WO2016178913A1

WO2016178913A1 - Power path with feedthrough planetary for concentric/coaxial applications

Info

Publication number: WO2016178913A1
Application number: PCT/US2016/029853
Authority: WO
Inventors: William F. WALTZ; Shaun E. Mepham
Original assignee: Dana Limited
Priority date: 2015-05-01
Filing date: 2016-04-28
Publication date: 2016-11-10

Abstract

A continuously variable transmission is provided with a variator assembly, a feedthrough planetary gearset coupled thereto and a rotatable shaft with multiple gears and clutches that extend the ratio range of the variator for concentric and coaxial applications for a transmission that will maintain the proper output rotation direction and output speed ratio.

Description

POWER PATH WITH FEEDTHROUGH PLANETARY FOR CONCENTRIC/COAXIAL

APPLICATIONS

CROSS-REFERENCE

[0001] The present application claims the benefit of U.S. Provisional Application No. 62/155,628, filed May 1, 2015, and U.S. Provisional Application No. 62/181,021, filed June 17, 2015, both of which are incorporated herein by reference in their entireties.

BACKGROUND OF THE INVENTION

[0002] Continuously variable transmissions (CVT) and transmissions that are substantially continuously variable are increasingly gaining acceptance in various applications. The range of ratios that may be spanned by a CVT may not be sufficient for some applications. A transmission may implement a combination of a CVT with one or more additional CVT stages (modes), one or more fixed ratio range splitters, or some combination thereof in order to extend the range of available ratios. The combination of a CVT with one or more additional stages further complicates the extraction of the ratio and power from the transmission, as the transmission may have multiple configurations that achieve the same final drive ratio.

[0003] Different transmission configurations can, for example, multiply input torque across the different transmission stages in different manners to achieve the same final drive ratio. However, some configurations provide more flexibility or better efficiency than other configurations providing the same final drive ratio.

SUMMARY OF THE INVENTION

[0004] Provided herein is a continuously variable transmission comprising a rotatable shaft operably coupleable to a source of rotational power; a variator assembly having a first traction ring assembly and second traction ring assembly in contact with a plurality of traction planets, each traction planet having a tiltable axis of rotation; wherein the first traction ring assembly is coupled to the rotatable shaft; a first planetary gearset having a first ring gear, a first sun gear, and a first carrier; wherein the first carrier is coupled to the first sun gear, and the first carrier is coupled to the first ring gear; a second planetary gearset having a second ring gear, a second sun gear, and a second carrier; wherein the second sun gear is coupled to the second carrier, the second carrier is coupled to the second ring gear, the second ring gear is coupled to the first carrier, and the second sun gear is coupled to the first sun gear; a feedthrough planetary gear set having a first feedthrough sun gear, a feedthrough carrier, and a second feedthrough sun gear; wherein the feedthrough carrier is coupled to the rotatable shaft, the first feedthrough sun gear is coupled to the second traction ring assembly, the first feedthrough sun gear is coupled to the feedthrough carrier, the second feedthrough sun gear is coupled to the feedthrough carrier, and the second feedthrough sun gear is coupled to the first sun gear; a first selectable clutch operably coupled to the first ring gear and ground; and a second selectable clutch operably coupled to the feedthrough carrier and the second carrier, and a third selectable clutch operably coupled to the second carrier and ground wherein the feedthrough planetary is located between the variator and the first and second planetary gear sets.

[0005] Provided herein is a continuously variable transmission comprising a rotatable shaft operably coupleable to a source of rotational power; a variator assembly having first traction ring assembly and second traction ring assembly in contact with a plurality of traction planets, each traction planet having a tiltable axis of rotation; wherein the first traction ring assembly is coupled to the rotatable shaft; a first planetary gearset having a first ring gear, a first sun gear, and a first carrier; wherein the first carrier is coupled to the first sun gear, the first carrier is coupled to the first ring gear, and the first sun gear is coupled to the second traction ring assembly; a second planetary gearset having a second ring gear, a second sun gear, and a second carrier; wherein the second sun gear is coupled to the second carrier, the second carrier is coupled to the second ring gear, the second ring gear is coupled to the first carrier, and the second sun gear is coupled to the first sun gear; a feedthrough planetary gear set having a first feedthrough ring gear, a feedthrough carrier, and a second feedthrough ring gear; and wherein the feedthrough carrier is coupled to ground; the first feedthrough ring gear is coupled to the feedthrough carrier, the first feedthrough ring gear is coupled to the second ring gear, the second feedthrough ring gear is coupled to the feedthrough carrier and the second feedthrough ring gear is coupled to the output; a first selectable clutch operably coupled to the first ring gear and ground; a second selectable clutch operably coupled to the second carrier and the rotatable shaft and a third selectable clutch operably coupled to the second carrier and the feedthrough carrier, wherein output power can be transmitted out of the transmission through the second feedthrough ring gear; and wherein the feedthrough planetary is located downstream of the variator and the first and second planetary gear sets.

[0006] Provided herein is a continuously variable transmission comprising a rotatable shaft operably coupleable to a source of rotational power; a variator assembly having first traction ring assembly and second traction ring assembly in contact with a plurality of traction planets, each traction planet having a tiltable axis of rotation; wherein the first traction ring assembly is coupled to the rotatable shaft; a first planetary gearset having a first ring gear, a first sun gear, and a first carrier; wherein the first carrier is coupled to the first sun gear, the first carrier is coupled to the first ring gear, and the first sun gear is coupled to the second traction ring assembly; a second planetary gearset having a second ring gear, a second sun gear, and a second carrier; wherein the second sun gear is coupled to the second carrier, the second carrier is coupled to the second ring gear, the second ring gear is coupled to the first carrier, and the second sun gear is coupled to the first sun gear; a feedthrough planetary gear set having a feedthrough ring gear, a feedthrough carrier, and a feedthrough sun gear; and wherein the feedthrough carrier is coupled to ground; the feedthrough ring gear is coupled to the feedthrough carrier, the feedthrough ring gear is coupled to the second ring gear, the feedthrough sun gear is coupled to the feedthrough carrier and the feedthrough sun gear is coupled to the output; a first selectable clutch operably coupled to the first ring gear and ground; a second selectable clutch operably coupled to the second carrier and the rotatable shaft and a third selectable clutch operably coupled to the second carrier and the feedthrough carrier, wherein output power can be transmitted out of the transmission through the feedthrough sun gear; and wherein the feedthrough planetary is located downstream of the variator and the first and second planetary gear sets.

[0007] Provided herein is a continuously variable transmission having planetary gear arrangements as illustrated in the Table of FIG. 9 utilized as the feedthrough planetary for the transmission. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to have a dual pinion gear set coupled to the feedthrough carrier. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to have a dual pinion gear set coupled to the feedthrough carrier. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to be a compound planetary gear set. In some embodiments of the continuously variable transmission, the first feedthrough ring gear is coupled to the feedthrough carrier and the second feedthrough ring gear is coupled to the feedthrough carrier. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to have three planetary gear stages.

INCORPORATION BY REFERENCE

[0008] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:

[0010] Figure 1 is a side sectional view of a ball-type variator.

[0011] Figure 2 is a magnified, side sectional view of a ball of a variator of Figure 1 having a symmetric arrangement of a first ring assembly and a second ring assembly.

[0012] Figure 3 is a representative lever diagram for the power path through a continuously variable planetary transmission.

[0013] Figure 4 is a representative velocity diagram for the power path through a continuously variable planetary transmission such as shown in FIG. 3 for powerpath layouts shown in FIGS. 5, 6, 7 & 8.

[0014] Figure 5 is a schematic diagram of a continuously variable transmission having multiple modes of operation for parallel shaft output.

[0015] Figure 6 is a schematic diagram of a continuously variable transmission having multiple modes of operation and a feedthrough planetary gear set for concentric/coaxial output.

[0016] Figure 7 is a schematic diagram of another continuously variable transmission having multiple modes of operation and a feedthrough planetary gear set for concentric/coaxial output.

[0017] Figure 8 is a schematic diagram of yet another continuously variable transmission having multiple modes of operation and a feedthrough planetary gear set for concentric/coaxial output which speeds up the output.

[0018] Figures 9-a & 9-b are an illustrative table with schematic diagrams la - 12b of other planetary gearsets which can be utilized, with connection points coinciding with FIGS. 6, 7 & 8 as identified.

DETAILED DESCRIPTION OF THE INVENTION

[0019] The preferred embodiments will now be described with reference to the accompanying figures, wherein like numerals refer to like elements throughout. The terminology used in the descriptions below is not to be interpreted in any limited or restrictive manner simply because it is used in conjunction with detailed descriptions of certain specific embodiments of the invention. Furthermore, embodiments of the invention can include several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the inventions described.

[0020] Provided herein are configurations of CVTs based on a ball type variators, also known as CVP, for continuously variable planetary. Basic concepts of a ball type Continuously Variable Transmissions are described in US20040616399 and AU2011224083A1, incorporated herein by reference in their entirety. Such a CVT, adapted herein as described throughout this specification, comprises a number of balls (planets, spheres) 997, depending on the application, two rings (discs) with a conical surface contact with the balls, as input 995 and output 996, and an idler (sun) 999 as shown on FIG. 1. The balls are mounted on tiltable axes 998, themselves held in a carrier (stator, cage). The axes 998 can be adjusted to achieve a desired ratio of input speed to output speed during operation of the CVT. In some embodiments, adjustment of the axes 998 involves control of the carrier position to impart a tilting of the axes 998 and thereby adjusts the speed ratio of the variator. Other types of ball CVTs also exist, like the one produced by Milner, but are slightly different.

[0021] The working principle of such a CVP of FIG. 1 is shown on FIG. 2. The CVP itself works with a traction fluid. The lubricant between the ball and the conical rings acts as a solid at high pressure, transferring the power from the input ring, through the balls, to the output ring. By tilting the balls' axes, the ratio can be changed between input and output. When the axis is horizontal the ratio is one, when the axis is tilted the distance between the axis and the contact point change, modifying the overall ratio. All the balls' axes are tilted at the same time with a mechanism included in the carrier and/or idler.

[0022] Upon reading this disclosure, one skilled in the art will recognize that the present invention includes a continuously variable transmission that may be employed in connection with any type of machine that is in need of a transmission. For example, the transmission may be used in (i) a motorized vehicle such as an automobile, motorcycle, ATV, utility, hybrid or watercraft (ii) a non- motorized vehicle such as a bicycle, tricycle, exercise equipment or (iii) industrial equipment, such as an end mill, lathe, drill press, pumps, power generating equipment, paper or textile mill to name a few machines that utilize transmissions. [0023] As used here, the terms "operationally connected," "operationally coupled", "operationally linked", "operably connected", "operably coupled", "operably linked," and like terms, refer to a relationship (mechanical, linkage, coupling, etc.) between elements whereby operation of one element results in a corresponding, following, or simultaneous operation or actuation of a second element. It is noted that in using said terms to describe inventive embodiments, specific structures or mechanisms that link or couple the elements are typically described. However, unless otherwise specifically stated, when one of said terms is used, the term indicates that the actual linkage or coupling may take a variety of forms, which in certain instances will be readily apparent to a person of ordinary skill in the relevant technology.

[0024] As used herein, the term "feedthrough planetary" is synonymous with similar terms used by those skilled in the art, such as; "feedthru planetary", "feed-thru planetary", "feed thru planetary", "feed through planetary", and "feed-through planetary", or simply "planetary".

[0025] For description purposes, the term "radial" is used here to indicate a direction or position that is perpendicular relative to a longitudinal axis of a transmission or variator. The term "axial" as used here refers to a direction or position along an axis that is parallel to a main or longitudinal axis of a transmission or variator. For clarity and conciseness, at times similar components labeled similarly (for example, a control piston 123A and a control piston 123B) will be referred to collectively by a single label (for example, control pistons 123).

[0026] It should be noted that reference herein to "traction" does not exclude applications where the dominant or exclusive mode of power transfer is through "friction." Without attempting to establish a categorical difference between traction and friction drives here, generally these may be understood as different regimes of power transfer. Traction drives usually involve the transfer of power between two elements by shear forces in a thin fluid layer trapped between the elements. The fluids used in these applications usually exhibit traction coefficients greater than conventional mineral oils. The traction coefficient (μ) represents the maximum available traction force which would be available at the interfaces of the contacting components and is the ratio of the maximum available drive torque per contact force. Typically, friction drives generally relate to transferring power between two elements by frictional forces between the elements. For the purposes of this disclosure, it should be understood that the CVTs described here may operate in both tractive and frictional applications. For example, in the embodiment where a CVT is used for a bicycle application, the CVT can operate at times as a friction drive and at other times as a traction drive, depending on the torque and speed conditions present during operation.

[0027] Referring now to FIG. 3, a lever diagram depicts a continuously variable transmission having a power path configuration with two simple planetary gear sets, each having a ring, a sun, and a carrier. The variator portion of the transmission drives the first sun gear SI and the second sun gear S2. The first carrier CI is attached to the second ring gear R2. The second ring gear R2 is the output. The first ring gear Rl is grounded through a clutch for the first forward mode (Mode 1, or Forward Low), but the first ring gear clutch is open for the second forward mode (Mode 2, or Forward High) and Reverse mode. The second carrier C2 is operably coupled through a selectable clutch to the main shaft for the second forward mode. The second carrier C2 is operably coupled through a selectable clutch to the ground for Reverse. The second carrier C2 is free when in the first forward mode.

[0028] Referring now to FIG. 4, consider a constant main shaft speed. The velocity diagram shows how the transmission can start in Mode 1 with the first ring gear Rl grounded at an underdrive condition of the variator, for example a speed ratio of 0.5. As the variator increases speed ratio to an overdrive ratio, for example a speed ratio of 1.8, the speed of the second ring gear R2 increases and the speed of the second carrier C2 will eventually match the main shaft speed. At this point, a synchronous mode shift can be made because the speeds of the second carrier C2 and the main shaft are matched. The first ring gear Rl can be de-clutched and the second carrier C2 can be clutched to the main shaft. Then the variator can be adjusted from overdrive to underdrive and the speed of the second ring gear R2 will continue to increase. In Mode 1, the power flow is direct through the variator. In Mode 2, because the second carrier C2 is clutched to the main shaft, there is power circulation between the main shaft pathway and the variator pathway. The power through the variator can be greater or less than the input power depending on the variator speed ratio and the planetary ratio chosen.

[0029] Still referring to FIG. 4, for reverse, the power flow is direct through the variator. With the second carrier C2 grounded, the velocity diagram depicts how the transmission can start in reverse at an underdrive speed ratio (0.5 is shown). As the variator increases speed ratio to an overdrive condition (1.8 is shown), the output speed in reverse increases.

[0030] Previous ideas for a concentric/coaxial output using the power path of FIGS. 3 & 4 needed a countershaft (parallel shaft) to get the mode planetary power out and then back on centerline, coaxial with the input centerline. The new idea is to use a concentric/coaxial feedthrough planetary that keeps all of the rotating transmission elements coaxial. With the use of the feedthrough planetary, it is possible to engage the required mode clutches while keeping the drive

concentric/coaxial. A countershaft is not needed.

[0031] Referring now to FIG. 5, in one embodiment a transmission 10 is provided with a variator 19 having a first traction ring assembly 11, a second traction ring assembly 12, each coupled to a number of traction planets 13 wherein each traction planet 13 has a tiltable axis of rotation. In one embodiment, the transmission 10 has a rotatable shaft 14 coupled to the first traction ring assembly 1 1. The transmission 10 is provided with a first planetary gear set 15 having a first sun gear 16, a first carrier 17, and a first ring gear 18. The transmission 10 is provided with a second planetary gear set 20 having a second sun gear 21, a second carrier 22, and a second ring gear 23. The first sun gear 16 and the second sun gear 21 are coupled to the second traction ring assembly 12. The transmission 10 is provided with a first selectable clutch 24 operably coupled to the first ring gear 18 and ground. The transmission 10 is provided with a second selectable clutch 25 operably coupled to the rotatable shaft 14 and the second carrier 22. The transmission 10 is provided with a third selectable clutch 27 operably coupled to the second carrier 22 and ground. In one

embodiment, a power output interface 26 is coupled to the first carrier 17. The first carrier 17 is coupled to the second ring 23. The layout could have a gear, chain, or belt off of the power output interface 26 to other downstream gears, differential, or other well-known devices to transmit output power.

[0032] The concentric/coaxial feedthrough planetary shown in FIG. 6 is considered a stepped planet compound planetary. The pinion sets are rotationally fixed to each other. The pinions could be of different diameters resulting in a speed increase or speed reduction (stepped), or the pinions could be the same diameter (1 : 1). As depicted in FIG. 6; if the carrier were to be held fixed and ring 1 turned, ring 2 would turn the same direction as ring 1.

[0033] The concentric/coaxial feedthrough planetary could also take the form of other compound planetaries, including but not limited to those shown in FIG. 9, comprising planetary configurations with the required output direction, pinion numbers and diameters needed for required speeds.

[0034] Referring now to FIG. 6: Provided herein is a continuously variable transmission 30 comprising a rotatable shaft 14 operably coupleable to a source of rotational power; a variator assembly 19 having a first traction ring assembly 1 1 and second traction ring assembly 12 in contact with a plurality of traction planets 13, each traction planet 13 having a tiltable axis of rotation; wherein the first traction ring assembly 1 1 is coupled to the rotatable shaft 14; a first planetary gear set 15 having a first ring gear 18, a first sun gear 16, and a first carrier 17; wherein the first carrier 17 is coupled to the first sun gear 16, and the first carrier 17 is coupled to the first ring gear 18; a second planetary gearset 20 having a second ring gear 23, a second sun gear 21, and a second carrier 22; wherein the second sun gear 21 is coupled to the second carrier 22, the second carrier 22 is coupled to the second ring gear 23, the second ring gear 23 is coupled to the first carrier 17, and the second sun gear 21 is coupled to the first sun gear 16.

[0035] Referring still to FIG. 6, in one embodiment a transmission 30 can be configured in a similar manner as transmission 10 (FIG. 5) with the addition of a feedthrough planetary gear set 32. In one embodiment, the feedthrough planetary gear set 32 is provided with a first feedthrough sun gear 33, a feedthrough carrier 34, and a second feedthrough sun gear 35. In some embodiments, the first feedthrough sun gear 33 is coupled to the second traction ring assembly 12. The feedthrough carrier 34 is coupled to the first feedthrough sun gear 33 and the rotatable shaft 14. The feedthrough carrier 34 is operably coupled to the second selectable clutch 25. The feedthrough carrier 34 is coupled to the second feedthrough sun gear 35. In one embodiment, the second feedthrough sun gear 35 is coupled to the first and second sun gears 16, 21 ; a first selectable clutch 24 is operably coupled to the first ring gear 18 and ground; a second selectable clutch 25 is operably coupled to the feedthrough carrier 34 and the second carrier 22, and a third selectable clutch 27 is operably coupled to the second carrier 22 and ground. In some embodiments, during operation of the transmission 30, the first and second sun gears 16, 21 rotate in the same direction as the second traction ring assembly 12.

[0036] The feedthrough planetary gear set 32 is shown as a "sun in/sun out" arrangement. It should be apparent to those skilled in the art, that the feedthrough planetary gear set 32 could also be a "ring in/ring out" or other configuration using a compound planetary for example. The feedthrough planetary gear set 32 is depicted schematically in FIG. 6 as a 1 : 1 ratio. The first feedthrough sun gear 33 and the second feedthrough sun gear 35 rotate at the same speed and direction, and in the same speed and direction of the second traction ring assembly 12 regardless of the speed of the feedthrough carrier 34. The feedthrough planetary 32 can be configured to decrease or increase the output speed. Increasing the ratio of the feedthrough planetary 32 changes the transmission output ratio and changes the torque through the variator 19. Increasing or decreasing the feedthrough planetary ratio may be advantageous for some applications. Another example is that a slight variance in the ratio of the feedthrough planetary would be beneficial to reduce harmonic noise and vibration.

[0037] The feedthrough planetary 32 can be configured so that the second feedthrough gear 35 (sun or ring) rotates in the opposite direction of the first feedthrough gear 33 (sun or ring). Having the feedthrough rotation direction reverse may be advantageous for some applications.

[0038] Referring now to FIG. 7: Provided herein is a continuously variable transmission 40 comprising a rotatable shaft 14 operably coupleable to a source of rotational power; a variator assembly 19 having first traction ring assembly 1 1 and second traction ring assembly 12 in contact with a plurality of traction planets 13, each traction planet 13 having a tiltable axis of rotation; wherein the first traction ring assembly 1 1 is coupled to the rotatable shaft 14; a first planetary gearset 15 having a first ring gear 18, a first sun gear 16, and a first carrier 17; wherein the first carrier 17 is coupled to the first sun gear 16, the first carrier 17 is coupled to the first ring gear 18, and the first sun gear 16 is coupled to the second traction ring assembly 12; a second planetary gearset 20 having a second ring gear 23, a second sun gear 21 , and a second carrier 22; wherein the second sun gear 21 is coupled to the second carrier 22, the second carrier 22 is coupled to the second ring gear 23, the second ring gear 23 is coupled to the first carrier 17, and the second sun gear 21 is coupled to the first sun gear 16.

[0039] Referring still to FIG. 7, in one embodiment, a transmission 40 can be configured with a feedthrough planetary 42. In one embodiment, the feedthrough planetary gear set 42 is provided with a first feedthrough ring gear 43, a feedthrough carrier 44, and a second feedthrough ring gear 45. In some embodiments, the first feedthrough ring gear 43 is coupled to the second ring gear 23. The first feedthrough ring gear 43 is coupled to the feedthrough carrier 44. The feedthrough carrier 44 is coupled to a second feedthrough ring gear 45. The second feedthrough ring 45 provides power output. The feedthrough planetary 42 is located downstream of the variator 19 and first and second planetary gear sets 15, 20. The feedthrough planetary carrier 44 is grounded to a housing (not shown); a first selectable clutch 24 operably coupled to the first ring gear 18 and ground; a second selectable clutch 25 operably coupled to the second carrier 22 and the rotatable shaft 14; and a third selectable clutch 27 operably coupled to the second carrier 22 and the feedthrough carrier 44. The feedthrough planetary 42 is shown as a "ring in/ring out" arrangement that gives the same output rotation direction and speed ratio as second ring gear 23. It should be apparent to those skilled in the art that the feedthrough planetary 42 could also be another configuration using a compound planetary for example. The feedthrough planetary 42 is depicted schematically in FIG. 7 as a 1 : 1 ratio. The feedthrough planetary 42 could also increase or decrease the output speed. Increasing the ratio of the feedthrough planetary 42 changes the transmission output ratio and changes the torque through the variator 19. Increasing or decreasing the feedthrough planetary ratio may be advantageous for some applications. Another example is that a slight variance in the ratio of the feedthrough planetary would be beneficial to reduce harmonic noise and vibration.

[0040] The feedthrough planetary 42 can be configured so that the second feedthrough gear 45 (sun or ring) rotates in the opposite direction of the first feedthrough gear 43 (sun or ring). Having the feedthrough rotation direction reverse may be advantageous for some applications.

[0041] Referring now to FIG. 8: Provided herein is a continuously variable transmission 50 comprising a rotatable shaft 14 operably coupleable to a source of rotational power; a variator assembly 19 having first traction ring assembly 1 1 and second traction ring assembly 12 in contact with a plurality of traction planets 13, each traction planet 13 having a tiltable axis of rotation; wherein the first traction ring assembly 1 1 is coupled to the rotatable shaft 14; a first planetary gearset 15 having a first ring gear 18, a first sun gear 16, and a first carrier 17; wherein the first carrier 17 is coupled to the first sun gear 16, the first carrier 17 is coupled to the first ring gear 18, and the first sun gear 16 is coupled to the second traction ring assembly 12; a second planetary gearset 20 having a second ring gear 23, a second sun gear 21, and a second carrier 22; wherein the second sun gear 21 is coupled to the second carrier 22, the second carrier 22 is coupled to the second ring gear 23, the second ring gear 23 is coupled to the first carrier 17, and the second sun gear21 is coupled to the first sun gear 16.

[0042] Referring still to FIG. 8, in one embodiment a transmission 50 can be provided with a feedthrough planetary gear set 52. In one embodiment, the feedthrough planetary gear set 52 is provided with a feedthrough ring gear 53, a feedthrough carrier 54, and a feedthrough sun gear 55. In one embodiment, the feedthrough ring gear 53 is coupled to the second ring gear 23. The feedthrough ring gear 53 is coupled to the feedthrough carrier 54. The feedthrough carrier 54 is coupled to the feedthrough sun gear 55. The feedthrough sun gear 55 provides power output. The feedthrough planetary 52 is located downstream of the variator 19 and the first and second planetary gear sets 15, 20. The feedthrough planetary carrier 54 is grounded to a housing (not shown); a first selectable clutch 24 operably coupled to the first ring gear 18 and ground; a second selectable clutch 25 operably coupled to the second carrier 22 and the rotatable shaft 14; and a third selectable clutch 27 operably coupled to the second carrier 22 and the third carrier 54.

[0043] As illustrated by the table in FIG. 9, numerous different planetary gear arrangements can be utilized as the feedthrough planetary for the transmissions described herein. Provided herein is a continuously variable transmission having planetary gear arrangements as illustrated in the Table of FIG. 9 utilized as the feedthrough planetary for the transmission. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to have a dual pinion gear set coupled to the feedthrough carrier. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to have a dual pinion gear set coupled to the feedthrough carrier. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to be a compound planetary gear set. In some embodiments of the continuously variable transmission, the first feedthrough ring gear is coupled to the feedthrough carrier and the second feedthrough ring gear is coupled to the feedthrough carrier. In some embodiments of the continuously variable transmission, the feedthrough planetary gear set is configured to have three planetary gear stages.

[0044] It should be noted that the description above has provided dimensions for certain components or subassemblies. The mentioned dimensions, or ranges of dimensions, are provided in order to comply as best as possible with certain legal requirements, such as best mode.

However, the scope of the inventions described herein are to be determined solely by the language of the claims, and consequently, none of the mentioned dimensions is to be considered limiting on the inventive embodiments, except in so far as any one claim makes a specified dimension, or range of thereof, a feature of the claim.

[0045] The foregoing description details certain embodiments of the invention. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the invention can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects of the invention should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the invention with which that terminology is associated.

Claims

CLAIMS WHAT IS CLAIMED IS:

1. A continuously variable transmission comprising:

a rotatable shaft operably coupleable to a source of rotational power; a variator assembly having a first traction ring assembly and second traction ring assembly in contact with a plurality of traction planets, each traction planet having a tiltable axis of rotation;

wherein the first traction ring assembly is coupled to the rotatable shaft, a first planetary gearset having a first ring gear, a first sun gear, and a first carrier; wherein the first carrier is coupled to the first sun gear and the first carrier is coupled to the first ring gear,

a second planetary gearset having a second ring gear, a second sun gear, and a second carrier;

wherein the second sun gear is coupled to the second carrier, the second carrier is coupled to the second ring gear, the second ring gear is coupled to the first carrier, and the second sun gear is coupled to the first sun gear,

a feedthrough planetary gear set having a first feedthrough sun gear, a feedthrough carrier, and a second feedthrough sun gear;

wherein the feedthrough carrier is coupled to the rotatable shaft, the first feedthrough sun gear is coupled to the second traction ring assembly, the first feedthrough sun gear is coupled to the feedthrough carrier, the second feedthrough sun gear is coupled to the feedthrough carrier, and the second feedthrough sun gear is coupled to the first sun gear, a first selectable clutch operably coupled to the first ring gear and ground;

a second selectable clutch operably coupled to the feedthrough carrier and the second carrier; and

a third selectable clutch operably coupled to the second carrier and ground;

wherein the feedthrough planetary is located between the variator and the first and second planetary gear sets.

2. A continuously variable transmission comprising:

a rotatable shaft operably coupleable to a source of rotational power; a variator assembly having first traction ring assembly and second traction ring assembly in contact with a plurality of traction planets, each traction planet having a tiltable axis of rotation;

wherein the first traction ring assembly is coupled to the rotatable shaft, a first planetary gearset having a first ring gear, a first sun gear, and a first carrier; wherein the first carrier is coupled to the first sun gear, the first carrier is coupled to the first ring gear, and the first sun gear is coupled to the second traction ring assembly, a second planetary gearset having a second ring gear, a second sun gear, and a second carrier;

a feedthrough planetary gear set having a first feedthrough ring gear, a feedthrough carrier, and a second feedthrough ring gear;

wherein the feedthrough carrier is coupled to ground, and

the first feedthrough ring gear is coupled to the second ring gear, the first feedthrough ring gear is coupled to the feedthrough carrier and the second feedthrough ring gear is coupled to the feedthrough carrier;

a first selectable clutch is operably coupled to the first ring gear and ground;

a second selectable clutch is operably coupled to the second carrier and the rotatable shaft; and

a third selectable clutch is operably coupled to the second carrier and the feedthrough carrier;

wherein output power can be transmitted out of the transmission through the feedthrough ring gear, and

wherein the feedthrough planetary is located downstream of the variator and the first and second planetary gear sets.

3. A continuously variable transmission comprising:

a feedthrough planetary gear set having a feedthrough ring gear, a feedthrough carrier and a feedthrough sun gear;

wherein the feedthrough carrier is coupled to ground, and

the feedthrough ring gear is coupled to the second ring gear, the feedthrough ring gear is coupled to the feedthrough carrier and the feedthrough sun gear is coupled to the feedthrough carrier;

a second selectable clutch is operably coupled to the second carrier and the rotatable shaft;

wherein output power can be transmitted out of the transmission through the feedthrough sun gear, and

A continuously variable transmission as described in any one of claims 1, 2 or 3 wherein alternate planetary gear arrangements as illustrated in the Table of FIG. 9 can be utilized as the feedthrough planetary for the transmission.

The continuously variable transmission of Claim 3, wherein the feedthrough planetary gear set is configured to have a dual pinion gear set coupled to the feedthrough carrier.

The continuously variable transmission of Claims 2, wherein the feedthrough planetary gear set is configured to have a dual pinion gear set coupled to the feedthrough carrier.

The continuously variable transmission Claims 1 or 2, wherein the feedthrough planetary gear set is configured to be a compound planetary gear set. The continuously variable transmission of Claim 1, the first feedthrough ring gear is coupled to the feedthrough carrier and the second feedthrough ring gear is coupled to the feedthrough carrier;

The continuously variable transmission of Claims 1, 2, or 3, wherein the feedthrough planetary gear set is configured to have three planetary gear stages.