WO2018022741A1

WO2018022741A1 - Planetary powertrain configuration with a ball variator continuously variable transmission having a power-take-off interface

Info

Publication number: WO2018022741A1
Application number: PCT/US2017/043922
Authority: WO
Inventors: Joseph J. HORAK
Original assignee: Dana Limited
Priority date: 2016-07-29
Filing date: 2017-07-26
Publication date: 2018-02-01

Abstract

Devices and methods are provided herein for the transmission of power in motor vehicles. Power is transmitted in a smoother and more efficient manner by splitting torque into two or more torque paths. A continuously variable transmission is provided with a ball variator having an array of balls, a planetary gearset coupled thereto, an arrangement of rotatable shafts and a power-take-off interface.

Description

PLANETARY POWERTRAIN CONFIGURATION WITH A BALL VARIATOR CONTINUOUSLY VARIABLE TRANSMISSION HAVING A POWER-TAKE-OFF INTERFACE RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Application No. 62/368,394 filed on July 29, 2016, which is incorporated herein by reference in its entirety. BACKGROUND

A driveline including a continuously variable transmission allows an operator or a control system to vary a drive ratio in a stepless manner, permitting a power source to operate at its most advantageous rotational speed.

SUMMARY

Provided herein is a powersplit variator including: a first rotatable shaft operably coupleable to a source of rotational power; a second rotatable shaft coaxial with the first rotatable shaft, the first rotatable shaft and the second rotatable shaft forming a main axis; a variator having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls, wherein each ball of the plurality of balls has a tiltable axis of rotation, the variator is coaxial with the main axis; a planetary gear set operably coupled to the first rotatable shaft and the variator; and a power-take-off interface coupled to the first traction ring assembly.

INCORPORATION BY REFERENCE

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

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

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

Figure 2 is a plan view of a carrier member that is used in the variator of Figure 1.

Figure 3 is an illustrative view of different tilt positions of the ball-type variator of Figure 1.

Figure 4 is a schematic diagram of a powersplit variator.

Figure 5 is a schematic diagram of a powersplit variator having a power- take-off (PTO) interface.

Figure 6 is a schematic diagram of a powersplit variator having a locking clutch.

Figure 7 is a schematic diagram of another powersplit variator having a locking clutch.

Figure 8 Is a schematic diagram of yet another powersplit variator having a locking clutch.

Figure 9 is a schematic diagram of a variator having a locking clutch coupled between a first traction ring assembly and a second traction ring assembly.

Figure 10 is a schematic diagram of a powersplit variator having a locking clutch and a power-take-off (PTO) interface.

Figure 11 is a table depicting operating modes of the powersplit variator of Figure 10. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 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. Furthermore, the preferred embodiments includes several novel features, no single one of which is solely responsible for its desirable attributes or which is essential to practicing the embodiments described.

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 United States Patent No. 8,469,856 and 8,870,711 incorporated herein by reference in their entirety. Such a CVT, adapted herein as described throughout this specification, comprises a number of balls (planets, spheres) 1 , depending on the application, two ring (disc) assemblies with a conical surface in contact with the balls, an input (first) traction ring 2, an output (second) traction ring 3, and an idler (sun) assembly 4 as shown on FIG. 1. The balls are mounted on tiltable axles 5, themselves held in a carrier (stator, cage) assembly having a first carrier member 6 operably coupled to a second carrier member 7. The first carrier member 6 rotates with respect to the second carrier member 7, and vice versa. In some embodiments, the first carrier member 6 is fixed from rotation while the second carrier member 7 is configured to rotate with respect to the first carrier member, and vice versa. In one embodiment, the first carrier member 6 is provided with a number of radial guide slots 8. The second carrier member 7 is provided with a number of radially offset guide slots 9, as illustrated in FIG. 2. The radial guide slots 8 and the radially offset guide slots 9 are adapted to guide the tiltable axles 5. The axles 5 are adjusted to achieve a desired ratio of input speed to output speed during operation of the CVT. In some embodiments, adjustment of the axles 5 involves control of the position of the first and second carrier members to impart a tilting of the axles 5 and thereby adjusts the speed ratio of the variator. Other types of ball CVTs also exist, but are slightly different. The working principle of such a CVP of FIG. 1 is shown on FIG. 3. 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 is changed between input and output. When the axis is horizontal the ratio is one, illustrated in FIG. 3, 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. Embodiments disclosed here are related to the control of a variator and/or a CVT using generally spherical planets each having a tiltable axis of rotation that are adjusted to achieve a desired ratio of input speed to output speed during operation. In some embodiments, adjustment of said axis of rotation involves angular misalignment of the planet axis in a first plane in order to achieve an angular adjustment of the planet axis in a second plane that is substantially perpendicular to the first plane, thereby adjusting the speed ratio of the variator. The angular misalignment in the first plane is referred to here as "skew", "skew angle", and/or "skew condition". In one embodiment, a control system coordinates the use of a skew angle to generate forces between certain contacting components in the variator that will tilt the planet axis of rotation. The tilting of the planet axis of rotation adjusts the speed ratio of the variator.

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, bearing 1011A and bearing 1011 B) will be referred to collectively by a single label (for example, bearing 1011).

As used here, the terms "operationally connected," "operationally coupled", "operationally linked", "operably connected", "operably coupled", "operably linked," "operably coupleable" 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 take a variety of forms, which in certain instances will be readily apparent to a person of ordinary skill in the relevant technology.

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 are typically 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 operate in both tractive and frictional applications. For example, in the embodiment where a CVT is used for a bicycle application, the CVT operates at times as a friction drive and at other times as a traction drive, depending on the torque and speed conditions present during operation.

Referring now to FIG. 4, in some embodiments, a powersplit variator 10 includes a first rotatable shaft 11 adapted to receive power from a source of rotational power (not shown). The powersplit variator 10 includes a second rotatable shaft 12 adapted to transmit a rotational power out of the powersplit variator 10. For example, the second rotatable shaft 12 is adapted to couple to a multiple speed gear box (not shown) to provide multiple modes of operation. In some embodiments, the second rotatable shaft 12 is adapted to couple to a fixed ratio automatic transmission such as well-known multiple speed automatic transmissions or simplified versions thereof utilizing alternative friction plate clutches. It should be appreciated that other embodiments of powersplit variators are optionally configured to couple to the power transmission devices disclosed herein. In some embodiments, the powersplit variator 10 includes a variator 13. The variator 3 is optionally configured to be a variator similar to the variator depicted in FIGS. 1-3. The variator 13 is provided with a first traction ring assembly 15 and a second traction ring assembly 14. In some embodiments, the powersplit variator 10 includes a planetary gear set 16 having a ring gear 17, a planet carrier 18, and a sun gear 19. The ring gear 17 is operably coupled to the second traction ring assembly 14. The sun gear 19 is operably coupled to the second rotatable shaft 12. In some embodiments, the second rotatable shaft 12 is coupled to the first traction ring assembly 15. It should be noted that in some embodiments, the first rotatable shaft 11 is adapted to transmit power out of the powersplit variator 10 and the second rotatable shaft 12 is adapted to operably couple to a source of rotational power.

Referring now to FIG. 5, in some embodiments, a powersplit variator 20 includes a first rotatable shaft 21 adapted to receive power from a source of rotational power (not shown). The powersplit variator 20 includes a second rotatable shaft 22 adapted to transmit a rotational power out of the powersplit variator 20. For example, the second rotatable shaft 22 is adapted to couple to a multiple speed gear box (not shown) to provide multiple modes of operation. In some embodiments, the second rotatable shaft 22 is adapted to couple to a fixed ratio automatic transmission such as well-known multiple speed automatic transmissions or simplified versions thereof utilizing alternative friction plate clutches. It should be appreciated that other embodiments of powersplit variators are optionally configured to couple to the power transmission devices disclosed herein. In some embodiments, the powersplit variator 20 includes a variator 23. The variator 23 is optionally configured to be a variator similar to the variator depicted in FIGS. 1-3. The variator 23 is provided with a first traction ring assembly 25 and a second traction ring assembly 24. In some embodiments, the powersplit variator 20 includes a planetary gear set 26 having a ring gear 27, a planet carrier 28, and a sun gear 29. The ring gear 27 is operably coupled to the second traction ring assembly 24. The sun gear 29 is operably coupled to the second rotatable shaft 22. In some embodiments, the second rotatable shaft 22 is coupled to the first traction ring assembly 25. It should be noted that in some embodiments, the first rotatable shaft 21 is adapted to transmit power out of the powersplit variator 20 and the second rotatable shaft 22 is adapted to operably couple to a source of rotational power.

In some embodiments, the powersplit variator 20 is provided with a power-take-off interface 30 operably coupled to the second traction ring assembly 25. In some embodiments, the PTO interface 30 includes a splined component adapted to transmit a rotational power from the powersplit variator 20 to auxiliary devices equipped on a vehicle having the powersplit variator 20. In some embodiments, the PTO interface 30 is a geared component configured to interface with gear sets to transmit rotational power from the powersplit variator 20 to auxiliary devices. Typically, auxiliary devices are not coupled to a main vehicle driveline used for propulsive power. In some embodiments, the auxiliary devices include hydraulic pumps, electric motors, electric and/or hydraulic compressors, electric and/or hydraulic wenches, among others. In some embodiments, the PTO interface 30 is accessible through an opening in a housing or enclosure surrounding the powersplit variator 20. During operation of the powersplit variator 20, a speed of the PTO interface 30 is controlled by adjusting the speed of the first rotatable shaft 21 or by adjusting the speed ratio of the variator 22. For example, the speed ratio of the variator 22 is capable of being adjusted to an overdrive ratio in operating conditions having a low speed input on the first rotatable shaft 21 to provide a higher speed for the PTO interface 30 to operate.

It should be noted, that the PTO interface 30 is optionally coupled to other spinning components of the variator 22 to provide variable speed during operation. In some embodiments, the powersplit variator 20 is optionally configured to have a spinning carrier assembly to which the PTO interface 30 is optionally coupled.

Referring now to FIG. 6, in some embodiments; a powersplit variator 60 includes a first rotatable shaft 61 adapted to receive power from a source of rotational power (not shown). The powersplit variator 60 includes a second rotatable shaft 62 adapted to transmit a rotational power out of the powersplit variator 60. For example, the second rotatable shaft 62 is adapted to couple to a multiple speed gear box (not shown) to provide multiple modes of operation. In some embodiments, the second rotatable shaft 62 is adapted to couple to a fixed ratio automatic transmission such as the General Motors 4L60/4L80 transmission, the Ford Motor Company 4R70, and other well-known multiple speed automatic transmissions or simplified versions thereof utilizing alternative friction plate clutches. It should be appreciated that embodiments of powersplit variators disclosed here are optionally configured to couple to any power transmission device. In some embodiments, the powersplit variator 60 includes a variator 63. The variator 63 is optionally configured to be a variator similar to the variator depicted in FIGS. 1-3. The variator 63 is provided with a first traction ring assembly 65 and a second traction ring assembly 64. In some embodiments, the powersplit variator 60 includes a planetary gear set 66 having a ring gear 67, a planet carrier 68, and a sun gear 69. The ring gear 67 is operably coupled to the second traction ring assembly 64. The sun gear 69 is operably coupled to the second rotatable shaft 62. In some embodiments, the second rotatable shaft 62 is coupled to the first traction ring assembly 65. In some embodiments, the powersplit variator 60 includes a locking clutch 70 operably coupled to the ring gear 67 and the planet carrier 68. It should be noted that in some embodiments, the first rotatable shaft 61 is adapted to transmit power out of the powersplit variator 60 and the second rotatable shaft 62 is adapted to operably couple to a source of rotational power.

Referring now to FIG. 7, in some embodiments; a powersplit variator 75 includes a first rotatable shaft 76 adapted to receive power from a source of rotational power (not shown). The powersplit variator 75 includes a second rotatable shaft 77 configured to transmit an output power from the powersplit variator 75. The powersplit variator 75 includes a variator 78 having a first traction ring assembly 80 and a second traction ring assembly 79. The powersplit variator 75 includes a planetary gear set 81 having a ring gear 82, a planet carrier 83, and a sun gear 84. In some embodiments, the ring gear 82 is operably coupled to the second traction ring assembly 79. The sun gear 84 is coupled to the second rotatable shaft 77. The first traction ring assembly 80 is coupled to the second rotatable shaft 77. In some embodiments, the powersplit variator 75 is provided with a locking clutch 85 coupled to the planet carrier 83 and the sun gear 84. It should be noted that in some embodiments, the first rotatable shaft 76 is adapted to transmit power out of the powersplit variator 75 and the second rotatable shaft 77 is adapted to operably couple to a source of rotational power.

Referring now to FIG. 8, in some embodiments; a powersplit variator 90 includes a first rotatable shaft 91 adapted to receive power from a source of rotational power (not shown). The powersplit variator 90 includes a second rotatable shaft 92 configured to transmit an output power from the powersplit variator 90. The powersplit variator 90 includes a variator 93 having a first traction ring assembly 95 and a second traction ring assembly 94. The powersplit variator 90 includes a planetary gear set 96 having a ring gear 97, a planet carrier 98, and a sun gear 99. In some embodiments, the ring gear 97 is operably coupled to the second traction ring assembly 94. The sun gear 99 is coupled to the second rotatable shaft 92. The first traction ring assembly 95 is coupled to the second rotatable shaft 92. In some embodiments, the powersplit variator 90 is provided with a locking clutch 100 coupled to the ring gear 97 and the sun gear 99. It should be noted that in some embodiments, the first rotatable shaft 91 is adapted to transmit power out of the powersplit variator 90 and the second rotatable shaft 92 is adapted to operably couple to a source of rotational power.

Referring now to FIG. 9, in some embodiments, a variator 160 is provided with a first traction ring assembly 161 and a second traction ring assembly 162 in contact with a plurality of balls. The variator 60 is similar to the variator depicted in FIGS. 1-3. The first traction ring assembly 161 is coupled to a first rotatable shaft 163. In some embodiments, the first rotatable shaft 163 is adapted to operably couple to a source of rotational power. In other embodiments, the first rotatable shaft 163 is adapted to transmit a power out of the variator 160. The second traction ring assembly 162 is operably coupled to a second rotatable shaft 164. In some embodiments, the second rotatable shaft 164 is adapted to transmit a power out of the variator 160. In other embodiments, the second rotatable shaft 164 is adapted to operably couple to a source of rotational power. The variator 160 is provided with a locking clutch 165 coupled to the first traction ring assembly 161 and the second rotatable shaft 64. The locking clutch 165 is configured to selectively engage the first traction ring assembly 161 and the second rotatable shaft 164 to thereby transmit power from the first rotatable shaft 163 to the second rotatable shaft 164. Control of the locking clutch 165 is optionally provided by the control process 150.

It should be appreciated that the locking clutch 25, the locking clutch 56, the locking clutch 70, the locking clutch 85, the locking clutch 100, and the lock clutch 165 disclosed herein are optionally configured as wet clutch, dry clutches, synchronizer clutches, one-way clutches, or mechanical diodes. In some embodiments, the continuously variable transmissions disclosed herein are optionally configured to include powersplit variator devices such as the devices disclosed in FIGS. 5-9, and described with related control methods in Patent Cooperation Treaty Patent Application No. PCT/US17/031666, which is hereby incorporated by reference.

Referring now to FIG. 10, in some embodiments a powersplit variator 200 includes a variator 201 having a first traction ring assembly 203 and a second traction ring assembly 202. In some embodiments, the variator 201 is similar to the variator depicted in FIGS. 1-3. The powersplit variator 200 includes a planetary gear set 204. In some embodiments, the planetary gear set 204 includes a ring gear, a set of planet gears supported in one or more planet carriers, and a sun gear. In other embodiments, the planetary gear set 204 is optionally configured to have other known configurations of gears. The planetary gear set 204 is operably coupled to a first rotatable shaft 205. The first rotatable shaft 205 is adapted to receive an input power from a source of rotational power (not shown). The planetary gear set 204 is operably coupled to a second rotatable shaft 206. The second rotatable shaft 206 is operably coupled to the first traction ring assembly 203 and a power-take-off (PTO) interface 207. The second rotatable shaft 206 is adapted to provide a power output from the powersplit variator 200. In some embodiments, the second rotatable shaft 206 is coupled to a multiple speed gear box (not shown). In some embodiments, the second rotatable shaft 206 is operably coupled to a driveline of a vehicle to provide propulsive power. The second rotatable shaft 206 is optionally configured to engage and disengage a driven load with a clutch or other device. In some embodiments, the powersplit variator 200 includes a clutch 208 arranged to couple to the planetary gear set 204 and the second traction ring assembly 202.

Still referring to FIG. 10, in some embodiments, the PTO interface 207 includes a splined component adapted to transmit a rotational power from the powersplit variator 200 to auxiliary devices equipped on a vehicle having the powersplit variator 200. In some embodiments, the PTO interface 207 is a geared component configured to interface with gear sets to transmit rotational power from the powersplit variator 200 to auxiliary devices. Typically, auxiliary devices are not coupled to a main vehicle driveline used for propulsive power. In some embodiments, the auxiliary devices include hydraulic pumps, electric motors, electric and/or hydraulic compressors, electric and/or hydraulic wenches, among others. In some embodiments, the PTO interface 207 is accessible through an opening in a housing or enclosure surrounding the powersplit variator 200. It should be noted that the PTO interface 207 is optionally provided on any of the powersplit variators disclosed herein, for example, the powersplit variators illustrated in FIGS. 1-9.

Turning now to FIG. 11 , during operation of the powersplit variator 200, the PTO interface 207 provides a path to extract power out of the powersplit variator 200. The table depicted in FIG. 11 illustrates exemplary modes of operation for the PTO interface 207. The second column of the table indicates engagement or disengagement of the clutch 208. The third column of the table indicates engagement or disengagement of the second rotatable shaft 206 to a driven load, for example, for propulsive vehicle power. The fourth column of the table indicates the means for controlling the speed of the PTO interface 207. For example, a first mode of operation corresponds to engagement of the clutch 208 and engagement of the second rotatable shaft 206 to a driven load. In the first mode of operation, the speed of the PTO interface 207 is controlled by varying the input speed to the powersplit variator 200. A second mode of operation corresponds to disengagement of the clutch 208 and engagement of the second rotatable shaft 206 to a driven load. In the second mode of operation, the speed of the PTO interface 207 is controlled by either varying the input speed to the powersplit variator 200 or varying the ratio of the variator 201. A third mode of operation corresponds to disengagement of the clutch 208 and disengagement of the second rotatable shaft 206 to a driven load. In the third mode of operation, the speed of the PTO interface 207 is controlled by either varying the input speed to the powersplit variator 200 or varying the ratio of the variator 201. In the third mode of operation, the PTO interface 207 is the primary power output path from the powersplit variator 200.

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 embodiments 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.

While preferred embodiments have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the preferred embodiments. It should be understood that various alternatives to the embodiments described herein may be employed in practice. It is intended that the following claims define the scope of the preferred embodiments and that methods and structures within the scope of these claims and their equivalents be covered thereby.

Claims

WHAT IS CLAIMED IS:

1. A powersplit variator comprising:

a first rotatable shaft operably coupleable to a source of rotational power;

a second rotatable shaft coaxial with the first rotatable shaft, the first rotatable shaft and the second rotatable shaft forming a main axis;

a variator having a first traction ring assembly and a second traction ring assembly in contact with a plurality of balls, wherein each ball of the plurality of balls has a tiltable axis of rotation, the variator is coaxial with the main axis; a planetary gear set operably coupled to the first rotatable shaft and the variator, the planetary gear set comprising a first planet carrier, a first ring gear and a first sun gear; and

a power-take-off interface coupled to the first traction ring assembly.

2. The powersplit variator of Claim 1 , wherein the power-take-off interface is a splined component.

3. The powersplit variator of Claim 1 , wherein the power-take-off interface is a geared component operably coupled to a gear set.

4. The powersplit variator of Claim 1 , wherein the power-take-off interface is operably coupled to an auxiliary device.

5. The powersplit variator of Claim 4, wherein the auxiliary device is a hydraulic pump.

6. The powersplit variator of Claim 4, wherein the auxiliary device is an electric motor.

7. The powersplit variator of Claim 4, wherein the auxiliary device is a wench.

8. The powersplit variator of Claim 1 , wherein the first planet carrier is coupled to the first rotatable shaft, the first ring gear is operably coupled to the second traction ring assembly, and the first sun gear is operably coupled to the second rotatable shaft.

9. The powersplit variator of Claim 8, further comprising a locking clutch operably coupled to the planetary gear set.

10. The powersplit variator of Claim 9, wherein the locking clutch is operably coupled to the first ring gear and the first planet carrier.

11. The powersplit variator of Claim 9, wherein the locking clutch is operably coupled to the first planet carrier and the first sun gear.

12. The powersplit variator of Claim 9, wherein the locking clutch is operably coupled to the first ring gear and the first sun gear.

13. The powersplit variator of Claim 1 , wherein the variator comprises a traction fluid.

14. A vehicle driveline comprising: a power source, a powersplit variator of Claim 1 drivingly engaged with the power source, and a vehicle output drivingly engaged with the powersplit variator.

15. The vehicle driveline of Claim 14, wherein the power source is drivingly engaged with the vehicle output.