Abstract:
To provide a rocker arm of a design effective to avoid occurrence of a loosening of the adjustment screw to ensure a proper operation of the internal combustion engine including the control of the opening of the valve body on the engine cylinder head, the rocker arm 1 is of a type capable of being rockingly driven by a cam 2 for selectively opening and closing a valve of an internal combustion engine. The rocker arm 1 includes an arm body 4 prepared from a steel plate by means of a press work to have a generally inverted U-shaped section. The arm body 4 has one end formed with an internally threaded hole 12 into which an adjustment screw 7 is threaded. This adjustment screw has one end defining a pivot piece 7b or a valve drive piece 7Ab. Two nuts 13 and 14 are threadingly mounted in overlapping relation to each other on one end portion of the adjustment screw 7 protruding outwardly from the arm body. Instead of the use of the two nuts 13 and 14, a flanged nut may be employed or a single nut 13 in combination with a washer 17 may be employed.
Abstract:
A pump tappet (21) transmits a rotation movement of a cam shaft (12) provided with a cam (12a) to a pump plunger (13) as a reciprocation linear movement, and performs a reciprocation linear movement together with the pump plunger (13). The pump tappet (21) includes a shaft (22), a roller bearing (31) arranged on an outer diameter side of the shaft (22) and rotatably supported on the shaft (22), and a case (23) to house the shaft (22) and the roller bearing (31). The roller bearing (31) includes an outer ring (32) abutting on the cam (12a), a plurality of rollers (33) arranged between the outer ring (32) and the shaft (22), and a retainer (34) to retain the plurality of rollers (33).
Abstract:
A positioning protrusion 14 is provided in a center of an outer diameter surface of a halved outer ring 11a in both circumferential and axial directions. The positioning protrusion 14 is configured to engage with a housing, which is placed on an outer diameter side of the halved outer ring, to position the halved outer ring 11a with respect to the housing. A protruding portion 17a and a recessed portion 17b are provided in each abutting portions 16a, 16b where a pair of the halved outer rings 11a abut on each other when fitted on a rotary shaft that is supported by a roller bearing. The protruding portion 17a and the recessed portion 17b are configured to mesh with each other to restrict axial movement of both halved outer rings 11a. The protruding portion 17a and the recessed portion 17b are point-symmetric with respect to a center 20 of the positioning protrusion 14.
Abstract:
An object of the present invention is to provide a chain guide superior in silence, which includes: a guide base extending in a traveling direction of a chain; a plurality of roller shafts attached to the guide base at an interval along the traveling direction of the chain; and rollers each rotatably supported by one of the roller shafts. The roller has a cylindrical outer circumferential surface for guiding the chain. The outer circumferential surface of the roller has a cylindricity not greater than 20 μm.
Abstract:
Provided are a gear and a gear drive unit which allow oil film formation to a sufficient degree between tooth surfaces of gears rotating at high-speed and which help to prevent generation of pitting, abrasion, and prevent scoring, temperature rise, and wear to thereby achieve an improvement in terms of durability. A tooth surface is provided with a multitude of minute recesses arranged at random, in which an axial surface roughness parameter Ryni of the surface thus provided with the recesses is set to a range: 0.8 μm≦Ryni≦2.3 μm. As a result, the tooth surface is endowed with a high oil film formation performance, and it is possible to attain a long service life even under a low-viscosity/thin-lubrication condition in which the oil film is extremely thin.
Abstract:
A needle roller bearing comprises an outer ring having a plurality of outer ring members split by split lines extending in an axial direction of the bearing, a plurality of needle rollers arranged on an orbit surface of said outer ring so that they can roll thereon, and a cage holding the needle rollers at intervals. The outer ring member has a projection serving as a positioning engaging part which engages with a housing for positioning, and an engaging click protruding from an axial end of the outer ring member inward along a diameter to prevent the cage from moving in an axial direction, in positions shifted from its circumferential center.
Abstract:
A stator unit for a torque converter includes a stator, a one-way clutch mounted radially inside the stator, and thrust bearings provided on both axial sides of the one-way clutch. The one-way clutch includes an outer ring having a peripheral wall and side walls extending radially inwardly from the respective side edges of the peripheral wall and each having a flange formed at the radially inner edge thereof, an inner ring which are in sliding contact with the flanges, and sprags disposed between the inner surface of the peripheral wall and the outer surface of the inner ring. The thrust bearings each have a stake which is pressed into one of engaging steps formed in the radially inner surface of the stator until the bearing ring of the thrust bearing is pressed against one of the side walls and one of axial end surfaces of the inner ring, thereby retaining the component parts so as to be inseparable from the stator.
Abstract:
There is provided a rocker arm of a kind in which even though the rocker arm is manufactured by the use of a press working technique the arm width can be minimized while the flat outer surface region of a required width is secured on an outer surface of the connecting wall, thereby contributing to reduction in size and weight of the rocker arm. This rocker arm 1 is capable of being driven by a cam 2 for selectively opening and closing a valve 3 of an internal combustion engine. This rocker arm 1 includes an arm body 4 prepared by bending a single plate material to represent a generally inverted U-shaped section including opposite side walls 5 and a connecting wall 6 bridging between the opposite side walls 5. A roller 10 engageable with the cam 2 is rotatably mounted on a portion of the arm body 4 generally intermediate of the length thereof. A valve drive element 8 is mounted on one end of the arm body 4 for driving the valve 4, while an end portion of the connecting wall 6 adjacent the other end of the arm body 4 is formed with an internally helically threaded hole 12 for threadingly receiving therein an externally helically threaded pivot member 7. An outer chamfered corner delimited between an outer surface of the connecting wall 6 and an outer surface of each of the opposite side walls and formed by bending is deformed to represent a plastically deformed portion 4a so formed by means of a plastic deformation technique that the outer chamfered corner represents a small radius of curvature R.
Abstract:
A roller bearing retainer (13) includes a pair of annular ring parts (14) and a plurality of column parts (15) each including a column center part (16) provided in an axial center region so as to be positioned relatively on the radial inner side, a pair of column end parts (17) provided in axial end regions so as to be positioned relatively on the radial outer side, and a pair of column sloped parts (18) positioned between the column center part (16) and the pair of column end parts (17), and connecting the pair of ring parts to each other. A thickness of each part of the column center part, the pair of column end parts, and the pair of column sloped parts is smaller than a thickness of a boundary part between the adjacent parts.
Abstract:
A caged roller bearing includes a plurality of rollers (1) and a roller retaining cage (2) having pockets (3) defined therein at circumferential locations thereof for accommodating the respective rollers (1) therein. A nickel plating layer, which is a plated backing layer (4), is applied to the entire surface of the roller retaining cage (2), and an Ni.PTFE plated layer (5), containing nickel and polytetrafluoroethylene, is applied to the surface of the nickel plating layer.