9758 results about "Automatic transmission" patented technology

A transmission assembly for a power tool comprises a first transmission path comprising a high speed transmission path and a second transmission path comprising a low speed transmission path. Driven gears of each transmission path are permanently driven during operation of the transmission. A controller is provided for engaging or disengaging the high speed transmission path in response to monitored operating current of an electric motor providing a driving torque to an input of the transmission. When disengaged, a driven gear of the high speed transmission path continues to be driven, but the driven gear is disengaged from an output of the transmission. Consequently, under these circumstances, the low speed transmission path is the ‘active’ transmission path providing a low speed, high torque drive to the transmission output. A clutch enables the low speed transmission path to operate at a lower speed than an output of the transmission assembly when the high speed transmission path is engaged and is providing a high speed, low torque drive to the transmission output.

A hydraulic circuit may include a proportional control solenoid valve controlling hydraulic pressure such that an operating hydraulic pressure required by the friction member is supplied to the friction member; a supply hydraulic path connecting the proportional control solenoid valve with the friction member, and adapted to supply hydraulic pressure controlled by the proportional control solenoid valve to the friction member; and a switch valve disposed in the supply hydraulic path so as to selectively open / close the supply hydraulic path.

A power transmission mechanism for an automatic transmission, configured to establish seven or more forward speeds and one reverse speed. The power transmission mechanism includes four simple planetary gears, three connection members interconnecting two of the rotating members of the planetary gears, three clutches selectively connectable between two of the rotating members, and four brakes each operable to hold selectively against rotation one of the rotating members.

A power train for eight forward and one reverse speeds may include input shaft, output gear, transmission case, speed shift unit, output unit, four clutches and two brakes. The speed shift unit includes a first operational member fixedly connected to the input shaft, a second operational member selectively coupled to the input shaft; a third operational member fixedly connected to the transmission case; a fourth operational member selectively coupled to the sixth operation member; and a fifth operational member selectively coupled to the fourth operational member. The output unit includes a sixth operational member fixedly connected to the fifth operational member, a seventh operational member selectively coupled to the input shaft and the transmission case, an eighth operational member selectively coupled to the input shaft, and a ninth operational member connecting the output gear. The four clutches and two brakes control pertinent operation members to change the rotational speed.

A planetary gear train of an automatic transmission may include an input shaft, an output gear, a first planetary gear set always outputting a negative rotation speed from a rotation speed input from the input shaft, a second planetary gear outputting the negative rotation speed input from the first planetary gear set or converting negative rotation speed into a positive rotation speed and outputting the positive rotation speed, a compound planetary gear set formed by third and fourth planetary gear sets and changing the rotation speed selectively through two paths and into nine forward speeds and one reverse speed, eight rotational members including two rotation elements connected to each other or one rotation element among the rotation elements of the first and second planetary gear sets and the compound planetary gear set, and a six friction members, and a transmission housing.

A method and a device for controlling the oil supply of an automatic transmission (gearbox) and to a starting element. The method can guarantee a sufficient supply of oil to a hydraulic control unit of the automatic transmission and / or the starting element, in particular an oil-cooled friction clutch, both during the operation of the internal combustion engine (4) and when the latter is at a standstill with the aid of an oil pump (2) that can be mechanically driven by the internal combustion engine (4) and a second oil pump (3) that can be electrically driven. In addition, the cooling oil supply of the starting element is guaranteed by the provision of a low-pressure oil by way of the electrically driven oil pump (3), at least during the starting operation, the stream cooling the starting element (11).

A gear train of an automatic transmission for vehicles has the advantages of improving power delivery performance and reducing fuel consumption as a consequence of realizing more than eight forward speeds by combining four planetary gear sets with three clutches and three brakes.

A multiple speed transmission includes an input and output; a first, second, third and fourth planetary gear sets, each gear set including a sun gear, a ring gear, a carrier, and pinions supported on the carrier and meshing with the sun gear and the ring gear; a first epicyclic gearing assembly including the first gear set, the second gear set, a first clutch, a first brake, a second brake, and first, second, third and fourth rotating members, said first clutch being operable to couple said first rotating member to the input, said first brake being operable to hold said fourth rotating member against rotation, and said second brake being operable to hold said second rotating member against rotation; and a second epicyclic gearing assembly including the third gear set, the fourth gear set, a second clutch, a third clutch, a third brake, and fifth, sixth, seventh and eighth rotating members, the third rotating member being secured to the eighth rotating member, said second control clutch being operable to couple said fifth rotating member to the input, said second control clutch being operable to couple said seventh rotating member to the input, said third brake being operable to hold the seventh rotating member against rotation, and said sixth rotating member being secured for rotation to the output.

A power train of an automatic transmission with eight forward speeds and two reverse speeds includes: a speed reduction unit including a first variable input member connected to an input shaft via a first clutch, first and second variably stopped members connected to a transmission case, and a reduced speed output member; an output unit including a reduced speed input member connected to the reduced speed output member, second and third variable input members connected to the input shaft via second and third clutches, respectively, a third variably stopped member connected to the transmission case, and a shifted speed output member connected to an output gear. A first brake variably stops the third variable stopped member; a second brake variably stops the first variable stopped member; and a third brake variably stops the second variable stopped member.

A power train of an automatic transmission attains eight forward speeds and one reverse speed. The power train includes first, second, and third planetary gear sets, four clutches, and two brakes. The first planetary gear set generates a reduced rotational speed, the second planetary gear set generates a reverse rotational speed, and the third planetary gear set generates the eight forward speeds and the one reverse speed by using the reduced rotational speed, the reverse rotational speed, and a rotational speed of an input shaft.

A gear train of an automatic transmission for a vehicle includes: a first planetary gear set that receives an input speed from an input shaft and outputs a reduced speed; a second planetary gear set that receives the reduced speed of the first planetary gear set and selectively outputs a same speed or a reversed speed; and a third planetary gear set that receives the reduced speed of the first planetary gear set, the input speed from the input shaft, and the output speed of the second planetary gear set, and then outputs a shifted output speed.