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US4658777A Expired / Lapsed US ⏱️ 0.0 years remaining

Balancer structure for three-cylinder engines

Assignee: Subaru Corp
•
Filing: 1985-11-06
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Granted: 1987-04-21
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Expires: 2005-11-06
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Abstract

Abstract A balancer structure for a three-cylinder engine for eliminating the vibration in the engine especially the vibration caused by an inertia couple about an axis perpendicular to the crankshaft of the engine. A countershaft is rotated at the same speed as the crankshaft but in opposite direction. Two counterweights are secured to the crankshaft corresponding to the first and third cylinders of both ends for balancing of reciprocating masses and rotating masses. A counterweight is secured to the crankshaft for balancing of rotating masses. At least two balancers are secured to the countershaft at both ends thereof.

Inventors

  • 👤 Tsunehiko Suzuki

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-05 11:10
CPC Classifications
F; F16; F16F; F16F15/00; F16F15/22; F16F15/26; F16F15/264; F02; F02B; F02B75/00; F02B75/16; F02B75/18; F02B75/20; F16C; F16C3/00; F16C3/04; F16C3/20; F02B2075/1804; F02B2075/1812; Y; Y10; Y10T; Y10T74/00; Y10T74/21; Y10T74/2173; Y10T74/2183

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 199 words
A balancer structure for a three-cylinder in-line engine having three cylinders, the latter comprising a first and third cylinder and a second cylinder disposed between said first and third cylinders, a crankshaft having crank arms disposed at angles of 120° with respect to each other and operatively connected to a piston assembly within each of said cylinders, respectively, consisting of: a single crankshaft adjacent and parallel to and rotated at the same speed as the crankshaft but in the opposite direction, means comprising first counterweights securely mounted on said crankshaft only at positions thereof corresponding to the first and third cylinders for balancing of a part of inertia forces of rotating masses and a part of inertia forces of reciprocating masses; means comprising at least one second counterweight securely mounted on said crankshaft substantially opposite to the crank arm corresponding to the second cylinder for balancing of the remainder of the inertia forces of rotating masses; at least two balancers respectively securely mounted on said countershaft at both ends respectively thereof for the balancing of the remainder of the inertia forces of reciprocating masses, and of the couple of inertia of the crankshaft about axes perpendicular to the crankshaft.
Claim 2
Dependent Claim 199 words
A balancer structure for a three-cylinder in-line engine having three cylinders, the latter comprising a first and third cylinder and a second cylinder disposed between said first and third cylinders, a crankshaft having crank arms disposed at angles of 120° with respect to each other and operatively connected to a piston assembly within each of said cylinders, respectively, consisting of: a single crankshaft adjacent and parallel to and rotated at the same speed as the crankshaft but in the opposite direction, means comprising first counterweights securely mounted on said crankshaft only at positions thereof corresponding to the first and third cylinders for balancing of a part of inertia forces of rotating masses and a part of inertia forces of reciprocating masses; means comprising at least one second counterweight securely mounted on said crankshaft substantially opposite to the crank arm corresponding to the second cylinder for balancing of the remainder of the inertia forces of rotating masses; at least two balancers respectively securely mounted on said countershaft at both ends respectively thereof for the balancing of the remainder of the inertia forces of reciprocating masses, and of the couple of inertia of the crankshaft about axes perpendicular to the crankshaft.
Claim 3
Dependent Claim 19 words
The balancer structure for a three-cylinder engine according to claim 1 wherein each counterweight comprises a pair of weights.
Claim 4
Dependent Claim 17 words
The balancer structure according to claim 1, wherein the cylinders are aligned spaced by equal distance therebetween.
Claim 5
Dependent Claim 35 words
The balancer structure according to claim 1, wherein said first counterweights include third counterweights for the first and third cylinders for the balancing of the reciprocating masses, the masses of said third counterweights are equal.
Claim 6
Dependent Claim 47 words
The balancer structure according to claim 4, wherein each of said balancers at respective ends of said countershaft are disposed at the same angular position as said third counterweights at remote ends of said crankshaft respectively when said second cylinder is in a top dead center condition.
Claim 7
Dependent Claim 38 words
The balancer structure according to claim 1, wherein said balancers are positioned on said countershaft axially offset with respect to said first counterweights so as not to engage with the first counterweights while crossing axially offset during rotation.
Claim 8
Dependent Claim 16 words
The balancer structure according to claim 6, wherein said countershaft is closely adjacent to said crankshaft.
Claim 9
Dependent Claim 27 words
The balancer structure for a three-cylinder engine according to claim 1 wherein said balancers are disposed in positions corresponding to bearings for both ends of said crankshaft.
Claim 10
Dependent Claim 49 words
The balancer structure according to claim 8, wherein said balancers are positioned on said countershaft axially offset with respect to said first counterweights so as not to engage with the first counterweights while crossing axially offset during rotation, said bearings are disposed such that said first counterweights are therebetween.
Claim 11
Dependent Claim 16 words
The balancer structure according to claim 9, wherein said countershaft is closely adjacent to said crankshaft.
Claim 12
Dependent Claim 82 words
The balancer structure according to claim 1, wherein said first counterweights include third counterweights for the first and third cylinders for the balancing of the reciprocating masses, respective of said third counterweights for the balancing of the reciprocating masses is respectively advanced and retarded by 30° from a position opposite a first and third of said crank arms, respectively, corresponding to said first and third cylinders, such that said third counterweights extend perpendicular to said crank arm corresponding to said second cylinder.
Claim 13
Dependent Claim 17 words
The balancer structure according to claim 11, wherein the cylinders are aligned spaced by equal distance therebetween.
Claim 14
Dependent Claim 46 words
The balancer structure according to claim 11, wherein said third counterweights are each formed in pairs and have composite masses which are equal and disposed at equal distances from a central axis perpendicular to said crankshaft passing through said crank arm corresponding to said second cylinder.
Claim 15
Dependent Claim 60 words
The balancer structure according to claim 1, wherein said first counterweights include third counterweights for the first and third cylinders for the balancing of the reciprocating masses as well as fourth counterweights for the balancing of the rotating masses, said fourth counterweights are separated from a corresponding of said third counterweights by an angle of plus and minus 30°, respectively.
Claim 16
Dependent Claim 21 words
The balancer structure according to claim 14, wherein said fourth counterweights and said third counterweights are at least partially integrally combined.
Claim 17
Dependent Claim 59 words
The balancer structure according to claim 15, wherein said third counterweights form a right angle with respect to the crank arm for the second cylinder, and said fourth counterweights for said first and third cylinders, respectively, are positioned 180° and with respect to a first and third of said crank arms, respectively, corresponding to said first and third cylinders.

References Cited (Backward Citations)

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GB844071A Cited
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GB1210245A Cited
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USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1990-04-20 1990-10-20 1991-04-21 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1994-04-20 1994-10-20 1995-04-21 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1998-04-20 1998-10-20 1999-04-21 $7700.00 Window Closed / Lapsed

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