A method of controlling an axle assembly. The method includes executing a speed synchronization mode and operating a clutch actuator to shift a clutch from a neutral position toward an engaged position. The method may also include executing a low torque synchronization mode when the clutch cannot be shifted from a neutral position to an engaged position within a first predetermined period of time.

At the time when a hydraulic actuator is operated to engage a dog clutch, after it is detected that a hydraulic pressure for operating the hydraulic actuator is higher than or equal to a predetermined hydraulic pressure, it is determined whether the dog clutch is not engaged. Therefore, non-engagement determination due to insufficient hydraulic pressure for operating the hydraulic actuator is prevented. Thus, at the time when the hydraulic actuator is operated to engage the dog clutch, it is possible to prevent consumption of time to engage the dog clutch due to unnecessary re-engagement operation.

A disconnect system for selectively coupling or disconnecting a drive member and a driven member. The disconnect system includes a clutch ring rotationally coupled to a drive member, a solenoid actuator, and a clutch ring configured to be moved by the solenoid actuator to selectively transition the clutch ring between an engaged position where the clutch ring is rotationally coupled to a driven member and a disengaged position where the clutch ring is disconnected from the driven member. A controller can be provided to control the axial velocity of the clutch ring (e.g., relative to the rotational axis thereof) to reduce unwanted noise, vibrations, or harshness that can occur during the transition between engaged and disengaged positions.

A transmission selectively coupled to an engine crankshaft of an internal combustion engine arranged on a vehicle includes an input shaft, a mainshaft, an output shaft, a first countershaft and a second countershaft. A first gear set includes a first mainshaft gear arranged on the mainshaft, a first countershaft gear arranged on the first countershaft and a first countershaft gear arranged on the second countershaft. A second gear set includes a second mainshaft gear arranged on the mainshaft, a first countershaft gear arranged on the second countershaft and a second countershaft gear arranged on the second countershaft. The gears of the first gear set all have a first helix angle. The gears of the second gear set all have a second helix angle. The first and second helix angles are selected to provide gear constant leading whereby thrust forces directed onto the first and second countershafts are balanced.

A powertrain of a vehicle can be operated. The powertrain can have at least one transmission housing, a clutch assembly which is arranged therein and which comprises a clutch that operates in a positively locking manner, and an actuation unit for actuating the clutch. The clutch comprises at least one first clutch component, which can be moved along an axial direction, and a second clutch component, said clutch components being connected together in a form-fitting manner upon actuating the clutch; wherein the actuation unit comprises an electromagnetic actuator with a piston, and the piston is moved from a starting position into an end position along the axial direction upon actuating the clutch, thereby moving the first clutch component.

Various methods and systems are provided for a multispeed transmission. In one example, a method to increasing a shift performance of a transmission with actuated clutches comprises controlling an engagement depth of a clutch based on a gear that is being selected by the clutch. A target engagement depth of the clutch may be retrieved from a gear selection matrix in a lookup table stored in the memory of a controller of the transmission. The target engagement depth may depend on an amount of torque expected to be transferred to the gear.

An engagement device includes: a first member including a plurality of engaged teeth; a second member arranged coaxially with the first member, the second member including a plurality of engaging teeth; a rotation unit configured to relatively rotate the first member and the second member about an axis; a movement unit configured to relatively move the first member and the second member in an axial direction; and a control unit configured to control operations of the rotation unit and the movement unit, and the engaged teeth are formed on the first member at a side opposing the second member along a circumferential direction around the axis, and the engaging teeth are formed on the second member at a side opposing the first member along the circumferential direction around the axis.

A control device for a vehicle is provided. The vehicle includes a transmission and an engine configured to input a torque into the transmission. The transmission has multiple transmission stages and includes a first engagement mechanism and a second engagement mechanism. The control device includes an ECU configured to: (a) control the second engagement mechanism when a second transmission stage is set such that the capacity of torque transmission of the second engagement mechanism is increased and a thrust for separating a first member and a second member of the first engagement mechanism from each other in an axial direction is generated; (b) calculate a decrement in an output torque of the transmission when the capacity of torque transmission of the second engagement mechanism is increased; and (c) increase a torque input into the transmission by the engine based on the decrement in the output torque by controlling the engine.

A control system for a meshing type engagement mechanism includes a meshing type engagement mechanism and an electronic control unit. The electronic control unit is configured to allow a fluid chamber to be filled with a fluid by putting a switching valve into a cut-off state after respective dog teeth mesh with each other by a second member reaching a predetermined position determined in advance in response to a fluid pressure of the fluid chamber such that the second member is pressed in the direction in which the second member is separated from a first member by a release force depending on the torque transmitted between a surface of a first tooth and a surface of a second tooth, the fluid pressure of the fluid chamber is increased, and an engagement state between the first member and the second member is maintained by the fluid pressure which is increased.

A powertrain of a vehicle can be operated. The powertrain can have at least one transmission housing, a clutch assembly which is arranged therein and which comprises a clutch that operates in a positively locking manner, and an actuation unit for actuating the clutch. The clutch comprises at least one first clutch component, which can be moved along an axial direction, and a second clutch component, said clutch components being connected together in a form-fitting manner upon actuating the clutch; wherein the actuation unit comprises an electromagnetic actuator with a piston, and the piston is moved from a starting position into an end position along the axial direction upon actuating the clutch, thereby moving the first clutch component.