Abstract: An automatic transmission has: a primary transmission mechanism including: an input shaft; a planetary gear set having a sun gear, planetary gears and a ring gear, each being a helical gear, the ring gear and sun gear being respectively connected to the input shaft and to a stationary member via a one-way clutch, and a carrier for the planetary gears is connected to a primary output shaft; and an centrifugal clutch engaged/released the input shaft with/from the primary output shaft in correspondence with a centrifugal force by a weight and a thrust force by the helical gear; and a secondary transmission mechanism connected to the primary output shaft, for controlling a gear-shift into two or more speed-changed conditions. A multiplicity of change-speed gears is obtained by selectively combining the released and engaged states of the centrifugal clutch for each of the speed-changed conditions of the secondary transmission mechanism.

Abstract: An automatic transmission has: a primary transmission mechanism including: an input shaft; a planetary gear set having a sun gear, planetary gears and a ring gear, each being a helical gear, the ring gear and sun gear being respectively connected to the input shaft and to a stationary member via a one-way clutch, and a carrier for the planetary gears is connected to a primary output shaft; and an centrifugal clutch engaged/released the input shaft with/from the primary output shaft in correspondence with a centrifugal force by a weight and a thrust force by the helical gear; and a secondary transmission mechanism connected to the primary output shaft, for controlling a gear-shift into two or more speed-changed conditions. A multiplicity of change-speed gears is obtained by selectively combining the released and engaged states of the centrifugal clutch for each of the speed-changed conditions of the secondary transmission mechanism.

Abstract: An automatic transmission including an input shaft connected to an output shaft of an engine. A first clutch of a first planetary gear unit is positioned between the input and first output shafts while a third clutch of a third planetary gear unit is interposed between the second and third output shafts. Each of the first and third clutches are engaged by the action of flyweights operated by centrifugal force and disengaged by thrust exerted on helical gears of the planetary gear units. A second planetary gear unit includes a second clutch interposed between the first and the second output shafts. Control means control the second clutch so as to engage the first and the second output shaft or disengage the first and the second output shafts from each other and provide smooth shockless upshifting and downshifting of the automatic transmission.

Abstract: A centrifugal friction clutch for an automatic transmission includes axially movable friction elements supported on and rotated with an input member. Axially slidable clutch elements are supported on a clutch cover, wherein centrifugal weights held by spring members are disposed at predetermined positions on the clutch cover. First retaining means on the clutch cover press the friction members and clutch members against each other so that power can be transmitted when the centrifugal weights are displaced. A first spring bearing member contacting one end of each of the spring members urges the centrifugal weights toward their initial positions while a second spring bearing member contacting the other end of each of the spring members is held in place on the clutch cover by second retaining means engaging the clutch cover. The first and second bearing members are axially movable relative to the input member.

Abstract: An automatic transmission for a vehicle comprises: an input shaft (2) connected to the output shaft of an engine; a first planetary gear unit (10) including a helical sun gear (12), helical planet pinions (13) supported for rotation on a planet carrier (14), and a helical ring gear (11); a first clutch (17) interposed between the input shaft (2) and the first output shaft (15) and capable of being engaged by an action of flyweights operated by centrifugal force and of being disengaged by thrust exerted on the helical gears; a second planetary gear unit (20) including a helical sun gear (22), helical planet pinions (23) supported for rotation on a planet carrier (24), and a helical ring gear (21); a second clutch (27) interposed between the first output shaft (15) and the second output shaft (25) and capable of being engaged by the action of flyweights operated by centrifugal force and of being disengaged by thrust exerted on the helical gears; and a two-speed transmission unit (30) including a first high-spee

Abstract: A variable speed gearing system includes two clutch units 30, 50 placed side by side in the axial direction and provides a plurality of transmission gear ratios in response to the state of engagement of clutches 31, 51 of the two clutch units 30, 50. Axially movable members 26a, 48a of the two clutch units 30, 50 are arranged in such a manner as to confront each other. A damper mechanism 60 is constituted by the combination of a piston member 62 provided on one of the confronting axially movable members 26a, 48a and a cylinder member 61 provided on the other thereof.

Abstract: A clutch disk made of a C/C composite for a wet multi-plate clutch is comprised of a disk body, and a pair of friction layers integral with and on opposite sides of the disk body for sliding contact with clutch plates. A relationship of V.sub.2 >V.sub.1 is established between the porosity V.sub.1 of the disk body and the porosity V.sub.2 of the friction layer, and the porosity V.sub.2 of the friction layer 4 is set in a range of 20%.ltoreq.V.sub.2 .ltoreq.60%, which provides a clutch disk with sufficient strength and excellent sliding characteristics.

Abstract: A cooling structure of a power transmission apparatus is provided. The power transmission apparatus has an electromagnetic clutch including a fixed outer member with an exciting coil and a rotary inner member adapted to be fixed to the outer member by controlling electric energy provided to the exciting coil, and a gear device connected to the inner member of the electromagnetic clutch. A cooling apparatus is positioned between the outer member and a gear case member housing the gear device, for cooling both of the electromagnetic clutch and the gear device concurrently.

Abstract: The apparatus comprises a planetary gear device and a magnetic particle type electromagnet clutch. The planetary gear device has a gear element connected to an input member, another gear element connected to an output member and a remaining other gear element. The electromagnetic clutch has a fixed member provided with a exciting coil and a rotary member adapted to be fixed to the fixed member by controlling intensity of electric current in the exciting coil. The rotary member is connected to the remaining other gear element.

Abstract: An centrifugal friction clutch for an automatic speed changing device to changeover speed change stage automatically in accordance with a change of rotational speed is provided.