Ntn Corporation

Borgwarner Morse Systems Japan K.k.

Akio Kato

Shinji Oishi

Takahiro Yamashita

Hisataka Hasegawa

Katsufumi Abe

Goro Nakao

Takashi Tsujimoto

Takushi Matsuto

Atsushi Ikeda

Yuuki Naitou

Shinji Tsuruta

Nobuhiro Mizuno

Hiroyuki Fukuyama

Makoto Okasaka

Youhei Yamashita

Yuta Oku

A feed screw mechanism includes a rotary member having a female screw portion, a linear motion member having a male screw portion screwed to the female screw portion and making a linear motion with rotation of the rotary member, a lubricant between the female and male screw portions, a housing housing the rotary and linear motion members, and a wall portion protruding, in a radial direction, from the outer peripheral surface of the linear motion member. The wall portion moves together with the linear motion member, and an outer radial end portion of the wall portion is disposed: to not contact the inner peripheral surface of the housing and a member provided on the inner peripheral surface of the housing; or to be slidable with respect to the inner peripheral surface of the housing or the member provided on the inner peripheral surface of the housing.

Feed screw mechanism and electric actuator

An electric actuator includes: an electric motor, a relay circuitthat switches ON/OFF of power supply to the electric motor, a motion conversion mechanismthat converts a rotary motion of the electric motorinto a motion in a direction different therefrom and outputs the motion, and a housing. The housingis configured by joining two housing split bodiesandto each other, and in an internal space formed by joining the two housing split bodiesand, the electric motor, the relay circuit, and the motion conversion mechanismare housed.

Electric actuator

An electric actuatorincludes: an electric motor; a first motion conversion mechanismthat has a screw shaftrotatably driven by the electric motorand a nutscrewed with the screw shaft, and converts a rotary motion of the screw shaftinto a linear motion of the nut; and a housingaccommodating the electric motorand the motion conversion mechanism. The housingincludes a pair of housing split bodiesandsplit by a plane parallel to an axial direction of the screw shaft

A chain transmission device includes chain guides capable of guiding a chain. The chain guides include a plurality of spaced apart rollers for guiding the chain, and a distance L (m) between contact points of a trained portion of the chain is set to satisfy the following inequality: where &#x3c9;is a maximum excitation frequency (Hz) from a crankshaft, &#x3c1; is a mass of the chain per unit length (kg/m), and T is a time-average tension of the chain (N).

Chain transmission device

A chain transmission device for driving camshafts includes a chain including a loose side chain portion, and the chain is trained around the crank sprocket and the cam sprockets. A chain guide is mounted on the outer side of the loose side chain portion so as to be pivotable about one of the two end portions of the chain guide, and the chain guide has a plurality of rotatable rollers. An adjustment force is applied to the other of the two end portions of the chain guide by a chain tensioner such that the chain guide is biased toward the chain, so that the rollers of the chain guide can guide the chain by rolling. The winding angle of the portion of the chain located on the outer periphery of the roller located closest to the crank sprocket is set to be 170 degrees or greater so as to reduce noise.

Chain transmission device for driving camshafts

A chain guide includes a guide base pivotable about a fulcrum shaft. The fulcrum shaft is between a roller bearing located at an end portion of the guide base, which is closer to the fulcrum shaft, and the center of the guide base in the longitudinal direction of the guide base such that the roller bearing is outside of the fulcrum shaft.

Chain guide and chain transmission device

A chain guide includes a curved guide base extending along the direction in which a torque transmitting chain moves. The guide base includes, on its surface opposed to the chain, a rolling guide portion including a plurality of roller element bearings which are rotatable and configured to guide the chain while kept in rolling contact with the chain, and a sliding guide portion in the form of a curved surface. The rolling guide portion reduces a loss in torque transmission, while the sliding guide portion reduces flapping of the chain, thus reducing noise and vibrations of the chain.

A chain guide includes a plurality of roller shafts provided on one side of a timing chain for torque transmission and spaced from each other in the longitudinal direction of a guide base facing the timing chain. The respective roller shafts rotatably support chain guiding rollers in the form of needle roller bearings. The rollers are cylindrical members having the same diameter over the entire axial direction such that the rollers are movable in the axial direction relative to the timing chain. The rollers are supported so as to be movable in the axial direction. When the rollers and the timing chain move relative to each other in the axial direction and the rollers move relative to the roller shafts in the axial direction, contact portions between the rollers and the roller shafts are displaced in the axial direction, so that radial loads are not locally applied.

A chain guide is provided which reduces moving resistance of a camshaft-driving, torque-transmitting timing chain. The chain guide includes a guide base provided on one side of the timing chain to face the timing chain and having an opposed pair of side plates. The side plates support respective ends of roller shafts each rotatably supporting a chain-guiding needle roller bearing. Each needle roller bearing includes a retainer guided by needle roller elements.

Chain tensioner and chain transmission device

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 &#x3bc;m.

Chain guide and chain drive apparatus

A chain guide includes a guide base () disposed to face one side of a timing chain () that transmits torque, the chain guide having an opposed pair of side plates () each formed with a plurality of shaft engaging portions () arranged along a circular arc. Roller shafts () have their ends supported by the respective shaft engaging portions (). Rollers () for guiding the chain are rotatably supported by the respective roller shafts (). Noncylidrical surface engaging portions are formed on the ends of the roller shafts () and on closed ends of the shaft engaging portions () to rotationally fix the roller shafts (), thereby preventing the roller shafts () from rotating under drag torque applied from the rollers ().

A chain guide and a chain tensioner device using the chain guide. A roller, brought into contact with a chain, comprises a support shaft supported by an opposing guide base provided along the running direction of the chain, and roller bearings each having a steel outer ring on the outer peripheral surface of the support shaft so as to be brought into contact with the chain. The roller is also configured to be assembled by inserting opposite ends of the support shaft into support recesses on facing wall surfaces of the guide base. The roller has a vibration damping material between the support shaft and the support recess of each of the plate members.

Chain guide and chain tensioner device

A chain guide includes roller element bearings adapted to guide, while rolling, a timing chain through which torque is transmitted. The chain guide further includes a guide base arranged along one side of the timing chain and having an opposed pair of side plates. Each side plate is formed with plural shaft engaging portions arranged so as to lie on a circular arc. The chain guide further includes roller shafts having their ends supported by the respective shaft engaging portions, and rotatably supporting the roller element bearings. An oil guide hole is formed in a wall surface of each shaft engaging portion facing the end surface of the roller shaft so as to extend through the side plate to its outer side surface.

A timing chain is looped over a driving sprocket attached to a crankshaft and driven sprockets attached to camshafts. A pivotable chain guide having a plurality of rotatable rollers for guiding movements of a timing chain is provided on one side of a slack side of the timing chain. Adjustment force of a chain tensioner is applied to a remote end of the pivotable chain guide remote from a center of pivoting movement of the pivotable chain guide, thereby pressing the plurality of rotatable rollers against the timing chain. The ratio (D/D) between a pitch circle diameter Dof the driving sprocket and an outer diameter Dof the plurality of rotatable rollers is determined within a range of 5/3 to 5/1.

Chain transmission device for driving camshaft

A chain guide having excellent durability is provided. The chain guide includes a guide base arranged along a portion of an outer periphery of a chain for transmitting torque and elongated in the direction in which the chain travels; a plurality of roller shafts attached to the guide base so as to be spaced apart from each other along the direction in which the chain travels; and rollers rotatably supported by the respective roller shafts. The distance between the centers of each adjacent pair of the rollers is set to be shorter in the area where a larger load is applied to the rollers.

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Shizuoka, Japan

Akio Kato