Abstract: A jump shift of an automatic transmission with multiple shift speeds such as, e.g., ten forward speeds involves operation of many engagement elements. The shifting operation for the jump shift is therefore complicated, making it difficult for the automatic transmission to respond quickly. After shifting to the seventh speed as a direct coupling speed is completed by engaging three clutches C1, C3, C4, the remaining other clutch C2 is also engaged at the seventh speed. In the case of a jump shift, e.g., a shift from the seventh speed to the fifth speed, shifting to the fifth speed is completed by disengaging the clutch C1 and performing control to disengage the clutch C3 and to engage a brake B1 with the remaining other clutch C2 kept in the engaged state. This facilitates the shifting operation from the direct coupling speed and allows the automatic transmission to respond quickly.

Abstract: A jump shift of an automatic transmission with multiple shift speeds such as, e.g., ten forward speeds involves operation of many engagement elements. The shifting operation for the jump shift is therefore complicated, making it difficult for the automatic transmission to respond quickly. After shifting to the seventh speed as a direct coupling speed is completed by engaging three clutches C1, C3, C4, the remaining other clutch C2 is also engaged at the seventh speed. In the case of a jump shift, e.g., a shift from the seventh speed to the fifth speed, shifting to the fifth speed is completed by disengaging the clutch C1 and performing control to disengage the clutch C3 and to engage a brake B1 with the remaining other clutch C2 kept in the engaged state. This facilitates the shifting operation from the direct coupling speed and allows the automatic transmission to respond quickly.

Abstract: An oil seal for sealing a hollow rotary shaft in a power transmission apparatus, wherein the rotary shaft is formed with an internal flow passage through which oil flows and constituted such that the oil flies out as the rotary shaft rotates, including: a fixed portion that is fixedly attached to a case of the power transmission apparatus; a seal portion that seals the rotary shaft at a position that is axially offset position from the fixed portion and allows the rotary shaft to rotate; and a radiator portion that is formed from a metallic material between the fixed portion and the seal portion, receives the oil that flies out as the rotary shaft rotates, and dissipates heat generated by the seal portion by exchanging heat with the oil.

Abstract: An oil seal for sealing a hollow rotary shaft in a power transmission apparatus, wherein the rotary shaft is formed with an internal flow passage through which oil flows and constituted such that the oil flies out as the rotary shaft rotates, including: a fixed portion that is fixedly attached to a case of the power transmission apparatus; a seal portion that seals the rotary shaft at a position that is axially offset position from the fixed portion and allows the rotary shaft to rotate; and a radiator portion that is formed from a metallic material between the fixed portion and the seal portion, receives the oil that flies out as the rotary shaft rotates, and dissipates heat generated by the seal portion by exchanging heat with the oil.