An automatic transmission includes: a brake device including a friction plate set configured with fixation friction plates and rotation friction plates alternately arranged, a piston, and an oil pressure chamber supplied with oil pressure that moves the piston toward the friction plate set side; a first rotating member; and second and third rotating members arranged at both respective axial sides of the first rotating member and each having an outer diameter smaller than that of the first rotating member. The friction plate set and the oil pressure chamber are arranged at both respective axial sides of the first rotating member and also arranged at an outer periphery side of the second rotating member and at the outer periphery side of the third rotating member, respectively. The piston extends from the oil pressure chamber toward the friction plate set side through the outer periphery side of the first rotating member.

An automatic transmission includes: a brake device including a friction plate set configured with fixation friction plates and rotation friction plates alternately arranged, a piston, and an oil pressure chamber supplied with oil pressure that moves the piston toward the friction plate set side; a first rotating member; and second and third rotating members arranged at both respective axial sides of the first rotating member and each having an outer diameter smaller than that of the first rotating member. The friction plate set and the oil pressure chamber are arranged at both respective axial sides of the first rotating member and also arranged at an outer periphery side of the second rotating member and at the outer periphery side of the third rotating member, respectively. The piston extends from the oil pressure chamber toward the friction plate set side through the outer periphery side of the first rotating member.

An in-line propeller gearbox of a turboprop gas turbine engine includes an epicyclic gearing arrangement that has a sun gear, a ring gear and at least one planet gear disposed between and meshing with both the sun gear and the ring gear. The propeller gearbox includes a disk brake that can be operated to slow down or stop altogether the rotation of the propeller. The disk brake has an axially extending shaft having at one end a disk and at the opposite end a gear having teeth that engage with one of the gears in the epicyclic gearing arrangement. The disk brake includes an hydraulic caliper or an electric caliper that can be actuated to slow down rotation of the disk to an eventual full stop and to hold the disk at full stop to thereby stop rotation of the propeller.

An in-line propeller gearbox of a turboprop gas turbine engine includes an epicyclic gearing arrangement that has a sun gear, a ring gear and at least one planet gear disposed between and meshing with both the sun gear and the ring gear. The propeller gearbox includes a disk brake that can be operated to slow down or stop altogether the rotation of the propeller. The disk brake has an axially extending shaft having at one end a disk and at the opposite end a gear having teeth that engage with one of the gears in the epicyclic gearing arrangement. The disk brake includes an hydraulic caliper or an electric caliper that can be actuated to slow down rotation of the disk to an eventual full stop and to hold the disk at full stop to thereby stop rotation of the propeller.

A motion conversion mechanism includes a shaft having an external thread and a cylinder having an internal thread that is screwed with the external thread. The motion conversion mechanism converts rotating motion of one of the shaft and the cylinder into linear motion of the other of the shaft and the cylinder. The cylinder is provided with two internal thread portions, each having the internal thread, such that a threadless portion is interposed between the two internal thread portions in an axial direction.

Disclosed is a transmission apparatus comprising: a sun gear connected to the input terminal; a plurality of first planetary gears engaging with an outer surface of the sun gear; a second planetary gear which forms a concentric circle with each first planetary gear, and which is integrally formed with the first planetary gears; a first ring gear engaging with outer surfaces of the first planetary gears and connected to the output terminal; a second ring gear engaging with an outer surface of the second planetary gear; a cage for supporting rotary shafts of the first and second planetary gears such that the first and second planetary gears can revolve about the sun gear; and a brake member.

Disclosed is a transmission apparatus comprising: a sun gear connected to the input terminal; a plurality of first planetary gears engaging with an outer surface of the sun gear; a second planetary gear which forms a concentric circle with each first planetary gear, and which is integrally formed with the first planetary gears; a first ring gear engaging with outer surfaces of the first planetary gears and connected to the output terminal; a second ring gear engaging with an outer surface of the second planetary gear; a cage for supporting rotary shafts of the first and second planetary gears such that the first and second planetary gears can revolve about the sun gear; and a brake member.

A transmission system includes planetary gearing with a ring gear, a plurality of planet gears, a carrier, and a sun gear, a forward clutch operatively connected between the ring gear and carrier, a reverse brake operatively connected between the carrier and a rotationally fixed location, and a control subsystem to switch the transmission system between forward and reverse operational modes in the which the ring gear and the sun gear rotate in the same or opposite rotational directions, respectively. A control subsystem actuation stroke can actuate both the forward clutch and the reverse brake based on a common control signal.

The automatic transmission which includes a third brake element formed by a support member including a first cylindrical portion having a first sliding surface at an outer peripheral surface thereof, a second cylindrical portion having a second sliding surface at an inner peripheral surface thereof and a third cylindrical portion having a third sliding surface at an inner peripheral surface thereof, an inner side piston, inner edge portion of which is in contact with the first sliding surface and an outer edge portion of which is in contact with the second sliding surface and an outer side piston which includes a first piston cylindrical portion, outer edge of which is in contact with the second sliding surface over an entire periphery thereof and a second piston cylindrical portion, outer edge portion of which is in contact with the third sliding surface over an entire periphery thereof.

A power transmission apparatus including a transmission, a case that accommodates the transmission, a counter drive gear to which power from the transmission is transmitted, a counter driven gear that meshes with the counter drive gear, and a drive pinion gear that is disposed and spaced apart in an axial direction from the counter driven gear and that rotates together with the counter driven gear, the power transmission apparatus.