BALL TYPE CVT WITH POWERSPLIT PATHS
A variable transmission comprises an input shaft; three planetary gear sets; a Ravigneaux gear set; a variator comprising, a first ring assembly, a second ring assembly, a carrier assembly; various arrangements of brakes and clutches; and the output shaft. The variable transmissions comprise a continuously variable mode, an infinitely variable mode, or a combination thereof and can provide an input-coupled powersplit solution function. At least one configuration of the variable transmission comprises a direct drive mode.
This application is a continuation of U.S. application Ser. No. 14/426,139, filed on Mar. 4, 2015, which is the National Phase Entry of International Application No. PCT/US2013/058615, filed on Sep. 6, 2013, which claims the benefit of U.S. Provisional Patent Application No. 61/698,012, filed Sep. 7, 2012 and U.S. Provisional Patent Application No. 61/789,645, filed Mar. 15, 2013, all of which are incorporated herein by reference in their entireties.
BACKGROUND OF THE INVENTIONAutomatic and manual transmissions are commonly used on automobile vehicles. Those transmissions are becoming more and more complicated since the engine speed has to be more precisely controlled to limit the fuel consumption and the emissions of cars. This finer control of the engine speed in usual transmissions can only be done by adding more discrete step ratio gears and increasing the overall complexity and cost. Consequently, 6-speed manual transmissions then become more frequently used as are 8 or 9 speed automatic transmissions.
SUMMARY OF THE INVENTIONProvided herein is a variable transmission comprising: an input shaft; three planetary gear sets; a Ravigneaux gear set; a variator comprising, a first ring assembly, a second ring assembly, a carrier assembly; various arrangements of brakes and clutches; and the output shaft.
In some embodiments, the variable transmission comprises a continuously variable mode, an infinitely variable mode or a combination thereof.
In some embodiments the variable transmission can provide an input-coupled powersplit solution function.
In some embodiments, the transition between continuously variable transmission mode and infinitely variable transmission mode is accomplished by releasing or engaging one or more brakes, and/or alternatively releasing or engaging one or more clutches simultaneously.
In some embodiments, the variator is able to continuously change its ratios in both the continuously variable mode and infinitely variable mode to provide the best ratio achievable for the engine to optimize power consumption.
Provided herein is a variable transmission comprising: an input shaft; a first planetary gear set, a second planetary gear set and a third planetary gear set; a variator comprising a first ring assembly, a second ring assembly; a first clutch, a second clutch and a third clutch; and a first brake comprising a first brake member, wherein said input shaft is drivingly engaged with the first ring assembly of the variator, and mechanically coupleable to a first planetary sun of the first planetary gear set using the second clutch; wherein said input shaft is also drivingly engaged with the third sun of the third planetary gear set; wherein the second ring assembly is drivingly engaged with a ring of the third planetary gear set; wherein a first carrier of the first planetary gear set and a second carrier of the second planetary gear set are coupled together, wherein a third carrier of the third planetary gear set is mechanically coupleable to the first carrier of the first planetary and the second carrier of the second planetary through the third clutch; wherein the first brake member is coupled to the ring of the second planetary gear set; and wherein the first ring of the first planetary gear set is mechanically coupled to an output shaft of the variable transmission; wherein the third carrier is mechanically coupled to the second sun of the second planetary gear set; wherein the first sun of the first planetary gear set might be coupled to the first ring of the first planetary gear set with the first clutch.
In some embodiments, the variable transmission comprises two continuously variable modes, an infinitely variable mode and a direct drive mode. In some embodiments, the continuously variable modes of claim 2 comprise a low speed (CVM1) and a high speed (CVM2). In some embodiments, either or both of the continuously variable modes are enabled by blocking rotation of a variator carrier of the variator.
In some embodiments, power from the input shaft passes through the variator and simultaneously passes to a vehicle output. In some embodiments, a slipping clutch is not required between the input shaft and the variable transmission. In some embodiments, a torque converter is not required between the input shaft and the variable transmission
In some embodiments, engaging the second clutch and the first brake results in an infinitely variable mode. In some embodiments, reverse and low positive speeds can be obtained when the input shaft is directly engaged to the first sun of the first planetary gear set by engaging a second clutch.
In some embodiments, engaging the first clutch and the first brake at the second planetary gear set reduces speed of the second ring assembly and allows the first planetary gear set to turn at a 1:1 ratio, thereby engaging a first continuously variable mode (CVM1).
In some embodiments, engaging the first clutch and the third clutch directly drives the variator second ring assembly linked to the first carrier through a 1:1 output ratio from the variator which drives output of the first planetary gear set, thereby engaging a second continuously variable mode (CVM2).
In some embodiments, engaging the second clutch and the first brake engage an infinitely variable mode that allows positive, negative speeds and powered neutral.
In some embodiments, engaging the first clutch and the second clutch bypasses the variator and allows output of the first planetary gear set to turn at a 1:1 ratio with the input shaft, directly engaging a vehicle output, thus engaging a direct-drive mode, In some embodiments, the direct-drive mode is more efficient than either of the two continuously variable modes. In some embodiments, the native efficiency of the variable transmission is increased by using the variator in a power-splitting continuously variable mode.
Provided herein is a variable transmission comprising: an input shaft; a variator comprising a first ring assembly, a second ring assembly; a first planetary gear set, a second planetary gear set and a third planetary gear set; a Ravigneaux gear set; a first clutch; a first brake and a second brake, wherein the input shaft is drivingly engaged with a first sun of the first planetary gear set having the second brake coupled to the ring of this first planetary; wherein the input shaft is drivingly engaged with a second carrier of the second planetary gear set; wherein a second sun of the second planetary gear set is coupled to the first ring assembly of the variator, wherein the second ring assembly is drivingly engaged with a third sun of the third planetary gear, wherein the third ring of the third planetary gear set is fixed to ground , wherein a third carrier of the third planetary gear set is drivingly engaged to a second ring of the second planetary gear set; wherein a second ring of the second planetary gear set is drivingly engaged with the first sun of the Ravigneaux gear set, the Ravigneaux gear set being mechanically coupled to the first brake via its second sun; and wherein a carrier of the Ravineaux gear set is engaged with a first carrier of the first planetary gear set, and wherein the ring of the Ravigneaux gear set is engaged with a output of the variable transmission; wherein a first clutch engages the first sun of the Ravigneaux gear set to the carrier of the Ravigneaux gear set.
In some embodiments, the first brake holds the second sun of the Ravigneaux gear set.
In some embodiments, the variable transmission comprises a first continuously variable mode, a second continuously variable mode, and an infinitely variable mode. In some embodiments, the first sun of the Ravigneaux gear set is engaged to the third carrier of the third planetary gear set in all of the first continuously variable mode, the second continuously variable mode, and the infinitely variable mode. In some embodiments, the second brake is engaged to hold the first ring of the first planetary gear set, thereby engaging the infinitely variable mode. In some embodiments, the speed of second ring of the Ravigneaux is reduced.
In some embodiments, when the first brake is engaged the second sun is held which results in a first continuously variable mode (CVM1) of operation.
In some embodiments, when the first clutch is engaged, the Ravigneaux gear set is engaged which results in a second continuously variable mode (CVM2) of operation. In some embodiments, in the second continuously variable mode (CVM2) of operation the entire Ravigneaux gear set turns at the same speed, and achieves an efficient 1:1 ratio.
Provided herein is a variable transmission comprising: an input shaft; a variator comprising a first ring assembly, a second ring assembly; a first planetary gear set; a second planetary gear set; a third planetary gear set; a Ravigneaux gear set; a first clutch and a second clutch; and a first brake, a second brake, and a third brake, wherein the input shaft is drivingly engaged with a first sun of the first planetary gear set having the second brake coupled to the ring of this first planetary; wherein the input shaft is drivingly engaged with a second carrier of the second planetary gear set; wherein a second sun of the second planetary gear set is coupled to the first ring assembly of the variator, wherein the second ring assembly is drivingly engaged with a third sun of the third planetary gear set, wherein the third sun and the third carrier of the third planetary gear set are coupled by a second clutch; wherein the third brake is coupled to the ring of the third planetary; wherein the carrier of the third planetary gear set is drivingly engaged with a second ring of the second planetary gear set; wherein the second ring of the second planetary gear set is drivingly engaged with a first sun of the Ravigneaux gear set, and wherein the Ravigneaux gear set is coupled to the first brake by its second sun and wherein a carrier of the Ravineaux gear set is engaged with a first carrier of the first planetary gear set; wherein a first clutch engages the first sun of the Ravigneaux gear set to the carrier of the Ravigneaux gear set.
In some embodiments, the third brake is configured to release a third ring of the third planetary gear set.
In some embodiments, the variable transmission comprises a first continuously variable mode (CVM1), a second continuously variable mode CVM2), a continuously variable mode (CVM3), and an infinitely variable mode.
In some embodiments, the first sun of the Ravigneaux gear set is engaged to the carrier of the third planetary gear set.
In some embodiments, in the first continuously variable mode (CVM1), or the second continuously variable mode (CVM2), the third brake is engaged.
In some embodiments, in the infinitely variable mode the third brake is engaged.
In some embodiments, in the third continuously variable mode (CVM3), the third brake is disengaged, the first clutch is engaged, and the second clutch is engaged.
In some embodiments, when the third sun and third carrier of the third planetary are coupled by engaging the second clutch, the third planetary gear set to turn at a 1:1 ratio.
In some embodiments, the variator continuously changes its torque ratios in the first continuously variable mode (CVM1), the second continuously variable mode CVM2), the continuously variable mode (CVM3), and the infinitely variable mode to optimize power consumption.
In some embodiments, the variable transmission comprises a traction fluid.
Provided herein is a vehicle driveline comprising a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein disposed between an engine and a vehicle output. In some embodiments, the vehicle output comprises a differential and a drive axle. In some embodiments, the vehicle driveline comprises a torsional dampener disposed between the engine and the variable transmission. In some embodiments, the torsional dampener comprises at least one torsional spring.
Provided herein is a method comprising switching between an infinitely variable mode, a continuously variable mode, and a direct drive mode using a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein.
Provided herein is a method comprising switching between an infinitely variable mode and two continuously variable modes using a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein.
Provided herein is a method comprising switching between an infinitely variable mode and three continuously variable modes using a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein.
INCORPORATION BY REFERENCEAll 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.
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:
Continuously Variable Transmissions or CVTs are of many types: belts with variable pulleys, toroidal, and conical, for non-limiting example. The principle of a CVT is that it enables the engine to run at its most efficient rotation speed by changing steplessly the transmission ratio in function of the speed of the car and the torque demand (throttle position) of the driver. If needed for example when accelerating, the CVT can also shift to the most optimum ratio providing more power. A CVT can change the ratio from the minimum to the maximum ratio without any interruption of the power transmission, as opposed to the opposite of usual transmissions which require an interruption of the power transmission by disengaging to shift from one discrete ratio to engage the next ratio.
A specific use of CVTs is the Infinite Variable Transmission or IVT. Where the CVT is limited at positive speed ratios, the IVT configuration can perform a neutral gear and even reverse steplessly. A CVT can be used as an IVT in some driveline configurations.
Provided herein are configurations based on a ball type CVT, also known as CVP (for constant variable planetary) or a variator, herein. Aspects of an example CVT are described in US20060084549 or AU2011224083A1, incorporated herein by reference in their entirety. The type of CVT used herein is comprised a variator comprising a plurality of variator balls, depending on the application, two discs or annular rings (i.e. a first ring assembly and a second ring assembly) each having an engagement portion that engages the variator balls. The engagement portions may be in a conical or toroidal convex or concave surface contact with the variator balls, as input and output. The variator may include an idler contacting the balls as well as shown on
The variator 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 first ring assembly, through the variator balls, to the second ring assembly. By tilting the variator balls' axes, the ratio can be changed between input and output. When the axis of each of the variator balls 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 variator balls' axles are tilted at the same time with a mechanism included in the cage.
In a car, the CVT is used to replace traditional transmission and is located between the engine (ICE or internal combustion engine) and the differential as shown on
Embodiment variable transmissions (and resulting drivelines) are shown in
A first variator ball engagement surface is formed in a distal end of the first ring assembly. When describing a ring assembly of a tilting ball variator, the term distally refers to the portion of the ring assembly closest to the balls of the variator. In some embodiments, the first variator ball engagement surface is a conical surface or a concave or convex toroidal surface in contact with or slightly spaced apart from each of the variator balls. In some embodiments, the first variator ball engagement surface is in driving engagement with each of the variator balls of the carrier assembly through one of a boundary layer type friction and an elastohydrodynamic film.
The carrier assembly of the variator may be rotatably disposed in the housing and may be drivingly engaged with the first ring assembly. The carrier assembly comprises an annular arrangement of the plurality of tiltable variator balls each having tiltable ball axle shafts. In some embodiments, each of the ball axle shafts is adjusted using a cam style tilting mechanism. In some embodiments, each of the ball axle shafts is adjusted using a split carrier axle skewing mechanism.
As depicted in
A ball ramp on each side of the variator provides the clamping force necessary to transfer the torque. Ball ramps, indicated in
Provided herein is a series of configurations for a variable transmission comprising: an input shaft; three planetary gear sets; a variator comprising, a first ring assembly, a second ring assembly, a carrier assembly; at least one of a brake or a clutch; and the output shaft. Some of the configurations provided herein may further comprise a Ravigneaux gear set.
In some embodiments, the variable transmission comprises a continuously variable mode, an infinitely variable mode or a combination thereof. In some embodiments, the variable transmission comprises a direct drive mode.
In some embodiments the variable transmission provides an input-coupled powersplit solution function.
In some embodiments, the transition between continuously variable transmission mode and infinitely variable transmission mode is accomplished by releasing or engaging one or more brakes, and/or alternatively releasing or engaging one or more clutches simultaneously.
In some embodiments, the variator is able to continuously change its ratios in both the continuously variable mode and infinitely variable mode to provide the best ratio achievable for the engine to optimize power consumption.
Provided herein is a variable transmission comprising: an input shaft; a first planetary gear set, a second planetary gear set and a third planetary gear set; a variator comprising a first ring assembly, a second ring assembly; a first clutch, a second clutch and a third clutch; and a first brake comprising a first brake member, wherein said input shaft is drivingly engaged with the first ring assembly of the variator, and mechanically coupleable to a first planetary sun of the first planetary gear set using the second clutch; wherein said input shaft is also drivingly engaged with a third sun of the third planetary gear set; wherein the second ring assembly is drivingly engaged with a ring of the third planetary gear set; wherein a first carrier of the first planetary gear set and a second carrier of the second planetary gear set are coupled together, wherein a third carrier of the third planetary gear set is mechanically coupleable to the first carrier of and the second carrier through the third clutch; wherein the first brake member is coupled a second ring of the second planetary gear; and wherein the first ring of the first planetary gear set is mechanically coupled to the output of the transmission; wherein the third carrier is mechanically coupled to the second sun of the second planetary gear set; wherein the first sun of the first planetary gear set might be coupled to the first ring of the first planetary gear set with the first clutch.
In some embodiments, the variable transmission comprises two continuously variable modes and an infinitely variable mode and a direct drive mode. In some embodiments, the continuously variable modes of claim 2 comprise a low speed (CVM1) and a high speed (CVM2). In some embodiments, either or both of the continuously variable modes are enabled by blocking rotation of a variator carrier of the variator.
In some embodiments, power from the input shaft passes through the variator and simultaneously passes to a vehicle output. In some embodiments, wherein a slipping clutch is not required between the input shaft and the variable transmission. In some embodiments, wherein a torque converter is not required between the input shaft and the variable transmission
In some embodiments, engaging the second clutch and the first brake results in an infinitely variable mode. In some embodiments, reverse and low positive speeds can be obtained when the input shaft is directly engaged to the first sun of the first planetary gear set by engaging a second clutch.
In some embodiments, engaging the first clutch and the first brake at the second planetary gear set reduces speed of the second ring assembly and allows the first planetary gear set to turn at a 1:1 ratio, thereby engaging a first continuously variable mode (CVM1).
In some embodiments, engaging the first clutch and the third clutch directly drives the variator second ring assembly linked to the first carrier of the first planetary gear set through a 1:1 output ratio from the variator which drives output of the first planetary gear set, thereby engaging a second continuously variable mode (CVM2).
In some embodiments, engaging the first clutch and the third clutch directly links the output of the first planetary gear set (at the first ring) to the third carrier in a 1:1 output ratio
In some embodiments, engaging the second clutch and the first brake engage an infinitely variable mode that allows positive, negative speeds and powered neutral. (IVP).
In some embodiments, engaging the first clutch and the second clutch bypasses the variator and allows output of the first planetary gear set to turn at a 1:1 ratio with the input shaft, directly engaging a vehicle output, thus engaging a direct drive mode, In some embodiments, the direct drive mode is more efficient than either of the two continuously variable modes. In some embodiments, wherein native efficiency of the variable transmission is increased by using the variator in a power-splitting continuously variable mode.
Provided herein is a variable transmission comprising: an input shaft; a variator comprising a first ring assembly, a second ring assembly; a first planetary gear set, a second planetary gear set and a third planetary gear set; a Ravigneaux gear set; a first clutch; and a first brake and a second brake, wherein the input shaft is drivingly engaged with a first sun of the first planetary gear set having the second brake coupled to the ring of the first planetary gear set; wherein the input shaft is drivingly engaged with a second carrier of the second planetary gear set; wherein a second sun of the second planetary gear set is coupled to the first ring assembly of the variator, wherein the second ring assembly is drivingly engaged with a third sun of the third planetary gear set, the third ring of the third planetary gear set being fixed to ground wherein a third carrier of the third planetary gear set is drivingly engaged to a second ring of the second planetary gear set; wherein a second ring of the second planetary is drivingly engaged with the first sun of the Ravigneaux gear set, the Ravigneaux gear set being mechanically coupled to the first brake by its second sun; and wherein a carrier of the Ravigneaux gear set is engaged with the first carrier of the first planetary gearset; and wherein the ring of the Ravigneaux gear set is coupled to the variable transmission output; and wherein a first clutch engages the first sun of the Ravigneaux gear set to the carrier of the Ravigneaux gear set.
In some embodiments, the first brake holds the second sun of the Ravigneaux gear set. In some embodiments, the second brake holds the first ring of the first planetary gear set. In some embodiments, the ring of the Ravigneaux gear set is linked to a first carrier of the first planetary gear set.
In some embodiments, the variable transmission comprises a first continuously variable mode, a second continuously variable mode, and an infinitely variable mode. In some embodiments, first sun of the Ravigneaux gear set is engaged in all of the first continuously variable mode, the second continuously variable mode, and the infinitely variable mode to the carrier of the third planetary gear set.
In some embodiments, the second brake is engaged to hold the first ring of the first planetary gear set, thereby engaging the infinitely variable mode. In some embodiments, the speed of second ring of the Ravigneaux is reduced.
In some embodiments, when the first brake is engaged the second sun is held which results in a first continuously variable mode (CVM1) of operation.
In some embodiments, when the first clutch is engaged, the Ravigneaux gear set is engaged which results in a second continuously variable mode (CVM2) of operation. In some embodiments, in the second continuously variable mode (CVM2) of operation the entire Ravigneaux gear set turns at the same speed, and achieves an efficient 1:1 ratio.
Provided herein is a variable transmission comprising: an input shaft; a variator comprising a first ring assembly, a second ring assembly; a first planetary gear set, a second planetary gear set and a third planetary gear set; a Ravigneaux gear set; a first clutch and a second clutch; and a first brake, a second brake, and a third brake, wherein the input shaft is drivingly engaged with a first sun of the first planetary gear set having the second brake coupled to the ring of this first planetary gear set; wherein the input shaft is drivingly engaged with a second carrier of the second planetary gear set; wherein a second sun of the second planetary gear set is coupled to the first ring assembly of the variator, wherein the second ring assembly is drivingly engaged with a third sun of the third planetary gear set, wherein the third sun and the third carrier of the third planetary gear set are coupled by a second clutch; wherein the third brake is coupled to the third ring of the third planetary gear set; wherein the carrier of the third planetary gear set is drivingly engaged with a second ring of the second planetary gear set; wherein the second ring of the second planetary gear set is drivingly engaged with a first sun of the Ravigneaux gear set, the Ravigneaux gear set being coupled to the first brake by its second sun and wherein a carrier of the Ravigneaux gear set is engaged a first carrier of the first planetary gearset; wherein a ring of the Ravigneaux gear set is coupled to the variable transmission output; and wherein a first clutch engages the first sun of the Ravigneaux gear set to the carrier of the Ravigneaux gear set.
In some embodiments, the third brake is configured to release a third ring of the third planetary gear set.
In some embodiments, the variable transmission comprises a first continuously variable mode (CVM1), a second continuously variable mode (CVM2), a continuously variable mode (CVM3), and an infinitely variable mode.
In some embodiments, the first sun of the Ravigneaux gear set is engaged to the carrier of the third planetary gear set in each of the first continuously variable mode (CVM1), the second continuously variable mode (CVM2), the continuously variable mode (CVM3), and the infinitely variable mode.
In some embodiments, in the first continuously variable mode (CVM1), or the second continuously variable mode (CVM2), the third brake is engaged.
In some embodiments, in the infinitely variable mode the third brake is engaged.
In some embodiments, in the third continuously variable mode (CVM3), the third brake is disengaged, the first clutch is engaged, and the second clutch is engaged.
In some embodiments, when the third sun of the third planetary gear set and third carrier of the third planetary gear set are coupled, the third planetary gear set is configured to turn at a 1:1 ratio.
In some embodiments, the variator continuously changes its torque ratios in the first continuously variable mode (CVM1), the second continuously variable mode CVM2), the continuously variable mode (CVM3), and the infinitely variable mode to optimize power consumption.
In some embodiments, the variable transmission comprises a traction fluid.
Provided herein is a vehicle driveline comprising a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein disposed between an engine and a vehicle output. In some embodiments, the vehicle output comprises a differential and a drive axle. In some embodiments, the vehicle driveline comprises a torsional dampener disposed between the engine and the variable transmission. In some embodiments, the torsional dampener comprises at least one torsional spring.
Provided herein is a method comprising switching between an infinitely variable mode and a continuously variable mode using a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein.
Provided herein is a method comprising switching between an infinitely variable mode and two continuously variable modes using a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein.
Provided herein is a method comprising switching between an infinitely variable mode and three continuously variable modes using a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein.
Provided herein is a vehicle comprising a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein disposed between an engine and a vehicle output.
Example 1The embodiment of
The embodiment of
This configuration has an infinitely variable mode to provide a standstill, reversed and starting function; two continuously variable modes, one for low speeds and one for high speeds; and a fuel efficient direct drive mode. No starting device like a slipping clutch or torque converter is required, since the IVP mode takes care of the starting function.
In the embodiment depicted in
As shown in
In IVP mode, second clutch l la and first brake 13a are closed (engaged). The sun 5sa of the first planetary gear set 5a turns at motor 100 speed and the output speed of the variator is reduced at the second planetary gear set 6a. This is then linked to the first carrier 5ca of the first planetary gear set 5a. At the first ring 5ra of the first planetary gear set 5a, (output to differential) reversed and low positive speeds (IVP) when the ICE is coupled to the first sun 5sa of the first planetary gear set 5a by applying the second clutch 11a. In this mode, powersplitting occurs two times. A part of the input power goes to the first sun 5sa of the first planetary gear set 5a and part of it goes to the variator 8a. The latter then splits the power again, in a part going to the variator first ring assembly 81ra and a part going to the third sun 7sa of the third planetary gear set 7a.
In CVM1 mode, the first clutch 10a and first brake 13a are applied. The output speed of the variator is reduced at the second planetary gear set 6a. This is then linked to the first ring 5ra (output to the differential) by applying the first clutch 10a, allowing the first planetary gear set 5a to turn at a 1:1 ratio. In this mode there is powersplitting.
In CVM2 mode, the first clutch 10a and third clutch 12a are applied. The output speed of the variator is directly linked to the first carrier 5ca of the first planetary 5a. This is then linked to the output to the differential by applying the first clutch 10, allowing the first planetary gear set 5a to turn at a 1:1 ratio. In this mode there is powersplitting.
Direct drive mode provides an efficient way for high-speed driving, like on the highway. It is obtained by engaging first clutch 10a and second clutch 11a, therefore bypassing the CVP and allowing the output planetary (first planetary gear set 5a) to turn at a 1:1 ratio. The motor 100 is then directly linked to the differential without powersplitting.
This device is able to change continuously its ratio to provide the best ratio achievable for the engine in function of the objectives of consumption of power. In a manual or automatic transmission, only some predetermined and discrete ratios are available and an interruption of the power transmission is needed to shift of ratio. The only interruptions of power in this device are the modes shifting. Other advantages of this configuration are that a small variator can be chosen; spread is larger to a traditional gearbox and the native efficiency of the transmission is increased by using the variator in a powersplit device, therefore letting a part of the power passing through a more efficient mechanical path. This particular configuration has an extra advantage by having an efficient direct drive mode for cruising speeds, bypassing the less efficient variator.
Example 2The embodiment of
The embodiment depicted in
This configuration has an infinitely variable mode to provide a standstill, reversed and starting function and two continuously variable modes, one for low speeds and one for high speeds. No starting device like a slipping clutch or torque converter is required, since the infinitely variable mode takes care of the starting function.
The motor 100, such as an ICE, is coupled to the first sun 5sb of the first planetary gear set 5b and to the second carrier 6cb of the second planetary gear set 6b. The second sun 6sb of the second planetary gear set 6b is coupled to the variator first ring assembly 81ra. The variator second ring assembly 82rb is then coupled to the third sun 7sb of the third planetary gear set 7b, the third planetary gear set being linked to the ground at its ring 7rb and to the second ring 6rb of the second planetary gear set 6b by its carrier. The second ring 7rb of the second planetary gear set 7b is coupled to the first sun 91sb of the Ravigneaux gear set 9b and can be coupled to the carrier 9cb of the Ravigneaux 9b by engaging a first clutch 10b. By engaging that first clutch 10b, the Ravigneaux 9b turns in an efficient 1:1 ratio. The carrier 9cb of the Ravigneaux 9b is the coupled to the first carrier 6cb of the first planetary gear box 6b. The ring 9rb of the Ravigneaux 9b is coupled to the variable transmission output 50b which is coupled directly to the final drive and differential (i.e. the vehicle output). Two brakes, including first brake 13b and second brake 14b allow either holding the second Ravigneaux sun 92sb of the Ravigneaux 9b (by first brake 13b) or either the first ring 5rb of the first planetary 5b (by second brake 14b).
The first Ravigneaux sun 91sb is coupled to the output of the powersplit in the three modes. That powersplit output speed is shown on the first Ravigneaux sun 91sb axis.
The infinitely variable mode is activated by engaging the second brake 14b to hold the first ring 5rb of the first planetary gear set 5b. The Ravigneaux carrier 9cb of the Ravigneaux 9b being coupled to the first carrier 5cb of the first planetary gear set 5b, its speed is reduced to the point 708 shown on the axis 702. As the ring 9rb is the output of the variable transmission, the output speed achievable can be observed on the ring axis 703 of the speed diagram.
The first continuously variable mode (CVM1) is activated by holding the second Ravigneaux sun 92sb with the first brake 13b. The speed achievable can be observed in the speed diagram between speeds 710 and 711.
The second continuously variable mode (CVM2) is activated when the first clutch 10b is engaged, doing this, the whole Ravigneaux gear set 9b is turning at the same speed and achieving an efficient 1:1 ratio.
Example 3The embodiment of
The additional clutch 11c is placed between the variator second ring assembly 82rc and the third planetary gear set 7c carrier 7cc (still coupled to the second planetary ring 6rc) and the third brake 15c is allowed to release the third ring 7rc of the third planetary gear set 7c.
The additional brake 15c is engaged in the three former modes (IVP, CVM1, CVM2) while the additional clutch is released 11c.
To engage CVM3 mode, the third brake 15c is opened and the second clutch 11c is engaged, as well as the first clutch 10c. The sun 7sc and the third carrier 7cc of the third planetary gear set 7c are then coupled, making the third planetary gear set turn at an efficient 1:1 ratio.
The variable transmission of embodiment of
Embodiments of the variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein, are contemplated for use in a variety of vehicle drivelines. For non-limiting example, the variable transmissions disclosed herein may be used in bicycles, mopeds, scooters, motorcycles, automobiles, electric automobiles, trucks, sport utility vehicles (SUV's), lawn mowers, tractors, harvesters, agricultural machinery, all terrain vehicles (ATV's), jet skis, personal watercraft vehicles, airplanes, trains, helicopters, buses, forklifts, golf carts, motorships, steam powered ships, submarines, space craft, or other vehicles that employ a transmission. Provided herein is a vehicle comprising a variable transmission described herein or that would be obvious to one of skill in the art upon reading the disclosure herein disposed between an engine and a vehicle output.
While the figures and description herein are directed to ball-type variators (CVTs), alternate embodiments are contemplated another version of a variator (CVT), such as a Variable-diameter pulley (VDP) or Reeves drive, a toroidal or roller-based CVT (Extroid CVT), a Magnetic CVT or mCVT, Ratcheting CVT, Hydrostatic CVTs, Naudic Incremental CVT (iCVT), Cone CVTs, Radial roller CVT, Planetary CVT, or any other version CVT.
While preferred embodiments of the present invention 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 invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that methods and structures within the scope of these claims and their equivalents be covered thereby.
Claims
1. A variable transmission comprising:
- an input shaft;
- a variator comprising a first ring assembly and a second ring assembly;
- a first planetary gear set, a second planetary gear set and a third planetary gear set;
- a Ravigneaux gear set;
- a first clutch and a second clutch; and
- a first brake, a second brake, and a third brake; wherein the input shaft is drivingly engaged with a first sun gear of the first planetary gear set having the second brake coupled to a first ring gear of this first planetary gear set, the input shaft is drivingly engaged with a second carrier of the second planetary gear set, a second sun gear of the second planetary gear set is coupled to the first ring assembly of the variator, the second ring assembly of the variator is drivingly engaged with a third sun gear of the third planetary gear set through the second clutch, the third sun gear and a third carrier of the third planetary are coupled by a second clutch, the third brake is coupled to a third ring gear of the third planetary, the third carrier of the third planetary gear set is drivingly engaged with a second ring gear of the second planetary gear set, the second ring gear of the second planetary gear set is drivingly engaged with a fourth sun gear of the Ravigneaux gear set which is coupled to the first brake by a fifth sun of the Ravigneaux gear set, the first clutch engages the fourth sun of the Ravigneaux gear set to a fourth carrier of the Ravigneaux gear set, a fourth ring of the Ravigneaux gear set is coupled to an output of the variable transmission, and the fourth carrier of the Ravigneaux gear set is coupled to a first carrier of the first planetary gear set.
2. The variable transmission of claim 1, wherein the third brake is configured to release the third ring of the third planetary gear set.
3. The variable transmission of claim 1, comprising a first continuously variable mode (CVM1), a second continuously variable mode (CVM2), a continuously variable mode (CVM3), and an infinitely variable mode.
4. The variable transmission of claim 3 wherein the fourth sun of the Ravigneaux gear set is engaged to the third carrier of the third planetary gear set in each of the first continuously variable mode (CVM1), the second continuously variable mode (CVM2), the continuously variable mode (CVM3), and the infinitely variable mode.
5. The variable transmission of claim 3, wherein in the first continuously variable mode (CVM1), or the second continuously variable mode (CVM2), the third brake is engaged.
6. The variable transmission of claim 3, wherein in the infinitely variable mode the third brake is engaged.
7. The variable transmission of claim 3, wherein in the third continuously variable mode (CVM3), the third brake is disengaged, the first clutch is engaged, and the second clutch is engaged.
8. The variable transmission of claim 6, wherein when the third sun and third carrier of the third planetary are coupled, the third planetary gear set to turn at a 1:1 ratio.
9. The variable transmission of claim 1, wherein the variator continuously changes its torque ratios in the first continuously variable mode (CVM1), the second continuously variable mode (CVM2), the continuously variable mode (CVM3), and the infinitely variable mode to optimize power consumption.
10. The variable transmission of claim 1, comprising a traction fluid.
11. A vehicle driveline comprising the variable transmission of claim 1 disposed between an engine and a vehicle output.
12. The vehicle driveline of claim 11, wherein the vehicle output comprises a differential and a drive axle.
13. The vehicle driveline of claim 11, comprising a torsional dampener disposed between the engine and the variable transmission.
14. The vehicle driveline of claim 11, wherein the torsional dampener comprises at least one torsional spring.
15. A method comprising switching between an infinitely variable mode and a continuously variable mode using the variable transmission of claim 1.
16. A method comprising switching between an infinitely variable mode and two continuously variable modes using the variable transmission of claim 1.
17. A method comprising switching between an infinitely variable mode and three continuously variable modes using the variable transmission 1.
18. A vehicle comprising the variable transmission of claim 1 disposed between an engine and a vehicle output.
19.-29. (canceled)
Type: Application
Filed: Mar 11, 2016
Publication Date: Jul 7, 2016
Inventors: Mark R.J. VERSTEYHE (Oostkamp), Matthias W.J. BYLTIAUW (Hooglede)
Application Number: 15/067,752