1. A method of operating a hybrid powertrain; wherein the hybrid powertrain includes an engine and a transmission; wherein the transmission has an input member connected with the engine, an output member, a stationary member, a first and a second motorgenerator, a first planetary gearing arrangement, and a second planetary gearing arrangement; wherein the input member is connected for rotation with a first member of the first planetary gearing arrangement; wherein the output member is connected for rotation with a first member of the second planetary gearing arrangement; wherein the first motorgenerator is connected for rotation with a second member of the first planetary gearing arrangement; wherein the second motorgenerator is connected for rotation with a second member of the second planetary gearing arrangement; an interconnecting member connecting a third member of the first planetary gearing arrangement for common rotation with a third member of the second planetary gearing arrangement; a plurality of torque-transmitting mechanisms including a first torque-transmitting mechanism selectively engagable to ground the first motorgenerator to the stationary member, a second torque-transmitting mechanism selectively engagable to connect the interconnecting member for rotation with the output member, a third torque-transmitting mechanism and a fourth torque-transmitting mechanism, the third and fourth torque-transmitting mechanisms being selectively engagable to connect different members of the second planetary gearing arrangement to the stationary member or for common rotation with one another; the method comprising:
establishing three different electrically-variable operating modes by engaging different ones of the second, third and fourth torque-transmitting mechanisms in response to different respective vehicle operating conditions;
establishing at least two different fixed ratio modes by engaging the first torque-transmitting mechanism in addition to the respective different ones of the second, third and fourth torque-transmitting mechanisms engaged to establish the electrically-variable operating modes; wherein the at least two different fixed ratio modes are established in response to different respective vehicle operating conditions requiring greater torque at the output member than the respective different vehicle operating conditions of the electrically-variable operating modes.
2. The method of claim 1, further comprising:
during at least one of said established fixed ratio modes, establishing a parallel hybrid operating mode by controlling the second motorgenerator to function as one of a motor to add torque and a generator to receive torque for regenerative braking.
3. The method of claim 1, wherein the first planetary gearing arrangement is a simple planetary gear set; wherein the first member of the first planetary gear set is a carrier member, the second member of the first planetary gear set is a sun gear member, and the third member of the first planetary gear set is a ring gear member;
wherein the second planetary gear set is a compound planetary gear set having a single ring gear member, first and second sun gear members, a carrier member and first and second sets of pinion gears; wherein the first member of the second planetary gear set is the single ring gear member, the second member of the second planetary gear set is a first of the two sun gear members, the third member of the second planetary gear set is the carrier member that rotatably supports the first set of pinion gears meshing with the first sun gear member and the single ring gear member and rotatably supports the second set of pinion gears meshing with the first set of pinion gears and the second sun gear member;
wherein the third torque-transmitting mechanism is selectively engagable to ground the first sun gear member to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to ground the second sun gear member to the stationary member.
4. The method of claim 1, wherein the first planetary gearing arrangement is a simple planetary gear set; wherein the first member of the first planetary gear set is a carrier member, the second member of the first planetary gear set is a sun gear member, and the third member of the first planetary gear set is a ring gear member;
wherein the second planetary gearing arrangement includes a second and a third simple planetary gear set, each having a ring gear member, a sun gear member, and a carrier member that rotatably supporting a set of pinion gears that meshes with the sun gear member and the ring gear member; wherein the first member of the second planetary gearing arrangement is the ring gear member of the third planetary gear set, the second member of the second planetary gearing arrangement is the sun gear member of the third planetary gear set, the third member of the second planetary gearing arrangement is the carrier member of the third planetary gear set;
wherein the third torque-transmitting mechanism is selectively engagable to ground the sun gear member of the third planetary gear set to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to connect the carrier member of the second planetary gear set to the ring gear member of the third planetary gear set; and wherein another interconnecting member connects the carrier member of the second planetary gear set for common rotation with the ring gear member of the third planetary gear set.
5. The method of claim 1, wherein the first planetary gearing arrangement is a first simple planetary gear set; wherein the first member of the first simple planetary gear set is a carrier member, the second member of the first simple planetary gear set is a sun gear member, and the third member of the first simple planetary gear set is a ring gear member;
wherein the second planetary gearing arrangement includes a second compound planetary gear set and a third simple planetary gear set; wherein the second compound planetary gear set has a single ring gear member, first and second sun gear members, a carrier member and first and second sets of pinion gears, wherein the first set of pinion gears meshes with the first sun gear member and the single ring gear member, wherein the second set of pinion gears meshes with the first set of pinion gears and the second sun gear member; wherein the third simple planetary gear set has a ring gear member, a sun gear member, and a carrier member rotatably supports a set of pinion gears that meshes with the sun gear member and the ring gear member; wherein the first member of the second planetary gearing arrangement is the ring gear member of the third planetary gear set, the second member of the second planetary gearing arrangement is the first sun gear member of the second compound planetary gear set, the third member of the second planetary gearing arrangement is the carrier member of the third planetary gear set;
wherein the third torque-transmitting mechanism is selectively engagable to ground the ring gear member of the second compound planetary gear set to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to ground the second sun gear member of the second compound planetary gear set to the stationary member; and wherein another interconnecting member connects the carrier member of the second compound planetary gear set for common rotation with the sun gear member of the third planetary gear set.
6. A method of operating a hybrid powertrain; wherein the hybrid powertrain includes an engine and a transmission; wherein the transmission has an input member connected with the engine, an output member, a stationary member, a first and a second motorgenerator, a first planetary gearing arrangement, and a second planetary gearing arrangement; wherein the input member is connected for rotation with a first member of the first planetary gearing arrangement; wherein the output member is connected for rotation with a first member of the second planetary gearing arrangement; wherein the first motorgenerator is connected for rotation with a second member of the first planetary gearing arrangement; wherein the second motorgenerator is connected for rotation with a second member of the second planetary gearing arrangement; an interconnecting member connecting a third member of the first planetary gearing arrangement for common rotation with a third member of the second planetary gearing arrangement; a plurality of torque-transmitting mechanisms including a first torque-transmitting mechanism selectively engagable to ground the first motorgenerator to the stationary member, a second torque-transmitting mechanism selectively engagable to connect the interconnecting member for rotation with the output member, a third torque-transmitting mechanism and a fourth torque-transmitting mechanism, the third and fourth torque-transmitting mechanisms being selectively engagable to connect different members of the second planetary gearing arrangement to the stationary member or for common rotation with one another; the method comprising:
establishing a first electrically-variable operating mode in response to a first set of vehicle operating conditions by engaging only one of the third and fourth torque-transmitting mechanisms and controlling the first motorgenerator to function as a generator and the second motorgenerator to function as a motor;
establishing a second electrically-variable operating mode in response to a second set of vehicle operating conditions by engaging only the second torque-transmitting mechanism and controlling the first motorgenerator to function as a generator and the second motorgenerator to function as a motor;
establishing a third electrically-variable operating mode in response to a third set of vehicle operating conditions by engaging only the other of the third and fourth torque-transmitting mechanisms and controlling the first motorgenerator to function as a generator and the second motorgenerator to function as a generator;
establishing a first fixed ratio mode by engaging the first torque-transmitting mechanism in addition to the only one of the third and fourth torque-transmitting mechanisms that is engaged in establishing the first electrically-variable operating mode, wherein the first fixed ratio mode is established in response to a fourth set of vehicle operating conditions;
establishing a second fixed ratio mode by engaging the first torque-transmitting mechanism in addition to the second torque-transmitting mechanism that is engaged in establishing the second electrically-variable operating mode, wherein the second fixed ratio mode is established in response to a fifth set of vehicle operating conditions; and
establishing a third fixed ratio mode by engaging the first torque-transmitting mechanism in addition to the other of the third and fourth torque-transmitting mechanisms that are engaged in establishing the third electrically-variable operating mode, wherein the third fixed ratio mode is established in response to a sixth set of vehicle operating conditions.
7. The method of claim 6, wherein the first planetary gearing arrangement is a simple planetary gear set; wherein the first member of the first planetary gear set is a carrier member, the second member of the first planetary gear set is a sun gear member, and the third member of the first planetary gear set is a ring gear member;
wherein the second planetary gear set is a compound planetary gear set having a single ring gear member, first and second sun gear members, a carrier member and first and second sets of pinion gears; wherein the first member of the second planetary gear set is the single ring gear member, the second member of the second planetary gear set is a first of the two sun gear members, the third member of the second planetary gear set is the carrier member that rotatably supports the first set of pinion gears meshing with the first sun gear member and the single ring gear member and rotatably supports the second set of pinion gears meshing with the first set of pinion gears and the second sun gear member;
wherein the third torque-transmitting mechanism is selectively engagable to ground the first sun gear member to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to ground the second sun gear member to the stationary member.
8. The method of claim 6, wherein the first planetary gearing arrangement is a simple planetary gear set; wherein the first member of the first planetary gear set is a carrier member, the second member of the first planetary gear set is a sun gear member, and the third member of the first planetary gear set is a ring gear member;
wherein the second planetary gearing arrangement includes a second and a third simple planetary gear set, each having a ring gear member, a sun gear member, and a carrier member that rotatably supports a set of pinion gears that meshes with the sun gear member and the ring gear member; wherein the first member of the second planetary gearing arrangement is the ring gear member of the third planetary gear set, the second member of the second planetary gearing arrangement is the sun gear member of the third planetary gear set, the third member of the second planetary gearing arrangement is the carrier member of the third planetary gear set;
wherein the third torque-transmitting mechanism is selectively engagable to ground the sun gear member of the third planetary gear set to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to connect the carrier member of the second planetary gear set to the ring gear member of the third planetary gear set; and wherein another interconnecting member connects the carrier member of the second planetary gear set for common rotation with the ring gear member of the third planetary gear set.
9. A hybrid powertrain that includes:
an engine and a transmission; wherein the transmission has an input member connected with the engine, an output member, a stationary member, a first and a second motorgenerator, a first planetary gearing arrangement, and a second planetary gearing arrangement; wherein the input member is connected for rotation with a first member of the first planetary gearing arrangement; wherein the output member is connected for rotation with a first member of the second planetary gearing arrangement; wherein the first motorgenerator is connected for rotation with a second member of the first planetary gearing arrangement; wherein the second motorgenerator is connected for rotation with a second member of the second planetary gearing arrangement; an interconnecting member connecting a third member of the first planetary gearing arrangement for common rotation with a third member of the second planetary gearing arrangement; a plurality of torque-transmitting mechanisms including a first torque-transmitting mechanism selectively engagable to ground the first motorgenerator to the stationary member, a second torque-transmitting mechanism selectively engagable to connect the interconnecting member for rotation with the output member, a third torque-transmitting mechanism and a fourth torque-transmitting mechanism, the third and fourth torque-transmitting mechanisms being selectively engagable to connect different members of the second planetary gearing arrangement to the stationary member or for common rotation with one another;
a controller operatively connected to the transmission and configured to receive sensor signals indicative of vehicle operating conditions, and to process the control signals and provide control signals in response to vehicle operating conditions, the control signals being operable to establish three electrically-variable operating modes and at least two fixed ratio modes of the transmission;
wherein the at least two fixed ratio modes are established in response to vehicle operating conditions indicative of towing or uphill driving.
10. The hybrid powertrain of claim 9, wherein the first planetary gearing arrangement is a simple planetary gear set; wherein the first member of the first planetary gear set is a carrier member, the second member of the first planetary gear set is a sun gear member, and the third member of the first planetary gear set is a ring gear member;
wherein the second planetary gear set is a compound planetary gear set having a single ring gear member, first and second sun gear members, a carrier member and first and second sets of pinion gears; wherein the first member of the second planetary gear set is the single ring gear member, the second member of the second planetary gear set is a first of the two sun gear members, the third member of the second planetary gear set is the carrier member that rotatably supports the first set of pinion gears meshing with the first sun gear member and the single ring gear member and rotatably supports the second set of pinion gears meshing with the first set of pinion gears and the second sun gear member;
wherein the third torque-transmitting mechanism is selectively engagable to ground the first sun gear member to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to ground the second sun gear member to the stationary member.
11. The hybrid powertrain of claim 9, wherein the first planetary gearing arrangement is a simple planetary gear set; wherein the first member of the first planetary gear set is a carrier member, the second member of the first planetary gear set is a sun gear member, and the third member of the first planetary gear set is a ring gear member;
wherein the second planetary gearing arrangement includes a second and a third simple planetary gear set, each having a ring gear member, a sun gear member, and a carrier member that rotatably supports a set of pinion gears that meshes with the sun gear member and the ring gear member; wherein the first member of the second planetary gearing arrangement is the ring gear member of the third planetary gear set, the second member of the second planetary gearing arrangement is the sun gear member of the third planetary gear set, the third member of the second planetary gearing arrangement is the carrier member of the third planetary gear set;
wherein the third torque-transmitting mechanism is selectively engagable to ground the sun gear member of the third planetary gear set to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to connect the carrier member of the second planetary gear set to the ring gear member of the third planetary gear set; and wherein another interconnecting member connects the carrier member of the second planetary gear set for common rotation with the ring gear member of the third planetary gear set.
12. The hybrid powertrain of claim 9, wherein the first planetary gearing arrangement is a first simple planetary gear set; wherein the first member of the first simple planetary gear set is a carrier member, the second member of the first simple planetary gear set is a sun gear member, and the third member of the first simple planetary gear set is a ring gear member;
wherein the second planetary gearing arrangement includes a second compound planetary gear set and a third simple planetary gear set; wherein the second compound planetary gear set has a single ring gear member, first and second sun gear members, a carrier member and first and second sets of pinion gears, wherein the first set of pinion gears meshes with the first sun gear member and the single ring gear member, wherein the second set of pinion gears meshes with the first set of pinion gears and the second sun gear member; wherein the third simple planetary gear set has a ring gear member, a sun gear member, and a carrier member rotatably supporting a set of pinion gears that meshes with the sun gear member and the ring gear member; wherein the first member of the second planetary gearing arrangement is the ring gear member of the third planetary gear set, the second member of the second planetary gearing arrangement is the first sun gear member of the second compound planetary gear set, the third member of the second planetary gearing arrangement is the carrier member of the third planetary gear set;
wherein the third torque-transmitting mechanism is selectively engagable to ground the ring gear member of the second compound planetary gear set to the stationary member, and the fourth torque-transmitting mechanism is selectively engagable to ground the second sun gear member of the second compound planetary gear set to the stationary member; and wherein another interconnecting member connects the carrier member of the second compound planetary gear set for common rotation with the sun gear member of the third planetary gear set.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. An arrangement of concentric, independently rotating shafts for a rotating gear train system, the arrangement comprising:
an inner shaft, the inner shaft operatively coupled to a rotating element;
an outer shaft, the outer shaft concentric with the inner shaft and arranged radially outward from the inner shaft;
a first bearing stack, the first bearing stack arranged radially outward from the inner shaft and comprising at least one preloaded ball bearing;
a second bearing stack, the second bearing stack arranged radially outward from the outer shaft and comprising at least one ball bearing; and
a bearing stack retainer, mating with the first and second bearing stacks to hold the first and second bearing stacks in position with respect to the inner and outer shafts.
2. The arrangement of claim 1, wherein the bearing stack retainer comprises a retaining ring for holding the stack retainer in position with respect to the outer shaft.
3. The arrangement of claim 1, wherein the bearing stack retainer defines at least one castellation, the castellation designed to hold the stack retainer in position with respect to the outer shaft.
4. The arrangement of claim 3, wherein the outer shaft defines at least one matching castellation, the at least one matching castellation designed to mate with the at least one castellation of the bearing stack retainer.
5. The arrangement of claim 1, wherein the bearing stack retainer comprises an oil retaining dam.
6. The arrangement of claim 1, further comprising a preload disc, the preload disc applying pressure to a race of the preloaded ball bearing of the first bearing stack.
7. The arrangement of claim 1, wherein the bearing stack retainer applies pressure to a race of the ball bearing of the first bearing stack to provide pre-load for the first bearing stack.
8. A method for arranging concentric, independently rotating shafts for a rotating gear train system, the method comprising:
providing an inner shaft;
operatively coupling the inner shaft to a rotating element;
arranging an outer shaft radially outward from the inner shaft, the outer shaft concentric with the inner shaft;
arranging a first bearing stack radially outward from the inner shaft, the first bearing stack comprising at least one preloaded ball bearing;
arranging a second bearing stack radially outward from the outer shaft, the second bearing stack comprising at least one ball bearing; and
mating a bearing stack retainer with the first and second bearing stacks to hold the first and second bearing stacks in position with respect to the inner and outer shafts, the bearing stack retainer coupled with the outer shaft and rotating with the outer shaft.
9. The method of claim 8, wherein the bearing stack retainer defines at least one castellation, the castellation designed to hold the stack retainer in position with respect to the outer shaft.
10. The method of claim 9, wherein the outer shaft defines at least one matching castellation, the at least one matching castellation designed to mate with the at least one castellation of the bearing stack retainer.
11. The method of claim 8, the method further comprising providing an oil retaining dam using the bearing stack retainer.
12. The method of claim 8, further comprising applying pressure for preload of the first bearing stack using a preload disc, the preload disc applying pressure to a race of the preloaded ball bearing of the first bearing stack.
13. The method of claim 8, further comprising applying pressure for preload of the first bearing stack using the bearing stack retainer, the bearing stack retainer applying pressure to a race of the ball bearing of the first bearing stack.
14. A gas turbine engine comprising:
a fan section, the fan section including a rotating element;
a compressor section downstream of the fan section;
a combustor section downstream of the compressor section;
a turbine section downstream of the combustor section;
an inner shaft, the inner shaft operatively coupled to the rotating element of the fan section;
an outer shaft, the outer shaft concentric with the inner shaft and arranged radially outward from the inner shaft;
a first bearing stack, the first bearing stack arranged radially outward from the inner shaft and comprising at least one preloaded ball bearing;
a second bearing stack, the second bearing stack arranged radially outward from the outer shaft and comprising at least one ball bearing; and
a bearing stack retainer, the bearing stack retainer mating with the first and second bearing stacks to hold the first and second bearing stacks in position with respect to the inner and outer shafts.
15. The gas turbine engine of claim 14, wherein the compressor section comprises a high pressure compressor and a low pressure compressor and the turbine section comprises a low pressure turbine and a high pressure turbine.
16. The gas turbine engine of claim 15, wherein the inner shaft interconnects to the low pressure compressor and the low pressure turbine and the outer shaft interconnects to the high pressure compressor and the high pressure turbine.
17. The gas turbine engine of claim 14, wherein the bearing stack retainer defines at least one castellation, the castellation designed to hold the stack retainer in position with respect to the outer shaft.
18. The arrangement of claim 17, wherein the outer shaft defines at least one matching castellation, the at least one matching castellation designed to mate with the at least one castellation of the bearing stack retainer.
19. The gas turbine engine of claim 14, further comprising a preload disc, the preload disc applying pressure to a race of the preloaded ball bearing of the first bearing stack.
20. The gas turbine engine of claim 14, wherein the bearing stack retainer applies pressure to a race of the ball bearing of the first bearing stack to provide pre-load for the first bearing stack.