A variable speed transmission having a plurality of tilting balls and opposing input and output discs is illustrated and described that provides an infinite number of speed combinations over its transmission ratio range. The use of a planetary gear set allows minimum speeds to be in reverse and the unique geometry of the transmission allows all of the power paths to be coaxial, thereby reducing overall size and complexity of the transmission in comparison to transmissions achieving similar transmission ratio ranges.

A gearbox having an input shaft (8) and an output shaft (20); a first epicyclic gear (10) connected to the input shaft (8); a second epicyclic gear (12) connected to the first epicyclic gear (10); a first electrical machine (14) connected to the first epicyclic gear (10); a second electrical machine (16) connected to the second epicyclic gear (12); a first main shaft (34) connected to the first epicyclic gear (10); a second main shaft (36) connected to the second epicyclic gear (12). A first coupling unit (56) disengagingly connects two rotatable components (22, 26, 50) at the first epicyclic gear (10), and a second coupling unit (58) disengagingly connects two rotatable components (28, 32, 51) at the second epicyclic gear (12), such that at least one of the rate of revolution and the torque at the first and the second main shafts (34, 36) can be influenced by controlling at least one of the first and the second coupling units (56, 58) to a condition of the rotatable components (22, 26, 50; 28, 32, 51) that is engaged or disengaged. Also a vehicle (1) having such a gearbox (2), a method to control such a gearbox (2), a computer program (P) to control a gearbox, and a computer program product comprising program code for an electronic control unit (48) or another computer (53) in order to implement the method.

A method is provided for moving off of a vehicle with a hybrid drive line, comprising a combustion engine; a gearbox with input shaft connected to the combustion engine and output shaft; a first planetary gear, which is connected to the input shaft, a first main shaft; a second planetary gear connected to the first planetary gear and a second main shaft; a first and second electrical machines respectively connected to the first and second planetary gears; a gear pair connected with the first main shaft; and a gear pair connected with the second main shaft. The method comprises: a) ensuring that the rotatable components of the first and second planetary gears are respectively disconnected from each other, b) ensuring that the corresponding gear pairs are engaged, and c) activating the first and second electrical machines so that a torque is generated in the output shaft.

A vehicle includes a drive axle, a multi-mode transmission, and a controller coupled to the multi-mode transmission. The multi-mode transmission includes a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, a first motor/generator coupled to the first gear set, a second motor/generator coupled to the second gear set and selectively coupled to a connecting shaft, a brake positioned to selectively limit a rotational movement of a ring gear of the second gear set when engaged, a first clutch selectively rotationally coupling the first gear set and the second gear set to the drive axle when engaged, and a second clutch selectively rotationally coupling the second motor/generator to the connecting shaft when engaged. The controller is configured to engage the brake and the clutches to selectively reconfigure the multi-mode transmission to an intermediate shift mode of operation.

A gear scheme for an infinitely variable transmission includes an input shaft, an output shaft, a variator, and a pair of planetary gearsets located beside the variator rather than in front of or behind the variator. The variator and the planetary gearsets are coupled between the input and output shafts.

A vehicle includes a drive axle, a multi-mode transmission, and a controller coupled to the multi-mode transmission. The multi-mode transmission includes a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, a first motor/generator coupled to the first gear set, a second motor/generator coupled to the second gear set and selectively coupled to a connecting shaft, a brake positioned to selectively limit a rotational movement of a ring gear of the second gear set when engaged, a first clutch selectively rotationally coupling the first gear set and the second gear set to the drive axle when engaged, and a second clutch selectively rotationally coupling the second motor/generator to the connecting shaft when engaged. The controller is configured to engage the brake and the clutches to selectively reconfigure the multi-mode transmission to an intermediate shift mode of operation.

A vehicle includes a connecting shaft, a drive axle, a multi-mode transmission, and a controller. The multi-mode transmission includes a first gear set having a first planetary gear carrier and a second gear set having a second planetary gear carrier, a first motor/generator coupled to the first gear set, a second motor/generator electrically coupled to the first motor/generator and coupled to the second gear set, a brake selectively limiting movement of a portion of the second gear set, and a clutch selectively rotationally coupling the second motor/generator to the connecting shaft. The first gear set is coupled to the connecting shaft, and the planetary gear carriers are rotatably coupled. The controller is configured to selectively configure the multi-mode transmission into an active neutral startup mode of operation by engaging the clutch and the brake such that at least one of the first motor/generator and the second motor/generator produces a voltage.

A power transmission device of a work vehicle includes a motor control unit that controls first and second motors to keep the transmission speed ratio at a maximum value when a vehicle speed is greater than a second vehicle speed where the transmission speed ratio reaches the maximum value obtainable by the power transmission device, and less than a third vehicle speed where a rotation speed of the second motor reaches a predetermined limit value. A controller increases a rotation speed of an engine from a second rotation speed of the engine when the vehicle speed is greater than the second vehicle speed and less than a third vehicle speed, and increases the rotation speed of the engine from a third rotation speed of the engine when the vehicle speed is greater than the third vehicle speed.

A method is provided to control a hybrid powertrain, comprising: a) engaging a gear corresponding to either a gear pair connected with a first planetary gear in the gearbox or corresponding to a gear pair connected with a second planetary gear and an output shaft; b) selecting a gear by connecting two rotatable components in the first planetary gear with each other, via a first coupling device and/or connecting two rotatable components in the second planetary gear with each other, via a second coupling device; and c) controlling a switch such that a first electrical machine is set into a waiting state, if the second coupling device connects the two rotatable components of the second planetary gear with each other, and such that a second electrical machine is set into a waiting state, if the first coupling device connects the two rotatable components of the first planetary gear with each other.

The current invention discloses a multi-mode electro-mechanical variable speed transmission. The transmission includes an input shaft, an output system, planetary gear set having at least three braches each represents a co-axial rotating member, two electric machines along with the associated controllers for the electric machines, and a clutch. The first branch couples to the first electric machine with a constant speed ratio; the second branch couples to the output system with a constant speed ratio; and the third branch couples to the input shaft with a constant speed ratio; the second electric machine selectively couples to two different the branches of the planetary gear set with two different constant speed ratios, respectively. The multi-mode electro-mechanical variable speed transmission is capable of providing multiple operation modes including two electric drive modes and two power split operation modes. Different operation modes cover different speed ratio regimes and are suitable for different power requirements. At the mode switching point, the corresponding clutch or clutches is automatically synchronized. This avoids shock loads during operation mode switching. The transmission is capable of providing operations with at least a fixed output to input speed ratio.