Multi-speed dual-clutch transmission for a hybrid vehicle

Abstract

A dynamically shiftable multi-speed dual-clutch transmission (18) for functional connection to an engine (12) and to an electric motor (82; 82A) in a hybrid vehicle, the transmission (18) comprising: an input element (26, 93, 108); an output element (124); a first clutch (20) selectively engageable to couple the engine (12) to the input member (26, 93, 108) and configured to transfer torque of the engine (12) during startup and to withstand energy of the vehicle during startup from rest; a second clutch (46) engageable to select a first set of forward speed ratios between the input member (26, 93) and the output member (124), and configured to withstand the combined torque of the electric motor (82; 82A) and torque of the engine (12) during shifts to the first set of speed ratios, but not the torque of the engine (12) at launch or the power of the vehicle at launch; and a third clutch (99) engageable to select a second set of forward speed ratios, alternating with the speed ratios of the first set, between the input member (93, 108) and the output member (124), and configured to withstand the combined torque of the electric motor (82; 82A) and torque of the engine (12) during shifts to the second set of speed ratios, but not the torque of the engine (12) at launch or the power of the vehicle at takeoff, a transmission housing (19) arranged to enclose the input and output members (26, 93, 108, 124) and the first, second and third clutches (20, 46, 99), wherein the electric motor (82; 82A) is arranged within the transmission housing (19) and has a rotor (92; 92A) and a stator (88; 88A), a rotor support (93; 93A) for supporting the rotor (92; 92A) providing a first mounting plate providing a reaction surface for the third clutch (99), a fixed support (80; 80A) for supporting the stator (88; 88A), and a second mounting plate (36) engaging the rotor carrier (93; 93A) and providing reaction surfaces for the first clutch (20) and for the second clutch (46), characterized by an oil supply, a coolant supply and a coolant outlet fitting (78, 86, 87) arranged on the fixed support (80), wherein oil is used to operate the second and third clutches (46, 99) and coolant is used to cool the electric motor (80; 80A).

Description

The invention relates to a multi-speed dual clutch transmission for a hybrid vehicle.In modern vehicles, multi-speed dual clutch transmissions (DCTs) are generally used because of their increased mechanical efficiency as compared to typical torque converter equipped automatic transmissions. In addition, multi-speed dual clutch transmissions are often preferred over typical automated manual transmissions because of the ability of the DCTs to provide higher value gear shifts.A typical DCT employs two friction clutches to shift between its forward ratios, and achieves such shifts by alternative engagement between one and the other of the two friction clutches. Such a multi-speed dual clutch transmission may be used in a hybrid vehicle, i.e., a vehicle that uses two or more different power sources such as an engine and an electric motor to transfer propulsion energy to the driven wheels of the subject vehicle. However, packaging the DCT components along with the multiple power sources in a hybrid vehicle may present a challenge.DE 10 2006 036 758 A1 discloses multi-gear dual clutch transmissions in which no starting clutch is mounted upstream of the dual clutch arrangement. Cooling of an electric motor is not the subject matter.The post-published DE 10 2007 060 165 A1 and DE 10 2007 003 107 A1 each disclose a multi-gear dual clutch transmission for a hybrid vehicle according to the preamble of claim 1.It is the object of the invention to provide a better cooling for the previously known transmissions.This object is achieved by a multi-speed dual clutch transmission having the features of claim 1.An advantageous embodiment is given in the dependent claim.The invention is described below by way of example: FIG. 1 is a schematic illustration of a hybrid powertrain in a fragmentary and partial cross-sectional view employing a dynamically shiftable dual clutch transmission in accordance with a first embodiment; and FIG. 2 is a schematic illustration of a hybrid powertrain in a fragmentary and partial cross-sectional view employing a dynamically shiftable dual clutch transmission in accordance with a second embodiment. FIG. 3 is a schematic cross-sectional front view of the dual clutch dynamically shiftable transmission shown in FIGS. 1 and 2 showing the orientation of the oil supply, coolant supply and coolant outlet fittings.A dynamically shiftable multi-speed dual clutch transmission (DCT) may be applied as part of a powertrain for a hybrid vehicle to further improve the efficient use of non-renewable energy sources such as fossil fuels. Such DCT may be provided for a "strong hybrid type" P2 powertrain, where the vehicle is alternatively propelled by an engine, by an electric motor, or by a combination of the two.As used herein, the term "dynamically shiftable" refers to the use of a combination of two friction clutches and multiple dog clutches / synchronizers to achieve "power-on" shifts or dynamic shifts by alternating between engagement of one friction clutch and the other. Generally, the on-coming ratio synchronizers are physically "preselected" before the dynamic shift is actually performed. As those skilled in the art will readily understand, synchronizers are "preselected" prior to actually shifting the torque path from one clutch to the other to the necessary positions of both the on-coming and off-going ratios before "dynamic shifting" is made. The preselection condition is shifted as far as possible to minimize spin losses, since the preselection of the next ratio forces a speed difference in the open, i.e. non-engaged clutch. This particular gear arrangement enables the combination of torque-transmitting mechanisms for any ratio and its adjacent ratio (i.e., ratio N and ratio N+1) without obtaining a mechanical stall in the transmission.Referring to FIG. 1, a "hybrid strong P2 powertrain" 10 is shown. For simplicity, the powertrain 10 is shown only about an axis of rotation A, but as understood by those skilled in the art, the powertrain components shown below extend under axis A. The hybrid powertrain 10 includes an engine 12 such as, for example, an internal combustion (FC) engine or a fuel cell. As understood by those skilled in the art, the engine 12 utilizes a crankshaft 14 to convert the reciprocating motion into rotational motion. At an engine-transmission interface 16, the engine 12 is connected to a DCT 18 by any suitable means including fasteners (not shown), such as threaded bolts and pins. As described below, the DCT 18 includes a transmission housing 19 to receive elements of the hybrid powertrain 10.A first clutch 20 includes a clutch plate 21 connected to the crankshaft 14 by a plurality of bolts 22 at a clutch plate hub 24. The clutch plate 21 is therein driven by the crankshaft 14 at the rotational speed of the engine 12. The clutch disc hub 24 is rotationally coupled to a central shaft 26 via a bearing 28 to position the central shaft concentrically with respect to the crankshaft 14. The clutch plate 21 includes a follower plate 30 fixed to the hub 24 and a friction pad 32 fixed to the follower plate 30. The hub 24 and friction lining 32 are fixed to the drive plate 30 by any suitable method, such as riveting or bonding, as understood by those skilled in the art. The pulley 30 holds torsion dampers 31 for absorbing engine vibration and torque peaks during vehicle launch.The first clutch 20 also includes a pressure plate 34 positioned generally parallel with respect to a reaction surface 37 of a mounting plate 36. The pressure plate 34 is operatively connected to the mounting plate 36 for synchronous rotation therewith. The clutch plate 21 is clamped between the pressure plate 34 and the reaction surface 37. Thus, in operation, due to frictional contact with clutch plate 21, mounting plate 36 functions as a heat sink for clutch plate 21. mounting plate 36 is positioned in close proximity parallel to a fixed cover plate 38 to allow air pumped from the plate to transfer heat to a coolant body 39 when the mounting plate is in motion relative to the cover plate. The air pumped from the disc reduces the heat transfer resistance by reducing the boundary layer and thereby increases the heat transfer from the mounting plate 36 through the cover plate 38 to the coolant body 39.The clamping of the clutch disc 21 is effected at the friction lining 32 by a clutch spring 40 which acts on the pressure plate 34. Because of the advantageous spring tension versus spring extension characteristics, the clutch spring 40 typically uses a coned "Belleville" spring, as understood by those skilled in the art. The clutch spring 40 is externally operated via a lever 41 acting via a fulcrum 42 and a thrust bearing 44. Thus, when the lever 41 is operated and the clutch plate 21 is clamped, the mounting plate 36 is driven synchronously with the crankshaft 14, thereby transmitting the torque of the engine 12 to the mounting plate 36. On the other hand, when the lever 41 is released, the clamping force between the pressure plate 34 and the friction lining 32 is removed, releasing the mounting plate 36 from the crankshaft 14, thereby interrupting the torque flow of the engine 12.A second clutch 46 includes a clutch plate 48 splined to a hub 50 on the central shaft 26 for axial movement along the axis of rotation A. The clutch plate 48 is thereby arranged for synchronous rotation with the central shaft 26. Clutch plate 48 includes a cam plate 52 fixed to hub 50 and a friction facing 54 fixed to cam plate 52 by any of the methods described above with respect to friction facing 32 of plate 21. A snap ring 56 is installed in the mounting plate 36 to prevent a reaction plate 58 from moving into contact with the clutch plate 21.The second clutch 46 also includes a pressure plate 60 positioned generally parallel with respect to the reaction plate 58 and the adjacent surface 61 of the mounting plate 36. The reaction plate 58 and the pressure plate 60 are operatively connected to the mounting plate 36 for synchronous rotation therewith. An actuator 62 passes through an opening 64 in the mounting plate 36 to urge the pressure plate 60 into contact with the clutch plate 48 to thereby clamp the clutch plate 48 between the reaction plate 58 and the pressure plate 60. As a result of frictional contact with the clutch plate 48, the reaction plate 58, the pressure plate 60, and the mounting plate 36 function as a heat sink for the clutch plate 48. when the second clutch 46 is engaged by clamping the plate 48 together with an engaged first clutch 20, the central shaft 26 transfers torque from the engine 12 to propel the vehicle.During engagement of the second clutch 46, the actuator 62 is urged toward the pressure plate 60 by the action of pressurized oil within a cavity 66 that displaces a piston 68 via a plain bearing 70. The piston 68 includes seal rings 72 and 74 for sealing the pressurized oil from access to the clutch plate 48 Oil is supplied into the cavity 66 via a localized oil passage 76 in fluid communication with an oil supply fitting 78. Oil is supplied into the oil supply fitting 78 by an oil pressure source such as an oil pump (not shown).The oil passage 76 and the oil supply fitting 78 are inserted into a fixed support 80 of an electric motor 82. Also inserted into the fixed bracket 80 are a coolant passage 84, a coolant supply, i.e., coolant inlet fitting 86 as shown in FIGS. 1, 2, and 3, and a coolant outlet fitting 87 as shown in FIG. 3. FIG. 3 shows the coolant outlet fitting 87 angularly spaced from the coolant supply fitting 86 to maximize radial coverage of the coolant jacket portions 81 and 83 for more effective cooling of the high heat concentration regions within the DCT 18. The coolant jacket portions 81 and 83 are in fluid communication with the coolant body 39.As shown in FIG. 3, the oil supply fitting 78 is positioned radially between the coolant outlet fitting 87 and the coolant supply fitting 86 to achieve more efficient packing of the oil and coolant passages. In Fig. 3, arrows show the direction of oil and coolant flow. The oil supplied to the oil passage 76 is a highly refined mineral-based fluid that is typically optimized for friction and gear lubrication requirements of transmissions. The coolant under consideration provided to the coolant passage 84 is a typical solution of a suitable organic chemical (most commonly ethylene glycol, diethylene glycol or propylene glycol) in water.The oil supply fitting 78 and the coolant supply fittings 86 and 87 may be threaded to facilitate assembly with the fixed carrier 80 and may protrude through the housing 19 for connection to external oil and coolant supply sources (not shown). The oil supply fitting 78 and the coolant supply fittings 86 and 87 are installed after the electric motor 82 is mounted inside the housing 19. Thus installed, the oil supply fitting 78 and the coolant supply fittings 86 and 87 are engaged with the housing 19 via dedicated openings (not shown) in the housing that function as physical positioning elements and securing for the fixed carrier 80 within the DCT 18 with respect to the transmission housing 19.The cover plate 38 is fixed to the fixed support 80 to hold the coolant body 39 adjacent to the fixed support. Thus secured, the cover plate 38 is positioned in close proximity parallel to the mounting plate 36 and thus provides the disc which pumps air and increased heat transfer to the coolant body 39 as described above. The fixed support 80 is configured to support a stator subassembly of an iron (steel) core 88 and a wire coil, i.e., winding 90, of the electric motor 82. A rotor 92 is positioned within the iron core 88. As will be understood by those skilled in the art, the rotor 92 is rotated by a magnetic field generated when electric current is passed through the winding 90. The rotor 92 is fixed to a rotor support 93. The rotor carrier 93 accommodates a resolver 94, i.e., an electronic device configured to sense the rotational position of the rotor 92. The rotor carrier 93 includes a hollow shaft portion 96, and the hollow shaft portion 96 is supported on the fixed carrier 80 via bearings 97. The central shaft 26 extends axially within the hollow shaft portion 96, and the mounting plate 36 is splined for axial movement on the shaft portion along the rotational axis A on the shaft portion 96 of the rotor carrier 93. The rotor carrier 93 also includes a reaction surface 95 for a third clutch 99.The third clutch 99 includes a clutch plate 100. Clutch plate 100 includes a cam plate 102 fixed to hub 104 and a friction facing 106 fixed to cam plate 102 by any of the methods described above with respect to friction facing 32 of plate 21. The clutch plate 100 is splined for axial movement along the axis of rotation A at the hub 104 on the outer shaft 108. Thereby, the clutch plate 100 is arranged for synchronous rotation with the outer shaft 108. When the third clutch 99 is engaged by clamping the disc 100, the outer shaft 108 transfers torque from the engine 12 and / or from the electric motor 82 to the gear set 109 of the transmission. As shown, the third clutch 99, as well as the first clutch 20 and the second clutch 46, are dry type friction clutches. However, these clutches may also be configured as a wet friction type, with the friction material immersed in a specially prepared mineral oil, as is commonly done in automatic transmission applications and as understood by those skilled in the art.Electric motors tend to generate large heat during operation. As shown, the electric motor 82 is a permanent magnet type that typically has a relatively high torque density, i.e., a relatively high output potential, but tends to demagnetize, i.e., lose its function, at temperatures that exceed approximately 150 degrees Celsius. As shown, the powertrain 10 is configured to receive an induction type of electric motor 82, which would typically not be rendered inoperative by the same thermal levels at which the permanent magnet type is rendered inoperative. In addition, in selecting the selection between the two types of electric motors, the fact that induction-type electric motors are typically less expensive but have a lower torque density than permanent magnet-type electric motors is to be weighed.In order to treat the elevated temperatures inherent in the operation of the electric motor 82 and prevent possible demagnetization if a permanent magnet type electric motor is employed, the above-mentioned coolant passage 84 is provided. The coolant passage 84 is configured as a network of localized fluid channels that connect coolant jacket regions positioned to dissipate concentrations of thermal energy proximate sensitive components of the electric motor 82 and remove heat from the clutches 20, 46, and 99. The cross section of hybrid powertrain 10 as shown in FIG. 1 is selected at the localized channels of fluid coolant passage 84 to more clearly show the fluid communication between coolant jacket portion 81 and coolant jacket portion 83. Thus, the coolant passage 84 supplies coolant to the coolant jacket portion 81 within the fixed support 80 to remove heat generated in the coil 90 during operation of the electric motor 82 and conducted into the iron core 88. Additionally, the coolant passage 84 provides coolant to the coolant jacket region 83 within the fixed carrier 80 to remove heat absorbed by the rotor carrier 93 during application of the third clutch 99. The coolant jacket region 83 is sealed from the electric motor 82 by a cover plate 98. The cover plate 98 is secured to the stationary support 80 and removes coupling heat in a similar manner to that described with respect to the cover plate 38.The third clutch 99 additionally includes a pressure plate 110 positioned generally parallel with respect to a reaction surface 95 of the rotor carrier 93. The pressure plate 110 is operatively connected to the rotor carrier 93 for synchronous rotation therewith. The clutch plate 100 is clamped between the pressure plate 108 and the reaction surface 95 by the clamping action of a clutch spring 112, which may be a "Belleville spring" as described above with respect to the clutch spring 40. Consequently, the rotor carrier 93 additionally functions as a heat sink for the clutch disk 100 due to the frictional contact with the clutch disk 100. With the friction lining 106 thus clamped, the outer shaft 108 is thereby driven synchronously with the rotor carrier 93 at the rotational speed of the electric motor 82. The clutch spring 112 is actuated by the action of pressurized oil within a cavity 114. The pressurized oil is provided to the cavity 114 through a dedicated oil passage (not shown) in the gear set 109 to displace a piston 116 via an apply bearing 118. The piston 116 includes seal rings 120 and 122 for sealing the pressurized oil from access to the clutch plate 100. Oil is supplied to cavity 114 via an oil pressure source, such as an oil pump (not shown).The transmission 18 is operated to select speed ratios between an input member, which may be the central shaft 26 or the rotor carrier 93 or the outer shaft 108 or a combination of the above, depending on the required speed ratio, and an output member, i.e. an output shaft 124 of the transmission. As applied in automotive manual transmissions and as known to those skilled in the art, a transmission gear set 109 (not shown) includes gears each having a specific number of teeth. Thus, by selectively meshing, i.e., connecting together, specific adjacent gears having an unequal number of teeth, an appropriate speed ratio (and torque ratio) can be selected. As additionally used in automotive manual transmissions, transmission 18 includes dog clutch synchronizers (not shown) for synchronizing the speeds of adjacent gears upon engagement.As shown, the first clutch 20 is a launch clutch, i.e., a clutch that can be engaged to transfer direct torque of the engine 12 and sustain the energy of the vehicle during such launch, and that is disengaged to end this torque transfer. The second clutch 46 is shown as a clutch engageable to select odd forward speed ratios or a first set of forward speed ratios between one or more input members including the central shaft 26, the rotor carrier 93, and the outer shaft 108, and the output member, shaft 124, of the transmission. The third clutch 99 is shown as a clutch engageable to select even forward speed ratios or a second set of forward speed ratios between the one or more input members including the central shaft 26, the rotor carrier 93, and the outer shaft 108, and the shaft 124. It is noted that as configured, all three clutches, the first clutch 20, the second clutch 46, and the third clutch 99, are normally disengaged. Thus, these clutches are unable to transmit significant torque unless an appropriate amount of force is applied across the apply bearings 44, 70, and 118 for their respective engagements.Clutches 46 and 99 operate solely as disconnect and shift clutches, i.e., engaged / disengaged, to affect speed ratio changes between odd and even ratios. Moreover, clutches 46 and 99 are configured to withstand the input energy during such shifts, but not to withstand direct torque of engine 12 or the energy of the vehicle when starting from rest. The second clutch 46 and the third clutch 99 are specifically configured to slip under an input torque that exceeds the calculated torque to be transmitted at their respective speed ratios. The ability of clutches 46 and 99 to slip under excessive powertrain torque provides a "backup" function that prevents gearset 109 from overloading and prevents such disturbances from reaching the vehicle passenger compartment.FIG. 2 shows a powertrain 10A according to an alternative embodiment. All elements in FIG. 2 are the same as the like numbered elements in FIG. 1 except for an electric motor 82A instead of the electric motor 82, the powertrain 10A is generally configured the same as the powertrain 10 shown in FIG. 1. The electric motor 82A is configured with an iron core 88A positioned inside the rotor 92A. The fixed support 80A is configured to support a stator sub-assembly of an iron core 88A and a winding 90A. The rotor 92A is fixed to a rotor support 93A. The rotor carrier 93A includes a hollow shaft portion 96, and the hollow shaft portion 96 is supported on the fixed carrier 80A via bearings 97. Such a configuration allows the coolant jacket 81A to be positioned within the electric motor 82A, thereby releasing space for a larger diameter, higher torque output electric motor or allowing the same torque output to be maintained in a larger diameter, but shorter, electric motor.For purposes of illustration, powertrain operation will be described with reference to elements of the powertrain 10 shown in FIG. 1, but operation of the powertrain 10A shown in FIG. 2 is the same. In operation, the transmission 18 may transmit torque from one or more of the input members including the central shaft 26, the rotor carrier 93, and the output shaft 108 to generate multiple forward speed ratios (and at least one reverse speed ratio) for the output shaft 124. Moreover, the transmission of torque from the input members to the output shaft 124 at forward speeds is performed by dynamically shifting between the clutches 46 and 99. When the third clutch 99 is engaged and the clutch plate 46 is disengaged, the outer shaft 108 transfers torque of the hybrid powertrain 10 to the gear set 109 thereby allowing appropriate shifting to achieve selection of any even forward speed ratio. When the second clutch 46 is engaged and the clutch plate 100 is disengaged, the central shaft 26 transfers torque of the hybrid powertrain 10 to the gear set 109 thereby allowing appropriate shifting to achieve the selection of any odd forward speed ratio.Although in the embodiment the central shaft 26 is described as providing a torque path at odd speed ratios and the outer shaft 108 is described as providing a torque path at even speed ratios, a reverse configuration may be provided. As understood by those skilled in the art, if the nature of the device remains unchanged, the gear set 109 may be configured such that the central shaft 26 provides a torque path to even speed ratios while the outer shaft 108 provides a torque path to odd speed ratios.When the subject vehicle is propelled solely on electric power via the electric motor 82 to illustrate operation of the powertrain 10, the engine 12 is off, the second clutch 46 is engaged, and the first clutch 20 is disengaged. The electric motor 82 drives the shaft 96. Since electric motors typically have an infinite torque at low speeds, clutch slip is not required during starting, i.e. friction starting, when driving solely via the electric motor 82. Thus, propulsion of a vehicle that uses only the electric motor 82 at a first speed ratio is obtained via a disengaged third clutch 99 and a fully engaged, i.e., slip-free, second clutch 46 that transfers electric motor torque to the shaft 26. In preparation for making a dynamic shift to the second speed ratio, appropriate synchronizers are then preselected in the gear set 109. To obtain a second speed ratio, the third clutch 99 is engaged while simultaneously disengaging the second clutch 46.If the power of an on-board electrical storage device (not shown), such as one or more batteries, is exhausted while the vehicle is at a higher ratio, such as a second speed ratio or above, the engine 12 is started to provide propulsion assist. To start the engine 12, torque of the electric motor 82 is commanded to increase while the first clutch 20 is simultaneously engaged via the lever 41. Engagement of the first clutch 20 transfers torque of the electric motor 82 to rotate the engine 12. As a result, the engine 12 ignites and accordingly accelerates to what is called a "flying start", depending on the engaged speed ratio, to match the road speed of the vehicle. When the engine 12 is started and the vehicle is propelling, the electric motor 82 may be driven by the engine as a motor / generator to recharge the electrical storage device, or the electric motor may be applied to supplement the engine torque.When the subject vehicle is propelled solely via the engine 12, the electric motor 82 is off, the first clutch 20 is engaged, the second clutch 46 is applied to engage odd speed ratios, and the third clutch 99 is applied to engage even speed ratios. Because the engine 12 has torque characteristics that depend, for the most part, on engine speed, friction launch is typically required, particularly at vehicle launch, to overcome vehicle inertia. Thus, a vehicle launch utilizing only the engine 12 in a first speed ratio is obtained via a fully engaged second clutch 46, a disengaged third clutch 99, and a modulated slipping first clutch 20 that transfers engine torque to the shaft 26 while the clutch 46 acts as a backup. A shift from the first to the second speed ratio is performed for the vehicle driven only by the electric motor 82 as described above. To propel the subject vehicle through a combination of engine 12 and motor 82 while first clutch 20 is engaged, the electric storage device powers the motor to transfer motor torque to mounting plate 36.

Claims

A multiple speed, dynamically shiftable dual clutch transmission (18) for operatively connecting to an engine (12) and to an electric motor (82; 82A) in a hybrid vehicle, the transmission (18) comprising: an input member (26, 93, 108); an output member (124); a first clutch (20) selectively engageable to couple the engine (12) to the input member (26, 93, 108) and configured to transmit torque of the engine (12) at start-up and to resist energy of the vehicle at start-up from rest; a second clutch (46) engageable to select a first set of forward speed ratios between the input member (26, 93) and the output member (124) and configured to resist the common torque of the electric motor (82; 82A) and engine (12) torque during shifts to the first set of speed ratios, but not engine (12) torque at launch or vehicle energy at launch; and a third clutch (99) engageable to select a second set of forward speed ratios alternating with the first set speed ratios between the input member (93, 108) and the output member (124) and configured to withstand the common torque of the electric motor (82; 82A) and engine (12) torque during shifts to the second set of speed ratios but not engine (12) torque at start-up or vehicle energy at start-up, a transmission housing (19) arranged to enclose the input and output members (26, 93, 108, 124) and the first, second and third clutches (20, 46, 99), the electric motor (82; 82A) being arranged within the transmission housing (19) and having a rotor (92; 92A) and a stator (88; 88A), a rotor carrier (93; 93A) for supporting the rotor (92; 92A) providing a first mounting plate providing a reaction surface for the third clutch (99), a stationary carrier (80; 80A) for supporting the stator (88; 88A), and a second mounting plate (36) engaging the rotor carrier (93; 93A) providing reaction surfaces for the first clutch (20) and for the second clutch (46), characterized an oil supply, a coolant supply and a coolant outlet fitting (78, 86, 87) disposed on the fixed carrier (80), wherein oil is applied to operate the second and third clutches (46, 99) and coolant is applied to cool the electric motor (80; 80A).The dual clutch transmission (18) of claim 1, wherein the oil and coolant fittings (78, 86, 87) function as positioning members for the fixed carrier (80; 80A) with respect to the housing (19).

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