Abstract:
In one aspect, the present disclosure is directed to a tappet assembly for a machine. The assembly may include a tappet body, a pin fixedly mounted in the tappet body, and a substantially cylindrical roller mounted about the pin. The roller may have a substantially cylindrical outer surface with a circumferential dimension and a width dimension, the width dimension being defined by two lateral edges. The roller may be configured to provide rolling contact between the outer surface of the roller and a cam lobe. The outer surface of the roller may be crowned such that at maximum operational loading conditions of the machine a footprint of contact pressure from the cam lobe is spread substantially the full width of outer cylindrical surface of the roller.
Abstract:
The invention relates to a switchable cam follower of a valve train of an internal combustion engine, comprising an outer follower and an inner follower interposed between the lateral walls thereof. A roller extends between arms of the inner follower, float-mounted on a pin, as the counter face for an eccentric disk. The followers are disposed on one end on a common axis. On the distal end, they have elongate seats that, at the base of the cam, are mutually aligned. A coupling element is located in the seat of the outer follower and can be displaced step by step into the seat (here follower surface) of the inner follower. The pin on the inner follower slightly projects over the arms of the inner follower with one projection each. When coupled, upper sides of the projections rest against lower sides of stop surfaces that are mounted on the inner surfaces of the lateral walls of the outer follower.
Abstract:
A roller seating device has a hollow-cylindrical element (1) in which a roller (4) is received in seats (8, 10) perpendicular to a center axis (6) of the hollow-cylindrical element (1). A securing element (12) is configured and arranged to couple in a form-fit to the hollow-cylindrical element (1) in the interior (14) of the hollow-cylindrical element (1) in a direction that is axial and rotatory with respect to the center axis (6) of the hollow-cylindrical element (1) and in such a manner as to fix the roller (4) on its faces (16, 18) axially to the center axis (6) of the roller (4).
Abstract:
A rocker arm supported by a support portion of an engine and to be driven by a cam includes a sheet-metal rocker arm body manufactured by plastic working and including a cam follower, a fulcrum portion manufactured by cutting and including a through hole supplying lubricant, and a lubricant discharging hole. The cam follower includes a first slide-contact surface being in sliding contact with the cam. The lubricant discharging hole is defined by an outer surface of the fulcrum portion and an outer surface of the sheet-metal rocker arm body and in communication with the through hole. The lubricant discharging hole biases the lubricant supplied from the through hole in a direction toward the first slide-contact surface.
Abstract:
The present invention relates to a variable valve operating device and makes it possible to inhibit friction during driving force transmission and provide high durability through the use of a compact configuration.A first roller 170, which comes into contact with a drive cam surface 124 of a camshaft 120, has a larger diameter than a second roller 172, which comes into contact with a slide surface 156 of a swing member 150. A coupling shaft 174 couples the first roller 170 to the second roller 172 so that the rollers 170, 172 can rotate independently. The slide surface 156 is curved toward the drive cam surface 124.
Abstract:
A variable valve system includes a transmission mechanism T which transmits a valve actuating force to an inlet valve 11 and which varies a maximum lift amount of the inlet valve 11 and biasing members 60. A sub-cam 40 oscillatably supported on a holder 30 driven by a control member 70 has a roller 43 contacting the inlet cam 15a, a drive cam portion 46 outputting the valve actuating force, and acting portions A contacting the biasing members 60. The acting portions A are provided in the vicinity of the roller 43 so that biased contact points 45a1, 45b1 are positioned nearer to a cam contact point 43a than an oscillation center line Ls and that an acting line L1 of a biasing force is superposed on the roller 43 as viewed in the direction of the oscillation center line Ls.
Abstract:
A valve-deactivation hydraulic valve lifter including a recessed face on the pin housing for making contact with the a crowned surface region of a roller follower. The lifter includes a pin housing that is slidably disposed within an axial bore in a lifter body. Pins for variably locking the pin housing to the lifter body may be disengaged to place the lifter in lost-motion mode by application of engine oil to the outer ends of the pins. A surface of the pin housing, preferably configured as a dished surface, is formed on the bottom end face of the pin housing that approaches the cam-following lifter roller for making contact with the roller follower so as to avoid contacting the roller follower's crowned surface region.
Abstract:
A variable valve system includes a transmission mechanism T which transmits a valve actuating force to an inlet valve 11 and which varies a maximum lift amount of the inlet valve 11 and biasing members 60. A sub-cam 40 oscillatably supported on a holder 30 driven by a control member 70 has a roller 43 contacting the inlet cam 15a, a drive cam portion 46 outputting the valve actuating force, and acting portions A contacting the biasing members 60. The acting portions A are provided in the vicinity of the roller 43 so that biased contact points 45a1, 45b1 are positioned nearer to a cam contact point 43a than an oscillation center line Ls and that an acting line L1 of a biasing force is superposed on the roller 43 as viewed in the direction of the oscillation center line Ls.
Abstract:
A rolling bearing that attains long life against surface damage such as surface-originating separation or internally originating separation and allows caulking of its shaft end face, a cam-follower with roller employing the rolling bearing, and a cam are obtained. The rolling bearing includes an outer-roller, a roller shaft located inside the outer-roller, and a rolling element interposed between the outer-roller and the roller shaft. At least one member of the outer-roller and the roller shaft has a nitrogen enriched layer. A surface portion of an area in a rolling contact surface where the rolling element rolls has austenite grain size of No. 11 or larger. The end portion has hardness of not larger than HV300.
Abstract:
A rocker arm formed of material in a shape of sheet has a pair of side wall portions, a connection portion for a valve stem receiving portion and a connection portion for a pivot receiving portion which interconnect the side wall portions, and an open portion for arranging a roller which is formed between the two connection portions. A distance between outer side surfaces of the pair of side wall portions in the connection portion for the valve stem receiving portion is reduced in a direction from upper edges to lower edges in a step-like shape having two or more step differences, whereby a first outer side surface and a second outer side surface are formed.