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^ ^ H ^ I H ^ H ^ II ^ II ^ ^ ^ ^ ^ H ^ ^ ^ H ^ ^ ^ ^ ^ I ^ � European Patent Office Office europeen des brevets EP 0 758 060 A1

(12) EUROPEAN PATENT APPLICATION

(43) Date of publication: (51) |nt Cl.e: F16F 15/26 12.02.1997 Bulletin 1997/07

(21) Application number: 96305092.7

(22) Date of filing: 10.07.1996

(84) Designated Contracting States: (72) Inventor: Diggs, Matthew Byrne DE ES GB Farmington, Michigan 48335 (US)

(30) Priority: 07.08.1995 US 512378 (74) Representative: Messu lam, Alec Moses A. Messulam & Co. (71) Applicants: 24 Broadway • FORD MOTOR COMPANY LIMITED Leigh-on-Sea Essex SS9 1 BN (GB) Brentwood Essex (GB) Designated Contracting States: GB • FORD-WERKE AKTIENGESELLSCHAFT 50735 Koln (DE) Designated Contracting States: DE • Ford Motor Company Dearborn, Ml 48126 (US) Designated Contracting States: ES

(54) Planar balance system

(57) A balance system for a planar crankshaft on a (12), and a mechanism (40,42,44,46,48,50) intercon- V configuration internal combustion engine (14) includ- necting the first balance shaft (32), the planar crankshaft ing a first balance shaft (32) located above the planar (1 2) and the second balance shaft (34) to rotate the first crankshaft (12) inside a vee of the engine and a second balance shaft (32) and the second balance shaft (34) in balance shaft (34) located below the planar crankshaft opposite directions to balance the engine.

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Description planar crankshaft and the second balance shaft to rotate the first balance shaft and the second balance shaft in The present invention relates generally to planar opposite directions to balance the engine. on internal combustion engines and, more One advantage of the present invention is that a bal- specifically, to a balance system for a planar crankshaft 5 ance system is provided for a planar crankshaft on V- on a V configuration internal combustion engine. configuration internal combustion engine which cancels It is known to use a "V" configuration for an internal out the inherent second order imbalance, resulting in re- combustion engine on automotive vehicles. A majority duced noise, vibration and harshness. Another advan- of V-8 configuration engines employ a "cruciform" or tage of the present invention is that the balance system "90-degree" style crankshaft; that is, a crankshaft with 10 has one balance shaft located above the crankshaft in- four throws which are each offset by ninety degrees side the vee and another balance shaft located below (90°). This crankshaft configuration is preferred over the crankshaft, making it more compact and eliminating other available choices for a V-8 because it allows for a the use of space on the side of the engine for the balance fully balanced engine with proper counterweights on the system. crankshaft. is15 The invention will now be described, by way of ex- Three other crankshafts which can be employed in ample, with reference to the accompanying drawings, the V-8 configuration engine to achieve even firing are in which: "180-degree" style crankshafts; that is, a crankshaft with throws that are offset by one hundred eighty degrees FIG. 1 is a perspective view of a balance system, (180°) instead of ninety degrees (90°). This crankshaft 20 according to the present invention, for a planar configuration is called "planar" or "flat" since all of the crankshaft on a V configuration internal combustion journals and throws are co-planar. The planar - engine; shaft allows for even firing banks of cylinders, i.e., each FIG. 2 is a perspective view of the planar crankshaft bank of cylinders has a consistent 180 degree firing in- on the V configuration internal combustion engine terval whereas a V-8 engine with a cruciform crankshaft 25 of FIG. 1; does not. This provides improved consistency in the air- FIG. 3 is perspective view of a portion of the balance flow which makes the engine run smoother and more system of FIG. 1 ; efficiently. The cruciform crankshaft V-8 engine is the FIG. 4 is a front view of the balance system of FIG. only commonly produced which 1 with the engine shown in phantom lines; does not have even firing banks of cylinders. 30 FIG. 5 is a view similar to FIG. 4 of another embod- Although the planar crankshaft has worked well in iment, according to the present invention, of the bal- the V configuration engine, it suffers from the disadvan- ance system of FIG. 1 ; tage of an inherent second order imbalance which con- FIG . 6 is an enlarged view of a portion of the balance sists of shaking forces and moments that cycle at twice system of FIG. 5; the speed of the crankshaft. 35 FIG. 7 is a view similar to FIG. 4 of yet another em- One attempt to achieve total balance in a planar bodiment, according to the present invention, of the crankshaft V-8 configuration engine is disclosed in U.S. balance system of FIG. 1 ; and Patent No. 4,936,238 to Randle. This patent discloses FIG. 8 is a view similar to FIG. 4 of still another em- a balance system having dual counter-rotating balance bodiment according to the present invention, of the shafts which act to cancel out the vibrations which are 40 balance system of FIG. 1 . inherent to the V configuration engine. The patented bal- ance system is mounted on a side of the V configuration Referring to the drawings and in particular to FIG. engine. 1, one embodiment of a balance system 10, according One disadvantage of the above patented balance to the present invention, is shown for a planar crankshaft system is that space is needed on the side of the engine 45 1 2 on a "V" configuration internal combustion engine 1 4. to mount the balance system which may not be availa- The V configuration internal combustion engine 14 has ble. Therefore, there is a need in the art to provide a an 16 with a plurality of cylinders 18 in a balance system for a planar crankshaft on a V configu- first bank 20 and a second bank 22 which is separated ration engine which is compact and does not require by a block valley 24 to form a vee. The V configuration space on the side of the engine. so internal combustion engine 14 also has a 26 at- Accordingly, the present invention is a balance sys- tached to the engine block 1 6 opposite the block valley tem for a planar crankshaft on a V configuration internal 24. It should be appreciated that the V configuration in- combustion engine. The balance system includes a first ternal combustion engine may be a four- V-8 or a balance shaft located above the planar crankshaft in- two-stroke V-4. It should also be appreciated that the V side the vee of a V configuration internal combustion en- 55 configuration internal combustion engine is convention- gine and a second balance shaft located below the pla- al and known in the art. nar crankshaft. The balance system also includes a Referring to FIGS. 1 and 2, the planar crankshaft mechanism interconnecting the first balance shaft, the 12 is mounted in suitable bearings (not shown) within

2 3 EP 0 758 060 A1 4 the engine block 16 as is known in the art. The planar ance shaft 34, member 42 of the planar crankshaft 12 crankshaft 12 has a shaft 27 with a plurality of lobes or and the first member 46 of the idler 44. It should be ap- counterweights 28 interconnected by throws or pins 30. preciated that the members 42 and 46 are typically ei- It should be appreciated that the planar crankshaft 1 2 is ther sprockets for a chain drive system or pulleys for a of the mirror-image type although two other types of pla- 5 cogged drive system. nar crankshafts may be used for the V-8. It should also In operation of the balance system 10, the crank- be appreciated that the planar crankshaft 12 is conven- shaft 1 2 drives or rotates the member 42 which, in turn, tional and known in the art. moves or drives the belt or chain 50. The belt or chain Referring to FIGS. 1, 3 and 4, the balance system 50 drives or rotates the member 40 of the second bal- 10, according to the present invention, includes a first 10 ance shaft 34 and the first member 46 of the idler 44 in balance shaft 32 located above a horizontal plane the same direction as the planar crankshaft 12. The through the centreline of the planar crankshaft 12 and drive ratios combine to give a 2: 1 ratio versus the planar a second balance shaft 34 located below the horizontal crankshaft 12. Rotation of the idler 44 causes the first plane. The balance shafts 32, 34 are equidistant from member 46 and second member 48 to rotate in the same the horizontal plane and are in a common vertical plane is direction. Engagement between the second member 48 which bisects the vee of the first and second banks 20 and the member 40 of the first balance shaft 32 causes and 22. The first balance shaft 32 is located above the the second member 48 to rotate the member 40 and first planar crankshaft 12 inside the vee and is housed or balance shaft 32 in an opposite direction relative to the mounted in suitable bearings (not shown) in the block planar crankshaft 12. The balance shaft 34 rotates in valley 24 of the engine block 16. The second balance 20 the same direction as the planar crankshaft 1 2. It should shaft 34 is located below the planar crankshaft 12 and be appreciated that the first and second balance shafts housed or mounted in suitable bearings (not shown) in 32 and 34 rotate at twice engine speed. the engine block 16. The second balance shaft 34 may Referring to FIGS. 5 and 6, another embodiment be attached to bearing caps (not shown) as an assembly 110 of the balance system 10 is shown. The balance or integral to a girdle style design of the engine block 1 6. 25 system 1 1 0 has like parts of the balance system 1 0 with As illustrated in FIG. 3, the balance shafts 32 and like reference numerals increased by one hundred 34 have at least one or a pair of moment balance lobes (100). The balance system 110 includes a first belt or 36 spaced axially from each other. The balance shafts chain 150 disposed about the member 140 of the sec- 32 and 34 also have at least one shaking force balance ond balance shaft 1 34 and the member 1 42 of the planar lobe 38 disposed between the moment balance lobes 30 crankshaft 12. The balance system 110 also includes a 36. For balance shaft manufacturing, this will allow for member 152 such as a sprocket or pulley attached to separate balancing of each set of balance lobes 36, 38 one end of each 154 of the engine 14. The - one operation for the moment balance lobes 36 and balance system 1 1 0 further includes a member 1 56 such one operation for the shaking force balance lobes 38. as a helical spur gear, sprocket or pulley attached to the The balance shafts 32 and 34 have a member 40 35 planar crankshaft 12. As illustrated in FIGS. 5 and 6, the such as a gear, sprocket or pulley attached to one end balance system 1 1 0 further includes a planetary gearset for a function to be described. The shaking force bal- 1 58 for the first balance shaft 1 32. The planetary gearset ance lobe 38 is centred on the #3 (not 158 has the member 140 of the first balance shaft 132 shown) of the engine 1 4 and the moment balance lobes to act as the sun gear. The planetary gearset 158 has a 36 are spaced as far as possible for minimal size. The 40 ring gear 160 disposed about the gear 140. The plane- lobes 36 and 38 are weights which, in conjunction with tary gearset 1 58 also has a plurality of pinion gears 1 62 the balance shafts 32 and 34, cancel the second order disposed between the ring gear 160 and the gear 140 imbalance of the V-8 using a planar crankshaft which and attached to a planet carrier (not shown). The planet consists of both a shaking force and a moment. It should carrier is held stationary by suitable means (not shown). be appreciated that the balance shafts 32 and 34 can 45 The balance system 110 also includes a second chain be used with a two-stroke V-4 engine configuration, as or belt 1 64 disposed about the members 1 52 of the - well as a four-stroke engine configuration. shafts 1 54, member 1 56 of the planar crankshaft 1 2 and Referring to FIG. 4, the balance system 10 includes the ring gear 160 of the planetary gearset 158. a member 42 such as a sprocket or pulley attached to In operation of the balance system 110, the planar one end of the planar crankshaft 12 and an idler, gen- so crankshaft 12 drives or rotates the members 142 and erally indicated at 44, mounted or housed in suitable 156 which, in turn, moves or drives the belts or chains bearings (not shown) in the engine block 16. The idler 150 and 164, respectively. The first belt or chain 150 44 includes a shaft (not shown) having a first member drives or rotates the member 140 and the second bal- 46 such as a sprocket or pulley and a second member ance shaft 1 34 in the same direction as the planar crank- 48 such as a helical spur gear. The second member 48 55 shaft 1 2 at twice engine speed. The second belt or chain engages the member 40 of the first balance shaft 32. 1 64 drives or rotates the members 1 52 of the The balance system 10 further includes a belt or chain 1 54 and the ring gear 1 60 of the planetary gearset 1 58 50 disposed about the member 40 of the second bal- in the same direction as the planar crankshaft 12. Ro-

3 5 EP 0 758 060 A1 6 tation of the ring gear 160 causes the pinion gears 162 a first balance shaft (32) located above the pla- to rotate and, in turn, rotate the member 140 and first nar crankshaft (12) inside a vee of the V con- balance shaft 132 in an opposite direction. It should be figuration internal combustion engine (14); appreciated that the second balance shaft 1 34 is driven a second balance shaft (34) located below the at a 2:1 ratio and rotates in the same direction as the 5 planar crankshaft (12); and planar crankshaft 12. It should also be appreciated that a mechanism (40,42,44,46,48,50) intercon- the first balance shaft 132 is driven at a 2:1 ratio and necting said first balance shaft (32), the planar rotates in the opposite direction as the planar crankshaft crankshaft (12) and said second balance shaft 12. (34) to rotate said first balance shaft (32) and Referring to FIG. 7, another embodiment 210 of the 10 said second balance shaft (34) in opposite di- balance system 10 is shown. The balance system 210 rections to balance the engine. has like parts of the balance system 10 with like refer- ence numerals increased by two hundred (200). The 2. A balance system as claimed in claim 1, wherein balance system 210 has only one member 246 of the said first balance shaft and said second balance idler 244. is shaft are located in a common vertical plane parallel In operation of the balance system 210, the planar to a plane which bisects the vee of the V configura- crankshaft 12 drives or rotates the member 242 which, tion internal combustion engine. in turn, moves or drives the belt or chain 250. The belt or chain 250 drives or rotates the member 240 and the 3. A balance system as claimed in claim 1 or 2, where- second balance shaft 234 in the same direction as the 20 in each of said first balance shaft and said second planar crankshaft 12. The belt or chain 250 also drives balance shaft include at least one shaking force bal- or rotates the member 240 and the first balance shaft ance lobe and at least one moment balance lobe. 232 in the direction opposite to the planar crankshaft 1 2. It should be appreciated that the balance shafts 232 and 4. A balance system as claimed in any one of the pre- 234 are driven at a 2:1 ratio and in counter-rotation to 25 ceding claims, wherein said mechanism comprises each other. a first member attached to one end of said first bal- Referring to FIG. 8, another embodiment 310 of the ance shaft and a second member attached to one balance system 10 is shown. The balance system 310 of said second balance shaft and a third member has like parts of the balance system 10 with like refer- attached to one end of the planar crankshaft. ence numerals increased by three hundred (300). The 30 balance system 310 is used on a V-8 engine having a 5. A balance system as claimed in claim 4, wherein girdle 370 attached to the engine block 16 by suitable said mechanism further comprises an idler having means such as fasteners 372. The first balance shaft at least one fourth member and means for coupling 332 is located in the engine block 16 and the second said first member, said second member, said third balance shaft 334 is located in the girdle 370. The mem- 35 member and said fourth member together. bers 340 are gears which engage each other. The first balance shaft 332 includes a member 374 such as a 6. A balance system as claimed in claim 4, wherein sprocket or pulley at one end thereof. The belt or chain said mechanism further comprises an idler having 150 is disposed about the member 342 of the planar a fourth member and a fifth member engaging said crankshaft 12 and the member 374 of the first balance 40 first member and means for coupling said second shaft 332. member, said third member and said fourth member In operation of the balance system 310, the planar together. crankshaft 12 drives or rotates the member 342 which, in turn, moves or drives the belt or chain 350. The belt 7. A balance system as claimed in claim 4, wherein or chain 350 drives or rotates the member 374, member 45 said mechanism further comprises a fourth member 340 and first balance shaft 332 in the same direction as attached to the planar crankshaft, a fifth member the planar crankshaft 12. Rotation of the member 340 attached to each camshaft of the V-configuration in- of the first balance shaft 332 causes the rotation of the ternal combustion engine and a planetary gearset member 340 and second balance shaft 334 in a direc- attached to said first balance shaft wherein said first tion opposite to the planar crankshaft 12 at twice the so member acts as a sun gear of said planetary speed of the planar crankshaft 12. gearset.

8. A balance system as claimed in claim 7, wherein Claims said planetary gearset comprises a ring gear dis- ss posed about said first balance shaft and a plurality 1. A balance system for a planar crankshaft on a V of pinion gears disposed between and engaging configuration internal combustion engine compris- said ring gear and said sun gear. ing:

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9. A balance system as claimed in claim 8, wherein said mechanism further comprises a first means for coupling said second member and said third mem- ber together and a second means for coupling said fourth member, said fifth member and said ring gear s together.

10. A balance system as claimed in claim 1, wherein said first balance shaft and said second balance shaft are equidistant from a horizontal plane 10 through the centreline of the planar crankshaft.

11. A V configuration internal combustion engine com- prising: 15 an engine block; a planar crankshaft mounted in said engine block; a first balance shaft located above the planar crankshaft between banks of cylinders of the 20 engine block; a second balance shaft located below the pla- nar crankshaft; and a mechanism interconnecting said first balance shaft, the planar crankshaft and said second 25 balance shaft to rotate said first balance shaft and said second balance shaft in opposite di- rections at twice crankshaft speed to balance the engine. 30 12. A V configuration internal combustion engine as claimed in claim 11 including a girdle attached to said engine block, said first balance shaft being mounted in said engine block and said second bal- ance shaft being mounted in said girdle. 35

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Patent Number J) European EUROPEAN SEARCH REPORT Application Office EP 96 30 5092

DOCUMENTS CONSIDERED TO BE RELEVANT Citation of document with indication, where appropriate, Relevant CLASSIFICATION OF THE Category of relevant passages to claim APPLICATION (Int.CI.6) US 4 683 849 A (BROWN ARTHUR E) 4 August 1-6,10 F16F15/26 1987 * the whole document * Y 7,8

Y FR 900 456 A (AUGSBURG NURNBERG AG) 29 7,8 June 1945 * the whole document * A 9

Y PATENT ABSTRACTS OF JAPAN 11,12 vol. 011, no. 318 (M-632), 16 October 1987 & JP 62 101938 A ( CORP), 12 May 1987, * abstract *

DE 36 25 246 A (AUDI NSU AUTO UNION AG) 4 11,12 February 1988 * the whole document *

PATENT ABSTRACTS OF JAPAN 1,2,10 TECHNICAL FIELDS SEARCHED (Int.CI.6) vol. 008, no. 244 (M-337), 9 November 1984 & JP 59 121237 A (HINO JIDOSHA KOGYO KK) , F16F 13 July 1984, F02B * abstract *

US 4 936 268 A (RANDLE STEVEN J) 26 June 1990 * the whole document *

The present search report has been drawn up for all claims Place of search Date of completion of the search Examiner THE HAGUE 25 October 1996 Van der Veen, F CATEGORY OF CITED DOCUMENTS T : theory or principle underlying the invention E : earlier patent document, but published on, or X : particularly relevant if taken alone after the filing date Y : particularly relevant if combined with another D : document cited in the application document of the same category L : document cited for other reasons A : technological background O : non-written disclosure & : member of the same patent family, corresponding P : intermediate document document

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