Selective lubrication in the shaft for a wet clutch

Abstract

Transmission system comprising: a lubrication valve that connects a lubrication line in fluid communication with a multi-disc wet clutch; a clutch line in fluid communication with a clutch actuator of the wet multi-disc clutch and the lubrication valve; a clutch control valve fluidly connected to the clutch line; and a controller configured to adjust a pressure of the clutch line to open and close the lubrication valve based on a temperature of the wet clutch.

Description

TECHNICAL FIELD

[0001] This description relates to a shaft with a lubrication system comprising a main lubrication line and a selective lubrication line fluidly connected to a wet clutch. A pressure-actuated valve can selectively open the selective lubrication line to the wet clutch at higher speeds. BACKGROUND AND OVERVIEW

[0002] Vehicles, such as electrified vehicles, may have a transmission that shifts a variety of different gears, with each of the different gears capable of delivering different torque and speeds for the same input torque. Electrified vehicles, including all-electric vehicles (EVs) and hybrid electric vehicles, may use electric machines to generate torque and drive the vehicle's wheels. The electric machine may be included in an electric powertrain, which may also include a gearbox, a driveshaft, a drive axle, and one or more clutches to control torque from the electric machine to the wheels and other components in between. The transmission, such as a manual transmission, may have multiple gears with different ratios (e.g.speeds), with each gear capable of delivering a different torque and speed for the same input torque and input speed. A wet clutch may selectively and rotatably couple an input and an output, each of which is part of or coupled to two rotating elements, e.g., a shaft and a gearbox. The wet clutch may include an actuator, e.g., a piston assembly including a piston, where the piston is operable by hydraulic forces applied in an actuating chamber by increasing or decreasing pressure via a hydraulic working fluid, such as oil. The piston may transmit power to a clutch pack including a plurality of wet clutch separator and friction plates. The force may compress the clutch pack and contact the separator and friction plates to engage the clutch and selectively engage and drive the input and output of the clutch.

[0003] Wet clutches can experience drag torque, which can be understood as residual torque when a clutch is disengaged due to the viscous action of oil or other lubricants. Drag torque can lead to continuous power losses, reducing the power transferred to the wheels and increasing the vehicle's energy consumption. The greater the volume of fluid absorbed by the clutch, the greater the drag torque. Reducing the supply of lubricants and other working fluids to the wet clutch can reduce the wet clutch's drag torque. However, at higher speeds, a wet clutch can experience greater friction and a greater buildup of heat energy from the rotational energy and torque at the clutch. Without effective heat energy dissipation, the heat energy can rise beyond a threshold and damage the clutch and surrounding components.To reduce drag torque and provide the desired lubrication for cooling the wet clutch, the shaft can contain a main lubrication line and a selective lubrication line. The main lubrication line supplies a constant volume of lubricant, and the selective lubrication line can supply an additional volume of fluid under certain circumstances. For example, the selective lubrication line can supply lubricant when a clutch is closed or in the process of closing. A selective lubrication sleeve in the backpressure chamber of a clutch can be moved by the clutch piston when the clutch is closed, allowing additional lubricant to flow from the selective lubrication line to the clutch. Electric machines can reach higher speeds than other prime movers, such as internal combustion engines.During rotation, centrifugal forces can be introduced into the piston's pressure chamber via the hydraulic clutch. Higher input speeds of the hydraulic clutch can lead to higher centrifugal loads on the clutch. If a certain pressure is exceeded, for example, the centrifugal force can cause the hydraulic clutch to close automatically. Likewise, the centrifugal forces can degrade the components and features of the clutch, such as the piston and the pressure chamber. The centrifugal forces can affect the engagement of the hydraulic clutch and can be minimized or eliminated below a certain pressure. Since the opening and closing of the selective lubrication line via the selective lubrication is influenced by the movement of the piston, self-closing can occur.Attempting to correct the self-retraction may also result in undesirable clutch resistance, as more lubricant may be consumed stopping and retracting the piston after self-retraction than stopping the self-retraction.

[0004] The inventors have recognized these and other problems with such systems. In one example, a transmission system was developed that includes: a lubrication valve fluidly connecting a lubrication line to a wet multi-disk clutch; a clutch line fluidly connected to a clutch actuator of the wet multi-disk clutch and the lubrication valve; a clutch control valve fluidly connected to the clutch line; and a controller configured to adjust a clutch line pressure to open and close the lubrication valve based on the temperature of the wet clutch.

[0005] The lubrication valve may be pressure-activated so that a pressure signal can open or close the lubrication valve. A first pressure signal with a higher pressure than the previous state can open the valve. Upon a second pressure signal with a lower pressure than the previous state, the spring force of a spring and the pressure of a first backpressure chamber for the lubrication valve can return the valve to a closed state. The lubrication valve can open or close the selective lubrication line. The first pressure signal to open the lubrication valve is less than the pressure flow to operate the clutch actuator and close the wet clutch. A pressure to advance the clutch actuator and close the wet clutch can open the valve. The valve may have a passage through which fluid can flow. The valve may be a spool valve.Hydraulic fluid can flow through the passage to the clutch line and is used to open or close the clutch with a pressure signal. The hydraulic fluid is transported from the clutch line to the clutch actuator. The flow of hydraulic fluid at a first pressure to actuate the clutch can cause the valve to open. Likewise, a flow of hydraulic fluid at a second pressure that is lower than the first pressure and too low to actuate the clutch can cause the valve to open. Opening the valve allows lubricant to flow to lubricate the clutch and increases the pressure in a second back pressure chamber of the clutch to an activation pressure. The activation pressure can prevent the clutch from closing automatically, e.g. due to hydraulic load at higher speeds, by counteracting the force of the pressure in an actuation chamber of the clutch actuator.

[0006] It should be understood that the above summary is intended to introduce, in simplified form, a selection of concepts that are further explained in the detailed description. It is not intended to identify the most important or essential features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that address the disadvantages noted above or elsewhere in this disclosure. SHORT DESCRIPTION OF THE CHARACTERS Fig. 1 shows an exemplary schematic representation of a vehicle that may include the transmission of the present disclosure. Fig. 2A shows a cross-sectional view of a coupling assembly and a shaft in which a valve of the present disclosure is closed. Fig. Figure 2B shows the sectional view of the coupling assembly and the shaft when the valve of the present disclosure is opened. Fig. 3A shows a cross-sectional view of the clutch assembly and shaft with the valve of the present disclosure connected to a selective lubrication line. Fig. Figure 3B shows a cross-sectional view of the clutch assembly and shaft with the valve of the present disclosure open to the selective lubrication line. Fig. Figure 4A shows a schematic representation of a hydraulic circuit diagram of a clutch for a transmission in which the clutch is open. Fig. Figure 4B shows a schematic representation of the hydraulic circuit diagram of the clutch for the transmission when the clutch is closed. Fig. 5 shows a sectional view of the valve of the present disclosure. Fig. 6 shows a sectional view of the valve of the present disclosure. Fig. Figure 7 shows a variety of timing diagrams for a standard control routine for closing and opening a clutch. Fig. Figure 8 shows a graph of the current and pressure controlled in the clutch over time. Fig. 9 shows a variety of timing diagrams for a pre- and / or post-cooling routine for the clutch. Fig. Figure 10 shows a method for selecting between normal and pre- and / or post-cooling routines for the clutch. DETAILED DESCRIPTION

[0007] The following description refers to a transmission system with a hydraulic actuation system and a lubrication system for a wet clutch of the transmission. The lubrication system includes a lubrication valve housed in a volume containing lubricant, wherein the lubrication valve is selectively connected to a selective lubrication line, wherein the lubrication valve can fluidically connect or fluidically seal a volume with the selective lubrication line in various states. A clutch control valve is selectively fluidically coupled to a clutch line so that the clutch control valve can be opened to fluidically couple to the clutch line or closed to fluidically seal. The terms "fluidic" and "fluidic" can be used interchangeably here. The lubrication system also includes a main lubrication line and other lubrication lines, such as the volume in which the lubrication valve is located.The main lubrication line can supply the clutch with a continuous lubricant flow and pressure. The selective lubrication line can be selectively opened via the lubrication valve to supply lubricant to the clutch. The hydraulic actuation system of the clutch also includes the clutch control valve, the clutch line, a clutch actuator, and a backpressure chamber of the wet clutch, with the clutch line being in fluid communication with the clutch actuator. The clutch can be driven via a drive component. The drive component can be or become rigidly connected to an inlet of the clutch. Components of the lubrication system, such as the main lubrication line, the selective lubrication line, and the lubrication valve, can be housed in the drive component. Components of the actuation system, such as the clutch line and the clutch control valve, can be housed in the drive component.The backpressure chamber is in fluid communication with the selective lubrication line and the main lubrication line. The clutch actuator may include and be actuated via an actuation chamber, wherein the actuation chamber may be in fluid communication with the clutch line. Pressure from the actuation chamber may press on and advance an actuation component of the clutch actuator. The actuating element may be a piston. Resistive forces from the backpressure chamber may counteract the advance of the actuating element, e.g., due to the forces of a spring and the pressure of a lubricant located in the backpressure chamber. When fluid flow flows via the selective line and the main line to the wet clutch, the pressure in the backpressure chamber may rise to an activation pressure. The actuation pressure may prevent the clutch from closing automatically, e.g., due to the hydraulic load at higher speeds.Higher speeds can be greater than or equal to 12,000 revolutions per minute (RPM). To engage the clutch via the clutch actuator, the pressure in the actuation chamber can be increased beyond the activation pressure. A wet clutch can be a multi-disk wet clutch with multiple friction and separating discs.

[0008] The following description also relates to a method for operating the lubrication system depending on the temperature and / or speed of the drive component. The method can select between opening and closing the lubrication valve to the selective lubrication line. The method can select between performing a first method or a second method to actuate a gear shift via the transmission, the wet clutch, and the lubrication valve via the lubrication system. The first method is a standard control routine for opening and closing the wet clutch via the clutch control valve while supplying lubricant via the main lubrication line.The second method is a pre- and / or post-cooling control routine for subjecting the wet clutch to increased cooling and an activation pressure via the clutch control valve before opening the wet clutch in a pre-cooling phase or closing the wet clutch in a post-cooling phase. During the pre- and / or post-cooling control routine, lubricant can be supplied to the wet clutch via the main lubrication line and the selective lubrication line. The method can open the lubrication valve to direct lubricant to the selective lubrication line when the temperature of the wet clutch rises above a first temperature threshold. The method can open the lubrication valve to direct lubricant to the selective lubrication line when the speed of the drive component or the speed of the clutch rises above a second threshold.

[0009] Fig. 1 shows an exemplary schematic representation of a vehicle that may include the transmission of the present disclosure. The vehicle in Fig. 1 may be an electrified vehicle, such as an electric vehicle or a hybrid vehicle with multiple torque sources, which may include an electric machine. Fig. 2A shows a cross-sectional view of a coupling assembly and a shaft in which a valve of the present disclosure is closed. Fig. Figure 2B shows the sectional view of the coupling assembly and the shaft when the valve of the present disclosure is opened. Fig. 3A shows a cross-sectional view of the clutch assembly and shaft with the valve of the present disclosure connected to a selective lubrication line. Fig. 3B shows a section through the clutch assembly and the shaft, with the valve of the present disclosure open to the selective lubrication line. The sectional view in Fig. 3A-3B can be recorded in a plane that is 90 degrees from the sectional view in Fig. 2A-2B away. Fig. Figure 4A shows a schematic representation of a hydraulic circuit diagram of a clutch for a transmission in which the clutch is open. Fig. Figure 4B shows a schematic representation of the hydraulic circuit diagram of the clutch for the transmission when the clutch is closed. Fig. 5 shows a sectional view of the valve of the present disclosure. Fig. 6 shows a sectional view of the valve of the present disclosure. Fig. Figure 7 shows a variety of timing diagrams for a standard control routine for closing and opening a clutch. Fig. Figure 8 shows a graph of the current and pressure controlled in the clutch over time. Fig. 9 shows a variety of timing diagrams for a pre- and / or post-cooling routine for the clutch. Fig. Figure 10 shows a method for selecting between normal and pre- and / or post-cooling routines for the clutch.

[0010] It should also be understood that the specific arrangements and systems illustrated in the accompanying drawings and described in the following description are exemplary embodiments of the inventive concepts defined herein. For purposes of explanation, the drawings will be described together. Thus, like elements may be referred to by like reference numerals and need not be repeated.

[0011] Fig. 1 and Fig. 4A-4B show schematic representations of an example configuration with relative positioning of the various components. Fig. 2A-3B and Fig. 5-6 show example configurations with approximate position. Fig. 2A-3B and Fig. Figures 5-6 are drawn approximately to scale; however, other relative dimensions may be used. The term "about," unless otherwise noted, means plus or minus five percent of the range. The term "substantially" is understood herein to mean greater or less than a factor of two when comparing one component / feature to one or more other components / features.

[0012] Furthermore, Fig. 1-6 show example configurations with the relative arrangement of the various components. When these elements are in direct contact with each other or are directly coupled, they may be referred to as being in direct contact or directly coupled, respectively, at least in one example. Similarly, elements shown side by side or adjacent to each other may be adjacent to each other or adjacent to each other, at least in one example. For example, components that are in surface-to-surface contact with each other may be referred to as being in surface-to-surface contact. As another example, in at least one instance, elements that are separated from each other with only a space between them and that do not have any other components may be referred to as such.In yet another example, elements depicted above / below, on opposite sides, or to the left / right of each other may be referred to as such, relative to each other. Further, in at least one example, as depicted in the figures, a topmost element or point of an element may be referred to as a "top" of the component, and a bottommost element or point of the element may be referred to as a "bottom" of the component. As used herein, the terms top / bottom, upper / lower, above / below may refer to a vertical axis of the figures and may be used to describe the positioning of elements of the figures relative to each other. Thus, in one example, elements displayed above other elements are arranged vertically above the other elements.As another example, the shapes of the elements depicted in the figures may be referred to as such (e.g., circular, straight, flat, curved, rounded, beveled, angled, or the like). Furthermore, in at least one example, depicted elements that intersect each other may be referred to as intersecting elements or as intersecting elements. Furthermore, an element depicted inside or outside another element may be referred to as such. Furthermore, the components may be described with respect to the reference axes included in the drawings.

[0013] Features described as axial may be approximately parallel to a datum axis unless otherwise specified. Features described as reverse may be approximately perpendicular to the datum axis unless otherwise specified. Features described as radial may circumferentially surround or extend outwardly from an axis, such as the datum axis, or a component or feature previously described as radial to a datum axis, unless otherwise specified.

[0014] Features described as longitudinal can be approximately parallel to a long axis. A lateral axis can be perpendicular to a long axis and a vertical axis. Features described as lateral can be approximately parallel to the lateral axis. A vertical axis can be perpendicular to a transverse axis and a long axis. Features described as vertical can be approximately parallel to a vertical axis.

[0015] In Fig. 1, a vehicle 100 is illustrated that includes a drivetrain 101 and a transmission 103. The vehicle 100 may have a front end 132 and a rear end 134 located on opposite sides of the vehicle 100. Objects, components, and features of the vehicle 100 referred to as being near the front may be closest to the front end 132 compared to the rear end 134. Objects, components, and features of the vehicle 100 referred to as being near the rear may be closest to the rear end 134 compared to the front end 132. The drivetrain 101 includes a prime mover 106 and a transmission 108.

[0016] The vehicle 100 may be a light, medium, or heavy-duty vehicle. The vehicle 100 may be an on-road vehicle, a passenger vehicle, including a car, a commercial vehicle that is an on-road vehicle, a semi-trailer truck, and / or a sports car. The vehicle may be an off-road vehicle or a vehicle that can be used both on-road and off-road, such as a construction vehicle, an agricultural vehicle, a sport utility vehicle, and / or a commercial vehicle that is an off-road vehicle. In one embodiment, the vehicle 100 may be a wheeled vehicle, such as an automobile. Additionally or alternatively, the vehicle 100 and / or one or more of its components, such as components of the powertrain 101 and / or the drivetrain 103, may be used in industrial, locomotive, military, agricultural, and / or aerospace applications.Additionally or alternatively, the vehicle 100 may be an aircraft, a boat, or other vehicle system that uses lubricants.

[0017] In one example, vehicle 100 is a fully electric vehicle or a vehicle with a fully electric mode of operation, such as a plug-in hybrid vehicle. Prime mover 106 may be an electric machine, such as an electric motor or an electric motor / generator. Furthermore, there may be other prime movers in the vehicle besides prime mover 106, such as when vehicle 100 is a hybrid vehicle.

[0018] The transmission 108 can be any type of transmission, such as a manual transmission, an automatic transmission, or a continuously variable transmission. Additionally, the transmission 108 can be a gear box, an axle, or a transaxle. The transmission 108 receives the torque generated by the prime mover 106 as input and outputs the torque to the geartrain 103 according to a selected gear ratio or setting. When the vehicle 100 is a hybrid vehicle, there are multiple torque inputs to the transmission 108, with at least one input coming from a prime mover other than the prime mover 106. The vehicle 100 can have a longitudinal axis 130. The driveline 101 and the geartrain 103 can have a length parallel to the longitudinal axis 130.

[0019] The prime mover 106 may be powered by energy from an energy storage device 105. In one example, the energy storage device 105 is a battery configured to store electrical energy. An inverter 107 may be disposed between the energy storage device 105 and the prime mover 106 and configured to convert direct current (DC) to alternating current (AC). The inverter 107 may include a variety of components and circuits with thermal requirements that affect the efficiency of the inverter.

[0020] In some examples, such as Fig. 1, the geartrain 103 includes a first axle assembly 102 and a second axle assembly 112. The first axle assembly 102 may be configured to drive a first set of wheels 104, and the second axle assembly 112 may be configured to drive a second set of wheels 114. In one example, the first axle assembly 102 is located near a front of the vehicle 100 and therefore includes a front axle, and the second axle assembly 112 is located near a rear of the vehicle 100 and therefore includes a rear axle. The geartrain 103 is shown in an all-wheel drive configuration, although other configurations are possible. For example, the geartrain 103 may include rear-wheel drive or all-wheel drive. Additionally, the geartrain 103 may include one or more tandem axle assemblies.Thus, the transmission train 103 may have other configurations without departing from the scope of this disclosure, and the configurations shown in . Fig. 1 is for illustrative purposes and is not limiting. In addition, the vehicle 100 may include additional wheels that are not coupled to the transmission 103.

[0021] In some configurations, such as Fig. 1, the powertrain 103 includes a transfer case 110 configured to receive the rotational power output from the transmission 108. A first input shaft 113 is drivingly connected to a first output 111 of the transfer case 110, while a second input shaft 122 is drivingly coupled to a second output 121 of the transfer case 110. The first input shaft 113 (e.g., a front input shaft) transfers the rotational power from the transfer case 110 to a first differential 116 of the first axle assembly 102 to drive the first set of wheels 104, while the second input shaft 122 (e.g., a rear input shaft) transfers the rotational power from the transfer case 110 to a second differential 126 of the second axle assembly 112 to drive the second set of wheels 114.For example, the first differential 116 is drivingly coupled to a first set of axleshafts 118 connected to the first set of wheels 104, and the second differential 126 is drivingly coupled to a second set of axleshafts 128 coupled to the second set of wheels 114. It should be understood that the first set of axleshafts 118 and the second set of axleshafts 128 may be disposed within a housing. The first drive shaft 113 and the second drive shaft 122 may be arranged to extend parallel to the longitudinal axis 130. In one example configuration of the vehicle 100, the second drive shaft 122 may be centered about the longitudinal axis 130.

[0022] The first differential 116 may provide some forward wheel drive (FWD) to the vehicle 100 as part of the rotational power transmitted via the first drive shaft 113. Likewise, the second differential 126 may provide rear wheel drive (RWD) to the vehicle 100 as part of the rotational power transmitted via the second drive shaft 122. The first differential 116 and the second differential 126 may provide FWD and RWD modes, respectively, as part of an all-wheel drive (AWD) for the vehicle 100.

[0023] The adjustment of the transmission 103 between the various modes, as well as the control of operation within each mode, may be based on a vehicle control system 154, including a controller 156. The controller 156 may be a microcomputer, including components such as a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values, e.g., a read-only memory chip, random access memory, diagnostic memory, and a data bus. The storage medium may be programmed with computer-readable data representing instructions executable by a processor to perform the methods described below, as well as other variations that are expected but not explicitly listed. In one example, the controller 156 may be a powertrain control module (PCM).

[0024] The controller 156 may receive various signals from sensors 158 coupled to various areas of the vehicle 100. The sensors 158 may include, for example, sensors on the prime mover 106 or another prime mover for measuring the speed and temperature of the prime mover, a pedal position sensor for detecting the actuation of a driver-operated pedal, e.g., an accelerator or brake pedal, a lever position sensor for detecting the adjustment of a lever, e.g., a brake lever, speed sensors on the first and second sets of wheels 104, 114, etc. The sensors 158 may detect the activation of the input device 164. After receiving the signals from the various sensors 158 Fig. 1, the controller 156 processes the received signals and deploys various actuators 160 of the vehicle 100 to adjust the operation of the transmission based on the received signals and the instructions stored in the memory of the controller 156. For example, the controller 156 may receive an indication of brake pedal application, signaling a desire for a lower vehicle speed. Vehicle braking may be directly proportional to the position of the accelerator pedal, e.g., the degree of application. Another example is that the controller 156 may receive an indication of accelerator pedal application, signaling a desire for a higher vehicle speed. Vehicle acceleration may be directly proportional to the accelerator pedal position, e.g., the degree of application. In response, the controller 156 may command actions such as shifting gears of the transmission 108.Alternatively, the gears of the transmission 108 can also be shifted manually, e.g., if the transmission 108 is a manual transmission. The vehicle 100 can include one or more input devices 164. The input devices 164 can be a shifting device that can input a command signal, e.g., a shift command, to change the state of the gear ratio selected via the transmission 108. A shifting device of the input device 164 can be an automatic gearshift or a manual gearshift. The input devices 164 can communicate with each other and send command signals to the controller 156 and the control system 154, e.g., via the sensors 158, and the actuators 160 can shift gears based on the signal.Additionally or alternatively, the input devices 164 can be selectively coupled and switched with the gears of the transmission 108, for example, to manually shift the transmission between gears.

[0025] In some examples, the vehicle 100 may additionally or alternatively be a hybrid vehicle with multiple torque sources, e.g., both a motor, e.g., an internal combustion engine (ICE), and an electric machine, each configured to power the first axle assembly 102 or the second axle assembly 112. For example, one or both of the first axle assembly 102 and the second axle assembly 112 may be powered by power from the electric machine in a first operating mode in which the electric machine is not operating to provide power (e.g., a motor-only mode), by power from the electric machine in a second operating mode in which the motor is not operating to provide power (e.g., a pure electric mode), and by power from both the motor and the electric machine in a third operating mode (e.g., an electric-assist mode).In another example, one or both of the first axle assembly 102 and the second axle assembly 112 may be an electric axle assembly configured to be driven by an integrated electric machine. In these examples, the main drive 106 may be a motor and the second drive 120 may be an electric machine. The second inverter 120 may be powered by the energy storage device 105 and electrically connected to the inverter 107.

[0026] In some embodiments, the transmission 108 may additionally or alternatively be a first transmission that further includes a second transmission disposed on the second set of axle shafts 128. The transmission 108 may be a gear box. Alternatively, the transmission 108 may also be an axle transmission or a transaxle transmission.

[0027] To compare the views in the Fig. A series of reference axes 201 are provided. The reference axes 201 denote an x-axis, a y-axis, and a z-axis. The x-axis may be a transverse axis, the y-axis a longitudinal axis, and the z-axis a vertical axis. In one example, the z-axis may be parallel to a direction of gravity and the xy-plane may be parallel to a horizontal plane upon which a coupling assembly 202 may rest. When specifying direction, "positive" may refer to the arrow direction of the y-axis, x-axis, and z-axis, and "negative" may refer to the opposite arrow direction of the y-axis, x-axis, and z-axis. A circle may represent an axis of the reference axes 201 that is perpendicular to a view. A filled circle may represent an arrow and axis that point toward or positively toward a view.An open circle can represent an arrow and an axis that is facing away from or negative to a view.

[0028] In the Fig. 2A-2B show a first view 200 of a clutch assembly 202. The first view 200 is a sectional view, wherein the first view 200 may be taken in a plane including an axis 208, the plane being parallel to a plane formed between the y-axis and the z-axis of the reference axes 201. The clutch assembly 202 may be centered on the axis 208 such that the clutch assembly 202 is positioned about the axis 208. The axis 208 may be a central axis for the clutch assembly 202. Likewise, the axis 208 is a longitudinal axis for the assembly and may be a rotational axis for the rotating elements of the clutch assembly 202. The clutch assembly 202 may have a first side 204 and a second side 206, wherein the first side 204 is opposite the second side 206. The second page 206 may be located outside the first view 200.The clutch assembly 202 includes a valve 262, where the valve 262 may be a spool valve (e.g., having a spool configuration). The valve 262 may be selectively opened or closed to allow fluid flow to a fluid passage that may transport fluid through the clutch assembly 202, e.g., a selective lubrication line. Fig. Figure 2A shows a portion of a clutch assembly 202 from the first view 200 when the valve 262 is in a closed position. Fig. Figure 2B shows the portion of the clutch assembly 202 from the first view 200 when the valve 262 is in an open position.

[0029] The valve 262 can be translated in a first direction 212 or a second direction 214 to open or close, where the first direction 212 is opposite the second direction 214. The first direction 212 and the second direction 214 can be parallel to the axis 208. For example, the valve 262 can translate in the first direction 212 to close, and the valve can translate in the second direction 214 to open. When translated in the first direction 212, the valve 262 is positioned closer to the first side 204 from an initial position. When translated in the second direction 214, the valve is moved from an initial position closer to the second side 206.

[0030] The clutch assembly 202 may include a clutch part 216 and a gear part 218. The clutch assembly 202 also includes a clutch, wherein the clutch is a wet clutch. The clutch may include or have components that are fixedly connected to the clutch component 216. The gear component 216 may be a driven component that can be driven via the drive component 218, e.g., when the clutch is closed. The gear component 216 includes a gear that can mesh and driveably couple with other gears or rotating elements. The clutch assembly 202 may be surrounded by an exterior region 224, wherein the exterior region 224 can be a volume, e.g., a packaging space. The drive component 218 can be a rotating element, e.g., a shaft. The drive component 218 can drive the clutch of the clutch assembly 202.The gear member 216 may include a cavity 220 and a passageway 222. The cavity 220 may receive the drive component 218 via the passageway 222. The drive component 218 may be supported via a first bearing assembly 232 and a second bearing assembly 234. The first bearing assembly 232 and the second bearing assembly 234 may be disposed around, e.g., radially, and in surface contact with the drive component 218. The first bearing assembly 232 and the second bearing assembly 234 may include an inner ring, an outer ring, and a single or multiple bearings. For example, the first bearing assembly 232 and the second bearing assembly 234 may include a plurality of bearings, such as ball bearings. The second bearing assembly 234 may be located between, e.g., radially between, the passageway 222.The first bearing assembly 232 may be located between, for example, a radially fixed feature and the drive component 218, where the fixed feature may be a fixed feature of a transmission containing the clutch assembly 202, such as a housing of the transmission. The second bearing assembly 234 may allow the drive component to rotate freely from the transmission component 216.

[0031] The drive component 218 may include a plurality of fluid passages and other fluid volumes that can receive and transport fluid, such as working fluid and lubricant / coolant. The drive component 218 may include a first fluid passage 242 and a second fluid passage 244. The first fluid passage 242 may be an actuation line that supplies working fluid to the clutch of the clutch assembly 202 to actuate the clutch. For example, the first fluid passage 242 may supply working fluid and increase the pressure in an actuation chamber to advance an actuator of the clutch in a direction to contact and compress the clutch pack of the clutch. The second fluid passage 244 may be a first lubrication line that can supply lubricant to a clutch. The second fluid passage 244 may be a main lubrication line that supplies a constant volume flow to the clutch.The second fluid passage 244 can deliver lubricant to components of the clutch, such as the clutch pack, for lubrication and cooling. The second fluid passage 244 can also direct lubricant into a backpressure chamber of the clutch to prevent the clutch from self-closing.

[0032] The drive component 218 may also include a first chamber 246, a second chamber 247, and a third chamber 251. The first chamber 246, the second chamber 247, and the third chamber 251 may be formed from a common volume, e.g., a fluid passage or a fluid cavity that can accommodate the valve 262. The valve 262 may divide the common volume into the first chamber 246, the second chamber 247, and the third chamber 251. The common volume may be part of another fluid conduit, e.g., a lubrication conduit, that is fluidly connected to and separate from the fluid source and the second fluid passage 244. The first chamber 246, the second chamber 247, and the third chamber 251 may have continuous surfaces. The drive component 218 may include a port 248 with a first opening 250. The port 248 may be in fluid communication with and coupled to the valve 262.The first opening 250 may be located on the first side 204 and fluidly connected to a fluid source, e.g., a lubricant. The opening 248 may be housed in a common volume including the first chamber 246, the second chamber 247, and the third chamber 251. The first fluid passage 242, the first chamber 246, the second chamber 247, the port 248, and the first opening 250 may be centered on the axis 208 so as to be radially disposed about the axis 208. The second fluid passage 244 may have a centerline and a length parallel to the axis 208. The second chamber 247 may be sandwiched between the first fluid passage 242 and the valve 262. The first chamber 246 may be disposed between opposite ends of the valve 262. The third chamber 251 may be disposed between the valve 262 and the port 248. When the valve 262 is in a closed position, as shown in . Fig. 2A, the valve 262 may be adjacent to the opening 248, and the third chamber 251 may be located at the interface between the valve 262 and the opening 248.

[0033] The first fluid passage 242 and the second chamber 247 may be connected to each other via a first channel 252 so that they are in fluid communication. The first channel 252 may be located between the first fluid passage 242 and the second chamber 247. The first channel 252 may be centered on the axis 208, for example, radially about the axis 208. A spring 260 may be located in the second chamber 247. The spring 260 may be clamped between a surface 278 of the second chamber 247 and the valve 262. The second fluid passage 244 may be in fluid communication with the first chamber 246 via a second channel 254. An insert 264 may extend into the first chamber 246. The insert 264 may abut the valve 262. The insert 264 may be a stop and prevent movement of the valve 262, for example. B. when the valve 262 rests on the insert 264.

[0034] The fluid in the first chamber 246 may be separated and sealed from the second chamber 247 by the valve 262. Likewise, the fluid from the third chamber 251 and the port 248 may be fluidly separated and sealed from the first chamber 246 via the features of the valve 262. The valve 262 may also be hollow so that it contains at least one passage that can fluidly connect the second chamber 247 to the third chamber 251. An increase in the flow rate and pressure in the third chamber 251, e.g., via the port 248, may exert a force on the valve 262 and move the valve in the second direction 214. An increase in the flow rate and pressure in the third chamber 251 may increase the flow rate and pressure in the second chamber 247 there, wherein the increased flow rate and pressure in the second chamber 247 may increase the flow rate and pressure in the first fluid passage 242.

[0035] The third chamber 251 may be an actuation chamber for the valve 262, where the valve 262 may be opened or closed by the force of pressure changes in the third chamber 251, e.g., pressure from port 248. The first chamber 246 may be a lubricant flow chamber, through which the lubricant can flow from the second fluid passage 244 to other passages and volumes of the drive component 218. The second chamber 247 may be a backpressure chamber for the valve 262, in which the force of the fluid pressure and the spring force of the spring 260 can counteract the force of the valve 262 in the second direction. The third chamber 251 is a separate actuation chamber from the actuation chamber described above, which can actuate the clutch. Likewise, the second chamber 247 is a different backpressure chamber than the backpressure chamber, which can exert a resistive force on the clutch (see above).

[0036] The second fluid passage 244 may include a plurality of openings, e.g., a second opening 256 and a third opening 266. The second opening 256 may communicate with the outer side 224. The second opening 256 may be in fluid communication with the second channel 254. The second fluid passage 244 may be a blind hole that can be closed. For example, a third opening 266 of the second fluid passage 244 may be closed with a plug 268. The second fluid passage 244 may also include one or more of a plurality of third channels 258 and one or more of a plurality of fourth channels 259. The third channels 258 and the fourth channels 259 may be radial channels that extend radially from the center of the shaft (e.g., the axis 208). The third channels 258 may be in fluid communication with the outer side 224. The fourth channels 259 may be in fluid communication with the cavity 220.For example, the third channels 258 and / or the fourth channels 259 may be supply holes for lubricant consumers, such as bearings. Another example is that the third channels 258 and / or the fourth channels 259 may be vent holes.

[0037] The valve 262 may include a core 270, a first land 272, a second land 274, and a boss 276. The core 270 may be connected to and sandwiched between the first land 272 and the second land 274. The core 270 may be a stem. The first land 272 may be a first piston and the second land 274 may be a second piston. The boss 276 may extend from the first land 272, e.g., in the first direction 212 from the first land 272. The boss and / or the first land 272 may be closest to and encompass a first end of the valve 262. The second land 274 may encompass and be closest to a second end of the valve 262. The first end of the valve 262 is opposite the second end of the valve 262. The boss 276 may be received and housed within the second chamber 247. The spring 260 may be positioned around the boss 276, e.g., radially around the boss 276.The first land 272 can fluidly seal and separate the second chamber 247 from the first chamber 246. The second land 274 can seal and separate the first chamber 246 from the third chamber 251. The compressive and spring force of the spring 260 in the second chamber 247 can press on the first land 272 in the first direction 212. The compressive force in the first chamber 246 can press on the first land 272 in the second direction 214 and the second land 274 in the first direction 212. The compressive force in the third chamber 251 can press on the second land 274 in the second direction 214. The first land 272 can abut the insert 264 when the valve 262 is in the closed position. Fig. 2A. The first web 272 can prevent the valve 262 from moving further in the first direction 212, e.g., if the valve 262 hits the first web 272.

[0038] In Fig. 2B, the valve 262 is pushed into an open position. The valve 262 is moved in the second direction 214 from the closed position into Fig. 2B. In the open position, the spring 260 and the second chamber 247 are compressed. The third chamber 251 is also expanded. The first land 272 must not be in surface contact with the insert 264. The shoulder 276 can abut the surface 278 and seal against the first channel 252. A passage extending through the valve 262 can fluidly couple the first channel 252 via the shoulder 276.

[0039] In the Fig. 3A-3B, a second view 300 of the coupling assembly 202 is shown. The second view 300 is a sectional view, wherein the second view 300 may be taken in a plane including an axis 208. The second view 300 may be taken in a view plane that is 90 degrees from the view plane of the first view 200 of the Fig. 2A-2B. The viewing plane of the second view 300 may be parallel to a plane lying between the x-axis and the y-axis of the reference axes 201. Fig. 3A shows a portion of a clutch assembly 202 in the second view 300 when the valve 262 is in a closed position. In the closed position, the valve 262 can close off a selective lubrication line, preventing the selective lubrication line from receiving and transporting fluid flow, e.g., lubricant. Fig. 3B shows the portion of the clutch assembly 202 in the second view 300 when the valve 262 is in an open position. In the open position, the valve 262 can be opened to the selective lubrication line, allowing the selective lubrication line to receive and transport a fluid flow. The valve 262 can selectively fluidly connect the lubricant source to the selective lubrication line.

[0040] The drive component 218 may include a third fluid passage 348. The third fluid passage 348 may be the selective lubrication line through which fluid may be selectively supplied to a clutch of the clutch assembly 202. The third fluid passage 348 may supply lubricant for lubricating and cooling components of the clutch, such as the clutch pack. Additionally, the third fluid passage 348 may direct lubricant into a backpressure chamber of the clutch to prevent the clutch from self-closing.

[0041] The common volume for the first chamber 246, the second chamber 247, and the third chamber 251 may have a plurality of inlets, such as a fifth channel 354 and a sixth channel 356. The fifth channel 354 may provide fluid communication between the first chamber 246 and the third fluid passage 348. The first land 272 may block and fluidically seal the fifth channel 354 from the first chamber 246, e.g., when the valve 262 is in a closed position. Likewise, the first land 272 may block and fluidically seal the sixth channel 356 from the first chamber 246.

[0042] The third fluid passage 348 may be a blind hole that can be closed. For example, a fourth opening 362 of the third fluid passage 348 may be closed and fluidically sealed with a second plug 366. Likewise, the sixth channel 356 may be a blind hole that can be closed. For example, a fifth opening 364 of the sixth channel 356 may be closed by a third plug 368.

[0043] In Fig. 3B, where the valve 262 is in an open position, the first land 272 must not block and seal the fifth channel 354 or the sixth channel 356. When the valve 262 is in the open position, fluid can flow from the first chamber 246 via the fifth channel 354 to the third fluid passage 348.

[0044] Fig. 4A shows a hydraulic circuit diagram 402 for a hydraulic system of a transmission 404 in a first state 400. The first state 400 is an open state in which a clutch arrangement 416 of the hydraulic system is open. Fig. 4B shows the hydraulic circuit diagram 402 of the hydraulic system in a second state 460. The second state 460 is a closed state in which the clutch assembly 416 of the hydraulic system is closed. The clutch assembly 416 includes a clutch. When the clutch assembly 416 is open, the clutch is open. When the clutch assembly 416 is closed, the clutch is closed. In the first open state, no torque may be transmitted across the clutch assembly 416, e.g., between an input and an output of the clutch assembly 416. When closed in the second state 460, the clutch assembly 416 may rotationally couple the input and output of the clutch assembly 416. When the clutch assembly 416 is closed, the clutch assembly 416 may engage a gearbox or other gear reduction set to allow power to flow across the clutch assembly 416 and through the gear reduction set.The components of the . Fig. 4A-4B and the differences between the first state 400 and the second state 460 may be referred to collectively herein. The first state 400 may be referred to herein as the open state 400. Likewise, the second state 460 may be referred to herein as the closed state 460. The opening and closing of the clutch assembly 416 and the transition between the open state 400 and the closed state 460 may be controlled via commands from a controller 410. The controller 410 may be a microcomputer, including components such as a microprocessor unit, input / output ports, an electronic storage medium for executable programs and calibration values, e.g., a read-only memory chip, random access memory, diagnostic memory, and a data bus.The storage medium may be programmed with computer-readable data representing instructions executable by a processor to perform the methods described below, as well as other variations that are expected but not explicitly listed. Controller 410 may be the controller 156 of FIG. Fig. 1 and / or be part of a larger control system, such as the control system 154 of Fig. 1.

[0045] The clutch assembly 416 may be part of the transmission system of a transmission 404. The transmission 404 may be a vehicle transmission, such as the transmission 108 of the vehicle 100 of Fig. 1. The clutch assembly 416 can be selectively coupled to a reduction gear of the transmission 404, for example, to a gear set 428. In the selectively open state 400, no power flow may be transmitted to the transmission 428 via the clutch assembly 416. Likewise, in the selectively closed state 460, a power flow may be transmitted to the transmission 428 via the clutch assembly.

[0046] The transition between the open state 400 and the closed state 460 may be controlled by changes in the states of a first valve 412, a second valve 414, and a piston assembly 418. The first valve 412 may be a control valve for the clutch assembly 416 (e.g., a pilot clutch valve) that controls the flow of hydraulic / actuating fluid to the piston assembly 418 by allowing or restricting the flow of hydraulic / actuating fluid. The first valve 412 may also be, and be referred to as, a selector / propeller valve for the clutch assembly 416, where the first valve 412 may influence gear selection by increasing or decreasing pressure on an actuator, such as the piston assembly 418.The second valve 414 may be a lubrication valve that controls the flow of lubricant to the clutch assembly 416 and the piston assembly 418 by allowing or restricting the flow of lubricant. The piston assembly 418 may be the clutch actuator, which can apply force to the clutch of the clutch assembly 416, moving it from an open state to a closed state and vice versa. In the controlled state, the first valve 412 and the second valve 414 may control fluid flow by opening to start flow or closing to stop flow. The first valve 412 and / or the second valve 414 may have a single open state and a single closed state, where the open state may be a fully open state allowing maximum volumetric flow, and the closed state may be a fully closed state allowing no volumetric flow.Alternatively, the first valve 412 and / or the second valve 414 may have multiple open states, wherein the cross-sectional areas of the openings of the first valve 412 and / or the second valve 414 vary in size between the cross-sectional areas of the fully open and fully closed states. The first valve 412 and / or the second valve 414 are partially opened to increase the cross-sectional area and volumetric flow rate compared to a previous state, or partially closed to decrease the cross-sectional area and volumetric flow rate compared to a previous state.

[0047] The clutch assembly 416 is a wet clutch that includes a clutch pack 420 with a plurality of friction plates 422 and a plurality of separator plates 424. The friction plates 422 and the separator plates 424 are nested within one another. In the open state 400, the friction plates 422 and the separator plates 424 must not touch, so that the clutch assembly 416 remains open. In the closed state 460, the friction plates 422 and the separator plates 424 can touch, thereby closing the clutch assembly 416. The clutch of the clutch assembly 416 can be a multi-disk wet clutch, in which the clutch pack 420 is a multi-disk clutch pack, the friction plates 422 are a plurality of friction plates, and the separator plates 424 are a plurality of separator plates.

[0048] The clutch assembly 416 may be selectively connected to the gear set 428 via a gear 430 and a driven component 426. The clutch assembly 416 may be selectively coupled to the gear set 428 in the closed state 460. When the clutch assembly 416 is selectively coupled to the transmission 428, it may be drivingly connected to the transmission 428 to transfer power flow to the transmission 428. The rotational energy of the power flow through the clutch assembly 416 and to the gear set 428 may be transferred via torque. The driven component 426 may physically couple or lock the output of the clutch assembly 416. Engagement of the reduction gear via the clutch assembly 416 may select a gear (e.g., a transmission ratio) for a transmission in which the reduction gear is housed, such as a B. the gearbox 108 from Fig. 1. Clutch assembly 416 can selectively engage and transfer power flow to a driven component 426. Driven component 426 can be rotatably and drivingly coupled to transmission 430. Gear 430 can be an input gear of transmission 428.

[0049] The piston assembly 418 includes an actuation chamber 432 and a backpressure chamber 434 separated by a piston 436. A spring 438 may be located in the backpressure chamber 434. The piston 436 may be the actuating element of the piston assembly 418. The pressure forces of the fluid in the actuation chamber 432 may push on the piston 436 and move it toward the clutch assembly 416. The force of the fluid in the actuation chamber 432 may be referred to herein as the actuation force. The resistive forces housed in the backpressure chamber and the spring 438 from the pressure of a fluid, such as a lubricant, may push on the piston 436 in the opposite direction to the actuation forces. The piston 436 may be driven by the actuation forces to push on the clutch pack 420.The actuation forces can be transmitted to the clutch pack 420 to bring the friction and separating plates into contact and close the clutch assembly 416. In the open state 400, the piston 436 does not press on the clutch pack 420. In the closed state 460, the piston 436 presses on the clutch pack 420.

[0050] In the open state 400, the first valve 412 is controlled to a no-flow state and may be open to a reservoir 442. In the zero-flow state, the first valve 412 is closed to a first pressure source 444, and no fluid may be driven or pressurized through the first valve 412. No fluid may flow through the first fluid line 452, and the piston assembly 418 is not pressurized to move the piston 436 toward the clutch pack 420. In the closed state 460, the first valve is controlled to a first open flow state and may be open to a first pressure source 444. In the first open flow state, fluid may be driven through the first valve 412 via the pressure differential between the first pressure source 444 and the piston assembly 418. The first pressure source 444 is a hydraulic / actuating fluid source.The first pressure source 444 may be a pump or may be located upstream of its output.

[0051] The first valve 412 may be fluidly connected to a first fluid line 452, wherein the first fluid line 452 may transport fluid to the piston assembly 418. The first fluid line 452 may be a clutch line that supplies the piston assembly 418 with hydraulic / actuating fluid, such as the first fluid passage 242 in the Fig. 2A-3B. The fluid may be directed to the piston assembly 418 via the first fluid line 452 and move the piston 436 toward the clutch pack 420.

[0052] In the open state 400, the second valve 414 is controlled to a reduced flow state (e.g., a throttle flow) to direct a first, smaller volumetric flow to the clutch assembly 416 and the piston assembly 418. In the reduced flow state, the second valve 414 may be closed to a second pressure source 446; however, a fluid line restriction 448 may be open to the second pressure source 446. The fluid line restriction 448 may be a fluid passage and / or a fluid channel in fluid communication with the second pressure source 446, e.g., a channel open to a pressure source feeding a main fluid line, such as the second fluid passage 244 of the Fig. 2A-2B. The second pressure source 446 is a lubricant source. The second pressure source 446 can be connected upstream of the output of a pump. In the closed state 460, the second valve 414 is controlled to an open flow state to direct a second, larger volumetric flow to the clutch assembly 416 and the piston assembly 418. Even in the closed state 460, the fluid line throttle 448 remains open to the pressure source 446, as in the open state 400. The fluid can be driven via a pressure differential between a first pressure at the second pressure source 446 and a second pressure in the clutch assembly 416 and the piston unit 418.

[0053] The second valve 414 may be connected to a second fluid line 454. The fluid line restriction 448 may be connected to a third fluid line 456. The second and third fluid lines 454, 456 may be lubrication lines that transport and deliver lubricant. The third fluid line 456 may be a main lubrication line, such as the second fluid passage 244 in Fig. 2A-2B. The second fluid line 454 may be a selective lubrication line, such as the third fluid passage 348 in Fig. 3A-3B. The second fluid line 454 and the third fluid line 456 can transport fluid to the clutch assembly 416 and the piston assembly 418.

[0054] A first fluid stream, supplied via the first valve 412, and a second fluid stream, supplied via the second valve 414 and the fluid line restrictor 448, can be directed to opposite sides of the piston 436. Fluid can flow from the first valve 412 to the actuation chamber 432 via the first fluid line 452, pressurizing it. Fluid from the second valve 414 and the fluid line restrictor 448 can flow into the backpressure chamber 434 via the second fluid line 454 and the third fluid line 456, respectively, and pressurizing it. The fluid directed to the piston assembly 418 via the second and third fluid lines 454, 456 can resist the actuation forces on the piston 436.

[0055] The first valve 412 may be a solenoid valve that can be actuated from open to closed by a magnet. The second valve 414 may be a pressure valve that can be switched from open to closed by hydraulic actuation. The second valve 414 may be controlled to open to the second pressure source 446 via the opening of the first valve 412 to the first pressure source 444. The second valve 414 may be controlled by the pressure of the first pressure source 444. When the first valve 412 is open, the pressure of the first pressure source 444 may open the second valve 414. Working fluid and pressure from the first pressure source 444 may be supplied via a fourth fluid line 458 to open the second valve 414. The fourth fluid line 458 may be a branch of the first fluid line 452. The first fluid line 452 and the fourth fluid line 458 may be connected to a fluid branch, e.g.a T-junction. The pressure in the first fluid line 452 and the fourth fluid line 458 may equalize. When the first valve 412 is closed, the pressure in the first fluid line 452 and the fourth fluid line 458 may decrease. The second valve 414 has a spring 462. The spring 462 may exert a spring force on the second valve 414. Below a threshold value for the pressure from the fourth fluid line 458, the compressive force exerted on the second valve 414 may become less than the spring force of the spring 462. At a compressive force that is less than the spring force, the spring 462 may extend and return the second valve 414 to the closed position to the second pressure source 446. The spring 462 may be the spring 260 of . Fig. 2A-3B.

[0056] The hydraulic circuit diagram 402 may apply to a clutch lubrication system and a clutch actuation system of the clutch assembly 416. The clutch assembly 416 may be part of the transmission system of the transmission 404. The transmission 404 may be a vehicle transmission, such as the transmission 108 of the vehicle 100 of Fig. 1. The clutch assembly 416 can be selectively coupled to a reduction gear of the transmission 404, for example, to a gear set 428. In the selectively open state 400, no power flow may be transmitted to the transmission 428 via the clutch assembly 416. Likewise, during selective closing in the second state 460, a power flow may be transmitted to the transmission 428 via the clutch assembly.

[0057] In Fig. 5 shows a third view 500 of a valve assembly 502 including valve 262. The third view 500 is a sectional view, wherein the third view 500 may be taken on a plane parallel to a plane formed between the y-axis and the z-axis. The valve assembly 502 may be centered on the axis 508, with the valve assembly 502 positioned about the axis 508. The axis 508 may be a central axis for the valve assembly 502. Likewise, the axis 508 is a longitudinal axis and may be an axis of rotation for rotating elements of the valve assembly 502. The assembly 502 may have a first side 504 and a second side 506, with the first side 504 opposite the second side 506. A conduit 510, line AA, may extend transversely through the valve assembly 502. The line 510 may be vertical. A sectional view can be taken on line 510.

[0058] The valve assembly 502 includes a passage 512 and walls 514. The passage 512 can accommodate the valve 262. The passage 512 can cover all or a portion of the first chamber 246, the second chamber 247, and / or the third chamber 251 of Fig. 2A-2B. The walls 514 may be tubular and cylindrical. Likewise, the passage 512 may have a cylindrical shape. The walls 514 may radially curve around the passage 512, and the passage 512 may extend radially around the axis 508. The walls 514 may have an outer surface 516 and an inner surface 518. The inner surface 518 may be the surface of the passage 512. The outer surface 516 and the inner surface 518 may be cylindrical and tubular.

[0059] The assembly includes an anti-rotation element 522. The anti-rotation element 522 may be a separate component from the valve 262 and the walls 514, e.g., a cap. The anti-rotation element 522 may be a rigid structure, e.g., a clip or a fastening component. The anti-rotation element 522 may fit into a first slot 524 and a second slot 526 of the walls 514. The first slot 524 and the second slot 526 are arranged to be centered about a second axis 528 such that the centerlines of the first slot 524 and the second slot 526 are approximately coaxial with the second axis 528. The second axis 528 may be vertical. The line 510 may divide the anti-rotation element 522, the first slot 524, and the second slot 526. The anti-rotation element 522 can prevent rotation of the valve 262, for example when the valve 262 is housed in the passage 512.

[0060] The first land 272 may include a first surface 532 and a second surface 534, wherein the first surface 532 and the second surface 534 are located on opposite sides of the first land 272. Likewise, the second land 274 may include a third surface 536 and a fourth surface 538, wherein the third surface 536 and the fourth surface 538 are located on opposite sides of the first land 272. The second surface 534 and the third surface 536 may extend radially from the core 270.

[0061] The passage 512 may have a first diameter 540. The first land 272 and the second land 274 may have a second diameter 542 and a third diameter 544, respectively. The core 270 may have a fourth diameter 546. The second diameter 542 may be approximately the same size as the first diameter 540, such that the first land 272 can form a fluid-tight seal with the passage 512 and the inner surface 518. Likewise, the third diameter 544 may be approximately the same size as the first diameter 540, such that the second land 274 can form a fluid-tight seal with the passage 512 and the inner surface 518. The first diameter 540 and the second diameter 542 may be approximately the same size. Because the second diameter 542 and the third diameter 544 are approximately the same size, a first differential area of ​​the first surface 532 and a second differential area of ​​the fourth surface 538 are approximately the same size.Furthermore, the fourth diameter 546 can be approximately constant. A third differential area of ​​the second surface 534 and a fourth differential area of ​​the third surface 536 can be approximately equal. Pressure can act on equal differential areas with the same force. The equal differential areas of the second surface 534 and the third surface 536 can prevent pressure between the second and third surfaces 534, 536 from pushing the valve 262 in the first direction 212 or the second direction 214.

[0062] Alternatively, the first differential area of ​​the first surface 532 may be smaller than the second differential area of ​​the fourth surface 538. For example, if the valve 262 has a boss 276 extending from the first surface 532, the first differential area of ​​the first surface 532 may be smaller than the second differential area of ​​the fourth surface 538. If a first chamber containing the fourth surface 538 and a second chamber containing the first surface 532 have the same pressure, a first force from the pressure exerted on the fourth surface 538 may be greater than a second force from the pressure exerted on the first surface 532, thereby moving the valve 262 toward the second side 506.

[0063] In Fig. 6 shows a fourth view 600 of the valve assembly 502 with the valve 262. The fourth view 600 is a sectional view taken on the first line 510 of Fig. 5, wherein a view plane of the first line 510 is parallel to another plane formed by the x- and z-axes of the reference axes 201. A second line 610, line BB, may extend across the valve assembly 502. The second line 610 may be vertical and may divide the anti-rotation element 522 and the first slot 524.

[0064] The valve 262 includes a passageway 622 and a third slot 624. The passageway 622 may be a passageway that extends through the valve 262 from an end closest to the first side 504 to an end closest to the second side 506. The passageway 622 may extend about the axis 508. The passageway 622 may have an opening adjacent to and extending from the fourth surface 538. For example, the passageway 622 may extend to have an opening adjacent a surface of the boss 276, the surface being perpendicular to the axis 508. As another example, the passageway 622 may extend to the first surface 532 and have an opening adjacent thereto. The anti-rotation member 522 may be fitted into the third slot 624. The third slot 624 may have a first opening 628 and a second opening 630 on an outer surface 626 of the valve 262.The first opening 628 and the second opening 630 can receive the anti-rotation element 522. When the anti-rotation element 522 is housed in the first slot 524, the second slot 526, and the third slot 624, it can abut the surfaces of the first slot 524, the second slot 526, and the third slot 624. The anti-rotation element 522 can be rigidly connected to the valve 262, e.g., by being received in the third slot 624. The anti-rotation element 522 can rigidly connect the valve 262 to the walls 514, e.g., when the anti-rotation element is received by the first slot 524, the second slot 526, and the third slot 624. Therein, the anti-rotation element 522 can lock the valve 262 to the walls 514.

[0065] The passageway 622 may have a first surface 642 and a second surface 644. The passageway 622 may have a partially circular shape. The first surface 642 may be curved and have a curvature with a radius 652. The radius 652 may extend from the axis 508 and be radial thereto. The radius 652 may extend to the first surface 642. The second surface 644 may be flat. The second surface 644 may have a surface parallel to a plane formed by the y-axis and the z-axis of the reference axes 201.

[0066] Thus, a lubricant distribution system of a transmission system is disclosed, comprising a main lubrication line and a selective lubrication line that transport lubricant to the clutch pack and the backpressure chamber of a clutch, wherein the main lubrication line is open to a lubricant source and the selective lubrication line can be selectively opened and closed to the lubricant source via a spool valve. A rotating component (e.g., a drive component) that drives the clutch includes the main lubrication line and the selective lubrication line, and the rotating component houses the spool valve. The main lubrication line is a fluid passage of the drive component. The rotating component can be a shaft. The spool valve is activated by pressure, and the spool valve can be opened to a pressure source via a port on the shaft.The pressure source may be the pressure source for supplying a working fluid to advance a piston of the clutch from an end stop toward the clutch pack, wherein a clutch line connected to an actuation chamber for the piston is in fluid communication with the pressure source. Therein, the spool valve can be opened via the pressure to close the clutch. The spool valve can also be opened by a hydraulic load, e.g., a centripetal force when the rotating component is rotated at speeds above a threshold. The spool valve has a passage connecting the pressure source and the port to the clutch line. The spool valve is connected to an anti-rotation element that prevents the spool valve from rotating or spinning. The spool valve has a fluid passage that can connect a pressure source to the clutch line.A cavity housing the spool valve may be divided into a plurality of chambers, including an actuation chamber in which a compressive force can place the spool valve in an open state, a backpressure chamber that resists the force from the actuation chamber and returns the spool valve to a closed state, and a lubricant flow chamber through which lubricant can flow from a lubricant source to the selective lubrication line.

[0067] Fig. 7 and Fig. 9 show a variety of timing diagrams for operating sequences for shifting gears in a transmission. Fig. 7 shows a plurality of timing diagrams 700 of a first operating method for shifting gears, the first operating method being a normal method using a standard control routine. Fig. 9 shows a plurality of timing diagrams 900 of a second operating method for shifting gears, wherein the second operating method is a method that uses a pre- and / or post-cooling control routine. During the pre- and / or post-cooling control routine, there may be a pre-cooling phase before the wet clutch is opened and a post-cooling phase before the wet clutch is opened, during which additional lubricant is supplied to the wet clutch.

[0068] The operating procedures for the time diagrams 700 of Fig. 7 and the timing diagrams 900 of Fig. 9 can be accessed via the systems and components of Fig. 1-6. The operating sequences of a manual transmission for timing diagrams 700 and 900 apply to a clutch assembly of the present disclosure, such as a clutch assembly 416 of Fig. 4A-4B. The coupling assembly is configured to include a spool valve for varying the amount of lubricant that can be directed through the spool valve to the lubrication channels / lines. The coupling assembly includes a first fluid passage and a second fluid passage for transporting lubricant. The spool valve may be valve 262 of Fig. 2A-3B, which is also part of the valve assembly 502 of Fig. 5-6. The first fluid passage is a primary lubrication line, such as the second fluid passage 244 in Fig. 2A-2B. The second fluid passage is a selective lubrication line, such as the third fluid passage 348 in Fig. 3A-3B.

[0069] The axes of each plot of the timing diagrams 700 (e.g., first curve 702, second curve 704, third curve 706, and fourth curve 708) and each plot of the timing diagrams 900 (e.g., first curve 902, second curve 904, third curve 906, and fourth curve 908) may increase in the directions indicated by the axes' arrows. For example, for the timing diagrams 700, time may increase horizontally along all four plots from t0 to t3, with the intervals between the times marked. Similarly, for the timing diagrams 900, time may increase horizontally along all four plots from t0-t5. The diagrams are time-aligned such that the first curve 702, the second curve 704, the third curve 706, and the fourth curve 708 of the time diagrams 700 and the first curve 902, the second curve 904, the third curve 906, and the fourth curve 908 show the change of a variable over time.The horizontal axis of each graph represents time, and time increases from the left side of the graph to the right side of each graph. The vertical lines at times t0-t3 represent points of interest during the operation of the timing diagrams 700 of FIG. Fig. 7. Likewise, the vertical lines at times t0-05 represent times of interest during the operating sequence of the timing diagrams 900 in Fig. 9.

[0070] It should be understood that time represents relative time, such that t1 is some time after t0, t2 some time after t1, etc., but does not indicate specific or proportional amounts of time. For example, although t2 and t3 are farther apart than t1 and t2 in the timing diagrams 700, the distance between t2 and t3 may be relatively less than the distance between t1 and t2. Furthermore, the timing diagrams 700 and 900 show an example of various measurements during the operation of the clutch, the valve, and the pressure on the clutch, but do not limit the operation of the clutch, the valve, or the pressure on the clutch. In the timing diagrams 700 of Fig. 7 Between t0 and t1, for example, the fourth curve 708 shows that the pressure on a clutch increases gradually to a closed pressure in an infinitely small period of time. However, in different valve embodiments, the shape of the pressure increase on the clutch may vary, e.g., with a flatter linear gradient or a more parabolic gradient.

[0071] The first curve 702 in Fig. 7 and the first curve 902 in Fig. 9 represent the state of a transmission over time, where the state of the transmission is the ratio (e.g., gear) selected by the transmission. The transmission may be the transmission 108 of Fig. 1 and / or the gearbox 404 of Fig. 4A-4B. The selected ratio can be for a gearbox, such as the gearbox 428 in Fig. 4A-4B, apply. When the first curve 702 or the first curve 902 is labeled first gear on the vertical axis, the transmission is signaled to shift into or remain in a first gear, with the transmission shifting and transferring rotational energy through the first gear. When the first curve 702 is at a point labeled "second gear" on the vertical axis, the transmission is signaled to shift into or remain in a second gear, with the transmission shifting and transferring rotational energy through the second gear. In first gear, a first transmission may be selected; the first transmission may be transmission 428. In second gear, a second shift may be selected. The first curve 702 or the second curve 904 may shift to a first gear of the first gear and the second gear at or above a first threshold signal 712.Likewise, the first curve 702 or the second curve 904 may shift to a second gear of the second gear and the second tick at or below a second threshold signal 714. The command signal to shift the transmission from first to second gear may be changed by a user input (e.g., an operator input). A command signal, such as a shift command to change the gear of the transmission, may be input via a shifting device, such as an automatic shifter, a manual shifter, or a shift input device of the input devices 164 of FIG. Fig. 1.

[0072] The second curve 704 represents the clutch states for a standard control routine. The second curve 904 represents the clutch states for a control routine before and / or after cooling. The clutch states of the second curve 704 and the second curve 904 are closed and open, represented by a closed and an open check mark, respectively. The clutch may be a clutch of the clutch assembly 416 of Fig. 4A-4B. The clutch may be closed in a closed state, wherein rotational energy and power may be transmitted through the clutch. The clutch may be open in an open state, wherein no rotational energy and power are transmitted through the clutch. The clutch may be closed and in the closed state when the second curve 704 or the second curve 904 is at or above a third threshold signal 722. The clutch may be open and in the open state when the second curve 704 or the second curve 904 is at or below a fourth threshold signal 724. In the closed state, the clutch may connect the first input to the first transmission. The clutch may be in an open state, wherein rotational energy and power cannot be transmitted through the clutch.

[0073] The third curve 706 represents the valve states of the valve for a standard control routine. The third curve 906 represents the valve states of the valve for a control routine before and / or after cooling. The valve can be open or closed, represented by an open checkmark or a closed checkmark, respectively. When the valve is open, fluid flow can flow into a selective lubrication line. When closed, the valve is in a closed mode in which the selective lubrication line is occluded by the valve, so that no fluid flow can flow via the valve to and through the selective lubrication line. The clutch can be closed when the third curve 706 or the third curve 906 is at or above a fifth threshold signal 732. The clutch can be open when the third curve 706 or the third curve 906 is at or below a sixth threshold signal 734.The relationship between the third curve 706 and the second curve 704 may be inversely proportional, with the third curve 706 placing the valve in an open state when the second curve 704 placing the clutch in a closed state, and vice versa. Likewise, the relationship between the third curve 906 and the second curve 904 may be inversely proportional, with the third curve 906 placing the valve in an open state when the second curve 904 placing the clutch in a closed state, and vice versa. The valve and selective lubrication line may be the valve 262 and the third fluid passage 348 of the . Fig. 2A-3B trade

[0074] The fourth curve 708 represents the pressure exerted on the clutch and a clutch piston during a standard control routine. The fourth curve 908 represents the pressure exerted on the clutch and a clutch piston for a control routine before and / or after cooling. The fourth curve 708 and the fourth curve 908 may fluctuate from a pressure at or above the closed pressure to a minimum pressure, represented by a closed pressure tick and a minimum pressure tick, respectively. At or above the closing pressure, the clutch may close. The pressure may be at or above the closed pressure tick when the fourth curve 708 or the fourth curve 908 is at or above a first pressure threshold 742. The pressure may reach the minimum pressure when the fourth curve 708 or the fourth curve 908 is at a second pressure threshold 744.

[0075] As in Fig. 7, the operating sequence for timing diagrams 700 begins at t0. At t0 and between t0 and t1, the selected gear ratio may be indeterminate, with either the second gear ratio being selected or no gear ratio being selected. For the first curve 702, neither the first nor the second gear ratio is selected. At t0 and between t0 and t1, the second curve 704 shows that the clutch may be in an open state. Likewise, the third curve 706 at t0 and between t0 and t1 shows that the valve may be in a closed state. At t0 and between t0 and t1, the fourth curve 708 is at the minimum pressure, where the minimum pressure is the starting pressure.

[0076] At t1, a signal is sent to shift the transmission and shift to first gear, and the first curve 702 begins recording the first threshold signal 712. At time t1, the second curve 704 rises to the third threshold signal 722, and the clutch transitions to the closed state. Likewise, at t1, the third curve 706 decreases to the sixth threshold signal 734, and the valve transitions to an open state. At t1, the fourth curve 708 rises to the first pressure threshold 742, and the clutch reaches a closing pressure to close. The clutch closes at the closing pressure while the valve opens. The first curve 702, the second curve 704, the third curve 706, and the fourth curve 708 increase or decrease incrementally so that the first gear ratio engages, the clutch closes, the valve opens, and the closed pressure is reached approximately instantaneously.Between t1 and t2, the states of the gear ratio, the clutch, the valve and the pressure on the clutch remain constant, as shown by the first curve 702, the second curve 704, the third curve 706 and the fourth curve 708, respectively.

[0077] At t2, a signal is sent to change gear and shift the transmission into second gear, and the first curve 702 decreases to the second threshold signal 714. At time t2, the second curve 704 decreases to the fourth threshold signal 724, and the clutch transitions to an open state. Likewise, at t2, the third curve 706 increases to the fifth threshold signal 732, and the valve transitions to the closed state. At t2, the fourth curve 708 decreases to the second pressure threshold 744, and the clutch drops below the closing pressure to open. The clutch opens at the minimum pressure while the valve closes. The first curve 702, the second curve 704, the third curve 706, and the fourth curve 708 increase or decrease incrementally so that the first gear ratio disengages, the clutch opens, the valve closes, and the minimum pressure is reached approximately instantaneously.Between t2 and t3, the states of the gear ratio, the clutch, the valve, and the clutch pressure remain constant, as shown by the first curve 702, the second curve 704, the third curve 706, and the fourth curve 708, respectively. At t3, the operating sequence ends.

[0078] In Fig. 8, diagram 800 is shown. Diagram 800 is a time diagram of the control signals and the pressure on a clutch assembly. Diagram 800 may illustrate a method for changing the states of the clutch assembly with a pre- and / or post-cooling phase. Diagram 800 includes a first axis 810 indicating time, a second axis 812 indicating pressure, and a third axis 814 indicating a signal. The pressure of second axis 812 is a clutch pressure, wherein the clutch pressure is a pressure on a piston of a piston assembly and a clutch assembly, such as piston 436 of piston assembly 418 and clutch assembly 416 of Fig. 4A-4B. The pressure of the second axis 812 is the net pressure to an actuation chamber, such as the actuation chamber 432 of Fig. 4A-4B. As a net pressure, a pressure opposite to the pressure in the actuating chamber, e.g., a pressure in a backpressure chamber, can be subtracted from the pressure of a curve recorded with the second axis 812. The backpressure chamber can be the backpressure chamber 434 of Fig. 4A-4B. The third axis signal 814 may be a signal to open a first valve. The first valve may supply the piston assembly and the clutch assembly with working fluid, such as the first valve 412. Fig. 4A-4B. The first valve may be a solenoid valve, and the third axis 814 signal may be a solenoid signal. The first valve may be referred to here as a piston valve. The vertical lines at times t0-t11 represent the times of interest during the operating sequence.

[0079] The diagram 800 includes two curves, a first curve 816 and a second curve 818, which are shown in diagram 800 and in a figure legend 820. The first curve 816 shows the clutch pressure over time. The first curve 816 is shown by continuous lines. The first curve 816 has a minimum pressure at a point 826 on the second axis 812. The minimum pressure at the checkmark 826 may be a minimum pressure in the piston chamber, for example, when the valve is closed and the piston is fully retracted to the stop. The checkmark 826 and the minimum chamber pressure may be, for example, 0 bar. The second curve 818 is a representation of the third axis 814 signal over time of the first axis 810. The second curve 818 is shown by dashed lines. The first curve 816 shows the change in pressure on the piston over time.The second curve 818 shows the change in state of the piston valve over time, where the piston valve can change its state almost instantaneously with the signal. The piston valve can be in a first state at a first tick 822 on the third axis 814, where the signal of the second curve 818 has a current to close the piston valve. The piston valve can be in a second state at a second tick 824 on the third axis 814, where the signal of the first curve 816 has a current to open the piston valve.

[0080] The axes of the diagram 800 (e.g., the first axis 810, the second axis 812, and the third axis 814) may increase in the directions indicated by the axis arrows. For example, time may increase horizontally along the first axis 810 from t0 to t11, with the intervals between the times marked. The diagrams are time-oriented such that a variable of a first curve 816 and a variable of a second curve 818 change over time. It should be understood that time represents relative time, such that t1 is some time after t0, t2 is some time after t1, and so on, but does not indicate specific or proportional amounts of time. For example, although t2 and t3 are farther apart than t1 and t2 in the diagram 800, the distance between t2 and t3 may be relatively less than the distance between t1 and t2.Furthermore, the graph 800 shows an example of various measurements during operation of the clutch, the piston valve, and the pressure on the clutch, but does not limit the operation of the clutch, the piston valve, or the pressure on the clutch. For example, the first curve 816 between t2 and t3 shows that the pressure on a clutch decreases with a linear slope. However, with different embodiments of the piston valve and the backpressure chamber, the shape of the first curve 816 may appear different, e.g., with a flatter or steeper linear slope, or a more parabolic shape.

[0081] A method for the clutch operation may begin at t0. T0 is the start time for graph 800. At t0, the first curve 816 may be at a minimum pressure at tick 826 and the second curve 818 may be at the first tick 822 for the spool valve to be in a closed state. Between t0 and t1, the state of the first curve 816 and the second curve 818 remains constant and does not decrease or increase along the second axis 812 or the third axis 814, respectively. At t1, the signal of the second curve 818 increases along the third axis 814 until the second tick 824. At the second tick 824, the spool valve for the piston transitions to the second state, where the spool valve opens. Between t1 and t9, the second curve remains at the second tick 824, and the spool valve is in the open state. When the piston valve is open, fluid flow and pressure can flow into an actuating chamber of the piston.Between t1 and t2, the piston pressure may remain at the minimum pressure at tick 826, which may delay the path of fluid and / or pressure from a pressure source through the piston valve and to the actuation chamber. At t2, the pressure in the actuation chamber may begin to rise, and the pressure of the first curve 816 may begin to rise. Between t2 and t3, the pressure of the first curve 816 may increase. Between t2 and t3, the pressure of the first curve 816 may increase to a stroke pressure 832, at which point the pressure of the first curve 816 begins to move the piston from the piston chamber end stop toward the clutch assembly. It is understood that the stroke pressure may be achieved by a high hydraulic load, such as a hydraulic load from an electric machine. A pressure range between the minimum pressure at tick 826 and the stroke pressure 832.Alternatively, the time between t1 and t2 may be infinitesimal, and in these cases, t1 and t2 may have a vertical line or a different t-value instead of t1 and t2.

[0082] At t3, the pressure of the first curve 816 may reach a first pressure plateau 834, at which the pressure of the first curve 816 no longer increases. Between t3 and t4, the pressure of the first curve 816 remains constant. At t4, the first pressure plateau 834 ends, and the pressure of the first curve 816 begins to decrease. At t4, the backpressure from the backpressure chamber may increase, thereby reducing the net pressure on the piston. The pressure in the backpressure chamber may be increased by opening a lubrication valve and a selective lubrication line, such as through the valve 262 and the third fluid passage 348 in Fig. 2A-3B. Between t4 and t5, the pressure in the first curve 816 may continue to decrease. The pressure in the backpressure chamber may increase faster than in the actuation chamber. At t5, the pressure between the actuation chamber and the backpressure chamber may equalize. Between t5 and t6, the pressure may remain constant. Between t5 and t6, the piston may continue to move toward the clutch of the clutch assembly. Likewise, between t5 and t6, the piston may contact the clutch, but not push and compress it. At t6, the pressure of the first curve 816 may increase to a kissing pressure, where the kissing pressure 836 is a threshold pressure that moves the piston against the clutch of the clutch assembly and compresses it.

[0083] Between t6 and t7, the pressure of the first curve 816 increases as the piston encounters resistance and is held in place by the clutch, a backpressure chamber spring, and the backpressure chamber lubricant pressure. At t7, the first curve 816 has an inflection point 838 where the gradient increases and the pressure of the first curve 816 increases at a faster rate. At the inflection point 838 and at the inflection point, the clutch of the clutch assembly can close, with the friction plates and separator plates, as well as the clutch pack, no longer being allowed to compress. Between t7 and t8, the pressure of the first curve 816 continues to increase at the increased rate. At t8, the pressure of the first curve 816 may reach a second pressure plateau 840 where the pressure of the first curve 816 no longer increases. Between t8 and t10, the pressure may remain constant, and the pressure plateau may continue.At t9, the signal of the second curve 818 decreases along the third axis 814 until the first tick 822. At the first tick 822, the piston valve for the piston transitions to the first state in which the piston valve is closed. Between t9 and t10, the pressure of the piston may remain at the second pressure plateau 840, which may represent a delay for the end of the fluid and / or pressure wave after the piston valve closes. At t10, the pressure drops rapidly in a vanishingly small period of time to the minimum pressure at tick 826. When the pressure in the first curve 816 drops below the lift pressure, the lubrication valve may close, closing the selective lubrication line to the coupling assembly. Between t10 and t11, the pressure of the first curve 816 remains at the minimum pressure and tick 826. At t11, the first curve 816 and the second curve 818 may end. Likewise, the procedure for the operation shown in diagram 800 can be terminated.

[0084] Back to Fig. 9: At t0, the operating sequence for timing diagrams 900 begins. At t0 and between t0 and t2, the selected gear ratio can be indeterminate, with either the second gear ratio being selected or no gear ratio being selected. For the first curve 902, neither the first nor the second gear ratio is selected between t0 and t2. At t0 and between t0 and t2, the second curve 904 shows that the clutch can be in an open state. Likewise, the third curve 906, at t0 and between t0 and t1, shows that the valve can be in the closed state. At t0 and between t0 and t1, the fourth curve 908 is at the minimum pressure, where the minimum pressure is the output pressure.

[0085] At t1, a pre-cooling phase for the clutch begins. At t1, the third curve 906 decreases to the sixth threshold signal 734, and the valve transitions to an open state. At t1, the fourth curve 908 increases to a third pressure threshold 952. At or above the third pressure threshold 952, the fourth curve 908 increases to or above an activation pressure. The activation pressure is indicated by an activation pressure hook on the clutch pressure axis. The activation pressure is a pressure that the piston overcomes to move toward and compress the clutch pack. The pressure in the piston's chamber may be greater than the activation pressure to move the piston toward the clutch pack. The activation pressure may prevent self-closing. At t1, the clutch pressure increases to or above the third pressure threshold 952, but does not close the clutch.The third curve 906 and the fourth curve 908 increase and decrease gradually, respectively, so that the valve opens and the activation pressure is reached at approximately time t1. Between t1 and t2, the states of the gear ratio, the clutch, the valve, and the pressure on the clutch remain constant, as shown by the first curve 902, the second curve 904, the third curve 906, and the fourth curve 908, respectively. Between t1 and t4, the third curve 906 and the valve state remain constant. Between t1 and t2, the fourth curve 908 and the pressure on the piston remain constant.

[0086] At t2, a signal is sent to shift gear and transition to first gear. At t2, the first curve 902 shows that the transmission system is being commanded to shift into first gear. At t2, the second curve 904 increases the third pressure threshold 952 and the clutch transitions to a closed state. At t2, fourth curve 908, the piston pressure increases to the closing pressure. At t2, the first curve 902, the second curve 904, and the fourth curve 908 gradually increase or decrease such that the gear ratio changes, the clutch closes, and the closing pressure is reached almost instantaneously at t2. Between t2 and t3, the states of the gear ratio, the clutch, and the pressure on the clutch remain constant, as shown by the first curve 902, the second curve 904, and the fourth curve 908, respectively.

[0087] At t3, a signal is sent to shift and transition the transmission into second gear. At t3, the first curve 902 indicates that the transmission system is being commanded to shift into second gear. At t3, the second curve 904 decreases to the fourth threshold signal 724 and the clutch transitions to the open state. At t3, the fourth curve 908 decreases to the third pressure threshold 952, at which the piston pressure drops below the closing pressure to allow the clutch to open. The clutch opens at the engage pressure while the valve closes. At t3, the first curve 902, the second curve 904, and the fourth curve 908 gradually increase or decrease so that the first gear ratio disengages, the clutch opens, and the apply pressure is reached almost instantaneously. Between t3 and t5, the states of the gear ratio and the clutch remain constant, as shown by the first curve 902 and the second curve 904, respectively.Between t3 and t4, the pressure state of the clutch remains constant, as shown by the fourth curve 908. At t4, the third curve 906 rises to the third threshold signal 722 and the valve closes. At t4, the fourth curve 908 falls to the second pressure threshold 744 and the piston pressure drops to the minimum pressure. Between t4 and t5, the valve state and the piston pressure remain constant, as shown by the third curve 906 and the fourth curve 908. At t5, the operating sequence ends.

[0088] Fig. 10 shows a method 1000 for selecting a standard control strategy or a pre- and / or post-cooled control strategy for a clutch that can be lubricated via an optional fluid passageway using a lubrication valve of the present disclosure, such as the third fluid passage 348 and the valve 262 of the Fig. 3A-3B. The clutch may be part of a clutch assembly, closed via a piston assembly, and part of a hydraulic system of the present disclosure, such as the clutch assembly 416, the piston assembly 418, and the hydraulic system of the hydraulic circuit diagram 402 of Fig. 4A-4B. The control strategies of method 1000 may supply the clutch and clutch assembly with lubricant for lubrication and cooling. The control strategies of method 1000 may supply working fluid to a piston chamber to actuate a piston of the piston assembly. The lubricant supplied to the clutch assembly may also be supplied to a backpressure chamber to prevent the clutch from self-closing by the piston contacting a clutch pack. Method 1000 may be implemented by a controller including a processor and memory, as previously described, such as controller 156 of control system 154 and / or controller 410.

[0089] At 1002, the method includes determining the operating conditions. The operating conditions may include the position of the input device (e.g., the position of the range selector), the clutch configuration, the transmission speed, the electric machine speed, the vehicle speed, the vehicle load, the ambient temperature, etc. The operating conditions may be determined via sensor inputs, modeling, lookup tables, and other suitable techniques.

[0090] At 1004, method 1000 measures the clutch temperature (e.g., the wet clutch temperature). The clutch temperature may be measured via one or more sensors. Sensors 158 of Fig. 1 may also include the sensors for monitoring the temperature of the clutch. At 1006, method 1000 determines whether the temperature of the clutch is above a first temperature threshold (e.g., a temperature threshold). If the temperature of the clutch is below the temperature threshold (1006 is NO), method 1000 continues to 1008.

[0091] At 1008, method 1000 determines whether the lubrication valve for a selective lubrication line is open. The selective lubrication line may be the third fluid passage 348 of Fig. 3A-3B and the second fluid line 454 of Fig. 4A-4B. When the selective lubrication line is open, the lubrication valve exerts an activation pressure on the clutch. The pressure of the lubricant in and flowing through the backpressure chamber of the clutch assembly can be increased to an activation pressure. The activation pressure is opposite the piston in the actuation chamber, so that the activation pressure exerts a force on the piston that is opposite to the direction of advance of the piston to close the clutch. The actuation pressure and force can prevent the clutch from closing automatically, e.g., at high speeds. However, the additional volume flow from the selective lubrication line and the larger volume of lubricant in the clutch assembly can increase the weight of the rotating element and the clutch assembly.The increased weight and splash of the larger fluid volume can result in greater power losses during rotation of a drive component that drives the clutch assembly and includes the lube valve, main lube line, and selective lube line. To reduce lubricant flow when it is not desired, the lube valve is closed. The increased lubricant flow may not be desired if the temperature is below the temperature threshold at 1006. If the lube valve to the selective line is open (1008 is YES), step 1000 proceeds to 1010, where the state of the lube valve is changed to turn off the activation pressure. At 1010, the lube valve to the selective lube line is closed. The pressure in the backpressure chamber of the clutch assembly may drop to a pressure below the activation pressure.Likewise, the amount of lubricant flowing through the drive component and clutch assembly may decrease. After 1010, method 1000 ends. Returning to 1008, if the lube valve is not open to the selective line (1008 is NO), method 1000 proceeds to 1012, where control takes no action and the settings of the lube valve, piston assembly, and clutch assembly remain the same. After 1012, method 1000 ends.

[0092] Returning to 1006, if the clutch temperature is above the temperature threshold (1006 is YES), method 1000 continues to 1022. At 1022, the speed of the drive component is measured. After 1022, method 1000 proceeds to 1024, where method 1000 determines whether the speed is at or above a second speed threshold (e.g., a speed threshold). Above the speed threshold, the drive component may be exerting a load on the clutch, which may cause the clutch to close itself. For example, the speed threshold may be 12,000 revolutions per minute (rpm). Above the speed threshold, the pre- and / or post-cooling method is permitted. Likewise, above the speed threshold, lubrication via the selective line is permitted to maximize clutch cooling.If the speed is not above the threshold (1024 is NO), procedure 1000 continues with 1012. If the speed is above the speed threshold (1026 is YES), procedure 1000 proceeds to 1026.

[0093] At 1026, method 1000 determines whether a request to actuate the piston and close the clutch has been made. If the clutch is to be closed (1026 is YES), method 1000 proceeds to 1028, where a signal is sent to open a piston valve so that clutch control pressure is applied to the clutch and piston. The piston valve may be the first valve 412 of Fig.4A-4B. The piston valve can connect a pressure source to the actuation chamber, increasing the actuation chamber to the clutch control pressure. The clutch control pressure acts on the clutch and piston via a force that advances the piston toward contact with the clutch. The control pressure also causes the lubrication valve to open, allowing lubricant to flow into the selective lubrication line and through the selective lubrication line into the clutch assembly. After 1028, method 1000 ends.

[0094] Returning to 1026 and not requesting the clutch to close (1026 is NO), method 1000 proceeds to 1032 where it is determined whether the lube valve to the selective line is open. If the lube valve to the lube line is open (1032 is YES), method 1000 proceeds to 1012. If the lube valve is not open to the lube line (1032 is NO), method 1000 proceeds to 1036 where a signal is provided to open the lube valve and apply activation pressure to the clutch assembly. The signal may be a pressure signal, such as a pressurized fluid flow from a pressurized source. The signal may open the lube valve to the selective lube line, and lubricant may flow from a lubricant source into and through the lube line. The lubricant from the lubricant source is pressurized.The lubricant from the selective lubrication line can increase the volume flow of lubricant to the clutch assembly compared to supply via the main lubrication line. The increased volume flow can improve the lubrication and cooling of the clutch elements, e.g., the clutch pack. The increased volume flow of the pressurized lubricant increases the back pressure to the activation pressure. For the clutch to engage, the pressure in the piston chamber rises above the activation pressure. The activation pressure prevents the clutch from engaging automatically before the clutch control pressure is reached in the actuation chamber.

[0095] It should be understood that in another example of method 1000, after the request to close the clutch (1026 is YES), a signal may be sent to apply a clutch control pressure and an enable pressure. For example, at 1028, opening the spool valve to the clutch control pressure source may place the pressure source in fluid communication with an actuation chamber of the lubrication valve. The pressure from the pressure source may open the lubrication valve. In doing so, opening the spool valve may open the lubrication valve via the clutch control pressure. Opening the lubrication valve causes fluid to flow into the clutch assembly via the selective lubrication line, applying the enable pressure to the clutch assembly. The clutch control pressure is the same as at 1028. Likewise, the enable pressure is the same as at 1036.

[0096] In this way, a method for changing the states of the clutch assembly with a pre- and / or post-cooling phase is disclosed. The method can be represented graphically by a plurality of curves and a diagram with two dependent axes. The method illustrates how a first valve, which is a solenoid valve and a piston valve, can be opened or closed. When signaled to be open, the first valve can supply working fluid and pressure to an actuation chamber to advance a piston of the clutch assembly. The method graphically illustrates and describes how signals change a net pressure on a piston of the clutch assembly, the method changing the net pressure from a minimum pressure to a stroke pressure, to a first pressure plateau at a first local maximum pressure, to a contact pressure, and to a second pressure plateau at a second local maximum pressure.The method also describes the effect of opening the first valve on a second valve, wherein the pressure source of the first valve can open the second valve and the second valve is a lubrication valve. The second valve is connected to a selective lubrication line to a fluid source and can open it.

[0097] In this way, a method for selecting and implementing normal operation or a pre- and / or post-cooling phase is disclosed. The method may monitor the temperature of a clutch and the speed of a drive component to select and provide an activation pressure for a lubrication valve. The lubrication valve is a pressure-actuated valve and may be a spool valve. If the temperature rises above a temperature threshold, the method may transition to further cooling methods through lubrication. If the speed rises above a threshold and the clutch is not selected for actuation, the method may apply an activation pressure to a selective lubrication line to open the clutch. The selective lubrication line may flow an additional volume of lubricant to lubricate a clutch pack of the clutch and increase the pressure of the lubricant in a backpressure chamber.When the speed increases above the threshold and the clutch is selected for actuation, the method may apply clutch control pressure to advance a piston by increasing the pressure in an actuation chamber and activate the lubrication valve to open the selective lubrication line.

[0098] Although various embodiments have been described above, they are to be considered as examples and not as limitations. Those skilled in the art will appreciate that the disclosed subject matter may be embodied in other specific forms without departing from the spirit of the subject matter. The embodiments described above are, therefore, to be considered in all respects as illustrative and not restrictive. Thus, the configurations and routines disclosed herein are exemplary, and the specific examples are not to be considered as limiting, as numerous variations are possible. For example, the technology described above may be applied to powertrains that include various types of power sources, including various types of prime movers, internal combustion engines, and / or transmissions.The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions and / or properties disclosed herein.

[0099] It should be understood that the configurations and routines disclosed herein are exemplary in nature, and that these specific embodiments are not intended to be limiting, as numerous variations are possible. Unless expressly stated otherwise, the terms "first," "second," "third," etc., are not intended to denote any order, position, quantity, or importance, but are used merely to distinguish the individual elements. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations, as well as other features, functions, and / or characteristics disclosed herein.

[0100] The following claims particularly point out certain combinations and subcombinations that are considered novel and non-obvious. These claims may refer to "a" element or "a first" element, or the equivalent thereof. Such claims are to be construed as including the inclusion of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether broader, narrower, the same as, or different from the original claims, are also considered to be within the subject matter of the present disclosure.

Claims

[1] Transmission system comprising: a lubrication valve that connects a lubrication line in fluid communication with a multi-disc wet clutch; a clutch line in fluid communication with a clutch actuator of the wet multi-disc clutch and the lubrication valve; a clutch control valve fluidly connected to the clutch line; and a controller configured to adjust a pressure of the clutch line to open and close the lubrication valve based on a temperature of the wet clutch. [2] The transmission system of claim 1, wherein the lubrication valve is a spool valve having an anti-rotation element, the anti-rotation element rigidly connecting the lubrication valve to a structure of the transmission system. [3] The transmission system of claim 2, wherein the spool valve divides a volume into a first chamber, a second chamber, and a third chamber, the first chamber being an actuation chamber and in fluid communication with a pressure source of the clutch line, the second chamber being in fluid communication with the lubrication line, the third chamber being a back pressure chamber for the lubrication valve and containing a spring. [4] A transmission system according to any one of the preceding claims, further comprising a drive component drivingly coupling an input to the multi-disk wet clutch, the drive component comprising a main lubrication line and a selective lubrication line, the main lubrication line being in fluid communication with the multi-disk wet clutch and the selective lubrication line being brought into fluid communication with the multi-disk wet clutch via the opening of the lubrication valve. [5] The transmission system of claim 4, wherein the drive component includes a cavity housing the lubrication valve, the cavity being in fluid communication with a source of lubricant, and the cavity being in selective fluid communication with the lubrication line via the lubrication valve. [6] The transmission system of claim 5, wherein the main lubrication line supplies a first fluid stream from the lubricant source to the multi-disk wet clutch. [7] The transmission system of claim 6, wherein the selective lubrication line supplies a second fluid stream from the lubricant source to the multi-disk wet clutch when the lubrication valve is open. [8] The transmission system of claim 7, further comprising a back pressure chamber for the clutch actuator in fluid communication with the main lubrication line and the selective lubrication line. [9] Transmission system according to claim 8, wherein the back pressure chamber is pressurized via the first fluid flow and the second fluid flow up to an activation pressure. [10] The transmission system of any one of claims 4 to 9, wherein the lubrication valve includes a passage, the passage placing a source of actuating fluid for the clutch control valve and the clutch actuator in fluid communication with the clutch line. [11] Valve arrangement comprising: a fluid passage; a slide valve and an anti-rotation element, wherein the anti-rotation element is a rigid structure; wherein the anti-rotation element rigidly connects the slide valve to the fluid passage and prevents rotation of the slide valve separately from the fluid passage. [12] The valve assembly of claim 11, wherein the slide valve includes a first land and a second land connected by a core. [13] The valve assembly of claim 12, wherein the spool valve divides the fluid passage into a first chamber, a second chamber, and a third chamber, the first chamber being an actuation chamber and in fluid communication with a pressure source for a clutch line for a wet clutch, the third chamber being a back pressure chamber for the spool valve and containing a spring. [14] The valve assembly of claim 13, wherein the spool valve is hollow and includes a passage extending through the first land and the second land and fluidly connecting the first chamber to the third chamber; and / or the valve assembly includes a boss that abuts the clutch conduit and fluidly seals it from the third chamber via compression of the spring; and / or the passage extends through the boss and is fluidly connected to the clutch conduit. [15] A valve assembly according to any one of claims 11 to 14, wherein walls of the fluid passage include a first slot and a second slot, the anti-rotation element being received by the first slot and the second slot to rigidly connect the spool valve to the fluid passage; and / or the spool valve includes a third slot, the anti-rotation element being received by the third slot to rigidly connect the spool valve to the fluid passage.

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