Chain transmission apparatus

A chain transmission comprising:

• a bushingless chain comprising pairs of outer link plates, pairs of inner link plates disposed between the pairs of outer link plates, connecting pins, and rollers, said chain being in the form of an endless loop;
• a plurality of sprockets having sprocket teeth that engage with the rollers of the chain whereby the chain travels along a direction of travel around the sprockets;
• and
• a tensioner, a movable guide operated by the tensioner, and a stationary guide, both guides having sliding contact surfaces on which the chain slides as the chain travels around said sprockets;
• wherein the pairs of inner link plates and the pairs of outer link plates are arranged in alternating sequence and linked together articulably by said connecting pins;
• wherein the connecting pins are fixed to the outer link plates and extend through holes in the inner link plates;
• wherein the inner link plates are directly supported by, and rotatable on, the connecting pins, and an inner link plate radial gap is formed between each said connecting pin and the inner surface of each hole in the inner link plate through which the connecting pin extends;
• wherein the chain is lubricated by oil from a oil supply;
• wherein oil from said oil supply is disposed in each said inner link plate radial gap;
• wherein one of said rollers is rotatable on each connecting pin and a film of said oil is disposed in a roller radial gap between the outer circumferential surface of each connecting pin and the inner circumferential surface of the roller thereon;
• wherein the link plates have back surfaces which face toward the outside of said endless loop and only the inner link plates come into contact with the sliding-contact surfaces of the guides, by contact between contact portions of the back surfaces of said inner link plates and the sliding contact surfaces of the guides, each of said inner link plates having only one contact portion, and each of said contact portions being continuous and having a length extending in a plane parallel to a plane in which said direction of travel of the chain lies;
• and
• wherein the entire length of each of said contact portions of the back surfaces of the inner link plates that come into contact with the sliding contact surfaces of the guides is in the form of a convex arc having an axis transverse to the direction of travel of the chain whereby said inner link plates are caused to oscillate upon engagement with an disengagement from the sliding contact surfaces of said guides;
• whereby, by oscillation of said inner link plates, oil from said inner link plate radial gap is pushed in the direction of the width of the chain and enters the roller radial gap.