Aisin Aw Co., Ltd.

Kengo Nomura

Kazumasa Tsukamoto

Masahiro Hayabuchi

Masaaki Nishida

Yoshihisa Yamamoto

Mikio Iwase

Minoru Todo

Kouji Ohbayashi

Takashi Morimoto

Naoki Okoshi

Mitsuhiro Takeda

Koji Ota

Takahiro Torii

Takumi Uchida

Kazunari Suzuki

In a gear pump, an outer inner wall surface of a suction port which is located on a downstream side in a rotor rotation direction, that is, a first inner wall surface, is located inward of a bottom land between internal teeth of an outer rotor, and the suction port has a shallow portion extended inward from the first inner wall surface on the downstream side in the rotor rotation direction, and a deep portion that is formed so as to be continuous with the shallow portion and that is deeper than the shallow portion. Communication between an inter-tooth chamber and the suction port is cut off with the inter-tooth chamber facing only the shallow portion.

Gear pump including an inner rotor having a plurality of teeth

A planetary carrier supports pinion gears of a planetary gear set via pinion shafts. Each hole in which a pinion shaft is mounted has a shallow hardened wall surface that is hardened by very-high-frequency induction heating and quenching. Therefore, the durability of the pinion shaft-supporting holes of a cold-forged piece or a pressed piece can be improved without thermal strain.

Planetary carrier and method of manufacture

Smooth driving of a vehicle is achieved by eliminating busy shift by providing a small gear ratio step between the two highest gear ranges while maintaining structural compactness of the transmission. In the second highest gear range or state, a first pinion P1 has a diameter smaller than that of a second pinion P2, both pinions P1 and P2 being coupled integrally and at least partially determining the second highest gear ratio. The gear ratio .lambda..sub.2 in the second highest gear range is described as 1+(Z.sub.S2 /Z.sub.R1).times.(Z.sub.P1 /Z.sub.P2). Since (Z.sub.P1 /Z.sub.P2) is always equal to 1.0 or less, the gear ratio can be made smaller without enlarging the diameter of the ring gear R1 significantly to decrease the gear ratio step to the highest gear range.

Automatic transmission

Growing community of inventors

Nukata, Japan

Kengo Nomura