Gear type transmission unit

Claim 1

A gear type transmission unit which comprises a transmission unit housing, a bearing retainer mounted at a front wall portion of said transmission unit housing, and a first bearing held in said bearing retainer for supporting an input shaft, the improvement comprising an upper portion of a bearing holding portion of said bearing retainer, formed to project toward the side of a gear speed changing mechanism, said projecting upper portion formed with an oil groove for introducing lubricating oil to be communicated with an oil hole formed in said bearing retainer for directing the oil and provide for bearing lubrication, further including an extension housing provided at the end portion thereof opposite to the front wall portion of said transmission unit housing, said extension housing including a forward wall and a further bearing provided in said forward wall for supporting an output shaft, said further bearing being composed of a seal bearing, said forward wall of said extension housing being formed with an oil discharge opening in a position around and outer periphery of said seal bearing at a height corresponding to that of a bearing portion in the rear end portion of said extension housing, and also, formed with an oil introducing opening for leading the lubricating oil into the extension housing in a position around the outer periphery of said seal bearing at a height higher than that of said oil discharge opening.