 18B) and a lower surface 452 (fig. 18A). The extension 454 is provided to define a chain-receiving passage 456 in the extension 454. As shown in fig. 18A, the lower surface 452 has water introduction openings 460, the water introduction openings 460 opening into passages 462 (fig. 18B) surrounding the cylinder wall 444. The oil passage 470 also extends between the lower surface 452 (fig. 18A) to the upper surface 450 (fig. 18B). A groove 472 (fig. 18A) is also provided in communication with the opening 474. As best shown in fig. 19, the orifice 474 communicates with a passage 476, which in turn communicates with a passage 478 of an injector 480. As described herein, the injector 480 includes an injector nozzle 482. In addition to the port 474, the port 486 is used to interconnect the cylinder liner 6 with the crankcase 4, as further described herein. As best shown in FIG. 19, cylinder liner 6 also includes a coupling 490 in communication with passage 456 and receiving injector 480.

As shown in fig. 20A, the head assembly 8 includes a lower surface 500 and an upper surface 502 shown in fig. 20B. A plurality of water inlet slots 504 are provided, the plurality of water inlet slots 504 surrounding the valves 506 (exhaust valves 506A and intake valves 506B) and opening into a cavity 510 (see fig. 21). A cavity 510 surrounds the head assembly 8 and communicates with a water outlet 512. As best shown in fig. 20A, an oil inlet orifice 520 is provided that extends between the lower surface 500 and the upper surface 502 shown in fig. 20B. An aperture 530 (fig. 20A) is provided for mounting the cylinder head assembly 8 to the cylinder liner 6, but the aperture 530 does not extend through the top surface 502 of the cylinder head assembly 8, but instead terminates inside the cylinder head assembly 8, such as best shown in fig. 22, as further described herein, the machined top surface 532 is provided to receive a fastener, such as a washer and a fastening nut.

As shown in FIG. 20A, the exhaust port 540 is disposed opposite the exhaust valve 506B, and as shown in FIG. 20B, the intake port 546 is disposed opposite the intake valve 506B (FIG. 20A). A chain receiving channel 550 is also provided in alignment with channel 456 (fig. 18B). The channel 550 is partially defined by a wall 560 (fig. 20B) having mounting apertures 562 and 564. Intermediate wall 570 is provided with mounting apertures 572 and 574. Walls 560 and 570 further include semi-cylindrical surfaces 580, 582, 584, and 586. It should be appreciated that receiving regions 580 and 584 receive overhead cams for the intake valves and that receiving regions 582 and 586 receive overhead cams for the exhaust valves.

Referring now to fig. 24 and 25, a cam retainer 600 is shown. As best shown in fig. 25, the cam retainer 600 includes semi-cylindrical regions 610, 612, 614, and 616, the semi-cylindrical regions 610, 612, 614, and 616 should be understood to overlap with semi-cylindrical receiving regions 580, 582, 584, and 586 (fig. 20B), respectively, to define a cylindrical receiving region for enclosing the overhead cam, as further described herein.

As shown in fig. 24 and 25, cam retainer 600 further includes an aperture 622 aligned with aperture 562 (fig. 20B), an aperture 624 aligned with aperture 564 (fig. 20B), an aperture 626 aligned with aperture 572, and an aperture 628 aligned with aperture 574 (fig. 20B). As also shown, the retainer 600 includes a channel 630, the channel 630 being aligned with the aperture 520 (fig. 20B) and in fluid communication with a groove 632 extending around the receiving area 612. The channel 632 communicates with the channel 634 through a passage 636. The passage 638 communicates with the passage 634 through the passage 640. Although not shown, the passages 642 and 632 still communicate in a similar manner as the passages 640.

Referring now to FIG. 26, a number of subassemblies will be described. Referring first to fig. 26, the crankshaft subassembly 12 is shown mounted within the crankcase portion 20 along with a balance shaft 700. The balance shaft 700 includes a gear 702 in meshing engagement with the gear 280 on the crankshaft subassembly, and further includes a weight 704, a shaft 706 positioned in the roller bearing 212, a bearing portion 708, and a drive portion 710. As shown, the shaft 706 has a square cross-section to increase stiffness and reduce deflection.

Referring now to fig. 27, the crankshaft subassembly 12 and balance shaft 700 are shown in meshing engagement, and the cam chain 720 is in meshing engagement with the gear 278. Cam chain 720 is in meshing engagement with upper gears 722 and 724, with gear 722 driving exhaust cam 726 and with gear 724 driving intake cam 728. Retainers 730 and 732 are shown, the retainers 730 and 732 retaining the chain at the proper tension and ensuring that the chain wraps around the associated gears. Also shown is an injector 480 (see also fig. 18A) that provides lubrication to the retainer and to the chain 720.

Referring now to fig. 28, the oil pump assembly 750 is shown in a position received within the oil pump mounting portion 80 of the crankcase portion 18. As shown in fig. 28, drive end 710 (of balance shaft 700) and drive end 274 (of crankshaft assembly 12) extend through crankcase portion 18 and are positioned within cavity 132. Seal 752 is positioned over bearing 72 and sprocket 754 is positioned over drive end 710 and secured in place by a fastener such as 756.

The oil pump assembly 750 includes an outer rotor 760, an inner rotor 762, a pump shaft 764 having a cross pin 766, and a pump housing 770. It should be appreciated that the outer rotor 760 may be positioned within the inner diameter portion 772 of the mounting portion 80. The inner rotor 762 is also positioned within the outer rotor 760 and the shaft 764 is positioned within the opening 774. The housing 770 and the mounting portion 80 are connected to each other by a fastener 780. It should be appreciated that a portion of the shaft 764 extends through the opening 782 of the housing 780 and the extending portion has a D-shaped cross-section that mates with a complementary opening 790 on the sprocket 792. The sprocket 792 is held in place by a fastener 794 that is threadably received in the end of the shaft 764. It should be appreciated that a chain such as 800 is trained around sprockets 754 and 792 to form an oil pump drive mechanism and to drive inner rotor 762. Accordingly, it should be appreciated that the inner rotor 762 of oil pump 750 is driven by the rotation of crankshaft assembly 12 through balance shaft 700. Fig. 29 shows the assembled oil pump assembly assembled to the crankcase portion 18.

Referring now to FIG. 30, the water pump assembly 24 is shown as including a water pump housing 36 and a water pump cover 38. The water pump assembly 24 also includes a water pump drive shaft 820, a gasket 822, a seal 824, a pump wheel 826, and a spacer 828. As shown, the water pump housing 36 includes an outer portion 830, wherein the outer portion 830 includes a channel for receiving the pump impeller 826 in communication with a discharge conduit 840. Conduit 840 communicates with orifice 842 (fig. 31A). The water pump cover 38 includes a suction conduit 850, wherein the suction conduit 850 is machined to receive a flexible rubber tubing and a clip (not shown) thereon. The water pump cap 38 is secured to the front surface 830 of the water pump housing 36 by a plurality of fasteners 852. When assembled, the pump wheel 826 is coupled to the shaft 820, and the shaft 820 protrudes through the aperture 844 of the pump housing 36 to the position shown in fig. 31B. It should also be appreciated that shaft 820 has a driven end in the form of a tongue 846 (fig. 31A) that mates with groove 276 (fig. 15). It should also be appreciated that the cavity 832 is formed in a stepped pattern, thereby allowing for varying pump wheel sizes. This allows the flow rate of the cooling water to be changed for other engine ratings.

Referring now to fig. 31A to 32, a magneto assembly 861 (fig. 39) will be described. As shown in fig. 31A, the water pump housing 36 includes an inner surface 860 and includes an internal cavity 862. A stator 864 is provided and the stator 864 is mounted to a threaded projection 868 within the cavity 862 by a fastener 866. Fig. 31B shows an installation state of stator 864. Note that a central opening 870 through stator 864 allows access to shaft 820 to drive water pump impeller 826 (fig. 30). Also shown in fig. 31A is starter motor gear assembly 880, which starter motor gear assembly 880 has a large drive gear 882 and a small driven gear 884 coupled about shaft 886. A shaft 886 is received in the orifice 888. Also shown in fig. 31B is a gear assembly 880 in an installed condition.

Referring now to fig. 32, a rotor 900 for a magneto assembly is shown to include an outer rotor wall 902 machined to overlap a stator 864, and the rotor 900 has an inner opening 904 machined to attach to crankshaft assembly 12. As shown in fig. 32, a starter gear 910 is shown, the starter gear 910 being received on the diametric portion 268 (fig. 14) and rotating relative to the bearing 912 at the diametric portion 268 (fig. 14). A slip clutch 920 is provided, the slip clutch 920 being mounted to an inner surface 922 of the rotor 900 by fasteners such as 924. The starter gear 910 includes an outer hub 926 that interacts with an inner opening 928 of the slip clutch 920.

Fig. 33 and 34 show the starter motor bearing assembled, wherein it will be appreciated that the starter motor 30 includes a starter motor shaft 930 in the form of a toothed bar. It should be appreciated that the starter motor 30 is mounted to the rear side of the mounting wall 140 (FIG. 8) with the starter shaft 930 projecting through the aperture 142 (FIG. 8). Thus, gears 882 and 884 rotate relative to shaft 886, with shaft 886 being secured on one side by aperture 888 (fig. 31A) and on the opposite side by mounting aperture 144 (fig. 8). With the components and subassemblies described above, the distribution of oil and the distribution of water will now be described.

Referring first to fig. 35, as the oil pump 750 operates, oil is drawn into the pump via the passage 100 in the direction of the arrow and discharged into the passage 106. The filter 26 is connected to the crankcase by a mounting bracket 950, the mounting bracket 950 having a passage 952 aligned with the passage 106 and extending into the filter 26. Referring now to fig. 36, oil is drawn out of filter 26, through passage 956 of bracket 950, and into passage 120 of crankcase portion 18. As previously described, the passageway 120 intersects the groove 122 corresponding to the diametric portion 268 (FIGS. 10 and 14) to lubricate the main bearings 70 on the crankshaft portion 268 (FIG. 37). As shown in fig. 37, the aperture 322 also extends through the crankshaft portion 268 (fig. 37) to intersect the passage 320 and enable oil from the passages 120, 122 (fig. 36) to enter the passage 320.

As best shown in fig. 37-39, oil in passage 320 flows in both directions from passage 322 (fig. 38). Oil flowing to the left as viewed in FIG. 39 lubricates the connection between the shaft 820 and the drive end 274. Bearings 912 (fig. 39) are also lubricated through passages 324. As shown in fig. 38, oil flowing to the right then continues to flow via passage 330 and into the interior volume 342 of the pin 264 via passage 340. The oil then lubricates the bearing 310 via the passage 350 (fig. 15) of the pin 264. The excess oil from the bearings 310 simply drips back into the oil sump of the crankcase.

Returning to fig. 36, oil via passage 120 is not only fed to groove 122 surrounding the main bearing, but also travels vertically via passage 126 to feed to a zigzag groove 128 (fig. 8). A portion of the zigzag groove is visible in fig. 36. Referring now to FIG. 41, oil via the zigzag grooves 128 is fed to the passages 470 and channels 472 of the cylinder liners 6. As previously described, oil via passage 470 is fed to passage 520 of head assembly 8, whereas oil via passage 472 is fed to injectors 480, onto the chain via nozzles 482. Referring again to FIG. 20B, the channel 520 extends upwardly, opening at the upper surface 502 within the wall 560. As previously described, oil is then fed to the passages 630 of the cam holder 600, and oil is then fed onto the cams via the passages around the camshafts.

Referring now to fig. 42, water from the water pump 24 is drawn in via a pipe (not shown) attached to the conduit 850 and discharged via the aperture 842 of the water pump housing 36. The water flows out into the crankcase portion 18 via the aperture 150 and then vertically via the passage 152. Referring again to fig. 40, water then proceeds through the bore 460 of the liner 6 and circulates around the cavity 462 to cool the cylinder wall 444. As shown in fig. 41 and 43, the water is then fed to the passage 504 into the cylinder head 8. As best shown in fig. 44, the cooling water continues to circulate around the passageway 510 and proceeds to the water outlet via the thermostat 980.

Referring now to fig. 45-50, a balance shaft 1000 is shown including a drive gear 1002, a weight 1004, and a shaft 1006. The end 1008 includes a drive end 1010 in the form of a tongue. Gear 1002 includes an external gear 1014 and a recoil gear 1012. A plurality of springs are positioned intermediate gears 1012, 1014 to provide a torsional spring load between mating ones of gears 1002 and 1002. Referring now to fig. 48 and 50, gear 1014 includes a spring receiving recess 1018 and gear 1012 includes a corresponding recess 1020 having a ramp 1022 (fig. 50). The spring will therefore fit between the recess 1018 and the ramp 1022 so that the gears 1014, 1012 can sit flush against each other and be spring loaded to rotate.

Referring now to fig. 1, the exhaust gas recovery chamber 1050 will be described, wherein the exhaust gas recovery chamber 1050 recirculates crankcase blowby gas back to the intake port via the valve 1050. As shown in fig. 51 and 52, the vent 1050 includes an opening 1054 that opens into the crankcase, and baffles 1056 and 1058. The drain passage 1060 connects the recovery chamber 1050 to the crankcase. As shown by the arrows in fig. 52, the blow-by gas from the crankcase undergoes a multi-directional change, which separates the oil from the blow-by gas, allowing the oil to drain back through the drain passage 1060, and allowing the blow-by gas to extend upward through the valve 1052 mounted on the upper surface 1062. Blow-by gas is then reintroduced via valve 1052, via the throttle and back via the intake port (546, see FIG. 20B).

Referring finally to FIG. 53, a dip filter 1100 is provided positioned in the crankcase sump and connected to the suction tube 86 to filter the oil to the oil pump.

While this invention has been described as having an exemplary design, the present invention may be further modified within the spirit and scope of this disclosure. This application is therefore intended to cover any variations, uses, or adaptations of the invention using its general principles. Further, this application is intended to cover such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains.

Claims (63)

1. An engine (2), the engine (2) comprising a crankcase (4), a crankshaft (12), a piston (390), a cylinder (6), and a head (8), the crankshaft (12) being journalled in the crankcase, the piston (390) being coupled to the crankshaft, the piston reciprocating in the cylinder (6), the head (8) being positioned above the piston and the cylinder; characterized in that the crankcase is split along a plane (60) to form a first and a second crankcase portion (18, 20), a fluid passage (100, 106, 120, 150, 152) being only in the first crankcase portion, the fluid passage communicating with the head to convey fluid to the head.

2. The engine of claim 1, characterized in that the fluid passage (100, 106, 120) is an oil passage.

3. The engine of claim 1, characterized in that the fluid passage (150, 152) is a water passage.

4. The engine of claim 1, characterized in that the fluid passages (100, 106, 120, 150, 152) are separate oil and water passages.

5. The engine of claim 1, characterized in that the crankcase is split along a vertical plane (60), the vertical plane (60) being transverse to a longitudinal axis of the crankshaft.

6. The engine of any of claims 1-5, characterized in that a first end (266) of the crankshaft is journalled in the first crankcase portion.

7. The engine of any of claims 1-6, characterized in that a water pump (24) and an oil pump (750) are coupled to a first end of the crankshaft.

8. The engine of any of claims 1-7, characterized in that a portion of the first end of the crankshaft protrudes through the first crankcase portion.

9. The engine of any one of claims 1 to 8, characterized in that the water pump is driven by the protruding crankshaft part.

10. The engine of any of claims 7-9, characterized in that the oil pump is positioned on an exterior of the crankcase and is driven by an oil pump transmission (754, 792).

11. The engine of claim 10, characterized in that the oil pump drive mechanism is partially positioned in the crankcase and extends through the crankcase to drive the oil pump.

12. The engine of any of claims 1-11, further characterized by an oil filter (26), the filter (26) being positioned external to the first crankcase portion and the oil filter (26) being attached to the first crankcase portion.

13. The engine of any of claims 7-12, further characterized by an oil pan (86), the oil pan (86) fluidly coupled to the oil pump.

14. The engine of claim 13, characterized in that the first crankcase portion includes a first oil passage (100) between the oil pan and the oil pump and a second oil passage (106) between the oil pump and the oil filter.

15. The engine of claim 14, characterized in that the first crankcase portion includes a third oil passage (120) between the oil filter and the crankshaft and a fourth passage (126) extending upwardly through a top surface (66) of the first crankcase portion.

16. The engine of any of claims 7-15, characterized in that a portion of the first end of the crankshaft protrudes through the first crankcase portion and drives a water pump.

17. The engine of claim 16, characterized in that the crankshaft includes an oil passage (320), the oil passage (320) being in fluid communication with the third oil passage to lubricate a transmission between the crankshaft and the water pump.

18. The engine of any of claims 16-17, characterized in that the first crankcase portion includes a cavity (132) surrounding the protruding crankshaft portion.

19. The engine of claim 18, characterized in that the oil pump is positioned in the cavity.

20. The engine of claim 18 or 19, characterized in that the water pump is positioned above and closes the cavity.

21. The engine of claim 20, characterized in that the cavity is defined by a peripheral wall (130) surrounding the protruding crankshaft portion and the cavity defines a mounting flange (134), and the water pump is mounted to the mounting flange.

22. The engine of claim 21, characterized in that a water passage (150) is located within the perimeter wall and the water passage (150) is sealingly connected to an output of the water pump, the water passage extending through a top surface of the first crankcase portion and communicating cooling water to the cylinder head.

23. An engine (2), said engine (2) comprising a crankcase (4), a crankshaft (12), a piston (390), a cylinder (6) and a cylinder head (8), said crankshaft (12) being journalled in said crankcase, said piston (390) being coupled to said crankshaft, said piston reciprocating in said cylinder (6), said cylinder head (8) being positioned above said cylinder, characterized in that a water pump assembly (24) is mounted above a first end (266) of said crankshaft and said water pump assembly (24) is drivingly coupled to said crankshaft.

24. The engine of claim 23, characterized in that the crankshaft has a longitudinally extending oil passage (320), the oil passage (320) lubricating a tongue and groove coupling.

25. The engine of any of claims 23 to 24, characterized in that the water pump assembly comprises a water pump housing (36), the water pump housing (36) having an inner cavity (862) and an outer cavity (832).

26. The engine of claim 25 further characterized by a magneto (861), the magneto (861) being drivingly coupled to the crankshaft and the magneto (861) being positioned in the internal cavity.

27. The engine of claim 26 wherein the magneto comprises a rotor (900) coupled to the crankshaft and a stator (864) attached to the internal cavity.

28. The engine of claim 27, characterized in that the water pump assembly further comprises a stub shaft (820) extending between the inner cavity and the outer cavity, wherein an outer portion of the stub shaft is coupled to a water pump impeller and an inner portion of the stub shaft is drivingly coupled to the crankshaft.

29. The engine of claim 28, characterized in that the stub shaft extends coaxially with the stator and the rotor.

30. The engine of claim 28 or 29, characterized in that the water pump shaft is coupled to the crankshaft by a tongue (846) and groove (276) coupling.

31. The engine of any of claims 23-30, characterized in that the crankcase is split transverse to a longitudinal axis of the crankshaft to define first and second crankcase portions (18, 20).

32. The engine of claim 31, characterized in that a first end (266) of the crankshaft is journalled in the first crankcase portion.

33. The engine of claim 32, wherein a portion of the first end of the crankshaft protrudes through the first crankcase portion.

34. The engine of claim 33, characterized in that the first crankcase portion includes a cavity (132) surrounding the protruding crankcase portion.

35. The engine of claim 34, characterized in that the water pump is positioned above the cavity.

36. The engine of claim 35, characterized in that the cavity is defined by a perimeter wall (130) surrounding the first crankcase portion, and the cavity defines a mounting flange, and the water pump is mounted to the mounting flange.

37. The engine of claim 36, wherein a water passage is positioned within the perimeter wall and sealingly connected to an output of the water pump, the water passage extends through a top surface of the first crankcase portion, and the water passage communicates cooling water to the cylinder head.

38. The engine of any of claims 25-37, characterized in that the crankcase is split along a vertical plane to form a first crankcase portion and a second crankcase portion, with a fluid passage (100, 106, 120, 150, 152) only in the first crankcase portion, the fluid passage communicating with the cylinder head to communicate fluid to the cylinder head.

39. The engine of claim 38, characterized in that an oil pump is connected to a first end of the crankshaft.

40. The engine of claim 39, characterized in that the oil pump is positioned on an exterior of the crankcase and is driven by an oil pump transmission.

41. The engine of claim 40, characterized in that the oil pump drive mechanism is partially positioned in the crankcase and extends through the crankcase to drive the oil pump.

42. The engine of claim 41, further characterized by an oil filter positioned outside of the first crankcase portion and attached thereto.

43. The engine of claim 42, further characterized by an oil sump.

44. The engine of claim 43, characterized in that the first crankcase portion includes a first oil passage between the oil pan and the oil pump and a second passage between the oil pump and the oil filter.

45. The engine of claim 44, wherein the first crankcase portion includes a third oil passage between the oil filter and the crankshaft, the third oil passage feeding oil to the longitudinally extending oil passage.

46. The engine of claim 45, wherein the first crankcase section includes a fourth passage extending upwardly therethrough and through a top surface of the first crankcase section.

47. An engine (2), the engine (2) comprising a crankcase (4), a crankshaft (12), a piston (390), a cylinder (6), a cylinder head (8), an oil pump (750), a magneto (861), and a water pump assembly (24), the crankshaft (12) being journalled in the crankcase, and the crankshaft (12) having a first end and a second end, the piston (390) being coupled to the crankshaft, the piston reciprocating in the cylinder (6), the cylinder head (8) being positioned above the cylinder, the magneto (861) comprising a rotor (900) and a stator (864); characterized in that the oil pump, the water pump and the magneto are all drivingly coupled to a first end (266) of the crankshaft.

48. The engine of claim 47, wherein a portion of the first end of the crankshaft protrudes through the crankcase.

49. The engine of claim 48, characterized in that the crankcase includes a cavity (132) surrounding the protruding crankshaft portion.

50. The engine of claim 49, characterized in that the water pump assembly (24) is positioned above the crankcase cavity.

51. The engine of claim 49 or 50, characterized in that the crankcase cavity is defined by a peripheral wall (130) surrounding the protruding crankcase portion and the crankcase cavity defines a mounting flange, and the water pump assembly is mounted to the mounting flange.

52. The engine of any one of claims 47 to 51, characterized in that the water pump assembly comprises a water pump housing having an inner cavity and an outer cavity.

53. The engine of claim 52, wherein the magneto is positioned in the internal cavity of the water pump housing.

54. The engine of claim 53 wherein the magneto comprises a rotor connected to the crankshaft and a stator attached to the internal cavity of the water pump housing.

55. The engine of claim 54, characterized in that the water pump assembly further comprises a stub shaft (820) extending between the inner and outer cavities of the water pump housing, wherein an outer portion of the stub shaft is coupled to a water pump impeller (826) and an inner portion of the stub shaft is drivingly coupled to the crankshaft.

56. The engine of claim 55, characterized in that said stub shaft extends coaxially with said rotor and said stator.

57. The engine of any of claims 49-56, characterized in that the oil pump is positioned in the crankshaft cavity.

58. The engine of claim 57, characterized in that the oil pump is driven by an oil pump drive (754, 792).

59. The engine of claim 58, characterized in that the oil pump drive mechanism is partially positioned in the crankcase and extends through the crankcase to drive the oil pump.

60. An engine (2), the engine (2) comprising a crankcase (4), a crankshaft (12), a piston (390), a connecting rod (265), a cylinder (6) and a cylinder head (8), the crankshaft (12) being journalled in the crankcase, the connecting rod (265) coupling the piston to the crankshaft, the piston reciprocating in the cylinder, the cylinder head (8) being positioned above the piston and the cylinder, the connecting rod having a first end (300) coupled to the crankshaft and a second end (304) coupled to the piston, characterized in that the second end tapers inwardly and upwardly and the piston comprises a complementary tapered coupling (412), a pin (404) coupling the second end to the piston.

61. An engine (2) comprising a crankcase (4), a crankshaft (12), a piston, a connecting rod (265), a cylinder (6) and a cylinder head (8), the crankshaft (12) journalled in the crankcase, the connecting rod (265) coupling the piston to the crankshaft, the piston reciprocating in the cylinder, the cylinder head (8) positioned above the piston and the cylinder, the connecting rod having a first end (300) coupled to the crankshaft and a second end (304) coupled to the piston, characterized in that the second end tapers inwardly and upwardly and carries a press-fit bushing (312) having indicia (362) to properly align the bushing within the second end.

62. The engine of claim 61, characterized in that the piston comprises a complementary tapered coupling device, a pin (404) coupling the second end to the piston.

63. The engine of claim 61 or 62, characterized in that the indicia (362) are slots that also facilitate rotational positioning of the bushing.