The object of the invention is to travel backward by an engine alone in a state where an electric motor is disconnected. Thus, external teeth are formed on the outer periphery of a ring gear which meshes with a first sun gear via a first pinion gear and a second pinion gear and to which power input from an electric motor is transmitted; a power transmission mechanism further includes a gear meshing with the external teeth of the ring gear; and a second clutch capable of non-rotatably fixing the ring gear at the time of causing a vehicle to travel backward with power input from an engine is provided between the ring gear and a transmission case.

A power transmission apparatus of a hybrid electric vehicle includes an input shaft configured of receiving an engine torque, a motor shaft configured of receiving a torque of a motor/generator, first and second planetary gear sets respectively having first to third rotation elements and fourth to sixth rotation elements, a first shaft connected to the first rotation element and selectively connectable to each of the input shaft and the motor shaft, a second shaft fixedly connecting the second and fifth rotation elements, and selectively connectable to the input shaft, the motor shaft, and a transmission housing, respectively, a third shaft fixedly connecting the third and fourth rotation elements and selectively connectable to the transmission housing, a fourth shaft fixedly connecting the sixth rotation element and an output gear, and a plurality of engagement elements including at least one clutch and at least one brake.

A transmission (G) for a motor vehicle includes an electric machine (EM), a first input shaft (GW1), a second input shaft (GW2), an output shaft (GWA), a planetary gear set (P1), a pre-ratio configured as a spur gear transmission (SRS), and at least four shift elements (A, B, C′, D). Different gears are selectable by selectively actuating the at least four shift elements (A, B, C′, D) and, in addition, in interaction with the electric machine (EM), different operating modes are implementable.

An electrified fire fighting vehicle includes a chassis, a cab coupled to the chassis, a body coupled to the chassis, a front axle coupled to the chassis, a rear axle coupled to the chassis, a water tank supported by the chassis, an energy storage system coupled to the chassis and positioned rearward of the cab, a water pump supported by the chassis, and an electromagnetic device electrically coupled to the energy storage system. The electromagnetic device is coupled to the water pump and at least one of the front axle or the rear axle. The electromagnetic device is configured to receive stored energy from the energy storage system and provide a mechanical output to selectively drive the water pump and the at least one of the front axle or the rear axle.

Transmission system for a vehicle having an input arranged for connection to a drive source, and an output arranged for connection to a load. The transmission includes a transmission. The transmission includes first input shaft, a first output shaft connected to the output, and a first speed transforming gear connecting the first input shaft and the first output shaft, and a second input shaft, a second output shaft connected to the output, and a second speed transforming gear connecting the second input shaft and the second output shaft. The transmission includes a first coupling member, arranged for coupling the input to the first input shaft at a first speed ratio and a second coupling member, arranged for coupling the input to the second input shaft at a second speed ratio. The first and second speed transforming gears together include a plurality of transmission gears, wherein the transmission gears are arranged such that successive shifting through respective first, second, third, fourth, fifth and sixth gears is effected by alternatingly engaging the first coupling member and the second coupling member.

A hybrid power transmission mechanism includes an engine; a motor/generator having a rotor and a stator; a driven machine; a planetary gear mechanism having a sun gear, an internal gear drivingly connected to the rotor, a planetary gear, and a planetary carrier shaft including first and second extension shaft parts extending from the planetary gear in opposite directions; a first clutch switchable between a state of allowing transmission of power between the first shaft and the internal gear and a state of not allowing transmission of power therebetween; and a second clutch switchable between a state of allowing rotation of the sun gear and a state of not allowing rotation thereof. A first shaft that outputs power of the engine and a second shaft that inputs power to the driven machine are drivingly connected to the first and second extension shaft parts of the planetary carrier shaft, respectively.

A control system for a hybrid vehicle that reduces a change in an engine torque when warming a catalyst. The hybrid vehicle comprises a catalyst that purifies exhaust gas, a first motor, a differential mechanism having a plurality of rotary elements, and an engagement device that selectively connects the first motor to an engine. A controller is configured to determine whether it is necessary to warm the catalyst, and disengage the engagement device while retarding an ignition timing of the engine when it is necessary to warm the purifying device.

A drive unit is disclosed. The drive unit includes a first drive source, a first torque converter, a second drive source, a second torque converter, and a transmission. A torque is inputted from the first drive source to the first torque converter. The first torque converter includes a first turbine. A torque is inputted from the second drive source to the second torque converter. The second torque converter includes a second turbine. The second turbine is coupled to the first turbine. The transmission is disposed between a drive wheel and both the first and second torque converters.

An electrified fire fighting vehicle includes a battery pack, an electromagnetic device, an engine, and a controller. The controller is configured to monitor a state-of-charge of the battery pack, operate the electromagnetic device using stored energy in the battery pack to provide a performance condition including (i) accelerating the electrified fire fighting vehicle to a driving speed of at least 50 miles-per-hour in an acceleration time and (ii) maintaining or exceeding the driving speed for a period of time, and start and operate the engine in response to a start condition to facilitate reserving sufficient stored energy in the battery pack such that the state-of-charge is maintained above a minimum state-of-charge threshold that is sufficient to facilitate the performance condition. The acceleration time is 30 second or less. An aggregate of the acceleration time and the period of time is at least 3 minutes.

A transmission system includes an input shaft, a transmission housing, and a planetary gear system rotatably coupled to the input shaft. The planetary gear system has a first and second gear ratio. The transmission system additionally includes an output shaft, a first electric machine, a second electric machine, and a shifting assembly. The shifting assembly includes a first stationary clutch element and a second stationary clutch element. The first electric machine is configured to apply rotational torque to the planetary gear system to synchronize rotational speed of the planetary gear system when moving between the first and second gear ratios, and the second electric machine is configured to provide rotational torque to the output shaft when the first electric machine applies rotational torque to the planetary gear system to synchronize rotational speed of the planetary gear system when moving between the first and second gear ratio.