System and device for lubricating a hybrid transmission and an input-split hybrid transmission

Abstract

An input-branched hybrid transmission comprising a planetary gear set arranged to transmit mechanical power between an internal combustion engine, a first electric machine, a second electric machine, and an output member; and a fluid distribution system, wherein the planetary gear set includes a sun gear, a plurality of planetary pinion gears arranged on a planet carrier, and a ring gear. The planet carrier is arranged on a first rotatable input member, which defines a first axis. The first rotatable input member has an axial line. The fluid distribution system is arranged to supply a lubricant to the planetary gear set by means of the axial line, which is located within the first rotatable input member.

Description

[0001] Hybrid powertrain systems generate drive torque from two or more energy sources, for example hydrocarbon-based fuels through an internal combustion engine, and electrical power through one or more electric machines, with electrical power stored in a DC power source.

[0002] DE 10 2014 117 744 A1 describes a transmission system of a hybrid electric vehicle which may have a first and a second motor / generator (MG1; MG2), a planetary gear set (PG), a first output gear (OG1) for the second motor / generator (MG2), a second output gear (OG2) for an internal combustion engine (ENG), a first clutch (CL1) and a second clutch (CL2) which are arranged on or coupled to an input shaft (IS). A hollow shaft (MS1) is arranged on an outer circumferential side of the input shaft (IS) to transmit acceleration power of the internal combustion engine (ENG) or power of the first engine / generator (MG1) to the second output gear (OG2), and an outer shaft (MS2) is arranged on an outer circumferential side of the hollow shaft (MS1) to transmit power of the second engine / generator (MG2) to the first output gear (OG1).The first and second clutches (CL1; CL2) are arranged adjacent to each other on one side of the internal combustion engine on the input shaft (IS) and selectively transmit each of the rotational power of the input shaft (IS) and of the rotational power of the hollow shaft (MS1) to the second output gear (OG2).

[0003] JP 2014 - 052 065 A describes a lubrication structure for a planetary gear system. This lubrication structure comprises an axial oil channel with an opening section located at the end face of a pinion gear of the planetary gear system and extending axially from the opening section; a first inlet oil channel for supplying lubricant flowing outward in a diametrical direction to the axial oil channel; and a second inlet oil channel for supplying lubricant flowing inward in a diametrical direction to the planetary gear system. The first and second inlet oil channels are split at a point on the opening section of the axial oil channel.

[0004] JP 2022 - 7 781 A describes a drive unit for a vehicle. Since an inner circumferential surface of an output gear is designed such that an inner diameter DIN increases in the direction of a first or second rolling bearing in a rotational axis direction, oil supplied to an inner circumference of the output gear flows to one of the outer rings of the first and second rolling bearings, and the oil is supplied between the outer rings and the inner circumferences of the end parts of the output gear. Since the oil supplied to the inner circumference of the output gear accumulates in a space formed on the inner circumference of the output gear, the oil that is backed up by the outer rings is supplied between the outer rings and the inner circumferences of the end parts of the output gear.

[0005] JP 2014-024412A describes a vehicle drive system. The vehicle drive system comprises an input element, an output element, a rotating electrical device, a differential gear device with three rotating elements, and an oil pump. The rotating electrical device comprises a cylindrical rotor shaft arranged coaxially on the input element and supporting a rotor body. A pump shaft, extending through the rotor shaft and connected to the input element, is connected to the pump rotor to rotate integrally with it. The input element and the second rotating element are driven and connected in such a way that they can be displaced relative to each other.

[0006] US 2016 / 0265652A1 describes a lubrication device for a hybrid vehicle. The lubrication device is intended for a hybrid vehicle comprising an internal combustion engine, a first electric motor, and a second electric motor as drive sources. The lubrication device includes a planetary gear set, a braking device, an oil pump, and a first oil supply device. The braking mechanism selectively locks a carrier of the planetary gear set by stopping the carrier's rotation. The oil pump is driven with a predetermined power to generate hydraulic pressure of the oil in a state where the carrier's rotation is stopped by the braking mechanism. The first oil supply device delivers the oil to an axle section of each pinion gear of the planetary gear set by generating hydraulic pressure.

[0007] Therefore, the object of the present invention is to provide a system that supplies pressurized lubricants for elements of a planetary gear set.

[0008] The problem is solved by the subject matter of the independent claims.

[0009] The concepts described herein provide a fluid distribution system for a hybrid transmission, which includes the provision of pressurized lubricant to elements of a planetary gear set in one embodiment.

[0010] In one embodiment, this comprises a fluid distribution system for an input-branched hybrid transmission architecture, wherein pressurized oil lubrication is provided for a complete complement of planetary pinion bearings of pinion drives by using an externally located fluid transfer device comprising a cover plate and a radial tube, with a sealed oil supply between a planet carrier for a planetary gear set and a rotatable input member. The lubricating fluid is regulated along the entire length of a rotatable input member by using a single oil channel or oil line and tunable channels located downstream of the single oil channel. This includes supplying lubricating fluid from a stationary component to a rotating component by using a single dynamic oil supply seal comprising a cover plate and a single banjo fitting in one embodiment.

[0011] An aspect of the invention comprises an input-branched hybrid transmission comprising a planetary gear set arranged to transmit mechanical power between an internal combustion engine, a first electric machine, a second electric machine, and an output element, and a fluid distribution system. The planetary gear set includes a sun gear, a plurality of planetary pinion gears arranged on a planet carrier, and a ring gear. The planet carrier is arranged on a first rotatable input element, which defines a first axis. The first rotatable input element has an axial line. The fluid distribution system is arranged to supply a lubricant to the planetary gear set by means of the axial line, which is located within the first rotatable input element.Furthermore, the input-branched hybrid transmission comprises a transmission housing having an outer section, a first side section, and an engine side section. The planetary gear set is arranged within the transmission housing. The first rotatable input member extends between the first side section and the engine side section and has a first end projecting through the first side section. The first end of the first rotatable input member has an opening that is fluidically coupled to the axial line located therein. The fluid distribution system comprises a longitudinal line located within the transmission housing, a banjo bolt, and an externally arranged fluid transfer device comprising a cover plate and a radial tube. The axial line is located within the first rotatable input member.Furthermore, a first radial line is included, which is arranged within the first rotatable input member. The first radial line is in fluidic communication with the axial line. The cover plate is sealed to the first side section of the gearbox housing above the axial line, which is arranged within the first rotatable input member, such that a first end of the radial tube is fluidically connected to the axial line. A second end of the radial tube is attached to the gearbox housing via the banjo bolt, so that the second end of the radial tube is fluidically connected to the longitudinal line. The lubricant is supplied from a pressure source that is fluidically connected to the longitudinal line.The lubricant flows from the pressure source to the planetary gear set via the longitudinal line located inside the gearbox housing, the banjo bolt, the cover plate encompassing the radial tube, the axial line located inside the first rotatable input member, and the first radial line located inside the first rotatable input member.

[0012] In a further embodiment, the first rotatable input member has a splined section. The axial line, which is arranged within the first rotatable input member, extends between a first end thereof and the splined section, and the first rotatable input member has a first radial line. The first radial line is arranged between the axial line and an outer surface of the first rotatable input member at the splined section.

[0013] In a further embodiment, the first rotatable input member has a plurality of second radial lines arranged between the axial line and an outer surface of the first rotatable input member that is located away from the splined section.

[0014] In another embodiment, the splined section of the first rotatable input element is splined to the planet carrier. The planet carrier has a third radial line that is aligned with the first radial line.

[0015] In another embodiment, the fluid distribution system is arranged to supply the lubricant to the planetary gear set by means of the axial line which is arranged inside the first rotatable input member, the first radial line and the third radial line.

[0016] In another embodiment, the fluid distribution system is arranged to supply lubricant to one of the sun gear, the plurality of planetary pinion gears, the planet carrier and the ring gear by means of the axial line which is arranged within the first rotatable input member.

[0017] Another aspect of the invention comprises a transmission for a drive train system, comprising a simple planetary gear set arranged to transmit mechanical power between a first torque-generating device, a second torque-generating device, a third torque-generating device, and an output element, and a fluid distribution system. The simple planetary gear set comprises a sun gear, a plurality of planet pinion gears arranged on a planet carrier, and a ring gear. The planet carrier is arranged on a first rotatable input element, which defines a first axis. The first rotatable input element has an axial line arranged therein. The fluid distribution system is arranged to supply a lubricant to the planetary gear set by means of the axial line located within the first rotatable input element.Furthermore, the transmission comprises a transmission housing having an outer section, a first side section, and a motor side section. The planetary gear set is arranged within the transmission housing. The first rotatable input member extends between the first side section and the motor side section and has a first end projecting through the first side section. The first end of the first rotatable input member has an opening that is fluidically coupled to the axial line located therein. The fluid distribution system comprises a longitudinal line located within the transmission housing, a banjo bolt, and an externally arranged fluid transfer device comprising a cover plate and a radial tube. The axial line is located within the first rotatable input member. A first radial line is also included, located within the first rotatable input member.The first radial line is in fluidic connection with the axial line. The cover plate is sealed to the first side section of the gearbox housing above the axial line, which is located inside the first rotatable input member, so that a first end of the radial tube is fluidically connected to the axial line. A second end of the radial tube is attached to the gearbox housing via the banjo bolt, so that the second end of the radial tube is fluidically connected to the longitudinal line. The lubricant is supplied from a pressure source that is fluidically connected to the longitudinal line.The lubricant flows from the pressure source to the planetary gear set via the longitudinal line located inside the gearbox housing, the banjo bolt, the cover plate encompassing the radial tube, the axial line located inside the first rotatable input member, and the first radial line located inside the first rotatable input member.

[0018] In one application, an input-branched hybrid transmission according to the invention for a vehicle drivetrain system can comprise a simple planetary gear set arranged to transmit mechanical power between an internal combustion engine, a first electric machine, a second electric machine, and an output element coupled to the vehicle's drivetrain, and comprising a fluid distribution system. The planetary gear set includes a sun gear, a plurality of planetary pinion gears arranged on a planet carrier, and a ring gear; the planet carrier being arranged on a first rotatable input element defining a first axis. The first rotatable input element has an axial line arranged therein, and the fluid distribution system is arranged to supply a lubricant to the planetary gear set by means of the axial line located within the first rotatable input element.

[0019] One or more embodiments are now described by way of example with reference to the attached drawings, in which: Fig. 1 An embodiment of a powertrain system comprising an internal combustion engine coupled to an input-split hybrid transmission, as shown schematically in the disclosure. Fig. 2 A cut-out end view of an embodiment of an input-branched hybrid transmission according to the disclosure is schematically illustrated. Fig. 3 A cut-out side view of an embodiment of an input-branched hybrid transmission according to the disclosure is schematically illustrated. Fig. 4 A cut-out side view of a section of an embodiment of an input-branched hybrid transmission according to the disclosure is schematically illustrated. Fig. 5 An isometric view of a section of an embodiment of an input-branched hybrid transmission according to the disclosure is schematically illustrated. Fig. 6 A cut-out side view of a section of an embodiment of an input-branched hybrid transmission according to the disclosure is schematically illustrated. Fig. Figure 7 schematically illustrates an isometric view of a section of an embodiment of an input-branched hybrid transmission according to the disclosure. Fig. Figure 8 schematically illustrates an isometric view of a section of an embodiment of an input-branched hybrid transmission according to the disclosure.

[0020] The accompanying drawings are not necessarily to scale and may represent a somewhat simplified depiction of various preferred features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, positions, and shapes. Details associated with such features are partly determined by the specific intended application and usage environment.

[0021] With reference to the drawings, which are provided for the purpose of illustrating certain embodiments and not for the purpose of limiting them, illustrates Fig. Figure 1 schematically shows a hybrid powertrain system 100 comprising an internal combustion engine 10, an input-split hybrid transmission 11, a first electric machine (motor A) 12, a second electric machine (motor B) 14, and an axle drive system 90 with an output element 95. The internal combustion engine 10, the first electric machine 12, and the second electric machine 14 are non-limiting examples of torque-generating devices and can be replaced by other combinations and arrangements of torque-generating devices.

[0022] The hybrid powertrain system 100 can, in one embodiment, be used on a vehicle to provide traction power, although the concepts described herein are not limited to this. When used on a vehicle, the vehicle may include, among others, a mobile platform in the form of a commercial vehicle, an industrial vehicle, an agricultural vehicle, a passenger car, an aircraft, a watercraft, a train, an all-terrain vehicle, a personal mobility device, a robot, and the like, to achieve the purposes of this disclosure.

[0023] The input-branched hybrid transmission 11 features a planetary gear set 24 and the axle drive system 90, which can be coupled to a vehicle's drivetrain to provide traction power.

[0024] In one embodiment, the planetary gear set 24 is arranged as a simple planetary gear set, although the concepts described herein are not limited to this. The planetary gear set 24 comprises a sun gear 29, a plurality of planetary pinion gears 27 arranged on a planet carrier 28 and rotatably coupled to it, and a ring gear 26 meshing with one another and rotating together.

[0025] The sun gear 29 is arranged on a first rotatable input element 30, which defines a first axis 13. The first rotatable input element 30 also serves as a rotor shaft for the first electric machine 12.

[0026] The planet carrier 28 is coupled to an output member or crankshaft of the internal combustion engine 10 and may include an intermediate torque converter or other torque management device.

[0027] The ring gear 26 is coupled to an extension ring gear 21 and rotates with it.

[0028] The second electric machine 14 has a rotor arranged on a second input element 16, defining a second axis 15. The second input element 16 has a motor pinion 23.

[0029] The motor pinion 23 of the second input member 16 and the extension ring gear 21 of the ring gear 26 are both meshing and rotate with a transmission gear 20, which is arranged on a transmission member 18.

[0030] The axle drive 90 comprises an axle drive pinion 92 and an axle drive ring gear 94, which is coupled to the output element 95 and rotates with it.

[0031] The transmission gear 20 is coupled to the axle drive pinion 92 and rotates with it.

[0032] The first input element 30 defines a first axis 13, the second input element 16 defines a second axis 15, the transmission element 18 defines a transmission axis 19, and the output element 95 defines a third axis 17. The first input element 30, the second input element 16, the transmission element 18, and the output element 95 are rotatable shaft elements arranged on corresponding first axis 13, second axis 15, transmission axis 19, and third axis 17, which are arranged in parallel.

[0033] This arrangement of the planetary gear set 24 and the axle drive system 90 advantageously transmits torque between the internal combustion engine 10, the first electric machine 12, the second electric machine 14 and the output element 95 for traction torque and / or electric charging, without having clutches.

[0034] Fig. 2 and Fig. Figure 3 schematically illustrates a cut-out end view ( Fig. 2) and a corresponding cut-out centerline side view ( Fig. 3) an embodiment of the input-split hybrid transmission 11, which, with reference to Fig. 1 is described, where the same reference symbols denote the same elements in the different views. Fig. Figure 2 represents an arrangement of elements of the input-branched hybrid transmission 11, including the first input element 30, the second input element 16, the transmission element 18 and the output element 95, and associated elements are housed in a transmission housing 60, which includes an outer housing section 63 (in Fig. 2 illustrated), comprising a first side section 61, which is arranged on a first side of the outer housing section 63, and a motor side section 62, which is arranged on a second, opposite side of the outer housing section 63.

[0035] Fig. Figure 3 further illustrates elements of a fluid distribution system 40 arranged to supply a pressurized lubricant to elements of the input-branched hybrid transmission 11 located within the transmission housing 60, including elements of the planetary gear set 24 and the axle drive 90.

[0036] The fluid distribution system 40 is arranged to distribute pressurized lubricant supplied by an internal fluid pump and reservoir 41.

[0037] The first input element 30 is a rigid shaft having a first end 30-1 and a second end 30-2. The first input element 30 defines an internal axial conduit 32 that is concentric to the first axis 13 and extends from an opening 31 in the first end 30-1 to near the second end 30-2.

[0038] The first input element 30 is arranged in the gearbox housing 60, wherein a section of the first end 30-1 extends through an opening in the first side 61 of the gearbox housing 60, wherein the opening 31 in the first end 30-1 is arranged outside the first end 30-1 of the gearbox housing 60.

[0039] The first input member 30 has a splined section 34 located proximal to the second end 30-2, as described in reference to Fig. 3, Fig. 6 and Fig. 7 illustrates.

[0040] With renewed reference to Fig. 3 The first inlet member 30 has at least one or a plurality of radial channels extending between the internal axial channel 32 and an outer surface of the first inlet member 30, thereby enabling fluid flow by means of fluid pressure or centrifugal force. The radial channels include a first radial channel 33 arranged in the first inlet member 30 at the splined section 34, as also described with reference to Fig. 6 illustrates.

[0041] The radial lines have one or a plurality of second radial lines 38 arranged in the first inlet member 30 at selected positions along its length, as described in reference to Fig. 6 and Fig. Figure 7 illustrates this. The specific positions, diameters, and other design details are application-specific and are selected to achieve the distribution of fluid, for example, lubricating oil, to various elements of the gearbox 11, while minimizing losses associated with sealing channels and providing centrifugal lubrication along the entire length of the axis of the first input member 30.

[0042] Fig. 4 and Fig. Figure 5 schematically illustrates details relating to the fluid distribution system 40, which is arranged to distribute pressurized lubricant originating from the internal fluid pump and sump 41.

[0043] The fluid distribution system 40 comprises a longitudinal line 42 arranged within the gearbox housing 60, a banjo bolt 44, and an externally arranged fluid transfer device 46, which is fluidically coupled to the opening 31 in the first end 30-1 of the first input member 30. The fluid distribution system 40 is arranged to transfer pressurized fluid originating from the internal fluid pump and reservoir 41 to the first radial line 33 located in the first input member 30, thereby supplying pressurized fluid to elements of the planetary gear set 24. The fluid distribution system 40 is arranged to transfer pressurized fluid originating from the internal fluid pump and sump 41 to the one or the plurality of second radial lines 38 arranged in the first input member 30, thereby supplying pressurized fluid to elements of the transmission, including the planetary gear set 24.

[0044] The fluid transfer device 46 is a manufactured device comprising a first section 48, a hollow radial tube 50, and a cover plate 52. An enclosed flow channel is formed by the first section 48, the hollow radial tube 50, and the cover plate 52.

[0045] The longitudinal line 42 includes a threaded section 43 which engages with a corresponding threaded shank section of the banjo bolt 44.

[0046] The banjo bolt 44 is an elongated metallic device comprising a head and a hollow shaft. The hollow shaft has a perforated recessed outer section near the head section through which fluid can flow independently of the bolt's rotational position, thus enabling fluid flow without requiring rotational alignment of the banjo bolt 44 with respect to the hollow radial tube 50.

[0047] The first section 48 of the fluid transmission device 46 is fluidically coupled to the longitudinal line 42 via the banjo bolt 44.

[0048] The cover plate 52 fits sealingly over the opening 31 in the first end 30-1 of the first input member 30 outside the first side 61 of the gearbox housing 60.

[0049] The fluid transfer device 46 is arranged to transfer the pressurized fluid from the longitudinal line 42 to the opening 31 in the first end 30-1 of the first input member 30 outside the first side 61 of the gearbox housing 60.

[0050] The cover plate 52 is sealed to an outer section of the first side 61 of the gearbox housing 60 above the opening 31 in the first end 30-1 of the first input member 30, so that a first end of the hollow radial tube 50 is fluidically connected to the opening 31 of the internal axial conduit 32.

[0051] Lubricant is supplied from the pressure source, which originates from an internal fluid pump and reservoir 41, fluidically connected to the longitudinal line 42. In other words, lubricant flows from the pressure source 41 to one or more elements of the planetary gear set 24 via the longitudinal line 42, which is arranged within the gear housing 60, the banjo bolt 44, the fluid transmission device 46, which includes the cover plate 52, the axial line 32, which is arranged within the first rotatable input member 30, and the first radial line 33, which is arranged within the first rotatable input member 30.

[0052] Fig. Figure 7 provides an isometric view of a section of the first rotatable input member 30 and the sun gear 29, with a splined section 34 arranged thereon to engage with the planet carrier 28. The splined section 34 of the first rotatable input member 30 has an indexed section 34A which includes the first radial line 33. Fig. Figure 8 provides a corresponding isometric view of a section of the planet carrier 28, with a splined section 28A arranged thereon to engage with the planet carrier 29. The splined section 28A of the planet carrier 28 has a third radial guide 39. The splined section 28A of the planet carrier 29 is splined with the splined section 34 of the first rotatable input member 30.

[0053] When the planet carrier 28 is arranged on the first rotatable input member 30, the first radial line 33 is aligned with the third radial line 39, thereby enabling and facilitating a flow of lubricating fluid from the axial line 32, which is arranged inside the first rotatable input member 30, to the various elements of the planet gear set 24.

[0054] The entire length of the first rotatable inlet element 30 is used to provide precise control of lubricating and cooling oil, while also providing the largest possible span between the main bearing guide features of the shaft. The design provides the supply of lubricating and cooling oil from the smallest possible diameter, which serves to minimize losses associated with sealing channels and also provides centrifugal lubrication along the entire length of the shaft.

Claims

[1] Input-split hybrid transmission (11), comprising: a planetary gear set (24) arranged to transmit mechanical power between an internal combustion engine (10), a first electric machine (12), a second electric machine (14) and an output element (95); and a fluid distribution system (40); a gearbox housing (60) with an outer section (63), a first side section (61) and a motor side section (62); wherein the planetary gear set (24) comprises a sun gear (29), a plurality of planetary pinion gears (27) arranged on a planet carrier (28) and a ring gear (26); wherein the planet carrier (28) is arranged on a first rotatable input element (30) which defines a first axis (13); wherein the first rotatable input element (30) has an axial line (32) arranged therein; wherein the fluid distribution system (40) is arranged to supply a lubricant to the planetary gear set (24) by means of the axial line (32) which is arranged within the first rotatable input member (30); wherein the planetary gear set (24) is arranged in the gearbox housing (60); wherein the first rotatable input element (30) extends between the first side section (61) and the motor side section (62) and has a first end (30-1) thereof which projects through the first side section (61); wherein the first end (30-1) of the first rotatable input member (30) has an opening (31) which is fluidically coupled to the axial conduit (32) which is arranged therein; and the fluid distribution system (40) comprises: a longitudinal line (42) arranged inside the gearbox housing (60), a banjo bolt (44), an externally arranged fluid transmission device (46) comprising a cover plate (52) and a radial tube (50), wherein the axial line (32) is arranged inside the first rotatable input member (30), and a first radial line (33) arranged inside the first rotatable input member (30); wherein the first radial line (33) is in fluidic communication with the axial line (32); wherein the cover plate (52) is sealedly attached to the first side section (61) of the gearbox housing (60) above the axial line (32) which is arranged inside the first rotatable input member (30), such that a first end of the radial tube (50) is fluidically connected to the axial line (32); wherein a second end of the radial tube (50) is attached to the gearbox housing (60) via the banjo bolt (44), so that the second end of the radial tube (50) is fluidically connected to the longitudinal line (42); wherein the lubricant is supplied from a pressure source (41) which is fluidically connected to the longitudinal line (42); and wherein the lubricant flows from the pressure source (41) to the planetary gear set (24) by means of the longitudinal line (42) which is arranged inside the gear housing (60), the banjo bolt (44), the cover plate (52) which includes the radial tube (50), the axial line (32) which is arranged inside the first rotatable input member (30), and the first radial line (33) which is arranged inside the first rotatable input member (30). [2] Input-split hybrid transmission (11) according to claim 1: wherein the first rotatable input element (30) has a splined section (34); wherein the axial conduit (32) which is arranged within the first rotatable input member (30) extends between a first end (30-1) thereof and the splined section (34); wherein the first rotatable input member (30) has a first radial line (33), wherein the first radial line (33) is arranged between the axial line (32) and an outer surface of the first rotatable input member (30) on the splined section (34). [3] Input-branched hybrid transmission (11) according to claim 2, wherein the first rotatable input member (30) has a plurality of second radial lines (38) arranged between the axial line (32) and an outer surface of the first rotatable input member (30) that is located away from the splined section (34). [4] Input-branched hybrid transmission (11) according to claim 2, wherein the splined section (34) of the first rotatable input member (30) is splined with the planet carrier (28); and wherein the planet carrier (28) has a third radial line (39) aligned with the first radial line (33). [5] Input-branched hybrid transmission (11) according to claim 4, wherein the fluid distribution system (40) is arranged to supply the lubricant to the planetary gear set (24) by means of the axial line (32) arranged within the first rotatable input member (30), the first radial line (33) and the third radial line (39). [6] Input-branched hybrid transmission (11) according to claim 1, wherein the fluid distribution system (40) arranged to supply the lubricant to the planet gear set (24) by means of the axial line (32) arranged within the first rotatable input member (30) comprises the fluid distribution system (40) arranged to supply the lubricant to one of the sun gear (29), the plurality of planet pinion gears (27), the planet carrier (28) and the ring gear (26) by means of the axial line (32) arranged within the first rotatable input member (30). [7] Transmission for a powertrain system (100), comprising: a simple planetary gear set (24) arranged to transmit mechanical power between a first torque-generating device, a second torque-generating device, a third torque-generating device and an output element (95); and a fluid distribution system (40); wherein the simple planetary gear set (24) comprises a sun gear (29), a plurality of planetary pinion gears (27) arranged on a planet carrier (28), and a ring gear (26); wherein the planet carrier (28) is arranged on a first rotatable input element (30) which defines a first axis (13); wherein the first rotatable input element (30) has an axial line (32) arranged therein; and wherein the fluid distribution system (40) is arranged to supply a lubricant to the planetary gear set (24) by means of the axial line (32) which is arranged within the first rotatable input member (30); further comprising a gear housing (60) with an outer section (63), a first side section (61) and a motor side section (62); wherein the planetary gear set (24) is arranged in the gearbox housing (60); wherein the first rotatable input element (30) extends between the first side section (61) and the motor side section (62) and has a first end (30-1) thereof which projects through the first side section (61); wherein the first end (30-1) of the first rotatable input member (30) has an opening (31) which is fluidically coupled to the axial conduit (32) which is arranged therein; and the fluid distribution system (40) comprises: a longitudinal line (42) arranged inside the gearbox housing (60), a banjo bolt (44), an externally arranged fluid transmission device (46) comprising a cover plate (52) and a radial tube (50), wherein the axial line (32) is arranged inside the first rotatable input member (30), and a first radial line (33) arranged inside the first rotatable input member (30); wherein the first radial line (33) is in fluidic communication with the axial line (32); wherein the cover plate (52) is sealedly attached to the first side section (61) of the gearbox housing (60) above the axial line (32) which is arranged inside the first rotatable input member (30), such that a first end of the radial tube (50) is fluidically connected to the axial line (32); wherein a second end of the radial tube (50) is attached to the gearbox housing (60) via the banjo bolt (44), so that the second end of the radial tube (50) is fluidically connected to the longitudinal line (42); wherein the lubricant is supplied from a pressure source (41) which is fluidically connected to the longitudinal line (42); and wherein the lubricant flows from the pressure source (41) to the planetary gear set (24) by means of the longitudinal line (42) which is arranged inside the gear housing (60), the banjo bolt (44), the cover plate (52) which includes the radial tube (50), the axial line (32) which is arranged inside the first rotatable input member (30), and the first radial line (33) which is arranged inside the first rotatable input member (30).

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