Abstract: A guide groove including a groove section extending from the vicinity of an entrance of a main passage to a side opposite the entrance is formed on the inner circumferential surface of a main passage. The groove section is provided in an inclined fashion with respect to the axial direction such that lubricating oil inside the groove section is sent towards the side opposite the entrance by rotation of a rotary shaft in a predetermined direction. Of a plurality of subsidiary passages, the entrance of a subsidiary passage that is most distant from the entrance of a main passage is disposed in the guide groove. In a lubrication structure for a transmission, insufficient lubrication is effectively prevented in parts requiring lubrication corresponding to the subsidiary passages, irrespective of the positions of the subsidiary passages in the axial direction, while avoiding increase in the size of the transmission.

Abstract: A guide groove including a groove section extending from the vicinity of an entrance of a main passage to a side opposite the entrance is formed on the inner circumferential surface of a main passage. The groove section is provided in an inclined fashion with respect to the axial direction such that lubricating oil inside the groove section is sent towards the side opposite the entrance by rotation of a rotary shaft in a predetermined direction. Of a plurality of subsidiary passages, the entrance of a subsidiary passage that is most distant from the entrance of a main passage is disposed in the guide groove. In a lubrication structure for a transmission, insufficient lubrication is effectively prevented in parts requiring lubrication corresponding to the subsidiary passages, irrespective of the positions of the subsidiary passages in the axial direction, while avoiding increase in the size of the transmission.