# Patent

## Title
Electro-hydraulic control system using shift valves for a hybrid drive unit

## Abstract

A valve body assembly for a hybrid drive unit includes a pressure regulator valve, a first on/off shift valve for controlling a stationary clutch, a second on/off shift valve for controlling a rotating clutch, and a third on/off shift valve for controlling a damper bypass clutch. The control system controls the stationary clutch and the rotating clutch to operate the hybrid drive unit in four different modes. The first shift valve, the second shift valve and the third shift valve do not include a regulated pressure feedback port, nor a pressure switch for indicating a clutch fill level.

## Background
TECHNICAL FIELD
The invention generally relates to a control system for controlling a hybrid drive unit.
BACKGROUND
Hybrid vehicles typically include one or more electric motors and an engine for generating a torque, and a hybrid drive unit, i.e., a transmission, for routing the torque to at least one wheel through a plurality of different gear sets. The hybrid drive unit typically includes a plurality of planetary gear sets, each including a plurality of gear members. The hybrid drive unit also includes a plurality of different torque transmitting devices, such as clutches and brakes that are configured for selectively interconnecting the engine and/or the electric motors with various members of the planetary gear sets.
A control system controls the operation of the hybrid drive unit. The control system includes a valve body assembly having a plurality of hydraulic valves housed in a valve body and configured for actuating, i.e., engaging or disengaging, the various torque transmitting devices to route the torque through different power flow paths to provide different operating modes. Additionally, the valve body assembly controls fluid flow for cooling and/or lubricating the various components of the vehicle, such as the gear sets and the electric motor(s).
SUMMARY
A control system for controlling a hybrid drive unit of a vehicle is provided. The control system includes a pressure regulator valve in fluid communication with a plurality of fluid lines. The pressure regulator valve regulates a line pressure of a fluid within the plurality of fluid lines. A first valve is disposed in fluid communication with at least one of the plurality of fluid lines. The first valve opens and closes fluid communication between the plurality of fluid lines and a first clutch for engaging and disengaging the first clutch respectively. A second valve is disposed in fluid communication with at least one of the plurality of fluid lines. The second valve opens and closes fluid communication between the plurality of fluid lines and a second clutch for engaging and disengaging the second clutch respectively. The first valve disengages the first clutch and the second valve disengages the second clutch to operate the hybrid drive unit in a first mode. The first valve engages the first clutch and the second valve disengages the second clutch to operate the hybrid drive unit in a second mode. The first valve engages the first clutch and the second valve engages the second clutch to operate the hybrid drive unit in a third mode. The first valve disengages the first clutch and the second valve engages the second clutch to operate the hybrid drive unit in a fourth mode. The first valve and the second valve each include a shift valve characterized by a lack of a regulated pressure feedback port.
A valve body assembly for controlling a hybrid drive unit of a vehicle is also provided. The valve body assembly includes a pressure regulator valve in fluid communication with a plurality of fluid lines. The pressure regulator valve regulates a line pressure of a fluid within the plurality of fluid lines. A first electronically controlled hydraulic valve is disposed in fluid communication with at least one of the plurality of fluid lines. The first electronically controlled hydraulic valve opens and closes fluid communication between the plurality of fluid lines and a first clutch for engaging and disengaging the first clutch respectively. A second electronically controlled hydraulic valve is disposed in fluid communication with at least one of the plurality of fluid lines. The second electronically controlled hydraulic valve opens and closes fluid communication between the plurality of fluid lines and a second clutch for engaging and disengaging the second clutch respectively. A third electronically controlled hydraulic valve is disposed in fluid communication with at least one of the plurality of fluid lines. The third electronically controlled hydraulic valve opens and closes fluid communication between the plurality of fluid lines and a third clutch for engaging and disengaging the third clutch respectively. A fourth electronically controlled hydraulic valve is disposed in fluid communication with at least one lubrication circuit and the pressure regulator valve. The fourth electronically controlled hydraulic valve regulates a flow of the fluid between the pressure regulator valve and the at least one lubrication circuit. The first valve disengages the first clutch and the second valve disengages the second clutch to operate the hybrid drive unit in a first mode. The first valve engages the first clutch and the second valve disengages the second clutch to operate the hybrid drive unit in a second mode. The first valve engages the first clutch and the second valve engages the second clutch to operate the hybrid drive unit in a third mode. The first valve disengages the first clutch and the second valve engages the second clutch to operate the hybrid drive unit in a fourth mode. The first valve, the second valve and the third valve each include a shift valve characterized by a lack of a regulated pressure feedback port. The first valve, the second valve and the third valve are each characterized by the lack of a pressure switch for indicating a clutch fill level.
The above features and advantages and other features and advantages of the present invention are readily apparent from the following detailed description of the best modes for carrying out the invention when taken in connection with the accompanying drawings.



BRIEF DESCRIPTION OF THE DRAWINGS
The FIGURE is a schematic diagram of a control system for a hybrid drive unit.



DETAILED DESCRIPTION
Referring to the FIGURE, a control system is shown generally at 20. The control system 20 controls the operation of a hybrid drive unit of a vehicle.
The hybrid drive unit, i.e., a transmission for a hybrid vehicle, includes a plurality of clutches configured for interconnecting, in various combinations, a first electric motor 22, a second electric motor 24 and an engine, with a plurality of gear sets. The engine may include any type of engine suitable for use in a hybrid vehicle. For example, the engine includes an internal combustion engine. However, it should be appreciated that the engine may include some other type of engine not described herein. The specific type, size, shape and/or configuration of the engine is not relevant to the description of the invention, and therefore is not described in detail herein. The first electric motor 22 and the second electric motor 24 may include any suitable type, size, shape and/or configuration of electric motor suitable for use in a hybrid vehicle. The specific type, size shape and/or configuration of the first electric motor 22 and the second electric motor 24 are not relevant to the description of the invention, and therefore are not described in detail herein.
As described herein, the hybrid drive unit includes a first clutch and a second clutch. The first clutch includes a stationary clutch 26, and the second clutch includes a rotating clutch 28. The hybrid drive unit operates in four modes: a first mode hereinafter referred to as an Electronic Torque Converter (ETC) mode, a second mode hereinafter referred to as a low mode, a third mode hereinafter referred to as a fixed gear mode, and a fourth mode hereinafter referred to as a high mode. When in the ETC mode, the first clutch and the second clutch are both disengaged. When in the low mode, the first clutch is engaged and the second clutch is disengaged. When in the fixed gear mode, both the first clutch and the second clutch are engaged. When in the high mode, the first clutch is disengaged and the second clutch is engaged. The low mode provides lower gear ratios for operating the hybrid drive unit at lower speeds, while the high mode provides higher gear ratios for operating the hybrid drive unit at higher speeds.
The hybrid drive unit further includes a third clutch, hereinafter referred to as a damper bypass clutch 30. The damper bypass clutch 30 directly interconnects the hybrid drive unit and the engine. The damper bypass clutch 30 is engaged to directly connect the hybrid drive unit and the engine when starting the engine. When engaged, the damper bypass clutch 30 provides a fixed connection between the engine and the hybrid drive unit. When disengaged, the damper bypass clutch 30 allows the hybrid drive unit to torsionally flex relative to the engine through a plurality of damper springs as is known.
A pump 32 pressurizes and circulates a fluid through the hybrid drive unit and the control system 20. The pump 32 may include any suitable type and/or size of pump 32 capable of providing sufficient flow and pressure. The specific type, size and/or configuration of the pump 32 are not relevant to the description of the invention, and is therefore not described in detail herein.
Referring to the FIGURE, the control system 20 includes a valve body assembly 33 that is coupled to the hybrid drive unit. The valve body assembly 33 includes, but is not limited to, a pressure regulator valve 34, a first valve hereinafter referred to as a stationary clutch valve 36, a second valve hereinafter referred to as a rotating clutch valve 38, a third valve hereinafter referred to as a damper bypass valve 40, a fourth valve hereinafter referred to as a lube regulator valve 42 and a compensator feed valve 44.
The stationary clutch valve 36, the rotating clutch valve 38 and the damper bypass valve 40 each include a shift valve. The shift valves 36, 38, 40 are actuated between an “on” position and an “off” position. The shift valves 36, 38, 40 are characterized by the lack of a regulated pressure feedback port that directs fluid pressure from a control signal output to an end of the valve, thereby differentiating the shift valves 36, 38, 40 from pressure regulator valves. The shift valves 36, 38, 40 are further characterized by the lack of a pressure switch for indicating a clutch fill level, thereby further differentiating the shift valves 36, 38, 40 from the pressure regulator valves. The shift valves are each actuated by an “on/off” solenoid to move between the on position and the off position.
The pump 32 pressurizes the fluid to a line pressure, and circulates the fluid at the line pressure to the damper bypass valve 40, the stationary clutch valve 36, the rotating clutch valve 38, the compensator feed valve 44, the pressure regulator valve 34, the lube regulator valve 42, an on/off solenoid 92, an on/off solenoid 114, an on/off solenoid 76, a mini direct acting solenoid 60, and a lube boost solenoid 142. Accordingly, the pump 32 is in direct fluid communication with the damper bypass valve 40, the stationary clutch valve 36, the rotating clutch valve 38, the compensator feed valve 44, the pressure regulator valve 34, the lube regulator valve 42, the on/off solenoid 92, the on/off solenoid 114, the on/off solenoid 76, the mini direct acting solenoid 60, the lube boost solenoid 142 through a system of high pressure fluid lines and/or passages in the valve body.
The valve body further includes a line blow-off 46. The line blow-off 46 is a pressure sensitive valve that opens in response to the line pressure reaching a pre-determined level. The line blow-off 46 prevents damage to the control system 20 and/or the hybrid drive unit by opening the line pressure to the atmosphere in response to the line pressure reaching a dangerously high level.
A primary feed pressure line 48 interconnects the pump 32 and the pressure regulator valve 34 to provide the fluid to the pressure regulator valve 34 at the line pressure. A suction return line 50 interconnects the pressure regulator valve 34 with a sump portion of the pump 32 for directing fluid back to the pump 32 to reduce the line pressure. The pressure regulator valve 34 includes a spool portion 52 that is moveable between a first position, a second position and a third position. The primary feed pressure line 48 includes a feed line 54 and a feedback line 56 for providing the fluid to the spool portion 52 at the line pressure. The feedback line 56 acts against an end of the spool portion 52 of the pressure regulator valve 34 to bias against the spool portion 52.
When in the first position, the pressure regulator valve 34 operates to maintain the existing line pressure. When in the first position, the spool portion 52 of the pressure regulator valve 34 prevents fluid flow from the feed line 54 from flowing back to the pump 32 via the suction return line 50, and also prevents fluid flow to the lube regulator valve 42 via a lube feed line 122, which interconnects the pressure regulator valve 34 and the lube regulator valve 42.
When in the second position, which is shown in the FIGURE, the spool portion 52 of the pressure regulator valve 34 opens fluid communication between the feed line 54 and lube feed line 122 to supply the lube regulator valve 42 with fluid at the line pressure, while still preventing fluid communication between the feed line 54 and the suction return line 50. The pressure regulator valve 34 moves into the second position in response to the fluid pressure reaching a minimum supply pressure, which is the level required to supply all priority operations of the control system 20. The priority operations of the control system 20 include supplying the damper bypass valve 40, the stationary clutch valve 36, the rotating clutch valve 38 and the compensator feed valve 44 with fluid at the line pressure. Once the priority operations of the control system 20 are satisfied, the pressure regulator valve 34 may move into the second position to supply the lube regulator valve 42, which is a secondary operation of the control system 20.
When in the third position, the spool portion 52 of the pressure regulator valve 34 maintains fluid communication between the feed line 54 and the lube feed line 122, while opening fluid communication between the feed line 54 and the suction return line 50. The pressure regulator valve 34 moves into the third position when the line pressure exceeds a maximum allowable pressure. When in the third position, the fluid is directed from the feed line 54 to the sump portion of the pump 32 to reduce the line pressure. Once the line pressure is reduced to an acceptable level, the pressure regulator valve 34 may move back into either the second position or the first position.
The pressure regulator valve 34 is controlled by the Mini Direct Acting (MDA) solenoid 60 in fluid communication with the primary feed pressure line 48. It should be appreciated that the solenoid 60 may include any suitable type of solenoid capable of controlling the spool portion 52 of the pressure regulator valve 34. The solenoid 60 of the pressure regulator valve 34 utilizes an electrical signal from a hybrid drive unit controller or a vehicle controller to open and close fluid communication from the primary feed pressure line 48 to an end of the spool portion 52 of the pressure regulator valve 34 to actuate the spool portion 52 of the pressure regulator valve 34. As such, the pressure regulator valve 34 is an electronically controlled hydraulic valve.
A pressure regulator signal line 62 interconnects the solenoid 60 of the pressure regulator valve 34 with an end of the spool portion 52 of the pressure regulator valve 34. The pressure regulator signal line 62 provides a fluid pressure, which acts against the spool portion 52 of the pressure regulator valve 34 to bias the spool portion 52 of the pressure regulator valve 34 against the fluid pressure provided by the feedback line 56 of the pressure regulator valve 34. The solenoid 60 of the pressure regulator valve 34 controls the fluid pressure of the pressure regulator signal line 62 to control movement of the spool portion 52 of the pressure regulator valve 34 between the first position, the second position and the third position. By reducing the fluid pressure of the pressure regulator signal line 62, the spool portion 52 of the pressure regulator valve 34 moves from the first position toward the second and/or the third position. By increasing the fluid pressure of the pressure regulator signal line 62 to the line pressure, the pressure regulator signal line 62, in combination with a regulator spring 64, move the spool portion 52 of the pressure regulator valve 34 into the first position.
The solenoid 60 of the pressure regulator valve 34 is normally open, or normally high, to maintain the fluid pressure of the pressure regulator signal line 62 at the line pressure to move the spool portion 52 of the pressure regulator valve 34 into the first position. The solenoid 60 of the pressure regulator valve 34 closes, or reduces the fluid pressure of the pressure regulator signal line 62 as the line pressure increases to above the minimum supply pressure and/or the maximum allowable pressure to move the spool portion 52 into the second position or the third position to regulate the line pressure.
The primary feed pressure line 48 interconnects the pump 32 and the damper bypass valve 40 to provide the fluid to the damper bypass valve 40 at the line pressure. A damper control line 68 interconnects the damper bypass valve 40 and the damper bypass clutch 30. The damper bypass valve 40 includes a spool portion 72 that is moveable between an open position and a closed position. When in the closed position, which is shown in the FIGURE, the spool portion 72 of the damper bypass valve 40 prevents fluid communication between the primary feed pressure line 48 and the damper control line 68 to prevent engagement of the damper bypass clutch 30, and exhausts fluid pressure from the damper control line 68 via an exhaust line 74 to disengage the damper bypass clutch 30. When in the open position, the spool portion 72 of the damper bypass valve 40 opens fluid communication between the primary feed pressure line 48 and the damper control line 68 to provide fluid to the damper bypass clutch 30 at the line pressure to engage the damper bypass clutch 30. Additionally, when in the open position, the spool portion 72 closes fluid communication between the damper bypass valve 40 and the exhaust line 74 to prevent disengagement of the damper bypass clutch 30.
The damper bypass valve 40 is controlled by the on/off solenoid 76. It should be appreciated that the on/off solenoid 76 may include any suitable type of solenoid capable of controlling the damper bypass valve 40. The solenoid 76 of the damper bypass valve 40 is in fluid communication with the primary feed pressure line 48 and utilizes an electrical signal from the hybrid drive unit controller or the vehicle controller to open and close fluid communication between the primary feed pressure line 48 and a damper bypass signal line 78. Accordingly, the damper bypass valve 40 is an electronically controlled hydraulic valve.
The damper bypass signal line 78 interconnects the solenoid 76 of the damper bypass valve 40 with a second end of the spool portion 72 of the damper bypass valve 40. The damper bypass signal line 78 provides a fluid pressure, which acts against the spool portion 72 of the damper bypass valve 40 to bias the spool portion 72 of the damper bypass valve 40 against a damper spring 80. The solenoid 76 of the damper bypass valve 40 controls the fluid pressure of the damper bypass signal line 78 to control movement of the spool portion 72 of the damper bypass valve 40 between the open position and the closed position. By increasing the fluid pressure of the damper bypass signal line 78 to the line pressure, the damper bypass signal line 78 overcomes the reactionary force provided by the damper spring 80, to move the spool portion 72 of the damper bypass valve 40 into the open position. By decreasing the fluid pressure of the damper bypass signal line 78, the damper spring 80 may overcome the pressure from the damper bypass signal line 78 and move the spool portion 72 into the closed position, thereby opening fluid communication with the exhaust line 74 and disengaging the damper bypass clutch 30. The solenoid 76 of the damper bypass valve 40 is normally closed, or normally low, to position the spool portion 72 of the damper bypass valve 40 in the closed position with the damper bypass clutch 30 disengaged. The solenoid 76 of the damper bypass valve 40 increases fluid pressure in the damper bypass signal line 78 when directed to engage the damper bypass clutch 30.
The primary feed pressure line 48 interconnects the pump 32 and the stationary clutch valve 36 to provide the fluid to the stationary clutch valve 36 at the line pressure. A stationary clutch control line 84 interconnects the stationary clutch valve 36 and the stationary clutch 26. The stationary clutch valve 36 includes a spool portion 88 that is moveable between an open position and a closed position. When in the closed position, which is shown in the FIGURE, the spool portion 88 of the stationary clutch valve 36 prevents fluid communication between the primary feed pressure line 48 and the stationary clutch control line 84 to prevent engagement of the stationary clutch 26, and exhausts fluid pressure from the stationary clutch control line 84 via the exhaust line 90 to disengage the stationary clutch 26. When in the open position, the spool portion 88 of the stationary clutch valve 36 opens fluid communication between the primary feed pressure line 48 and the stationary clutch control line 84 to provide fluid to the stationary clutch 26 at the line pressure to engage the stationary clutch 26. Additionally, when in the open position, the spool portion 88 of the stationary clutch valve 36 closes fluid communication between the stationary clutch control line 84 and the exhaust line 90 to prevent disengagement of the stationary clutch 26.
The stationary clutch valve 36 is controlled by the on/off solenoid 92. It should be appreciated that the on/off solenoid 92 may include any suitable type of solenoid capable of controlling the spool portion 88 of the stationary clutch valve 36. The solenoid 92 of the stationary clutch 26 is in fluid communication with the primary feed pressure line 48, and utilizes an electrical signal from the hybrid drive unit controller or the vehicle controller to open and close fluid communication between the primary feed pressure line 48 and a stationary clutch signal line 94. Accordingly, the stationary clutch valve 36 is an electronically controlled hydraulic valve.
The stationary clutch signal line 94 interconnects the solenoid 92 of the stationary clutch valve 36 with a second end of the spool portion 88 of the stationary clutch valve 36. The stationary clutch signal line 94 provides a fluid pressure, which acts against the spool portion 88 of the stationary clutch valve 36 to bias the spool portion 88 of the stationary clutch valve 36 against a stationary clutch spring 96. The solenoid 92 of the stationary clutch valve 36 controls the fluid pressure of the stationary clutch signal line 94 to control movement of the spool portion 88 of the stationary clutch valve 36 between the open position and the closed position. By increasing the fluid pressure of the stationary clutch signal line 94 to the line pressure, the stationary clutch signal line 94 overcomes the reactionary force provided by the stationary clutch spring 96, to move the spool portion 88 of the stationary clutch valve 36 into the open position. By decreasing the fluid pressure of the stationary clutch signal line 94 the stationary clutch spring 96 may overcome the pressure from the stationary clutch signal line 94 and move the spool portion 88 into the closed position, thereby opening fluid communication with the exhaust line 90 and disengaging the stationary clutch 26. The solenoid 92 of the stationary clutch valve 36 is normally closed, or normally low, to position the spool portion 88 of the stationary clutch valve 36 in the closed position with the stationary clutch 26 disengaged. The solenoid 92 of the stationary clutch valve 36 increases fluid pressure in the stationary clutch signal line 94 when directed to engage the stationary clutch 26.
An accumulator 98 is in fluid communication with the stationary clutch control line 84. The accumulator 98 dampens hydraulic shock within the system caused by movement of the fluid between the stationary clutch 26 and the stationary clutch valve 36.
The primary feed pressure line 48 interconnects the pump 32 with the rotating clutch valve 38 and the compensator feed valve 44. The primary feed pressure line 48 provides the fluid to the rotating clutch valve 38 and the compensator feed valve 44 at the line pressure. The compensator feed valve 44 provides a fluid back pressure to the rotating clutch 28 through the rotating clutch valve 38. A compensator supply line 102 interconnects the compensator feed valve 44 with the rotating clutch valve 38, and a compensator feed line 104 interconnects the rotating clutch valve 38 with a backside of the rotating clutch 28. The compensator feed valve 44 may include any type of valve suitable for regulating the fluid backpressure for the rotating clutch 28.
A rotating clutch control line 106 interconnects the rotating clutch valve 38 and the rotating clutch 28. The rotating clutch valve 38 includes a spool portion 110 that is moveable between an open position and a closed position. When in the closed position, which is shown in the FIGURE, the spool portion 110 of the rotating clutch valve 38 prevents fluid communication between the primary feed pressure line 48 and the rotating clutch control line 106 to prevent engagement of the rotating clutch 28, and exhausts fluid pressure from the rotating clutch control line 106 via an exhaust line 112 to disengage the rotating clutch 28. Additionally, when in the closed position, the rotating clutch valve 38 opens fluid communication between the compensator supply line 102 and the compensator feed line 104 to permit fluid flow to the back side of the rotating clutch 28. When in the open position, the spool portion 110 of the rotating clutch valve 38 opens fluid communication between the primary feed pressure line 48 and the rotating clutch control line 106 to provide fluid to the rotating clutch 28 at the line pressure to engage the rotating clutch 28. Furthermore, when in the open position, the spool portion 110 of the rotating clutch valve 38 closes fluid communication between the rotating clutch control line 106 and the exhaust line 112 to prevent disengagement of the rotating clutch 28. Additionally, when in the open position, the rotating clutch valve 38 closes fluid communication between the compensator supply line 102 and the compensator feed line 104 to limit and/or prevent fluid communication with the back side of the rotating clutch 28, which would otherwise act against the line pressure being applied to the rotating clutch 28 when the rotating clutch valve 38 is in the open position.
The rotating clutch valve 38 is controlled by the on/off solenoid 114. It should be appreciated that the on/off solenoid 114 may include any suitable type of solenoid capable of controlling the spool portion 110 of the rotating clutch valve 38. The solenoid 114 of the rotating clutch 28 is in fluid communication with the primary feed pressure line 48, and utilizes an electrical signal from the hybrid drive unit controller or the vehicle controller to open and close fluid communication between the primary feed pressure line 48 and a rotating clutch signal line 116. Accordingly, the rotating clutch valve 38 is an electronically controlled hydraulic valve.
The rotating clutch signal line 116 interconnects the solenoid 114 of the rotating clutch valve 38 with a second end of the spool portion 110 of the rotating clutch valve 38. The rotating clutch signal line 116 provides a fluid pressure, which acts against the spool portion 110 of the rotating clutch valve 38 to bias the spool portion 110 of the rotating clutch valve 38 against a rotating clutch spring 118. The solenoid 114 of the rotating clutch valve 38 controls the fluid pressure of the rotating clutch signal line 116 to control movement of the spool portion 110 of the rotating clutch valve 38 between the open position and the closed position. By increasing the fluid pressure of the rotating clutch signal line 116 to the line pressure, the rotating clutch signal line 116 overcomes the reactionary force provided by the rotating clutch spring 118, to move the spool portion 110 of the rotating clutch valve 38 into the open position. By decreasing the fluid pressure of the rotating clutch signal line 116, the rotating clutch spring 118 may overcome the pressure from the rotating clutch signal line 116 and move the spool portion 110 into the closed position, thereby opening fluid communication with the exhaust line 112 and disengaging the rotating clutch 28. The solenoid 114 of the rotating clutch valve 38 is normally closed, or normally low, to position the spool portion 110 of the rotating clutch valve 38 in the closed position with the rotating clutch 28 disengaged. The solenoid 114 of the rotating clutch valve 38 increases fluid pressure in the rotating clutch signal line 116 when directed to engage the rotating clutch 28.
The lube regulator valve 42 includes a spool portion 120 that is moveable between a first position, a second position and a third position. The lube feed line 122 interconnects the feed line 54 of the primary feed pressure line 48 and the lube regulator valve 42 for supplying fluid to the lube regulator valve 42. A rotor supply line 124 interconnects the lube regulator valve 42 with a rotor lubrication circuit 126. The rotor lubrication circuit 126 circulates the fluid through a heat exchanger 128 to cool the fluid, through a gearbox 130 of the hybrid drive unit, and then through the rotor of each of the first electric motor 22 and the second electric motor 24 to cool and lubricate the rotors. A regulated lube feedback line 132 interconnects the rotor supply line 124 with an end of the spool portion 120 of the lube regulator valve 42. The regulated lube feedback line 132 provides fluid to the lube regulator valve 42 to bias against the spool portion 120 of the lube regulator valve 42. A stator supply line 136 interconnects the lube regulator valve 42 with a stator lubrication circuit 138. The stator lubrication circuit 138 circulates fluid through the stator of each of the first electric motor 22 and the second electric motor 24 to cool the stators.
When the lube regulator valve 42 is in the first position, which is shown in the FIGURE, the spool portion 120 of the lube regulator valve 42 opens fluid communication between the lube feed line 122 and the rotor supply line 124, and closes fluid communication between the lube feed line 122 and the stator supply line 136, thereby allowing the fluid at the line pressure to flow through the rotor lubrication circuit 126. When the lube regulator valve 42 is in the second position, the spool portion 120 of the lube regulator valve 42 maintains fluid communication between the lube feed line 122 and the rotor supply line 124, and opens fluid communication between the lube feed line 122 and the stator supply line 136, thereby allowing the fluid to flow through the rotor lubrication circuit 126 and the stator lubrication circuit 138. When the lube regulator valve 42 is in the third position, the spool portion 120 of the lube regulator valve 42 minimizes fluid communication between the lube feed line 122 and the rotor supply line 124 and opens fluid communication between the lube feed line 122 and the stator supply line 136.
The lube regulator valve 42 is controlled by the lube boost solenoid 142. The lube boost solenoid 142 may include any solenoid capable of controlling the actuation of the spool portion 120 of the lube regulator valve 42. The primary feed pressure line 48 interconnects the pump 32 with the solenoid 142 of the lube regulator valve 42. The solenoid 142 of the lube regulator valve 42 utilizes an electrical signal from the hybrid drive unit controller or the vehicle controller to open and close fluid communication between the primary feed pressure line 48 and a lube boost signal line 146. Accordingly, the lube regulator valve 42 is an electronically controlled hydraulic valve.
The lube boost signal line 146 interconnects the solenoid 142 of the lube regulator valve 42 with a second end of the spool portion 120 of the lube regulator valve 42. The lube boost signal line 146 provides a fluid pressure, which acts against the spool portion 120 of the lube regulator valve 42 to bias the spool portion 120 of the lube regulator valve 42 along with a lube regulator spring 148. The solenoid 142 of the lube regulator valve 42 controls the fluid pressure of the lube boost signal line 146 to control movement of the spool portion 120 of the lube regulator valve 42 between the first position, the second position and the third position. The solenoid 142 of the lube regulator valve 42 is normally closed, or normally low, to prevent fluid communication between the primary feed pressure line 48 and the lube boost signal line 146 and allow the lube regulator spring 148 to bias the spool portion 120 of the lube regulator valve 42 against the fluid pressure supplied by the regulator lube feedback line 132. The solenoid 142 of the lube regulator valve 42 opens and/or increases fluid communication between the primary feed pressure line 48 and the lube boost signal line 146 when signaled to move the spool portion 120 of the lube regulator valve 42 from the third position or the second position into one of the second position or the third position.
A lube bypass line 154 interconnects the primary feed pressure line 48 and the lube feed line 122. The lube bypass line 154 includes a packaging protected orifice 156. Accordingly, if the pressure regulator valve 34 fails to open fluid communication to the lube feed line 122 to prevent excessive line pressures, the packaging protected orifice 156 is capable of allowing fluid flow through the lube bypass line 154 to provide limited lubrication and cooling to the electric motors 22, 24 and the transmission components.
The detailed description and the drawings or figures are supportive and descriptive of the invention, but the scope of the invention is defined solely by the claims. While some of the best modes and other embodiments for carrying out the claimed invention have been described in detail, various alternative designs and embodiments exist for practicing the invention defined in the appended claims.

## Claims

1. A control system for controlling a hybrid drive unit of a vehicle, the control system comprising:
a pressure regulator valve in fluid communication with a plurality of fluid lines and configured for regulating a line pressure of a fluid within the plurality of fluid lines;
a first valve in fluid communication with at least one of the plurality of fluid lines and configured for opening and closing fluid communication between the plurality of fluid lines and a first clutch; and
a second valve in fluid communication with at least one of the plurality of fluid lines and configured for opening and closing fluid communication between the plurality of fluid lines and a second clutch;
wherein the first valve closes fluid communication between the plurality of fluid lines and the first clutch to disengage the first clutch and the second valve closes fluid communication between the plurality of fluid lines and the second clutch to disengage the second clutch to operate the hybrid drive unit in a first mode, the first valve opens fluid communication between the plurality of fluid lines and the first clutch to engage the first clutch and the second valve closes fluid communication between the plurality of fluid lines and the second clutch to disengage the second clutch to operate the hybrid drive unit in a second mode, the first valve opens fluid communication between the plurality of fluid lines and the first clutch to engage the first clutch and the second valve opens fluid communication between the plurality of fluid lines and the second clutch to engage the second clutch to operate the hybrid drive unit in a third mode, and the first valve closes fluid communication between the plurality of fluid lines and the first clutch to disengage the first clutch and the second valve opens fluid communication between the plurality of fluid lines and the second clutch to engage the second clutch to operate the hybrid drive unit in a fourth mode; and
wherein the first valve and the second valve each include a shift valve characterized by a lack of a regulated pressure feedback port.

2. A control system as set forth in claim 1 wherein the first valve and the second valve are each characterized by the lack of a pressure switch for indicating a clutch fill level.

3. A control system as set forth in claim 1 further comprising a third valve in fluid communication with the plurality of fluid lines and configured for opening and closing fluid communication between the plurality of fluid lines and a third clutch for engaging and disengaging the third clutch respectively.

4. A control system as set forth in claim 3 wherein the third clutch includes a shift valve characterized by a lack of a regulated pressure feedback port.

5. A control system as set forth in claim 4 wherein the third valve is characterized by the lack of a pressure switch for indicating a clutch fill level.

6. A control system as set forth in claim 3 further comprising a fourth valve in fluid communication with at least one lubrication circuit and the pressure regulator valve and configured for regulating a flow of the fluid between the pressure regulator valve and the at least one lubrication circuit.

7. A control system as set forth in claim 6 wherein the pressure regulator valve opens fluid communication with the fourth valve in response to the line pressure of the fluid reaching a pre-determined level.

8. A control system as set forth in claim 7 wherein the at least one lubrication circuit includes a first lubrication circuit and a second lubrication circuit.

9. A control system as set forth in claim 8 wherein the fourth valve continuously maintains open fluid communication between the pressure regulator valve and the first lubrication circuit, and the fourth valve opens fluid communication with the second lubrication circuit in response to the line pressure of the fluid reaching a pre-determined level.

10. A control system as set forth in claim 6 wherein the first valve, the second valve, the third valve and the fourth valve each include an electronically controlled solenoid for actuating the first valve, the second valve, the third valve and the fourth valve respectively.

11. A control system as set forth in claim 1 further comprising an accumulator in fluid communication with the first valve and configured for damping fluid movement between the first valve and the first clutch.

12. A control system as set forth in claim 1 wherein the second clutch includes a rotating clutch and wherein the control system further includes a compensator feed valve in fluid communication with the plurality of fluid lines and the second valve and configured for supplying the fluid to the second valve, with the second valve configured for directing the fluid to the rotating second clutch to provide a back pressure in the rotating second clutch when the second valve disengages the rotating second clutch.

13. A valve body assembly for controlling a hybrid drive unit of a vehicle, the valve body assembly comprising:
a pressure regulator valve in fluid communication with a plurality of fluid lines and configured for regulating a line pressure of a fluid within the plurality of fluid lines;
a first electronically controlled hydraulic valve in fluid communication with at least one of the plurality of fluid lines and configured for opening and closing fluid communication between the plurality of fluid lines and a first clutch, wherein the first electronically controlled hydraulic valve opens fluid communication between the plurality of fluid lines and the first clutch to engage the first clutch, and wherein the first electronically controlled hydraulic valve closes fluid communication between the plurality of fluid lines and the first clutch to disengage the first clutch;
a second electronically controlled hydraulic valve in fluid communication with at least one of the plurality of fluid lines and configured for opening and closing fluid communication between the plurality of fluid lines and a second clutch, wherein the second electronically controlled hydraulic valve opens fluid communication between the plurality of fluid lines and the second clutch to engage the second clutch, and wherein the second electronically controlled hydraulic valve closes fluid communication between the plurality of fluid lines and the second clutch to disengage the second clutch;
a third electronically controlled hydraulic valve in fluid communication with at least one of the plurality of fluid lines and configured for opening and closing fluid communication between the plurality of fluid lines and a third clutch, wherein the third electronically controlled hydraulic valve opens fluid communication between the plurality of fluid lines and the third clutch to engage the third clutch, and wherein the third electronically controlled hydraulic valve closes fluid communication between the plurality of fluid lines and the third clutch to disengage the third clutch; and
a fourth electronically controlled hydraulic valve in fluid communication with at least one lubrication circuit and the pressure regulator valve, and configured for regulating a flow of the fluid between the pressure regulator valve and the at least one lubrication circuit;
wherein the first valve disengages the first clutch and the second valve disengages the second clutch to operate the hybrid drive unit in a first mode, the first valve engages the first clutch and the second valve disengages the second clutch to operate the hybrid drive unit in a second mode, the first valve engages the first clutch and the second valve engages the second clutch to operate the hybrid drive unit in a third mode, and the first valve disengages the first clutch and the second valve engages the second clutch to operate the hybrid drive unit in a fourth mode;
wherein the first valve, the second valve and the third valve each include a shift valve characterized by a lack of a regulated pressure feedback port; and
wherein the first valve, the second valve and the third valve are each characterized by the lack of a pressure switch for indicating a clutch fill level.

14. A valve body assembly as set forth in claim 13 wherein the pressure regulator valve opens fluid communication with the fourth valve in response to the line pressure of the fluid reaching a pre-determined level.

15. A valve body assembly set forth in claim 13 wherein the at least one lubrication circuit includes a first lubrication circuit and a second lubrication circuit.

16. A valve body assembly set forth in claim 15 wherein the fourth valve continuously maintains open fluid communication between the pressure regulator valve and the first lubrication circuit, and the fourth valve opens fluid communication with the second lubrication circuit in response to the line pressure of the fluid reaching a pre-determined level.

17. A valve body assembly set forth in claim 13 wherein the first valve, the second valve and the third valve each include an on/off solenoid.

18. A valve body assembly set forth in claim 13 further comprising an accumulator in fluid communication with the first valve and configured for damping fluid movement between the first valve and the first clutch.

19. A valve body assembly as set forth in claim 13 further comprising a compensator feed valve in fluid communication with the plurality of fluid lines and the second valve and configured for supplying the fluid to the second valve, with the second valve configured for directing the fluid to the second clutch to provide a back pressure in the second clutch when the second valve disengages the second clutch.