摘要:
A shell type needle roller bearing includes an outer ring and a plurality of needle rollers arranged along an inner raceway of the outer ring. A steel sheet to be formed into the shell type outer ring 1 by pressing is made of a medium to high carbon steel containing carbon by not less than 0.3 mass percent.
摘要:
To further reduce the manufacturing cost of a shell type needle roller bearing, and to ensure high quality of the shell type outer ring by subjecting the outer ring to a heat treatment that needs no adjustment of the atmosphere.The steel sheet to be formed into the shell type outer ring 1 by pressing is made of a medium to high carbon steel containing carbon by not less than 0.3 mass percent. With this arrangement, the material cost and thus the manufacturing cost are lower than when using a conventional low-carbon structural alloy steel sheet or a steel sheet for cold rolling and pressing. Also, it is possible to ensure high quality of the outer ring by subjecting the outer ring to simple heat treatment without the need for carburizing or carbonitriding, which needs adjustment of the atmosphere.
摘要:
A steel retainer (3), which retains needle rollers (2), is formed from a steel plate containing 0.15 to 1.10% by mass of carbon. After being formed, the steel plate is subjected to induction heat treatment which includes induction hardening and induction tempering. Such heat treatment can be carried out efficiently in a short period of time, using compact treatment facilities, even in small-lot production. The retainer (3) thus formed is sufficiently resistant to wear and surface damage, and is high in fatigue strength and fracture strength as a whole.
摘要:
A steel retainer (3), which retains needle rollers (2), is formed from a steel plate containing 0.15 to 1.10% by mass of carbon. After being formed, the steel plate is subjected to induction heat treatment which includes induction hardening and induction tempering. Such heat treatment can be carried out efficiently in a short period of time, using compact treatment facilities, even in small-lot production. The retainer (3) thus formed is sufficiently resistant to wear and surface damage, and is high in fatigue strength and fracture strength as a whole.
摘要:
The object is to efficiently subject steel retainers of needle roller bearings to heat treatment in a short period of time even in small-lot production using compact treatment facilities, thereby producing retainers having improved resistance to wear and surface damage and high in fatigue strength and fracture strength as a whole. The steel retainer 3, which retains needle rollers 2, is formed from a steel plate containing 0.15 to 1.10% by mass of carbon. After forming, the steel plate is subjected to induction heat treatment comprising induction hardening and induction tempering. Such heat treatment can be carried out efficiently in a short period of time, using compact treatment facilities, even in small-lot production. The retainer 3 thus formed is sufficiently resistant to wear and surface damage, and is high in fatigue strength and fracture strength as a whole.
摘要:
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.
摘要:
The present invention is to suppress wear of outer diameter surfaces of chain guiding rollers (41) in a chain guide and extend the life. Respective shaft ends of a plurality of roller shafts (31) are supported by pairs of facing side plate portions (22) of guide bases (21) arranged to face each other in a one-side part of a timing chain (5) for transmitting torque. Each of the rollers (41) formed by a plurality of chain guiding roller bearings is rotatably supported by each of the plurality of roller shafts (31). Rollers whose surface hardness is greater than surface hardness of the timing chain (5) by 4 points or more of Rockwell hardness are used as the rollers (41), so as to prevent earlier wear of the outer diameter surfaces of the rollers (41) due to contact with the timing chain (5).
摘要:
The present invention is to suppress wear of outer diameter surfaces of chain guiding rollers (41) in a chain guide and extend the life. Respective shaft ends of a plurality of roller shafts (31) are supported by pairs of facing side plate portions (22) of guide bases (21) arranged to face each other in a one-side part of a timing chain (5) for transmitting torque. Each of the rollers (41) formed by a plurality of chain guiding roller bearings is rotatably supported by each of the plurality of roller shafts (31). Rollers whose surface hardness is greater than surface hardness of the timing chain (5) by 4 points or more of Rockwell hardness are used as the rollers (41), so as to prevent earlier wear of the outer diameter surfaces of the rollers (41) due to contact with the timing chain (5).
摘要:
A timing chain (5) is looped over a driving sprocket (2) attached to a crankshaft (1) and driven sprockets (4) attached to camshafts (3). A pivotable chain guide (A1) having a plurality of rotatable rollers (41) for guiding movements of the timing chain (5) is provided on one side of the slack side of the timing chain (5). Adjustment force of a chain tensioner is applied to a remote end of the chain guide remote from the center of pivoting movement of the chain guide, thereby pressing the rollers (41) against the timing chain (5). The ratio (D1/D2) between the pitch circle diameter D1 of the driving sprocket (2) and the outer diameter D2 of the rollers (41) is determined within the range of 5/3 to 5/1. This prevents insufficient lubrication of the chain guiding rollers (41), makes it easy to lay out the engine.
摘要:
An outer ring for rocking bearing (11a) includes a raceway surface (12a) on the inner diameter side and has flange parts (13a) and (13b) provided by bending both axial ends to the inner diameter side. The flange parts (13a) and (13b) are provided with bent parts (17a) and (17b) axially bent toward the raceway surface (12a) side so as to enfold a retainer arranged on the inner diameter side. Thus, the retainer can be enfolded by the bent parts (17a) and (17b). Therefore, even when the retainer comes to be moved to the inner diameter side of the outer ring for rocking bearing (11a), the retainer is caught by the bent parts (17a) and (17b), so that the movement of the retainer to the inner diameter side is restricted and rollers and the retainer can be prevented from dropping off.