Split power infinitely variable transmission architecture incorporating a planetary type ball variator with multiple fixed ranges and low variator load at vehicle launch

A transmission includes an input shaft, an output shaft, a variable-ratio unit, and a plurality of torque transmitting mechanisms. The plurality of torque transmitting mechanisms include a first clutch, a second clutch, a third clutch, and a fourth clutch. The transmission is operable to (i) engage the first clutch and the second clutch in a first operating mode and (ii) engage the first clutch and the third clutch in a second operating mode. The transmission is further operable to (i) engage the fourth clutch and disengage the second clutch during a first period of time and (ii) engage the third clutch and disengage the fourth clutch during a second period of time following the first period of time to transition from the first operating mode to the second operating mode.

TECHNICAL FIELD

The present disclosure relates generally to infinitely variable transmissions, and more particularly, to the architectures of infinitely variable transmissions including ratio varying units.

BACKGROUND

Continuously variable transmissions (CVTs) utilize a ratio varying unit (e.g., a “variator”) to provide a continuous variation of transmission ratio rather than a series of predetermined ratios as provided in typical transmissions. The variator of a typical CVT is coupled between the transmission input and the transmission output via gearing and one or more clutches.

In one type of continuously variable transmission, referred to as an infinitely variable transmission (IVT), a zero output speed can be obtained independently of the rotational input speed provided to the transmission by the drive unit in a geared neutral mode. Infinitely variable transmissions may use a variator and a planetary gear train to direct power flow along multiple power paths. For instance, power may flow along a first path through the variator and along a second path through the planetary gear train. Power may also be recirculated to the variator, thereby increasing the load experienced by the variator during the operation of the infinitely variable transmission. Many current architectures for infinitely variable transmissions subject the variator to the entire power load recirculated through the infinitely variable transmission.

SUMMARY

According to one aspect of the present disclosure, a transmission includes an input shaft, an output shaft, a variable-ratio unit arranged between the input shaft and the output shaft, and a plurality of torque transmitting mechanisms arranged between the input shaft and the output shaft. The input shaft is configured to receive torque from a drive unit. The output shaft is configured to transmit torque to a load. The plurality of torque transmitting mechanisms include a first clutch, a second clutch, a third clutch, and a fourth clutch. The transmission is operable to (i) engage the first clutch and the second clutch in a first operating mode of the transmission and (ii) engage the first clutch and the third clutch in a second operating mode of the transmission. The transmission is further operable to (i) engage the fourth clutch and disengage the second clutch during a first period of time and (ii) engage the third clutch and disengage the fourth clutch during a second period of time following the first period of time to transition from the first operating mode to the second operating mode.

In some embodiments, the second period of time may immediately follow the first period of time. Additionally, in some embodiments, the transmission may be operable to engage the first clutch during the first period of time to define a fixed speed ratio between the input shaft and the output shaft during the first period of time. The transmission may be operable to receive a first plurality of input speeds at the input shaft, the transmission may be operable to provide a second plurality of output speeds at the output shaft, and one of the second plurality of output speeds may be equal to zero in the fixed speed ratio for the first plurality of input speeds.

In some embodiments, (i) the transmission may be operable to receive a first plurality of input speeds at the input shaft, (ii) the transmission may be operable to provide a second plurality of output speeds at the output shaft, (iii) the transmission may be operable to provide a first range of speed ratios between the first plurality of input speeds and the second plurality of output speeds in the first operating mode, and (iv) the first range of speed ratios may include a ratio in which one of the second plurality of output speeds is equal to zero for the first plurality of input speeds. The transmission may be operable to provide a second range of speed ratios between the first plurality of input speeds and the second plurality of output speeds in the second operating mode, and the second range of speed ratios may include a ratio in which one of the second plurality of output speeds is equal to zero for the first plurality of input speeds. The first range of speed ratios may overlap with the second range of speed ratios. In some embodiments, (i) the first range of speed ratios may include a plurality of negative speed ratios and a plurality of positive speed ratios, and (ii) the second range of speed ratios may include only the ratio and a plurality of positive speed ratios.

In some embodiments, the transmission may further include a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. Additionally, in some embodiments, the transmission may further include only a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset.

According to another aspect of the present disclosure, a transmission includes an input shaft, an output shaft, a variable-ratio unit arranged between the input shaft and the output shaft, and a plurality of torque transmitting mechanisms arranged between the input shaft and the output shaft. The input shaft is configured to receive torque from a drive unit. The output shaft is configured to transmit torque to a load. The plurality of torque transmitting mechanisms includes a first clutch, a second clutch, a third clutch, and a fourth clutch. The transmission is operable to (i) engage the first clutch and the second clutch in a first operating mode of the transmission and (ii) engage the first clutch and the third clutch in a second operating mode of the transmission. The transmission is further operable to (i) engage the fourth clutch and disengage the second clutch to transition from the first operating mode to a third operating mode and (ii) engage the third clutch and disengage the fourth clutch to transition from the third operating mode to the second operating mode.

In some embodiments, the plurality of torque transmitting mechanisms may include a fifth clutch. The transmission may be operable to (i) engage the third clutch and the fifth clutch in a fourth operating mode of the transmission and (ii) engage the second clutch and the fifth clutch in a fifth operating mode of the transmission. The transmission may be operable to (i) engage the fourth clutch and disengage the third clutch to transition from the fourth operating mode to a sixth operating mode and (ii) engage the second clutch and disengage the fourth clutch to transition from the sixth operating mode to the fifth operating mode. The transmission may be operable to engage the fifth clutch when the fourth clutch is engaged and the third clutch is disengaged to define a fixed speed ratio between the input shaft and the output shaft. Additionally, in some embodiments, (i) the transmission may be operable to receive a first plurality of input speeds at the input shaft, (ii) the transmission may be operable to provide a second plurality of output speeds at the output shaft, (iii) the transmission may be operable to provide a first range of speed ratios between the first plurality of input speeds and the second plurality of output speeds in the fourth operating mode, (iv) the transmission may be operable to provide a second range of speed ratios between the first plurality of input speeds and the second plurality of output speeds in the fifth operating mode, and (v) the first range of speed ratios may overlap with the second range of speed ratios.

In some embodiments, the transmission may further include a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. Additionally, in some embodiments, the transmission may further include only a first planetary gearset, a second planetary gearset, a third planetary gearset, and a fourth planetary gearset. The transmission may further comprise a housing, and at least three of the clutches may be engageable to couple an element of one of the planetary gearsets to the housing.

According to another aspect of the present disclosure, a method for operating a transmission that includes an input shaft, an output shaft, a variable-ratio unit arranged between the input shaft and the output shaft, and a plurality of clutches arranged between the input shaft and the output shaft includes (i) engaging a first clutch and a second clutch in a first operating mode to transmit torque received at the input shaft from the input shaft to the output shaft in the first operating mode, (ii) engaging a fourth clutch and disengaging the second clutch to transition from the first operating mode to a second operating mode and to prevent torque received at the input shaft from being transmitted through the variable-ratio unit to the output shaft in the second operating mode, and (iii) engaging a third clutch and disengaging the fourth clutch to transition from the second operating mode to a third operating mode to transmit torque received at the input shaft from the input shaft to the output shaft in the third operating mode.

In some embodiments, the method may further include (i) operating the variable-ratio unit to output a first torque ratio in the first operating mode, (ii) adjusting the variable-ratio unit to change the torque ratio output from the variable-ratio unit in the second operating mode, and (iii) operating the variable-ratio unit to output a second torque ratio in the third operating mode that may be different from the first torque ratio.

According to another aspect of the present disclosure, a transmission is operable in a plurality of operating modes and comprises an input shaft, a plurality of planetary gearsets, a variable-ratio unit, and a plurality of torque-transmitting mechanisms. The input shaft is configured to receive torque from a drive unit and transmit the torque to an output shaft of the transmission. The plurality of planetary gearsets is arranged between the input shaft and the output shaft. Each one of the plurality of planetary gearsets includes a sun gear, a ring gear, a carrier, and a plurality of planet gears. The plurality of planetary gearsets includes a first planetary gearset and a second planetary gearset. The variable-ratio unit is operable to produce continuously-variable torque output, and the variable-ratio unit includes an input ring coupled to the input shaft and an output ring coupled to the sun gear of the first planetary gearset. The plurality of torque transmitting mechanisms includes a variator bypass clutch and a first clutch. The variator bypass clutch is engageable to bypass the variable-ratio unit to prevent continuously-variable torque output from being produced in at least one operating mode of the transmission. The first clutch is engageable to couple the output ring of the variable-ratio unit to the carrier of the second planetary gearset through the sun gear of the first planetary gearset.

In some embodiments, the transmission may comprise a transmission housing. The plurality of torque transmitting mechanisms may include a second clutch. The second clutch may be engageable to couple the ring gear of the first planetary gearset to the transmission housing to brake the ring gear of the first planetary gearset.

In some embodiments, the plurality of torque transmitting mechanisms may include a third clutch. The third clutch may be engageable to couple the sun gear of the second planetary gearset to the transmission housing to brake the sun gear of the second planetary gearset.

In some embodiments, the plurality of planetary gearsets may include a third planetary gearset. The sun gear of the third planetary gearset may be coupled to the carrier of the second planetary gearset. The plurality of torque transmitting mechanisms may include a fourth clutch. The fourth clutch may be engageable to couple the carrier of the third planetary gearset to the transmission housing to brake the carrier of the third planetary gearset.

In some embodiments, the plurality of planetary gearsets may include a fourth planetary gearset. The ring gear of the third planetary gearset may be coupled to the ring gear of the fourth planetary gearset. Each component of the fourth planetary gearset may be configured to rotate. The plurality of torque transmitting mechanisms may include a fifth clutch. The fifth clutch may be engageable to couple the carrier of the second planetary gearset to the carrier of the fourth planetary gearset through the sun gear of the third planetary gearset.

According to another aspect of the present disclosure, a transmission is operable in a plurality of operating modes and comprises an input shaft, a plurality of planetary gearsets, a variable-ratio unit, and a plurality of torque transmitting mechanisms. The input shaft is configured to receive torque from a drive unit and transmit the torque to an output shaft of the transmission. Each of the plurality of planetary gearsets includes a ring gear, a sun gear, a carrier, and a plurality of planet gears. The plurality of planetary gearsets includes a first planetary gearset, a second planetary gearset, and a third planetary gearset. The variable-ratio unit is operable to produce continuously-variable torque output. The plurality of torque transmitting mechanisms includes a first clutch, a second clutch, and a third clutch. The first clutch is engageable to couple the carrier of the first planetary gearset to a transmission housing to brake the carrier of the first planetary gearset. The second clutch is engageable to couple the sun gear of the second planetary gearset to the carrier of the third planetary gearset. The third clutch is engageable to couple the ring gear of the second planetary gearset to the transmission housing to brake the ring gear of the second planetary gearset. The first clutch and the second clutch are contemporaneously engaged in a first operating mode of the transmission. The first clutch and the third clutch are contemporaneously engaged in a second operating mode of the transmission. The variable-ratio unit is configured to output torque at a first ratio preventing a synchronous transition from the first operating mode of the transmission to the second operating mode of the transmission.

In some embodiments, the plurality of torque transmitting mechanisms may include a variator bypass clutch. The variator bypass clutch may be engageable to bypass the variable-ratio unit to prevent continuously-variable torque output from being produced in at least one operating mode of the transmission. The variable-ratio unit may include an input ring and an output ring. The variator bypass clutch may be engageable to couple the input ring to the output ring to bypass the variable-ratio unit. The transmission may output torque at a ratio varying within a defined range in each of the first and second operating modes.

In some embodiments, the plurality of planetary gearsets may include a fourth planetary gearset, and the plurality of torque transmitting mechanisms may include a fourth clutch. The fourth clutch may be engageable to couple the sun gear of the first planetary gearset to the carrier of the fourth planetary gearset. The third clutch and the fourth clutch may be contemporaneously engaged in a third operating mode of the transmission. The second clutch and the fourth clutch may be contemporaneously engaged in a fourth operating mode of the transmission. The variable-ratio unit may be configured to output torque at a second ratio preventing a synchronous transition from the third operating mode of the transmission to the fourth operating mode of the transmission. The transmission may output torque at a ratio varying within a defined range in each of the third and fourth operating modes.

In some embodiments, the carrier of the third planetary gearset may be coupled to the sun gear of the first planetary gearset. The fourth clutch may be engageable to couple the carrier of the third planetary gearset to the carrier of the fourth planetary gearset through the sun gear of the first planetary gearset. Each component of the fourth planetary gearset may be configured to rotate. The plurality of torque transmitting mechanisms may include a fifth clutch. The fifth clutch may be engageable to couple the sun gear of the third planetary gearset to the transmission housing to brake the sun gear of the third planetary gearset. The ring gear of the third planetary gearset may be coupled to the input shaft. The carrier of the fourth planetary gearset may be coupled to the output shaft.

According to another aspect of the present disclosure, a transmission comprises an input shaft, a plurality of planetary gearsets, a variable-ratio unit, and a plurality of torque transmitting mechanisms. The input shaft is configured to receive torque from a drive unit and transmit the torque to an output shaft of the transmission in a first operating mode and a second operating mode of the transmission. Each of the plurality of planetary gearsets includes a ring gear, a sun gear, a carrier, and a plurality of planet gears. The plurality of planetary gearsets includes a first planetary gearset, a second planetary gearset, and a third planetary gearset. The variable-ratio is operable to produce continuously-variable torque output. The plurality of torque transmitting mechanisms includes a first clutch, a second clutch, a third clutch, and a fourth clutch. The first clutch is engageable to couple the carrier of the first planetary gearset to a transmission housing to brake the carrier of the first planetary gearset. The second clutch is engageable to couple the sun gear of the second planetary gearset to the carrier of the third planetary gearset. The third clutch is engageable to couple the ring gear of the second planetary gearset to the transmission housing to brake the ring gear of the second planetary gearset. The fourth clutch is engageable to couple the carrier of the third planetary gearset to the transmission housing to brake the carrier of the third planetary gearset. The first clutch and the second clutch are contemporaneously engaged in a first operating mode of the transmission. The first clutch and the third clutch are contemporaneously engaged in a second operating mode of the transmission. The first clutch and the fourth clutch are contemporaneously engaged in a third operating mode of the transmission to effect a synchronous transition from the first operating mode to the second operating mode. Torque received by the input shaft from the drive unit is not transmitted to the output shaft in the third operating mode.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now toFIG. 1, an illustrative motor vehicle100includes a drive unit102, a transmission104coupled to the drive unit102, and a vehicle load106coupled to the transmission104. The drive unit102may be embodied as any type of motor or internal combustion engine having a reciprocating or a rotary configuration that provides rotational power to the transmission104and therethrough to the vehicle load106. For instance, the drive unit102may be embodied as a four-stroke piston engine, a diesel engine, or a rotary engine. The vehicle load106may be embodied as, or otherwise include, drive wheels, caterpillar tracks, propels, etc. that impart the motor vehicle100with locomotion when driven by the drive unit102via the transmission104. Additionally, the vehicle load106may be embodied as an auxiliary gearbox (e.g., a transfer case or drop box) or a power take-off device, such as a pump, mixer, lifter, shoveler, compressor, compactor, or blower.

In use, rotational power generated by the drive unit102is transmitted to the transmission104via a drive unit output shaft108included in the drive unit102. The drive unit output shaft108is coupled to a transmission input shaft110included in the transmission104. Additionally, rotational power received by the transmission104at the input shaft110is transmitted to a transmission output shaft112and therefrom to the vehicle load106.

The transmission104ensures the controlled application of rotational power generated by the drive unit102to the vehicle load106. The transmission104, as discussed below, includes a plurality of gearsets that enable speed and torque generated by the drive unit102to be converted for use by the vehicle load106.

The transmission104is operable in a plurality of operating modes to transmit rotational power supplied by the drive unit102from the transmission input shaft110to the transmission output shaft112. Each operating mode enables at least one ratio of input speed (i.e., at the transmission input shaft110) to output speed (i.e., at the transmission output shaft112) to be achieved. As discussed below, operating modes of the transmission104in which a variator114is utilized enable a range of transmission ratios to be achieved whereas operating modes in which the variator114is not utilized enable only a single transmission ratio to be achieved.

The transmission104ofFIG. 1is illustratively embodied as an infinitely variable transmission. The transmission104includes the variator114, a plurality of clutches115, and a plurality of gearsets127in addition to the input shaft110and the output shaft112. Illustratively, the plurality of clutches115includes a first clutch116, a second clutch118, a third clutch120, a fourth clutch122, a fifth clutch124, and a variator bypass clutch126. Additionally, the illustrative plurality of gearsets127includes a first gearset128, a second gearset130, a third gearset132, and a fourth gearset134.

The infinitely variable transmission104is operable, as discussed below, to split rotational power supplied from the drive unit102between the variator114and the plurality of gearsets127. The transmission104is also operable, in at least one operating mode, to achieve zero output speed at the output shaft112in a mode referred herein to as a “geared neutral mode.” The transmission104is further operable to recirculate rotational power directed toward the output shaft112back toward the input shaft110in multiple operating modes. As discussed below, power recirculated back toward the input shaft110and received by the variator114is reduced as a result of the architecture of the infinitely variable transmission104. In this manner, the infinitely variable transmission104is similar to the infinitely variable transmission disclosed in U.S. Provisional Patent App. Ser. No. 61/798,476 entitled “SPLIT POWER INFINITELY VARIABLE TRANSMISSION ARCHITECTURE” by Brian Schoolcraft, the entirety of which is hereby incorporated by reference.

The variator114, the plurality of clutches115, and the plurality of gearsets127included in the transmission104are arranged between the input shaft110and the output shaft112of the transmission104. Each of the gearsets included in the plurality of gearsets127may be supported by a mainshaft of the transmission104and may be capable of rotating freely and independently thereof. Each of the clutches may be selectively engaged to transmit power along a particular path between components included in the transmission104as discussed below.

Each of the plurality of clutches115included in the transmission104is embodied as a torque-transmitting device configured to define a torque transfer path between components included in the transmission104. By selectively engaging each of the plurality of clutches115in combination with one another, the plurality of clutches115define a torque transfer path from the input shaft110to the output shaft112and thereby effect a change from one operating mode to another. In one example, one or more of the plurality of clutches115may be embodied as a three-position dog clutch such as the three-position dog clutch disclosed in U.S. Provisional Patent App. Ser. No. 61/799,200 entitled “THREE-POSITION DOG CLUTCH” by Brian Schoolcraft, the entirety of which is hereby incorporated by reference. In other embodiments, one or more of the plurality of clutches115may be embodied as multi-plate wet clutches or controllable mechanical diodes, the engagement/disengagement of which are used to accomplish changes between operating modes. As discussed below, in the illustrative embodiment, the second clutch118, the fourth clutch122, and the variator bypass clutch126are rotating clutches while the first clutch116, the third clutch120, and the fifth clutch124are stationary, non-rotating clutches. Additionally, the variator bypass clutch126, as discussed below, is engageable to lock a variator input ring136to a variator output ring140so that the variator114achieves a 1:1 ratio (i.e., variator input speed is equal to variator output speed). When the variator bypass clutch126is engaged, the power load experienced by the variator114is removed, and all the power transmitted to the variator114flows instead through the variator bypass clutch126.

Referring now toFIG. 2, in the illustrative embodiment, the variator114is embodied as a planetary-type ball variator and includes the input ring136and the output ring140. Each of the variator rings136,140are spaced apart as shown inFIG. 2to permit a ball138to be positioned between the rings136,140. The ball138is configured to tilt between the rings136,140to vary the ratio achieved using the variator114. An axle142encircles the ball138as shown inFIG. 2. The ball138is tilted by continuously tilting the axle142so that continuously-variable torque output is produced using the variator114.

Referring now toFIG. 3, the architecture of the transmission104is shown in which each gearset of the plurality of gearsets127is represented by a corresponding box (i.e., G1, G2, G3, and G4) and the variator114is designated as “VAR.” G1designates the first gearset128, G2designates the second gearset130, G3designates the third gearset132, and G4designates the fourth gearset134. Each clutch of the plurality of clutches127is also represented by a box such that the following designations apply: C1(the first clutch116), C2(the second clutch118), C3(the third clutch120), C4(the fourth clutch122), C5(the fifth clutch124), and C6(the variator bypass clutch126).

It should be appreciated that the architecture of the transmission104defines a plurality of power paths along which power is transmitted between components included in the transmission104during one or more operational modes. In the illustrative embodiment, the plurality of power paths includes a power path144, a power path146, a power path148, a power path150, and a power path152. As illustrated inFIGS. 6-17, power flow along the power path144is bi-directional in the plurality of operating modes of the transmission104, and power flow along the power path146is uni-directional in the plurality of operating modes of the transmission104.

The power path144is defined by a junction157, a junction153, a junction160, the first gearset128, the second gearset130, the first clutch116, a junction154, and a junction155. The input side of the power path144is defined at the junctions157,153. The junctions157,153may be embodied as couplings permitting power received by the input shaft110to be transmitted along the power path144and toward the first gearset128and the second gearset130. The junctions157,153also permit power received by the input shaft110to be transmitted toward or away from the variator114. As such, power may be transmitted along the power path144from the junction153to the first gearset128, and power transmitted to the first gearset128along the power path144may be transmitted thereafter to the junction155and/or recirculated toward the input shaft110through the second gearset130and thereafter along one of the power paths148,150as shown inFIGS. 6-17. Power may also be recirculated along the power path144from the first gearset128toward the input shaft110as shown inFIGS. 6-17.

As illustrated inFIGS. 6-17, the first gearset128is a “mixing” planetary gearset that allows one portion of power transmitted thereto to be transmitted to the junction155and therefrom to the output shaft112, and another portion of power transmitted thereto to be recirculated back toward the input shaft110. Each component of the first gearset128(i.e., each of a sun gear, a carrier, a ring gear, and a plurality of planet gears included in the first gearset128as described in more detail below) rotates and is configured to transmit power (i.e., no component of the first gearset128is grounded).

The power path144utilizes a “fixed” and a “variable” sub-path to transmit power, whereas the power path146utilizes only a “fixed” sub-path to transmit power. Power transmitted along the “fixed” sub-path is transmitted at a fixed mechanical ratio. Conversely, power transmitted along the “variable” sub-path is transmitted over a continuously-variable ratio range, i.e., embodied as power transmitted through the variator114. The “fixed” and “variable” sub-paths of the power path144are described below, and the “fixed” sub-path of the power path146is also described below.

The “fixed” sub-path of the power path144corresponds to power flowing from the junction153to the first gearset128and from the first gearset128to the junction155(e.g., as shown inFIGS. 7 and 10). The “variable” sub-path of the power path144corresponds to power flowing from the junction153to the junction154through both the first and second gearsets128,130and therefrom toward the variator114along one of the power paths148,150(e.g., as shown inFIGS. 7 and 10).

The power path146is defined by the junction154, the second clutch118, and the junction155. The power path146is utilized in conjunction with at least one of the power paths144,148,150,152to transmit power from the input shaft110to the output shaft112as shown inFIGS. 6-17. It should be appreciated that the power path146is “direct” in that power transmitted along the power path146is not split or recirculated as shown inFIGS. 6-17.

The “fixed” sub-path of the power path146corresponds to power flowing from the junction154to the junction155and therefrom to the output shaft112when the second clutch118is engaged (e.g., as shown inFIGS. 12-17). Power may be transmitted to the junction154from the input shaft110along one of the power paths148,150,152(e.g., as shown inFIGS. 13-14 and 16-17), or power may be transmitted to the junction154from the input shaft110along the power path144(e.g., as shown inFIG. 12).

The power path148is defined by a junction157, the variator114, a junction158, a junction159, a junction160, the variator bypass clutch126, the third gearset132, the third clutch120, a junction151, a junction156, and the junction154. Similar to the power path144, the power path148utilizes a “fixed” and a “variable” sub-path to transmit power between components of the transmission104. The “fixed” sub-path of the power path148corresponds to power flowing between the junctions159,154when the third clutch120and the variator bypass clutch126are contemporaneously engaged (e.g., as shown inFIG. 11). The “variable” sub-path of the power path148corresponds to power flowing between the junctions157,158(i.e., through the variator114) when the third clutch120is engaged and the variator bypass clutch126is not engaged (e.g., as shown inFIG. 10).

The power path150is defined by the junction157, the variator114, the junction158, the junction159, the junction160, the variator bypass clutch126, the fourth clutch122, the junction151, and the junction156. Similar to the power path148, the power path150utilizes a “fixed” sub-path and a “variable” sub-path to transmit power between components of the transmission104. The “fixed” sub-path of the power path150corresponds to power flowing between the junctions159,156when the fourth clutch122and the variator bypass clutch126are contemporaneously engaged (e.g., as shown inFIG. 8). The “variable” sub-path of the power path150corresponds to power flowing between the junctions157,158(i.e., through the variator114) when the fourth clutch122is engaged and the variator bypass clutch126is not engaged (e.g., as shown inFIGS. 6-7).

The power path152is defined by the junction157, the junction160, the junction153, the fourth gearset134, the fifth clutch124, and the junction156. As discussed below and shown inFIGS. 9 and 15, the power path152is utilized in a first transition operating mode to effect a synchronous transition from an operating mode in which power is transmitted along the power path150(i.e., the “Mode1” operating mode) to an operating mode in which power is transmitted along the power path148(i.e., the “Mode2” operating mode). Additionally, the power path152is utilized in a second transition operating mode to effect a synchronous transition from an operating mode in which power is transmitted along the power path148(i.e., the “Mode3” operating mode) to an operating mode in which power is transmitted along the power path150(i.e., the “Mode4” operating mode). The power path152does not utilize the variator114to transmit power between components of the transmission104, and therefore the power path152utilizes only a “fixed” sub-path to transmit power between the transmission104components.

Referring now toFIG. 4, the variator114, the plurality of gearsets127, and the plurality of clutches115of the transmission104are physically arranged between the input shaft110and the output shaft112of the transmission104. In the illustrative physical arrangement of the transmission104, the variator114is positioned in front of the plurality of clutches115and the plurality of gearsets127relative to the input shaft110as shown inFIG. 4.

The first gearset128of the plurality of gearsets127is configured to receive power supplied by the input shaft110and transmitted to the junction153and thereafter to the first gearset128as shown, for example, inFIGS. 7 and 10-12. The first gearset128is illustratively a simple planetary gearset that includes a ring gear162, a plurality of planet gears164, a carrier166, and a sun gear168. Each of the planet gears164is intermeshed with the ring gear162and the sun gear168, and each of the planet gears164is supported for rotation by the carrier166. Power from the input shaft110is transmitted to the junction153and therefrom to the sun gear168. The ring gear162of the first gearset128is coupled to the second gearset130, and the carrier166of the first gearset128is coupled to the output shaft112. The second clutch118is engageable to couple the carrier166of the first gearset128to the second gearset130.

The second gearset130of the plurality of gearsets127is configured to receive power supplied by the input shaft110and transmitted to the junction153and therefrom to the second gearset130through the first gearset128as shown in, for example,FIGS. 7 and 10-12. The second gearset130, similar to the first gearset128, is illustratively a simple planetary gearset that includes a ring gear170, a plurality of planet gears172, a carrier174, and a sun gear176. Each of the planet gears172is intermeshed with the ring gear170and the sun gear176, and each of the planet gears172is supported for rotation by the carrier174. The first clutch116is engageable to couple the carrier174to a stationary, non-rotating part of the transmission104, thereby preventing the carrier174from rotating (i.e., braking the carrier174). For instance, the first clutch116may be engaged to couple the carrier174to a housing of the transmission104. The ring gear170of the second gearset130is coupled to the ring gear162of the first gearset128. The second clutch118is engageable to couple the sun gear176of the second gearset130to the carrier166of the first gearset128. The sun gear176of the second gearset130is coupled to the fourth gearset134.

The third gearset132of the plurality of gearsets127is configured to receive power transmitted between the input shaft110and the output shaft112when the third clutch120is engaged as shown, for example, inFIGS. 10-11 and 13-14. The third gearset132is illustratively a simple planetary gearset that includes a ring gear178, a plurality of planet gears180, a carrier182, and a sun gear184. Each of the planet gears180is intermeshed with the ring gear178and the sun gear184, and each of the planet gears180is supported for rotation by the carrier182. The third clutch120is engageable to couple the ring gear178to a stationary, non-rotating part of the transmission104, thereby preventing the ring gear178from rotating (i.e., braking the ring gear178). For instance, the third clutch120may be engaged to couple the ring gear178to the housing of the transmission104. The sun gear184is coupled to the output ring140of the variator114, and the fourth clutch122is engageable to couple the sun gear184to the fourth gearset134. As such, the fourth clutch122is engageable to couple the output ring140of the variator114to the fourth gearset134through the sun gear184of the third gearset132. The fourth clutch122is also engageable to couple the carrier182to the fourth gearset134.

The fourth gearset134of the plurality of gearsets127is configured to receive power transmitted between the input shaft110and the output shaft112when the fifth clutch124is engaged as shown, for example, inFIGS. 9 and 15. The fourth gearset134is illustratively a simple planetary gearset that includes a ring gear186, a plurality of planet gears188, a carrier190, and a sun gear192. Each of the planet gears188is intermeshed with the ring gear186and the sun gear192, and each of the planet gears188is supported for rotation by the carrier190. The ring gear186is coupled to the input shaft110to receive power therefrom. The carrier190is coupled to the sun gear176of the second gearset130, and the second clutch118is engageable to couple the sun gear176of the second gearset130to the carrier166of the first gearset128. As such, the second clutch118is engageable to couple the carrier190of the fourth gearset134to the carrier166of the first gearset128through the sun gear176of the second gearset130. The fourth clutch122is engageable to couple the carrier190to the carrier182of the third gearset132and the sun gear184of the third gearset132. The fifth clutch124is engageable to couple the sun gear188to a stationary, non-rotating part of the transmission104, thereby preventing the sun gear188from rotating (i.e., braking the sun gear188). For instance, the fifth clutch124may be engaged to couple the sun gear188to the housing of the transmission104.

A power take-off device (not shown) may be coupled to the variator114to transmit power from the drive unit102to the variator114and therefrom to the power-take off device. The power take-off device may be coupled to the output ring140of the variator114. When the transmission104is placed in a neutral range, the variator114may be used to continuously vary the ratio of the power-take off device relative to the rotational speed of the drive unit output shaft108and the transmission input shaft110.

Referring now toFIG. 5, a table194illustrates the various operating modes of the transmission104, the clutches applied in each mode, the transmission ratio(s) achieved in each mode, and the figure(s) in which each mode is shown. The transmission104is operable in four operating modes to achieve a variable transmission ratio within a defined transmission ratio range. In all other operating modes, as discussed below, the transmission104achieves a single transmission ratio.

The transmission104is operable in the “Mode1” operating mode, when the first clutch116and the fourth clutch122are contemporaneously engaged as shown inFIG. 5, to achieve a variable transmission ratio within the range of −0.536 (minimum) to 0.020 (maximum). As suggested above, the variable transmission ratio is achievable in “Mode1” as a result of utilizing the variator114. The “Mode1” operating mode covers a reverse ratio range (i.e., a ratio range from −0.330 to 0.000) to a low forward ratio range (i.e., 0.000 to 0.020). The “Mode1” operating mode covers a zero ratio and therefore provides a first geared neutral mode.

The transmission104is operable in a first variator bypass operating mode (referred to as “Lock1” in table194), when the first clutch116, the fourth clutch122, and the variator bypass clutch126are contemporaneously engaged as shown inFIG. 5, to achieve a fixed transmission ratio of −0.179. Because the variator114is bypassed in the “Lock1” mode, only a single fixed transmission ratio is achieved by the transmission104. The “Lock1” operating mode covers a reverse ratio.

The transmission104is operable in a first transition operating mode (referred to as “Bypass1-2” in table194), when the first clutch116and the fifth clutch124are contemporaneously engaged, as shown inFIG. 5, to achieve a fixed transmission ratio of 0.000. The “Bypass1-2” mode therefore provides a second geared neutral mode. As discussed in more detail below, the “Bypass1-2” operating mode is utilized to effect a synchronous transition from transmitting power between the input shaft110and the output shaft112along the power path150in the “Mode1” operating mode to transmitting power between the input shaft110and the output shaft112along the power path148in the “Mode2” operating mode.

The ratios achieved by the transmission104in the “Mode1” and “Mode2” operating modes overlap such that the variator114output torque ratios in those modes overlap as well. Transitioning from transmitting power along the power path150in the “Mode1” operating mode to transmitting power along the power path148in the “Mode2” operating mode requires a first transition ratio in the overlapping portion of the variator114ratios to be determined The first transition ratio corresponds to a point at which the transmission104transitions from transmitting power along the power path150in “Mode1” to transmitting power along the power path148in “Mode2.” The variator114is operable to output torque at a first torque ratio at one end of the operating range of the variator114in the “Mode1” operating mode, and torque at a second torque ratio different from the first torque ratio at another opposite end of the operating range of the variator114in the “Mode2” operating mode. The first torque ratio is illustratively greater than the second torque ratio, but it should be understood that the first torque ratio may be less than the second torque ratio. Because transitioning from “Mode1” to “Mode2” at the first transition ratio requires the variator114to adjust from outputting torque at the first torque ratio (i.e., at the one end of the variator114operating range) to outputting torque at the second torque ratio (i.e., at the opposite end of the variator114operating range), the first transition ratio prevents a single-shift synchronous transition from transmitting torque along the power path150in the “Mode1” operating mode to transmitting torque along the power path148in the “Mode2” operating mode. The power path152is utilized, as discussed below, to effect a synchronous transition from transmitting power along the power path150in “Mode1” to transmitting power along the power path148in “Mode2.”

The power path152is utilized to enable the variator114to synchronously transition between outputting torque at the first and second torque ratios in the “Mode1” and “Mode2” operating modes, respectively, to effect a transition from the “Mode1” operating mode to the “Mode2” operating mode. Specifically, the fifth clutch124is engaged and the fourth clutch122is disengaged during a first period of time to permit power flow along the power path152and prevent power flow along the power path150in response to the variator114outputting torque at a ratio approaching the first transition ratio in the “Mode1” operating mode (seeFIG. 9). During the first period of time, the fifth clutch124is first engaged and the fourth clutch122is disengaged substantially immediately thereafter. Once the fifth clutch124has been engaged and the fourth clutch122has been disengaged thereafter, the variator114adjusts (i.e., at the first transition ratio) from outputting torque at the first torque ratio in “Mode1” to outputting torque at the second torque ratio in “Mode2.” Once the variator114adjusts to outputting torque at the second torque ratio associated with “Mode2,” the third clutch120is engaged and the fifth clutch124is disengaged during a second period of time following the first period of time to permit power flow along the power path148and prevent power flow along the power path152. The second period of time occurs substantially immediately after the first period of time. During the second period of time, the third clutch120is first engaged and the fifth clutch124is disengaged substantially immediately thereafter. Once the third clutch120has been engaged and the fifth clutch124has been disengaged thereafter, the transmission104is operable in the “Mode2” operating mode and the transition from the “Mode1” operating mode to the “Mode2” operating mode has been completed.

Referring back toFIG. 5, the transmission104is operable in the “Mode2” operating mode, when the first clutch116and the third clutch120are contemporaneously engaged, to achieve a variable transmission ratio within the range of 0.000 (minimum) to 0.185 (maximum). As suggested above, the variable transmission ratio is achievable in “Mode2” as a result of utilizing the variator114. The “Mode2” operating mode provides a third geared neutral mode and covers a forward ratio range (i.e., from 0.000 to 0.185).

The transmission104is operable in a second variator bypass operating mode (referred to as “Lock2” in the table194), when the first clutch116, the third clutch120, and the variator bypass clutch126are contemporaneously engaged as shown inFIG. 5, to achieve a fixed transmission ratio of 0.119. Because the variator114is bypassed in the “Lock2” operating mode, only a single fixed transmission ratio is achieved by the transmission104. The “Lock2” operating mode covers a forward ratio.

The transmission104is operable in the “Sync2-3” operating mode, when the first clutch116and the second clutch118are contemporaneously engaged as shown inFIG. 5, to achieve a fixed transmission ratio of 0.185. The ratio of 0.185 coincides with the maximum ratio achieved in the “Mode2” operating mode and the minimum ratio achieved in the “Mode3” operating mode (discussed below) so that the “Sync2-3” operating mode effects a synchronous transition between those two modes. A single fixed transmission ratio is achieved by the transmission104in the “Sync2-3” mode because the variator114is effectively bypassed. The “Sync2-3” operating mode covers another forward ratio.

The transmission104is operable in the “Mode3” operating mode, when the second clutch118and the third clutch120are contemporaneously engaged as shown inFIG. 5, to achieve a variable transmission ratio within the range of 0.185 (minimum) to 0.600 (maximum). As suggested above, the variable transmission ratio is achievable in “Mode3” as a result of utilizing the variator114. The “Mode3” operating mode covers another forward ratio range.

The transmission104is operable in a third variator bypass operating mode (referred to as “Lock3” in table194), when the second clutch118, the third clutch120, and the variator bypass clutch126are contemporaneously engaged as shown inFIG. 5, to achieve a fixed transmission ratio of 0.333. Because the variator114is bypassed in the “Lock3” operating mode, only a single fixed transmission ratio is achieved by the transmission104. The “Lock3” operating mode covers another forward ratio.

The transmission104is operable in a second transition operating mode (referred to as “Bypass3-4” in table194), when the second clutch118and the fifth clutch124are contemporaneously engaged, as shown inFIG. 5, to achieve a fixed transmission ratio of 0.600. As discussed in more detail below, the “Bypass3-4” operating mode is utilized to effect a synchronous transition from transmitting power between the input shaft110and the output shaft112along the power path148in the “Mode3” operating mode to transmitting power between the input shaft110and the output shaft112along the power path150in the “Mode4” operating mode.

The ratios achieved by the transmission104in the “Mode3” and “Mode4” operating modes overlap such that the variator114output torque ratios in those modes overlap as well. Transitioning from transmitting power along the power path148in the “Mode3” operating mode to transmitting power along the power path150in the “Mode4” operating mode requires a second transition ratio in the overlapping portion of the variator114ratios to be determined The second transition ratio corresponds to a point at which the transmission104transitions from transmitting power along the power path148in “Mode3” to transmitting power along the power path150in “Mode4.” The variator114is operable to output torque at a third torque ratio at one end of the operating range of the variator114in the “Mode3” operating mode, and torque at a fourth torque ratio different from the third torque ratio at another opposite end of the operating range of the variator114in the “Mode4” operating mode. The third torque ratio is illustratively greater than the fourth torque ratio, but it should be understood that the third torque ratio may be less than the fourth torque ratio. Because transitioning from “Mode3” to “Mode4” at the second transition ratio requires the variator114to adjust from outputting torque at the third torque ratio (i.e., at the one end of the variator114operating range) to outputting torque at the fourth torque ratio (i.e., at the opposite end of the variator114operating range), the second transition ratio prevents a single-shift synchronous transition from transmitting torque along the power path148in the “Mode3” operating mode to transmitting torque along the power path150in the “Mode4” operating mode. The power path152is utilized, as discussed below, to effect a synchronous transition from transmitting power along the power path148in “Mode3” to transmitting power along the power path150in “Mode4.”

The power path152is utilized to enable the variator114to synchronously transition between outputting torque at the third and fourth torque ratios in the “Mode3” and “Mode4” operating modes, respectively, to effect a transition from the “Mode3” operating mode to the “Mode4” operating mode. Specifically, the fifth clutch124is engaged and the third clutch120is disengaged during a third period of time to permit power flow along the power path152and prevent power flow along the power path148in response to the variator114outputting torque at a ratio approaching the second transition ratio in the “Mode3” operating mode (seeFIG. 15). During the third period of time, the fifth clutch124is first engaged and the third clutch120is disengaged substantially immediately thereafter. Once the fifth clutch124has been engaged and the third clutch120has been disengaged thereafter, the variator114adjusts (i.e., at the first transition ratio) from outputting torque at the third torque ratio in “Mode3” to outputting torque at the fourth torque ratio in “Mode4.” Once the variator114adjusts to outputting torque at the fourth torque ratio associated with “Mode4,” the fourth clutch122is engaged and the fifth clutch124is disengaged during a fourth period of time following the third period of time to permit power flow along the power path150and prevent power flow along the power path152. The fourth period of time occurs substantially immediately after the third period of time. During the fourth period of time, the fourth clutch122is first engaged and the fifth clutch124is disengaged substantially immediately thereafter. Once the fourth clutch122has been engaged and the fifth clutch124has been disengaged thereafter, the transmission104is operable in the “Mode4” operating mode and the transition from the “Mode3” operating mode to the “Mode4” operating mode has been completed.

Referring back toFIG. 5, the transmission104is operable in the “Mode4” operating mode, when the second clutch118and the fourth clutch122are contemporaneously engaged, to achieve a variable transmission ratio within the range of 0.556 (minimum) to 1.800 (maximum). As suggested above, the variable transmission ratio is achievable in “Mode4” as a result of utilizing the variator114. The “Mode4” operating mode covers another forward ratio range.

The transmission104is operable in a fourth variator bypass operating mode (referred to as “Lock4” in table194), when the second clutch118, the fourth clutch122, and the variator bypass clutch126are contemporaneously engaged as shown inFIG. 5, to achieve a fixed transmission ratio of 1.000. Because the variator114is bypassed in the “Lock4” operating mode, only a single fixed transmission ratio is achieved by the transmission104. The “Lock4” operating mode covers another forward ratio.

Referring now toFIGS. 6-17, power flow from the input shaft110to the output shaft112of the transmission104is illustrated in each of the operating modes discussed above. Beginning with the reverse ratio range of “Mode1” of table194, power flows from the input shaft110to the output shaft112of the transmission104are shown inFIG. 6. Input power195(designated by the solid arrows) flows from the input shaft110to the junction157as shown inFIG. 6. Input power195is transmitted from the junction157to the junction156through the variator114, the junctions158,159,151, and the fourth clutch122, and input power195reaching the junction156is transmitted to the first gearset128through the second gearset130and the junction154. Input power195reaching the first gearset128is modified by the “mixing” gearset128such that some of the power that is output from the first gearset128flows to the junction155and thereafter to the output shaft112and some of the power flows back to the junction157, as described in greater detail below.

Recirculated power196(designated by the dotted arrows) is recirculated from the first gearset128back to the junction157through the junctions153,160as shown inFIG. 6. At the junction157, recirculated power196is combined with input power195received from the input shaft110. Recirculated power196then flows in parallel with input power195from the junction157to the first gearset128through the variator114, the fourth clutch122, the second gearset130, and the junctions158,159,151,156,154in identical fashion to input power195. Hereafter, the combination of input power195and recirculated power196is referred to as “combined power” and is understood to be greater than input power195and recirculated power196.

The “mixing” gearset128breaks up the combined power into split power199(designated by the slashed arrows), which is transmitted to the junction155and back to the junction157, as shown inFIG. 6. In this way, some split power199flows from the junction155to the output shaft112, thereby adding to the power transmitted to the output shaft112. Some split power199also flows from the first gearset128to the junction157and, like recirculated power196, back through the variator114to the first gearset128in parallel with input power195.

Turning now to the forward ratio range of “Mode1” of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 7. Input power195(designated by the solid arrows) flows from the input shaft110to the junction157and thereafter to the first gearset128as shown inFIG. 7. Input power195flowing to the first gearset128is modified by the “mixing” gearset128such that some of the power that is output from the first gearset128flows to the junction155and thereafter to the output shaft112and some of the power flows back to the junction157, as described in greater detail below.

Recirculated power196(designated by the dotted arrows) is transmitted from the first gearset128back to the junction157as shown inFIG. 7. Specifically, recirculated power196is transmitted from the first gearset128to the junction156through the second gearset130and the junction154as shown inFIG. 7. From the junction156, recirculated power196is then transmitted to the junction157through the variator114, the junctions158,159,151, and the fourth clutch122. At the junction157, recirculated power196is combined with input power195received from the input shaft110. Recirculated power196then flows in parallel with input power195from the junction157to the first gearset128in identical fashion to input power195.

The “mixing” gearset128breaks up the combined power into split power199(designated by the slashed arrows), which is transmitted to the junction155and back to the junction157, as shown inFIG. 7. In this way, some split power199flows from the junction155to the output shaft112, thereby adding to the power transmitted to the output shaft112. Some split power199also flows from the first gearset128to the junction157through the second gearset130, the fourth clutch122, the variator114, and the junctions154,156,151,158,159and, like recirculated power196, back through the first gearset128in parallel with input power195.

Turning now to the “Lock1” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 8. Input power195(designated by the solid arrows) flows from the input shaft110to the junction157and thereafter to the junction160as shown inFIG. 8. Input power195is then transmitted from the junction160to the junction156through the junctions158,159,151, the variator bypass clutch126, and the fourth clutch122so that the variator114is bypassed (i.e., the variator114receives no power load). From the junction156, input power195is transmitted to the first gearset128through the second gearset130and the junction154. Input power195reaching the first gearset128is modified by the “mixing” gearset128such that some of the power that is output from the first gearset128flows to the junction155and thereafter to the output shaft112and some of the power flows back to the junction160, as described in greater detail below.

Recirculated power196(designated by the dotted arrows) is recirculated from the first gearset128back to the junction160through the junction153as shown inFIG. 8. At the junction160, recirculated power196is combined with input power195received from the input shaft110. Recirculated power196then flows in parallel with input power195from the junction160to the first gearset128through the variator bypass clutch126, the fourth clutch122, the second gearset130, and the junctions158,159,151,156,154in identical fashion to input power195. Hereafter, the combination of input power195and recirculated power196is referred to as “combined power” and is understood to be greater than input power195and recirculated power196.

The “mixing” gearset128breaks up the combined power into split power199(designated by the slashed arrows), which is transmitted to the junction155and back to the junction160, as shown inFIG. 8. In this way, some split power199flows from the junction155to the output shaft112, thereby adding to the power transmitted to the output shaft112. Some split power199also flows from the first gearset128to the junction160and, like recirculated power196, back through the variator bypass clutch126to the first gearset128in parallel with input power195.

Turning to the “Bypass1-2” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 9. Input power195(designated by the solid arrows) is transmitted from the input shaft110to the junction157and thereafter to the junction156through the fourth gearset134and the junctions160,153so that the variator114receives no power load as shown inFIG. 9. From the junction156, input power195is transmitted to the first gearset128through the second gearset130and the junction154. Input power195reaching the first gearset128becomes recirculated power196that is recirculated to the junction153as shown inFIG. 9. It should be appreciated that no power is transmitted from the first gearset128to the junction155and therefrom to the output shaft112. As such, no power is transmitted from the input shaft110to the output shaft112in the geared neutral mode provided by the “Bypass1-2” operating mode.

Recirculated power196(designated by the dotted arrows) is recirculated from the first gearset128to the junction153as shown inFIG. 9. At the junction153, recirculated power196is combined with input power195received from the input shaft110. Recirculated power196then flows in parallel with input power195from the junction153to the first gearset128through the gearsets130,134and the junctions156,154in identical fashion to input power195. Hereafter, the combination of input power195and recirculated power196is referred to as “combined power” and is understood to be greater than input power195and recirculated power196.

The “mixing” gearset128breaks up the combined power into split power199(designated by the slashed arrows), which is transmitted back to the junction153as shown inFIG. 9. In this way, split power199flows from the first gearset128to the junction153and, like recirculated power196, back through the gearsets130,134and the junctions154,156to the first gearset128in parallel with input power195.

Turning now to “Mode2” of table194, power flows from the input shaft110to the output shaft112of the transmission as shown inFIG. 10. Input power195(designated by the solid arrows) flows from the input shaft110to the junction157and thereafter to the first gearset128through the junctions160,153as shown inFIG. 10. Input power195flowing to the first gearset128is modified by the “mixing” gearset128such that some of the power that is output from the first gearset128flows to the junction155and thereafter to the output shaft112and some of the power flows back to the junction157, as described in greater detail below.

Recirculated power196(designated by the dotted arrows) is recirculated from the first gearset128to the junction157through the gearsets130,132, the junctions154,156,151,158,159, and the variator114as shown inFIG. 10. At the junction157, recirculated power196is combined with input power195received from the input shaft110. Recirculated power196then flows in parallel with input power195from the junction157to the first gearset128through junctions153,160in identical fashion to input power195. Hereafter, the combination of input power195and recirculated power196is referred to as “combined power” and is understood to be greater than input power195and recirculated power196.

The “mixing” gearset128breaks up the combined power into split power199(designated by the slashed arrows), which is transmitted to the junction155and back to the junction157, as shown inFIG. 10. In this way, some split power199flows from the junction155to the output shaft112, thereby adding to the power transmitted to the output shaft112. Some split power199also flows from the first gearset128to the junction157through the gearsets130,132, the junctions154,156,151,158,159, and the variator114and, like recirculated power196, back through the first gearset128in parallel with input power195.

Turning now to the “Lock2” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 11. Input power195(designated by the solid arrows) flows from the input shaft110to the junction157and thereafter to the first gearset128through the junctions160,153as shown inFIG. 11. Input power195flowing to the first gearset128is modified by the “mixing” gearset128such that some of the power that is output from the first gearset128flows to the junction155and thereafter to the output shaft112and some of the power flows back to the junction160, as described in greater detail below.

Recirculated power196(designated by the dotted arrows) is recirculated from the first gearset128to the junction160through the gearsets130,132, the junctions154,156,151,158,159, and the variator bypass clutch126as shown inFIG. 11. At the junction160, recirculated power196is combined with input power195received from the input shaft110. Recirculated power196then flows in parallel with input power195from the junction160to the first gearset128through the junction153in identical fashion to input power195. Hereafter, the combination of input power195and recirculated power196is referred to as “combined power” and is understood to be greater than input power195and recirculated power196.

The “mixing” gearset128breaks up the combined power into split power199(designated by the slashed arrows), which is transmitted to the junction155and back to the junction160, as shown inFIG. 11. In this way, some split power199flows from the junction155to the output shaft112, thereby adding to the power transmitted to the output shaft112. Some split power199also flows from the first gearset128to the junction160through the gearsets130,132, the junctions154,156,151,158,159, and the variator bypass clutch126and, like recirculated power196, back through the first gearset128in parallel with input power195.

Turning now to the “Sync2-3” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 12. Input power195(designated by the solid arrows) flows from the input shaft110to the junction157and thereafter to the first gearset128through the junctions160,153as shown inFIG. 12. Input power195reaching the first gearset128is modified by the “mixing” gearset128such that some of the power that is output from the first gearset128flows directly to the junction155and some of the power flows to the junction155through the second clutch118as shown inFIG. 12.

As shown inFIG. 12, the power flowing from the first gearset128to the junction155is designated input power198(shown in dashed). Input power198flows directly from the first gearset128to the junction155, and input power198also flows from the first gearset128to the junction155through the second gearset130, the junction154, and the second clutch118. Input power195, therefore, is reconstituted at the junction155and transmitted thereafter to the output shaft112. As shown inFIG. 12, the variator114is entirely bypassed and receives no power load.

Turning now to “Mode3” of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 13. Input power195(designated by solid arrows) flows from the input shaft110to the junction157and thereafter to the junction154through the variator114, the junctions158,159,151,156, and the third gearset132. From the junction154, input power195flows to the junction155and thereafter to the output shaft112through the second clutch118. Input power195flowing from the input shaft110to the output shaft112is not split, recirculated, or reconstituted as shown inFIG. 13.

Turning now to the “Lock3” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 14. Input power195(designated by solid arrows) flows from the input shaft110to the junction157and thereafter to the junction160as shown inFIG. 14. Input power195is then transmitted from the junction160to the junction154through the junctions158,159,151,156, the variator bypass clutch126, and the third gearset132so that the variator114receives no power load (i.e., the variator114is bypassed). From the junction154, input power195is transmitted to the junction155and thereafter to the output shaft112through the second clutch118. Input power195flowing from the input shaft110to the output shaft112is not split, recirculated, or reconstituted as shown inFIG. 14.

Turning now to the “Bypass3-4” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 15. Input power195(designated by the solid arrows) is transmitted from the input shaft110to the junction153through the junctions157,160and thereafter to the junction156through the fourth gearset134so that the variator114receives no power load. From the junction156, input power195is transmitted to the junction155and thereafter to the output shaft112through the second clutch118and the junction154. Input power195flowing from the input shaft110to the output shaft112is not split, recirculated, or reconstituted as shown inFIG. 15.

Turning now to “Mode4” of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 16. Input power195(designated by the solid arrows) is transmitted from the input shaft110to the junction157and thereafter to the junction156through the variator114, the fourth clutch122, and the junctions158,159,151,156as shown inFIG. 16. From the junction156, input power195is transmitted to the junction155and thereafter to the output shaft112through the second clutch118and the junction154. Input power195flowing from the input shaft110to the output shaft112is not split, recirculated, or reconstituted as shown inFIG. 16.

Turning now to the “Lock4” mode of table194, power flows from the input shaft110to the output shaft112of the transmission104as shown inFIG. 17. Input power195(designated by the solid arrows) is transmitted from the input shaft110to the junction160through the junction157and thereafter to the junction156through the junctions158,159,151, the variator bypass clutch126, and the fourth clutch122so that the variator114receives no power load as shown inFIG. 17. From the junction156, input power195is transmitted to the junction155and thereafter to the output shaft112through the second clutch118and the junction154. Input power195flowing from the input shaft110to the output shaft112is not split, recirculated, or reconstituted as shown inFIG. 17.

While the disclosure has been illustrated and described in detail in the drawings and foregoing description, such an illustration and description is to be considered as merely illustrative and not restrictive in character, it being understood that only illustrative embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.