Oil supply structure of transmission

1. An oil supply structure which supplies lubricating oil to a portion to be lubricated in a casing, the oil supply structure comprising:

an opening portion provided on a wall portion of the casing which corresponds to a shaft end portion of a rotary shaft supported by a bearing in the casing; and

an oil passage configured to provide communication from the opening portion to at least the bearing, wherein

the oil passage includes an inflow oil passage which communicates with the opening portion, and a connecting oil passage which extends obliquely upward from the inflow oil passage toward the bearing, and the opening portion is closed by a cap,

the oil supply structure comprises a first oil passage; a second oil passage; and a third oil passage, the third oil passage includes the inflow oil passage and the connecting oil passage,

the first oil passage communicates with a first introduction oil passage, which is provided on the wall portion of the casing, and through which lubricating oil is to be introduced into the casing, the first oil passage supplying lubricating oil into the casing from an inside of the rotary shaft,

the second oil passage communicates with a second introduction oil passage, which is provided on the wall portion of the casing, and through which lubricating oil is to be introduced into the casing, the second oil passage supplying lubricating oil into the casing from the inside of the rotary shaft, and

the third oil passage communicates with a third introduction oil passage, which is provided on the wall portion of the casing, and through which lubricating oil is to be introduced into the casing, the third oil passage supplying lubricating oil into the casing from the inside of the rotary shaft through the third introduction oil passage, the inflow oil passage, and the connecting oil passage,

the third introduction oil passage is disposed at a position lower than the first introduction oil passage and the second introduction oil passage, and

the inflow oil passage is disposed at a position lower than the connecting oil passage, wherein the inflow oil passage and the connecting oil passage are formed to have a substantially equal flow passage area.

2. The oil supply structure according to claim 1 , wherein

the first oil passage communicates with the first introduction oil passage so as to intersect on the wall portion of the casing,

the second oil passage communicates with the second introduction oil passage so as to intersect on the wall portion of the casing, and

the inflow oil passage is provided at a position where the third oil passage and the third introduction oil passage intersect with each other.

3. The oil supply structure according to claim 1 , wherein

the third oil passage includes a third shaft end oil passage and a third in-shaft oil passage, the third shaft end oil passage communicating with the connecting oil passage, and being provided on a shaft end side of the rotary shaft, and the third in-shaft oil passage being provided in the rotary shaft, and extending in an axial direction from the third shaft end oil passage, and

the third shaft end oil passage communicates with the bearing.

4. The oil supply structure according to claim 3 , wherein

the first oil passage and the second oil passage are configured to be partitioned by a first pipe member and a second pipe member, which are inserted into a shaft hole formed along an axis of the rotary shaft from a shaft end portion of the rotary shaft,

the second oil passage is provided so as to surround an outer side of the first oil passage by the first pipe member,

the third shaft end oil passage is provided so as to surround an outer side of the second oil passage by the second pipe member, and

the third in-shaft oil passage communicates with the third shaft end oil passage, and is provided in the rotary shaft at a position outward of the first oil passage and the second oil passage in a radial direction.

5. The oil supply structure according to claim 1 , wherein

the opening portion is provided for processing the connecting oil passage in the casing.

6. The oil supply structure according to claim 1 , wherein

the cap is detachably mounted on the opening portion.