Valve timing retarding system
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorsTateo Aoyama, Kenichi Sakurai, Shigeo Yamamoto
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Abstract
Several embodiments of variable camshaft timing means for twin overhead cam engines. There is provided a first timing altering means between the engine output shaft and one of the camshafts and a second timing altering means that is operative between the one camshaft and the other camshaft. Both timing altering means are operated by the same hydraulic pressure in several embodiments and a locking device is incorporated so as to avoid self-induced timing adjustment due to the change in driving loads.
Claims30
A camshaft arrangement for an internal combustion engine comprising a first camshaft journaled for rotation about a first axis and operating at least one intake valve of a cylinder of said engine, a second camshaft journaled for rotation about a second axis and operating at least one exhaust valve of said cylinder of said engine, a first drive element carried by said first camshaft at one end therefore, first positive drive means for driving said first drive element in timed relation from an output shaft of said engine, first variable timing means for driving said first camshaft from said first drive element and changing the timing relationship between said output shaft and said first camshaft, a second drive element carried at a point spaced from said one end of said first camshaft, second variable timing means for driving said second drive element from said first camshaft and for varying the timing of said second drive element relative to said first camshaft, and second positive drive means for driving said second camshaft in timed relation to said second drive element.
A camshaft arrangement for an internal combustion engine comprising a first camshaft journaled for rotation about a first axis and operating at least one intake valve of a cylinder of said engine, a second camshaft journaled for rotation about a second axis and operating at least one exhaust valve of said cylinder of said engine, first drive means for driving one of said camshafts from an output shaft of said engine at one end of said one camshaft, said first drive means including means for changing the timing relationship between said output shaft and said one camshaft, second driving means for driving the other of said camshafts from said one camshaft at the other end of said one camshaft, said second drive means including means for varying the timing of said other camshaft relative to said one camshaft, at least one of said drive means including a flexible transmitter, the means for varying the timing of at least one of said drive means includes means for effecting rotation of that camshaft relative to the driving element, means for varying the timing of the one camshaft including a hydraulically operated element, and looking means for precluding movement of said hydraulically operated element when hydraulic pressure is not applied so as to avoid self-adjusting.
A camshaft arrangement for an internal combustion engine comprising a first camshaft journaled for rotation about a first axis and operating at least one intake valve of a cylinder of said engine, a second camshaft journaled for rotation about a second axis and operating at least one exhaust valve of said cylinder of said engine, first drive means for driving one of said camshafts from an output shaft of said engine at one end of said one camshaft, said first drive means including means for changing the timing relationship between said output shaft and said one camshaft, second driving means for driving the other of said camshafts from said one camshaft at the other end of said one camshaft, said second drive means including means for varying the timing of said other camshaft relative to said one camshaft, at least one of said drive means including a flexible transmitter, means for varying the timing of at least one of the drive means includes means for effecting rotation of that camshaft relative to the driving element, both of the means for varying the timing being hydraulically operated and the means for varying the timing of said one camshaft including a hydraulically operated element, and a single control valve for controlling the application of hydraulic pressure to both of the timing adjusting means.
A camshaft arrangement for an internal combustion engine comprising a first camshaft journaled for rotation about a first axis and operating at least one intake valve of a cylinder of said engine, a second camshaft journaled for rotation about a second axis and operating at least one exhaust valve of said cylinder of said engine, first drive means for driving one of said camshafts from an output shaft of said engine at one end of said one camshaft, said first drive means including means for changing the timing relationship between said output shaft and said one camshaft, second driving means for driving the other of said camshafts from said one camshaft at the other end of said one camshaft, said second drive means including means for varying the timing of said other camshaft relative to said one camshaft, at least one of said drive means including a flexible transmitter, the means for varying the timing of said one camshaft includes a hydraulically operated element, and locking means for precluding movement of said hydraulically operated element when hydraulic pressure is not applied so as to avoid self-adjusting.
A camshaft arrangement for an internal combustion engine having first and second cylinder banks disposed at a V, a pair of first camshafts journaled for rotation about respective first axes relative to a respective one of said cylinder banks and operating at least one intake valve in said respective bank, a pair of second camshafts journaled for rotation about respective second axes relative to said cylinder banks and each operating at least one exhaust valve of a cylinder of said respective cylinder bank, first drive means for driving one of said camshafts of each of said cylinder banks from an output shaft of said engine at one end of said one camshafts, said first drive means including means for changing the timing relationship between said output shaft and said one camshafts, a pair of second driving means for driving the other of said camshafts from said one camshaft of each of said cylinder banks, each of said pair of second drive means including means for varying the timing of said other camshaft relative to said one camshaft, said pair of second drive means being located at the other end of the respective one camshaft.
A camshaft drive for an internal combustion engine comprising a driving shaft, a camshaft, drive means for driving same camshaft from said driving shaft, hydraulically operated means for altering the timing relationship between said driving shaft and said camshaft, and locking means for precluding a change in the timing relationship between said driving shaft and said camshaft when hydraulic pressure is not applied to said hydraulically operated means.
Dependencies are inferred from the claim text.