Patent Application
20150345629
The present invention relates to stepless (continuously variable) transmission (CVT) systems, which are capable of stepless speed change under load and/or while stopping with up to 95% power transmission efficiency, and transportation equipment, such as various vehicles containing a stepless transmission system.
Energy consumption, in particular oil consumption, is a persistent world problem. Due to its non-renewability and valuable properties, the crude oil is known as “black gold.” Global contentions for oil resources, such as economic wars, political wars and local wars fighting for territories, have never stopped. Accordingly, the U.S. federal government is proposing to set new automobile fuel-efficiency standards, requiring auto manufacturers to increase mileage on gas to 54.5 miles per gallon of gasoline by 2025. How to achieve high performance stepless speed change under load and/or while stopping with high power transmission efficiency while maintaining excellent fuel economy has become a prominent issue in the development of automotive transmissions.
Although mechanical CVT systems are in general more energy economic in comparison with automatic CVT systems, various issues exist, such as low capability to withstand overload and shock, low transfer power, and rough speed change transmission. The issues are more prominent especially when high-power machineries, such as automobiles, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles, etc., require stepless (continuously variable) transmission, in particular, stepless transmission under load.
Use automobile transmission systems to illustrate. Modern automobile transmissions widely use “stepwise planetary gear transmission” and “gear transmission” systems, which have characteristics such as reliable transmission, high transfer power, high efficiency, compact structure, and long life. In order to meet the needs of the automotive automation, modern automobiles use hydraulic mechanical continuously variable automatic transmission and use electronic technology in mechanical electronic automatic transmission. Whether hydraulic mechanical continuously variable automatic transmissions or electronic automatic mechanical continuously variable transmissions, or electronic automatic transmissions, they all incur power interruption in the process of gear shifting, thus resulting in loss of speed, power and speed differentiation. Automatic transmissions also have shortcomings such as high requirements of manufacturing technologies, complex structures, high costs, and difficult maintenance, etc. In particular, hydraulic mechanical continuously variable transmission and metal belt-type continuously variable transmissions also have vital shortcomings such as high power loss, i.e., high fuel consumption.
Automatic transmission generally costs more petroleum than mechanical transmission due to slip of its torque converter. Due to the adoption of the locking mechanism in high-speed region, the same economic efficiency could be achieved on automatic transmission as the mechanical transmission. But in low-speed region, the poor working performance of locking mechanism causes poor economic efficiency by about 10-15% on average. In other words, when running under the same conditions, a mechanical transmission automobile saves about 10-15% than automatic transmission automobile. See Automobile Engineering Manual, China Communications Press, May 2001, p. 134.
A “gear indicating system (gear indicator)” is suitable for mechanical shifting automobile. It is a system enabling driver to know the most economical running gear from indicating lamp on instrument on the basis of ensuring running performance. Shifting moment needs to be decided reasonably according to information such as automobile speed, engine rotating speed, air suction negative pressure, gear position of water temperature etc. Gear Indicating System is applied more frequently in the U.S., and its economic efficiency can be raised by 5-15%. In other words, a mechanical shifting automobile equipped with a “gear indicator” saves petroleum by 5-15% than mechanical shifting automobile without “gear indicator.” See Automobile Engineering Manual, China Communications Press, May 2001, p. 134.
However, when equipped with a “gear indicator,” a mechanical shifting automobile cannot realize automatic speed change, and manual speed change is guided via “gear indicator”. As a consequence, power is interrupted in speed change process, i.e., stepless speed change is unavailable, leading to power loss, speed loss, and speed difference loss. Meanwhile, due to the adoption of stepped transmission, optimal petroleum economy to match between engine rotating speed and automobile running speed is unavailable.
Moreover, gear transmissions are step-wise transmissions, which, when used in automobiles, contain three, four, five, or up to more than ten gears, thus causing inherent difficulties in automatic speed change. The more gears mean more complex automatic transmission, higher manufacturing cost and more difficult maintenance Gears cause power interruption when speed is changed. Therefore, dump trucks of higher than 100 tons cannot use gear transmissions, but can only use direct current (DC) motor for changing speed (i.e., electric wheel dump truck).
Therefore, fundamental technological breakthroughs on gear transmissions are needed in order to make automobile stepless transmissions and automatic stepless transmissions structurally simple, reliable, and having low manufacturing cost and convenient maintenance so that they can be widely used in micro, light and heavy-duty vehicles (including dump trucks of higher than 100 tons), as well as to improve automobile's power, reduce wear, and reduce fuel consumption.
The present invention represents an afore-mentioned fundamental technological breakthrough in gear transmissions, by providing a solution to this world's challenging problem. Specifically, the present invention provides gear, cam stepless (continuously variable) transmission systems comprising one or more planetary gear mechanisms, a splined coupling mechanism, a gear drive mechanism, a cam mechanism, a ramp mechanism, and a rack mechanism.
In one aspect the present invention provides a stepless transmission, comprising:
a power input axle;
a power output axle;
a planetary gear mechanism; and
a speed changing assembly deposited on said power input axle through one or more gears;
wherein said power input axle and said power output axle are functionally connected by said planetary gear mechanism, and
wherein the transmission is capable of stepless speed change.
In one embodiment, the planetary gear mechanism comprises a first planetary gear system and a second planetary gear system that are coupled with each other; wherein said first planetary gear system is connected to said power input axle, and said second planetary gear system is deposited on said power output axle; and wherein power is transmitted from said power input axle through said planetary gear mechanism to said power output axle.
In another embodiment, the speed changing assembly comprises an axle, a cam, a gear rack piece, a ramp mechanism, one or more push rods, a mandrel, one or more gears, one or more springs, and an overrunning clutch system; wherein said cam is deposited on the power input axle; wherein said push rod, mandrel, and cam are kept connected through said springs, and said speed changing assembly can rotate around the power input axle; and wherein said ramp mechanism works together with the cam, the gear rack piece, the push rod, the mandrel, the springs, the one or more gears, and the overrunning clutch to achieve stepless speed change. The “gear, cam stepless transmission” of the present invention comprises a plurality of groups of load variable speed components, including a planetary gear mechanism 14, gears 11 and 13, cam 10, and members 1, 2, 3, 4, 5, 6, 7, 8, 9, and 12 as illustrated in the various Figures. While power is input through shaft I into the H member of the planetary gear mechanism; cam 10; gear 11, and the loaded speed changing components shunt-input the post-speed change power into the planetary gear mechanism B component, and upon synthesizing by the planetary gear mechanism, output the power through a member shaft III of planetary gear mechanism A.
The present invention also provides vehicles comprising a stepless transmission as described herein, including but not limited to automobiles, aircrafts, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles, or the like.
The present invention has changed the history that a mechanical continuously variable transmission (CVT) can only use friction- or impulse-type stepless speed change mechanisms. The invention has also solved issues related to the mechanical continuously variable transmission, such as low capability to withstand overload and shock, low transfer power, and rough speed change transmission, especially those related high-power machineries, such as automobiles, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles, etc., which require stepless (continuously variable) transmission, in particular, stepless transmission under load.
In comparison with mechanical shifting, power of “Gear/Cam Continuously Variable Transmission” of the present invention is not interrupted in speed change process, i.e., stepless speed change is available, not leading to power loss, speed loss or speed differential loss. In the meantime, optimal petroleum economy to match between engine rotating speed and automobile running speed can be achieved by controlling speed change via computer. As estimated according to the petroleum economization conditions, “Gear/Cam Continuously Variable Transmission” automobile can save petroleum by 10-15% than mechanical shifting automobile using a “gear indicator.”
The apparatus of the present invention not only possesses all the advantages of a gear transmission, but can also achieve stepless speed change. It can also achieve speed change during power transfer and achieve power transfer during speed change, i.e., achieving stepless speed change under load. There is no loss of speed, power or speed differentiation during speed change. It can also achieve stepless speed change while stopping (i.e., achieving stepless speed change while the engine stops rotating and the automobile not moving). The invention can achieve a speed change and gearing efficiency of up to 95%, and in the meantime, the speed change control mechanism is simple, safe and reliable, and capable of achieving stepless speed change under any environmental conditions under load or while the automobile is not moving.
The present invention provides stepless (continuously variable) transmission systems, comprising a planetary gear mechanism, a splined coupling mechanism, a gear drive mechanism, a cam mechanism, a ramp mechanism, and a rack mechanism. In one embodiment, stepless transmission comprises a gear, a cam, a push rod, a mandrel, a ramp mechanism, and a planetary gear mechanism, the stepless transmission capable of stepless speed change. In one embodiment, the stepless transmission is characterized in that the cam pushes the push rod, and the push rod has four degrees of freedom to move radially up and down and axially left and right. In one embodiment, the stepless transmission comprises a pair of gears that causes the power-transmitting gear to do additional power transmission through the mandrel while transmitting the power. The stepless transmission of the present invention can achieve 95% transmission gearing efficiency, is structurally simple, safe and reliable, and is capable of stepless speed change under load and/or while stopping.
In one aspect the present invention provides a stepless transmission, comprising:
a power input axle;
a power output axle;
a planetary gear mechanism; and
a speed changing assembly deposited on said power input axle through one or more gears;
wherein said power input axle and said power output axle are functionally connected by said planetary gear mechanism, and
wherein the transmission is capable of stepless speed change.
In one embodiment of this aspect, the planetary gear mechanism comprises a first planetary gear system and a second planetary gear system that are coupled with each other; wherein said first planetary gear system is connected to said power input axle, and said second planetary gear system is deposited on said power output axle; and wherein power is transmitted from said power input axle through said planetary gear mechanism to said power output axle.
The planetary gear system can be of NGW, NW, or WW type, or combinations thereof.
In another embodiment of this aspect, the speed changing assembly comprises an axle, a cam, a gear rack piece, a ramp mechanism, one or more push rods, a mandrel, one or more gears, one or more springs, and an overrunning clutch system; wherein said cam is deposited on the power input axle; wherein said push rod, mandrel, and cam are kept connected through said springs, and said speed changing assembly can rotate around the power input axle; and wherein said ramp mechanism works together with the cam, the gear rack piece, the push rod, the mandrel, the springs, the one or more gears, and the overrunning clutch to achieve stepless speed change.
For illustration purpose, non-limiting examples of the stepless transmission system of the present invention are described in
In another embodiment of this aspect, the cam pushes a push rod, and the push rod has four degrees of freedom to move radially up and down and/or move axially left and right;
In another embodiment of this aspect, the mandrel is characterized that while transmitting power, a pair of gears cause a power-transmitting gear to make additional power transmission through the mandrel.
In another embodiment of this aspect, power is input through said power input axle into a first member of the first planetary gear system via said cam, one or more gears, and members of said speed changing assembly; the power input is shunt into a second member of the first planetary gear system; and after being synthesized and transmitted by the first planetary gear system, the power is output through the power output axle through the second planetary gear system.
In another embodiment of this aspect, the gear rack piece moves to change the bevel angle of the ramp mechanism, thus causing continuously variable speed change.
In another embodiment of this aspect, the cam pushes the push rod while moving up and down in the radial direction and moving left and right around the power input axle, and in the meantime the push rod moves axially left and right and pushes a power transmission gear for additional power rotation (i.e., the additional power transmission), wherein said power transmission gear is engaged with a second power transmission gear to cause other gears to change speed to input power into the first planetary gear mechanism via said overrunning clutch; and wherein after being synthesized and transmitted by the planetary gear mechanism, the driving gear member achieves power output through the axle (III) of the second planetary gear mechanism (A).
In another aspect the present invention provides a vehicle comprising a stepless transmission according to any of the embodiments described herein.
In one embodiment of this aspect, the vehicle is selected from automobiles, aircrafts, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles.
In a preferred embodiment of this aspect, the vehicle is selected from automobiles, tractors, and mine and construction vehicles.
In another aspect the present invention provides a stepless transmission comprising a power input axle, a power output axle, one or more planetary gear mechanisms, and a speed changing means comprising a cam and a ramp mechanism, wherein the transmission is capable of stepless speed change.
In one embodiment of this aspect, the speed changing means further comprises one or more push rods, a mandrel, a clutch, a gear rack piece, one or more gears, and one or more springs, wherein one or more push rods and mandrel are kept connected with each other through said one or more springs, and one of said one or more push rods.
In another embodiment of this aspect, the clutch is an overrunning clutch.
In another embodiment of this aspect, the cam pushes one of the push rods, and said one of the push rods has four degrees of freedom to move radially up and down and/or move axially left and right.
In another embodiment of this aspect, the mandrel is characterized that while transmitting power, a pair of gears causes a power-transmitting gear to make additional power transmission through the mandrel.
In another embodiment of this aspect, power is input through the power input axle (I) into a first member (H) of a first planetary gear mechanism (B) via cam 10, gear 11, and other members of said speed changing means (7, 5, 4, 3, 2, 1, and 13), see, e.g.,
In another embodiment of this aspect, the gear rack piece (9) moves to change the bevel angle of the ramp mechanism (8), and the cam (10) pushes a first push rod (7) while moving up and down in the radial direction and moving left and right around the shaft, and at the same time a second push rod (5) moves axially left and right and pushes a power transmission gear (3) for additional power rotation (i.e., the additional power transmission), wherein the power transmission gear (3) is engaged with another gear (11) to cause other gears (1 and 13) to change speed to input power into the first planetary gear mechanism (B) via an overrunning clutch (2), see
In another embodiment of this aspect, the present invention provides a stepless transmission substantially shown in
The planetary gear mechanism has a structure such as planetary gear mechanism (A), (B), and (H) as substantially shown in
In another embodiment of this aspect, the turn angle in the working travel of cam piece (10) is about 210°; three groups of loading speed change mechanisms drive gear piece (16) at the same time at most; at least two groups drive gear piece 16 at the same time; and the four groups drive alternatively.
In another embodiment of this aspect, the clutch piece (2) is characterized in that: when the rotating speed of gear piece 1 is higher than that of gear piece 4, the overrunning clutch piece (2) slides without transmitting power; and when the rotating speed of gear piece (1) is lower than that of gear piece (4), gear piece 4 is meshed via overrunning clutch piece 2 to transmit power to gear piece 1 and gear piece 16 for serving as power output of planetary gear nb member.
In another embodiment of this aspect, when cam piece 10 returns, gear piece 4 does not perform any additional rotating movement; and when its speed is lower than gear piece 1, the overrunning clutch slides, thus cam piece 10 returns without outputting power.
In another embodiment of this aspect, the push rod piece 5 is an inner-outer spiral involute spline sleeve, and its axial force P=0 is balanced to reduce radial force of cam and push rod; the spring piece 3 is designed to drive the push rod piece 5 and mandrel piece 14 to be always contacted with push rod piece 13; and the play or gap is not allowed so as to realize parking stepless speed change.
In another embodiment of this aspect, the spring piece 7 is designed to be taken as force sealing mechanism of cam piece 10 and push rods 11, 12 and 13, thus cam piece 10 and push rods 11, 12 and 13 are always in working state.
In another embodiment of this aspect, one face of the gear rack piece 9 is provided with a rack which is meshed with the gear of ramp piece 8, and the other face is provided with end face screw thread; four claws are designed for three-claw chuck via chisel; the centering performance of three-claw chuck has a centration error of about 0.025 mm; angles α of four slope pieces 8 can be adjusted by rotating disk in three-claw chuck via angle gear, thus loading stepless speed change is realized; and meanwhile, gear piece 9 is provided with “gap clearing” device specific to slope piece 8 and screw threads on disk end faces of three claws, thus making loading stepless speed change accurate.
In another embodiment of this aspect, the gear piece 4 and piece 15 are each provided with 50 or 25 teeth, wherein when tooth number of gear piece 15 “becomes” “50.1 . . . 50, 25 . . . 53 . . . 53.03” due to additional turn angle under the action of gear piece 4, the requirement of different transmission ratios of Z4/Z15 is met.
In another aspect, the present invention provides a vehicle comprising a stepless transmission according to any one of embodiments described here, in particular those substantially described in
The vehicles of the present invention include, but are not limited to, automobiles, aircrafts, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles, among which automobiles, tractors, and mine and construction vehicles are more preferred.
The present invention is applicable to stepless speed change and stepless speed change under load, such as automobiles, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles, or the like. If the automobile manual transmission is 15% more fuel efficient than the automatic CVT, the stepless transmission of the present invention is about 10% more fuel efficient than the manual transmission. When used in automobiles, the present invention is about 25% more fuel efficient than the hydraulic mechanical CVTs. Therefore, when used in automobiles, the present invention provides a safe, reliable, entirely new stepless transmission, which can save about 25% of refined oil, and at the same time, reduce about 25% of pollution emissions in comparison with the widely used hydraulic mechanical CVTs.
In another aspect, the present invention provides vehicles comprising a stepless transmission as described herein. The vehicles include, but are not limited to, automobiles, aircrafts, helicopters, tanks, warships, submarines, tractors, and mine and construction vehicles.
In the present disclosure, the term “stepless transmission” and “continuously variable transmission” are on occasions used interchangeably, and their meanings are well understood by a person of ordinary skill in the art.
The “planetary gear mechanism” as used in the present invention includes all types of planetary gear mechanisms (e.g. NGW, NW, WW, etc., gearing transmission types, or the like). The “planetary gear mechanism” also includes a series of two or more planetary gear mechanisms connected with each other in sequence. The three components of the “planetary gear mechanism” (e.g., see (a) and (b) of
The “gear drive mechanism” of the present invention includes all types of gear drive mechanisms, and also includes all types of gear tooth, such as involute profile, arc tooth profile, etc.
The “splined coupling mechanism” used in the present invention can be selected from splined coupling mechanisms, helical spline coupling mechanisms, as well as a spiro coupling mechanisms and rolling screw drive mechanisms.
The “cam mechanism” used in the present invention can be a planar cam mechanism or a spatial cam mechanism.
The “push rod” used in the cam mechanism as used in the present invention can be a spherical push rod, a cylindrical push rod, or a plate-shaped push rod, and can also be modular push rod (i.e., combination of spherical and cylindrical push rods, or a combination of spherical or cylindrical and plate shape push rods). The push rod of the present invention can be one having four degrees of moving freedom, i.e., capable of moving radially up and down while moving axially around (left and right), or having only two degrees of moving freedom.
The “rack mechanism” of the present invention includes a gear rack mechanism and a planar spiral rack mechanism.
For illustration purpose, in one embodiment, the working mechanism of the “gear, cam stepless transmission” of the present invention is briefly described below and illustrated in
In the “gears, cams stepless transmission” apparatus of the present invention, members 1, 2, 3, 4, 5, 6, 7, 8, 9, and 12 constitute a group of speed-changing components, the loaded speed-changing components being multi-group components.
Any terms used in the present disclosure, unless specifically defined otherwise, take ordinary meanings as understood by persons skilled in the art. The Figures and short-hand drawings of parts in the Figures, such as gears, planetary gear train, and overrunning clutches, etc. using standard symbols understood by those skilled in the art serve to illustrate the inventive concept of the present invention without limitation on the scope of the invention.
The following non-limiting examples set forth herein below illustrate certain aspects of the invention. The designs of functional prototypes of the present invention illustrated below may involve a number of mathematical formulas and calculations. As a person skilled in the art would appreciate, such mathematical formulas and calculations are provided solely as guidance on practice of the invention. None of the specific formulas or numbers is intended to be limiting on the scope of the invention. As a person skilled in the art would also understand, the numbers with long decimal points obtained from mathematic calculations illustrated below are provided merely for illustration purpose, but the numbers themselves are by no means limiting on the invention disclosed. Based on well-known and established mathematical principles, depending on situations and needs, such as types, sizes, and purposes of vehicles, specifications and dimensions of stepless transmissions, or parts thereof, may vary substantially, but they can be designed and manufactured to achieve the desired performance according to the present disclosure.
(1) Characteristics of Archimedes Spiral:
The polar coordinate of the Archimedes Spiral (see
The Archimedes Spiral has the characteristics that: a is a constant, and the value of Y varies with the value of φ.
When Δφ value of constant φ is equal, ΔY of the corresponding Y value is also equal (see
When a·φ=constant, ΔY is also equal to constant, i.e., ΔY=constant.
(2) Characteristics of Ramp Mechanism:
As shown in
When h is a constant value (i.e., h is a constant), Let: h=A and 1/tan α=Y, and the abovementioned formula is changed into: X=A·Y.
So, X=A·Y is a linear equation passing through the origin. Therefore, the characteristic of the ramp mechanism is that: when the value of h is unchanged, different X values can be obtained by changing the angle α value of the slope of piece 1 (see
(3) Helical Gear Engagement and the Characteristics of its Axial Movement:
See
Similarly, if gear Z2 moves axially from point A to point A2 by value L2, Z2 rotates by arc length AA2, namely, the rotation arc length AA2/(2Rπ/360)=angle φ2.
According to the calculation above, the value of turn angle φ of Z2 is only relevant to value L instead of the movement starting position of Z2 no matter where point A is positioned, that is, L is a constant value while increment (or decrement) Δφ=constant.
When helical gear Z1 is meshed with helical gear Z2 for performing rotating transmission at speed V1 and the transmission ratio is 1, if axial moving speed V of Z2 is equal to the value of the moving distance L of Z2 every time Z1 rotates by a circle, so i=(360±φ)/360. If spiral angle α is consistent with the rotating direction of V1, angle φ is a positive value (+φ); and if spiral angle α is opposite to the rotating direction of V1, angle φ is a negative value (−φ).
Z1=Z2=50 teeth, and modulus m=2. Z1 drives Z2 to rotate, Z1 rotates clockwise, the spiral direction of oblique teeth is a left-hand spiral direction, and β=36 degrees. The moving distance L of Z2 along the axis of Z1 is 20 mm every time Z1 rotates by a circle.
Find: When the moving distance L of Z2 along the axis of Z1 is 20 mm every time Z1 rotates by a circle while Z1 drives Z2 to rotate, find the transmission ratio i.
Solution:
Given the involute spline of helical gear: Z=16, m=2.5, Φα=42 mm, pitch Φ=16×2.5=40 mm, spiral angle β=35 degrees, Z1=Z2=50 teeth, modulus m=2. Z2 is connected with axle II via involute spline. Axial moving distance L of Z2=18 mm (see
Find: When the moving distance L of Z2 along the axis of Z1 is 18 mm every time Z1 rotates by a circle while Z1 drives Z2 to rotate, find the transmission ratio i.
Solution:
(1) Linear Equation.
Calculate the characteristics of linear equation of planetary gear mechanism in which NGW and NW type meshed transmission mode is adopted according to general formula for calculating planetary gear speed ratio.
General formula for calculating speed ratio of NGW planetary gear mechanism:
let Zb/Za=u,
n
a=(1+u)·nb−unb (1)
General formula for calculating speed ratio of NW planetary gear mechanism:
let Zb·Zc/Zd·Za=u,
n
a=(1+u)·nh−unb (2)
1) Planetary Gear Coupling
2) Linear Equation of Planetary Gear
(a) Figures of one member is fixed, one member for inputting, and one member for outputting.
Formula: na=18nh−17nb
a) If: 18nh=0, then: na=−17·nb, so: y=−17x. See
b) If: −17nb=0, then: na=18nh, so: y=18x. See
c) If: na=0, then: nb=(18/17)nh, so: y=(18/17)x. See
(b) Figures of linear equations in which two members are used for inputting and one member is used for outputting.
Formula: na=18nh−17nb
a) If nh=1, then: na=18−17nh, so: y=18−17x. See
b) If nb=1, then: na=18nh−17, so: y=−17+18x. See
c) If na=1, then: nb=(18/17)nh−(1/17),
(2) Adjustable Linear Equation and Figure
Formula: na=18nh−17nb (3)
−0.25=18−17x(55/50) (4)
1.4=18−17x(55/50) (5)
(1) P=Pa−Pb=0
According to
Then:
F=N/R (6)
Then:
P=tan β·F (7)
wherein, β refers to spiral angle of helical gear.
tan βa·N/Rc=tan βc·N/Ra
tan βc=tan βa·N·Rc/N·Ra.
tan βc·Ra=tan βa·Rc (8)
(2) Φ=Φa+Φc
1) Additional Turn Angle Φc
According to
2) Additional Turn Angle Φa
According to
Find: additional turn angle Φc of piece a
Solution: let: arc length AA′ be Ya
3) Additional Turn Angle Φ
According to
Then: the additional turn angle Φ of piece a relative to piece b is:
According to the principle in
Similarly, when the moving direction of piece c is consistent with that shown in the figure, the additional turn angle Φ of piece a is a positive value. If piece c moves opposite to that shown in the figure, the additional turn angle Φ of piece a is a negative value.
4) Calculation Formula of Additional Turn Angle Φ
∴Φ=(X·360/π)·(tan βc/dc+tan βb/db) (9)
a) shows a spiral guide rail of slotting helical gear on gear shaping machine. During slotting of the helical gear, the shaft of gear shaper cutter is parallel to the shaft of gear, which is equivalent to a pair of parallel axle helical gears are meshed together. During gear cutting, additional spiral movement is performed apart from upward and downward cutting movement and generating motion, so that the generating surface of cutting edge movement is equivalent to the toothed surface of the helical gear. The additional spiral movement is obtained by means of spiral guide rail of machine tool.
Since the spiral angle of “spiral guide rail” for slotting the helical gear cannot be varied, several “spiral guide rails” with different spiral angles for processing helical gear are provided, and a gear shaper cutter for processing corresponding slotted helical gear is equipped.
“Speed change mechanism” is designed innovatively by using “reverse thinking” method. Let: the processed helical gear be taken as power input, and transmission gear shaper cutter move up and down during meshed transmission. Then: transmission of main axle of the gear shaping machine by a turn angle is added during meshed transmission, thus the aim of changing one rotating speed of the main axle of the gear shaping machine to another rotating speed is fulfilled.
2. Basis for Changing Spiral Guide Rail into Slope:
Under the restriction of the spiral guide rail, the spiral angle of the gear slotting mechanism cannot be varied. Therefore, the additional turn angle cannot be varied and can only be applied to special use.
According to
It can be learned from all modern mechanical variable transmission books or data, the calculation of the speed ratio of step gear variable speed or mechanical stepless variable speed transmission is not independent of the concept of i=Z1/Z2=R2/R1. A special pulse type stepless variable speed transmission (such as crank rocker pulse type stepless speed change) is adopted for adjusting the position of crank to realize speed change, namely, the concept of i=X/Y.
A general formula for calculating the speed ratio of planetary gear mechanism can be deduced by applying mathematical tools. Proof: The planetary gear mechanism adopting NW meshed transmission can be completely taken as a speed change amplifying mechanism when members H and b are taken as inputs while member a is taken as output.
That is,
n
a=(1+u)·nh−unb (2)
Through mathematical operation reasoning, axial force of helical gear adopting parallel-axle single-stage meshed transmission can be fully balanced into zero.
Then:
tan βc·Ra=tan βa·Rc (8)
As proven by mathematical operation reasoning, the additional turn angle formula of Φ=Φa+Φc has an amplifying function.
Then:
φ=(X·360/π)·(tan βc/dc+tan βb/db) (9)
According to
In the Figure: gear piece 15/gear piece 4=50/50, gear piece 1/gear piece 16=50/51
Let: nh=1 r/min
Then: nb=(50/51)·(50/50)
So: na=18−17×(50/51)·(50/50)=1.3333333
When ramp mechanism piece 8 varies its angle α, plunger piece 14 is driven to move axially by value X while α=80° and the working travel moving distances h of cam push rod pieces 10, 11, 12 and 13=10.5 mm, then:
X=h/tan α=1.851433297 mm
Since top travel movement angle is equal to cam actuating travel movement angle Φd=210°, and four groups of loading stepless speed change mechanisms work together, top travel movement shall be calculated according to 2π. Then:
Xf=(X/210)·(360/50)=(1.851433297/210)·360=3.173885653 mm
According to
The additional turn angle Φ=Xf·360/π·(tan βc/Rc+tan βb/Rb) (9)
So:
So:
In
Since the turn angle in the working travel of cam piece 10 is 210°, three groups of loading speed change mechanisms drive gear piece 16 at the same time at most, at least two groups drive gear piece 16 at the same time, and the four groups drive alternatively.
The overrunning clutch piece 2 is characterized in that: when the rotating speed of gear piece 1 is higher than that of gear piece 4, overrunning clutch piece 2 slides without transmitting power; and when the rotating speed of gear piece 1 is lower than that of gear piece 4, gear piece 4 is meshed via overrunning clutch piece 2 to transmit power to gear piece 1 and gear piece 16 for serving as power output of planetary gear nb member.
Conversely, when cam piece 10 returns, gear piece 4 does not perform any additional rotating movement; and when its speed is lower than gear piece 1, the overrunning clutch slides, thus cam piece 10 returns without outputting power.
1) Overall dimensions: diameter×length=260 mm×660 mm.
2) Center height: h=130 mm.
3) Diameters of input and output shafts: Φ=30 mm.
1) Loading stepless speed change
2) Parking stepless speed change
3) Transmission efficiency: about 95%
4) Oil saving: about 30%.
5) Reduction in emission pollution: about 30%.
According to
1) oil saving: about 30% and 2) reduction in emission pollution: about 30%, it is consistent with American related policy and regulation of energy saving and emission reduction.
a. Gaps exist in spiral and gear and rack transmissions. Highly stable and accurate spiral and gear transmission or feeding amount is required, and fluctuation of feeding amount is not caused due to vibration of resistance. Therefore, “gap eliminating mechanism” must be designed.
One face of rack piece 9 is provided with a rack which is in meshed transmission with slope gear piece 8, and the other face is end face spiral which is meshed with “four-claw” chuck (see
Gear piece 9 is only taken as speed change mechanism instead of power transmission mechanism. Therefore, rack piece 9 can be designed into “bilateral automatic gap eliminating mechanism” so as to realize highly-accurate and stable speed change.
b. Since speed change is irrelevant to axial position of plunger piece 14, and is only relevant to slope of angle α of slope gear piece 8, slope gear piece 8, rack 9 and “four-claw” chuck are designed into components. After assembly of components, slope piece 8 is adjusted into: α=90°, and four groups of assemblies are processed at the same working position in a way that 8 α=90° so as to ensure that feeding angles α of the four groups are equal. Then, the components are placed into gearbox.
c. Four groups of spiral angles βa and βc of inner-outer spiral involute spline must be equal. Inner-outer spline broach can be adopted for processing during batch production so as to ensure that four groups of spiral angles βa and βc are equal. Inner spiral involute spline hole is processed by adopting high-accuracy spark processing on a single sample machine.
d. Pin roller type overrunning clutch having the characteristic of finely adjusting power transmission output is selected, thus errors occurring in speed change mechanism can be compensated while stable speed change output transmission is realized.
In moving axis wheel transmission, one or more wheel axes rotate around another wheel or more than one wheel axes or a public axis line, which is called planetary gear train (or epicyclic gear train).
When the wheel in a planetary wheel train is a gear, from which the name of planetary wheel come.
(1) In planetary gear train transmission, when one member is unmovable, one member is taken as input, and one member is taken as output, it is called planetary gear transmission.
(2) In planetary gear train transmission, when two members are taken as inputs and one member is taken as output, it is called planetary gear combined transmission.
(3) In planetary gear train transmission, when one member is taken as input and two members are taken as outputs, it is called planetary gear differential transmission.
In general, planetary gear train transmission is collectively referred to as planetary gear transmission, and planetary gear combined transmission is collectively referred to as planetary gear differential transmission.
1) Basic Members of Planetary Gear
As shown in
2) Planetary Gear Transmission Form
(i) Classification by Basic Members
For example, 2a-H, where a represents sun wheel member, H represents planet carrier member, and 2a-H represents two sun wheels and one planet carrier member.
(ii) Classification by Engagement Way
For example, NGW, where N represents inner engagement, W represents outer engagement, and G represents public planet wheel. NGW represents the presence of inner engagement and outer engagement transmission in planetary gear mechanism, and sharing of planet wheel.
For example, NW represents inner engagement and outer engagement transmission in planetary gear mechanism;
For example, WW represents outer engagement transmission in planetary gear mechanism.
<1> Fixed Axis Transmission
As shown in
n
a
/n
b=−(Zb/Za) (1)
After phase shift:
n
a=(−Zb/Za)nb (2)
(2) Speed Ratio Calculation Formula:
When nh≠0, −nh which is equal to nh in opposite rotating direction is added to formula (1), i.e., “Absolute motion does not influence the relation of relative motion”.
So, the calculation formula of planetary gear transmission mechanism is as follows:
(na−nh)/(nh−nh)=−(Zh/Za) (3)
After phase shift:
After sorting:
Z
a
n
a
−Z
a
n
h
=Z
b
n
h
−Z
b
n
b
Z
a
n
a=(Zbnh+Zanh)−Zbnb
n
a=(Zb/Za+Za/Za)nh−(Zb/Za)nb
∴na=(1+Zb/za)nh−(Za/Zb)nb (4)
n
b=(1+Za/Zb)nh−(Zb/Za)na (5)
n
h=1/(4+4)(Zana+Zbnb) (6)
Let: Zb/Za=u
Then:
n
a=(1+u)nh−unb (7)
n
b=(1+1/u)nh−(na/u) (8)
n
h=(na+unb)(1+u) (9)
See
According to the mechanism transmission diagram in
See
According to the mechanism transmission diagram in
n
a
−n
h
=u(nb−nh)=(unb−unh)
∴na=unb−(u−1)nh (11)
5. Deduction of Speed Ratio Calculation Formula of Planetary Gear Mechanism with the “Law of Conservation of Energy”
Acting force on planetary gear: (see
Ma=Fa·Ra
Where: Ra and Rb refer to pitch radii of the sun wheel and the inner gear respectively. (See
Rh takes the distance between the circle centers of Ra and Rb as the radius, i.e., the rotation radius of the planet carrier. (See
Let: the gear ratio of the inner gear Zb to the sun wheel Za be u,
Where: Rh refers to the central distance between the planet wheel and the sun wheel. According to the force balance condition of the planet wheel 4 in the horizontal direction:
So, torques on the sun wheel a, the inner gear b and the planet carrier are as follows:
M
a
=F
a
·R
a
M
b
=u·F
a
·R
a
M
h=−(1+u)·Fa·Ra (12)
According to the “Law of Conservation of Energy”, the algebraic sum of input and output powers on the three elements is zero.
i.e.:
M
a
·W
a
+M
b
·W
b
+M
h
·W
h=0 (13)
Where, Ma, Mb and Mh refer to the angular speeds of the sun wheel, the inner gear and the planet carrier respectively.
When Ma, Mb and Mh in formula (12) are substituted into formula (13):
If the angular speed is substituted by the rotating speed, then the formula above is changed to:
n
a
+n
b
·u−(1+u)·nh=0
∴na=(1+u)·nh−u·nb (14)
In conclusion, formula (14) and formula (7) are completely the same, proving the correctness of the formulae from different laws of nature.
Since automobile type is not specified for the preparation of the design specification, data such as the interface type and size of an engine output end, suspension form, suspension position and size, the installing space, position and size of the “Gear/Cam Continuously Variable Transmission”, etc. are unavailable. It is impracticable to make a design by adopting the overall dimensions of an existing automobile transmission since the “Gear/Cam Continuously Variable Transmission” differs greatly from the existing automobile transmission in appearance. The major task of the design of functional prototype is: carrying out automobile transmission rack test by using the functional prototype of “Gear/Cam Continuously Variable Transmission”, and carrying out rack test with reference to China Automobile Industry Standards QC/T29063-92 and QC/T568-1999.
Detection: functional indexes of the transmission efficiency of the “Gear/Cam Continuously Variable Transmission”, the reliability and service life of load stepless speed change performance, the properties, vibration and noise during matched output with an engine, etc. Consequently, the aim of comprehensively evaluating the performance of the “Gear/Cam Continuously Variable Transmission” is fulfilled.
Design of major performances: major performances of the “Gear/Cam Continuously Variable Transmission” include load stepless speed change, parking stepless speed change and transmission efficiency. The optimal match efficiency of the “Gear/Cam Continuously Variable Transmission” and an engine as well as indexes such as vibration, noise, service life, etc. shall reach standard values of automobile transmission.
The maximum transmitted torque of the functional prototype of “Gear/Cam Continuously Variable Transmission” is: 375 N/m.
The maximum power of the functional prototype of “Gear/Cam Continuously Variable Transmission” is: 100 KW (i.e.: 135.96 horsepower)
Single stage: m=3, shunt transmission: m=2, combined transmission of three groups of planet wheels via planetary gear: M=1.5.
Speed change range of a medium-sized automobile transmission is adopted, i.e.: i=−4−0.75
Load stepless speed change transmission efficiency: η=95%
Lubricating oil: gear oil and N150 gear oil.
Lubricating method: splash lubrication.
Vibration and noise shall reach specified standard values of automobile transmission.
Service life shall reach specified standard value of automobile transmission.
Test resulted efficiency of simulation optimal matching effect of “Gear/Cam Continuously Variable Transmission” and engine.
“Transmission” applied to automobile is a device for changing the torque and rotation speed output of an automobile engine to meet the requirements of various different fraction forces and various different rotation speeds on automobile wheels during starting, acceleration and running of the automobile and under various road conditions.
Thus, it is particularly important to evaluate the contribution of a “transmission” to the power performance, fuel economy (i.e., transmission efficiency of the “transmission”), safety, operating reliability, and transmission stability of the automobile.
One object of the present invention is to design a functional prototype of “Gear/Cam Continuously Variable Transmission” to perform verification calculation on the load stepless speed change and parking stepless variable transmission efficiency of the “Gear/Cam Continuously Variable Transmission” as well as its ideal dynamic properties to match with the engine based on the structure of the prototype, with a main objective of calculating the performance and efficiency of the “prototype”. The performance characteristics of the “Gear/Cam Continuously Variable Transmission” are concluded from “rack” testing and adjustments.
In design work, three methods, including experience, analogy and theory, were adopted for designing. Experimental data and existing calculation formula were unavailable in the design process of the “Gear/Cam Continuously Variable Transmission”, thus the three methods above are applied in combination to the calculation and design of the functional prototype of “Gear/Cam Continuously Variable Transmission”.
1. Transmission Gear Modulus
Transmission gear modulus was selected according to the National Standard GB1357-78 of People's Republic of China.
Set the gear transmission module of the transmission: M=3.
2. Design Calculation of Planetary Gear Mechanism:
Formula: na=(1+u)nh−unb. In order to design the planetary gear mechanism into a speed ratio amplifying mechanism, NW type planetary gear mechanism is selected (see
Let: Za=21, Zb=102, Ze=63, Zd=18, m=1.5, Nw=3.
So,
n
a=18nh−17nb=18−17nb (3)
3. Shut Transmission Calculation:
so, na=18−17nb=18−17×(50/51)·(50/50)=1.333333
na′=18−17nb′=18−17×(50/51)·(54.75/50)=−0.25
Design: tooth numbers of gear part 15, part 4 and part 1 is 50, and tooth number of part 16 is 51. Module: m=2.
Four groups of gear parts 1 and parts 5 are designed to drive alternatively.
4. Calculation of Additional Rotation Angle
Internal and external spiral involute spline assemblies 5 (see
Let: P=Pc=0,
tan βc·Rb=tan βb·Rc (8)
Let: βb=18°, Rb=15 mm, Rc=25 mm. Find: βc
Solution: tan βc=tan βb·Rc/Rb=tan 18°·25/15=0.541532827
βc=28.4369994°
1) Internal spiral involute spline parameters are designed to be:
Z=15, m=2, βb=18°, Rb=15 mm, d=30 mm
2) External spiral involute spline parameters are designed to be:
Z=25, M=2, βc=28.4369994°, βc=25 mm, D=50 mm
3) Additional rotation angle φ:
φ=(Xf·360/π)·(tan βc/dc+tan βb/db) (9)
So: (I)=Xf·2.482203636
5. Calculation of Overrunning Clutch:
As an illustrative example, allowable torque and main dimensions of CY1B-series roller-type overrunning clutch are shown in
Bearing model refer to ultralight and superlight-series deep groove ball bearings in old standard, and the new standard is within parenthesis.
Part 2 is a CYIB-series roller-type overrunning clutch. Specification: 100B, allowable torque: 250/N·m, maximum diameter: D=100 m, maximum length: L=68 mm (See Table 1).
Two components 2 are adopted for outputting at the same time in the transmission, then the maximum output torque of the transmission is:
where, 0.75 refers to a safety factor.
6. Design Calculation of Cam:
(1) General Design Requirements of Cam Member 10 (See
1) In order to reduce wear of cam, it is necessary to consider the maximum shaft diameter φmin of the input shaft while considering lowering the linear speed of the cam. Let: φmin=30 mm, the base radius of the cam is: Rb=16 mm.
2) In order to meet the working requirements of a linear equation mathematical model in which Δφ=constant and Δh=constant, the working profile curve and return curve of the cam are Archimedes spirals.
3) In order to decrease the weight ratio and increase the output power, “load stepless speed change mechanisms” in the “Gear/Cam Continuously Variable Transmission” are classified into four groups. (See
4) Closed type of cam push rod parts 11, 12 and 13: (See
5) Specific to the aim of preventing the internal and external spiral involute spline assemblies 5 and carrier rod part 14 to move leftwards and rightwards on shaft II, spring part 3 is designed to keep part 5 and part 14 always in contact with push rod piece 13. (See
6) Major design parameters of cam:
(a) Cam centering directly-operated mechanism is adopted.
(b) Cam extending stroke motion angle: φ=210°
(c) Cam reserved wear angle: φ=2×10=20°
(d) Cam return motion angle: φh=360−210−20−130°
(e) Extending motion angle stroke of push rod: Let: 2π stroke L=18 mm
(f) Radius of push rod roller: R=9 mm
(2) Cam Extending Stroke Curve and Pressure Angle
1) Extending Stroke Curve
2) Extending Stroke Pressure Angle
Pressure angle is relevant to the base diameter of the cam after the determination of Δt. The smaller the base diameter, the larger the pressure angle is; and the larger the base diameter, the smaller the pressure angle is. Therefore, the maximum extending stroke pressure angle αmax is calculated by using base Rb in the cam extending stroke (see
As shown in
a=√{square root over (2(R2×0.0006091727+Δ2×1.99993927)}
sin ∠c=sin 2° (Rb−Δ)/a=sin 2° (16−0.05)/0567358581
φc=78.84879439°
Extending stroke pressure angle: αt=90°−∠c−1°=10.15120561°
(3) Return Curve Equation and Pressure Angle
1) Return Curve Equation
Let: Δh=ha/φh=10.5/130=0.00076923, A=Rb=16 mm
Then: cam return Archimedes spiral equation is:
2) Return Pressure Angle
As shown in
sin ∠c=sin 2° (Rb−Δh)/a=sin 2° (16−0.08076923)/0.581369025
∠c=72.86808348°
Return pressure angle: αh=90°−∠c−1°=16.13191652°
(4) Issues Related with Cam Design and Calculation
7. Calculation of Variable Transmission:
(1) Gears of the Transmission of an Embodiment of “Mini-Cars”
Transmission ratio i of rear axle: 5.125
According to the transmission ratio: i=engine rotation speed/transmission output rotation speed. The output rotation speed of the “Gear/Cam Continuously Variable Transmission” is: na
Then: i=engine rotation speed/na; Let: the engine rotation speed=1 r/min
So, i=1/na or na=1/i.
(2) Find: transmission ratio Xz
Formula: na=18−17(50/51)Xz
Then: X, =(18−na)×51/17×50
Gear 1, Xz=(18−0.276)×51/17×50=1.06344
Transmission ratios Xz of other gears are shown in table 3
(3) Find: Additional Rotation Angle φf.
Basic rotation speed: gear part 15/gear part 4=1
So, φf=(Xz−1)×360
Gear 1, φf=(1.06344−1)×360=22.8384°
Additional rotation angles φf of other gears are shown in table 4.
(4) Find: 2π Feed Xf
φf=(Xf·360/π)·(tan βc/dc+tan βb/db)=Xf×114.591559×0.021661313=Xf×2.482203636
So, Xf=φf/2.482203636
Gear 1, Xf=22.8384/2.482203636=9.200856718
For 2π feed Xf of other gears, see table 5. (Refer to calculation
(5) Find: 210° Feed X
X=Xf 210/360=Xf×0.58333333
Gear 1, X=9.20086×0.5833333=5.367166419
210° feed X of other gears are shown in table 6. (Refer to calculation
(6) Find: Angle α of Slope Part 8
Formula: tan α=h/X, where: h=10.5 mm.
Then: in gear 1, tan α=10.5/5.367166419=1.956339562
Angle α of other slope gear part 8 is shown in table 7. (Refer to calculation
(7) Summary of Calculation of Gear Variable Transmission:
Let: na=0, 0.25, 0.5, 0.75, 1, 1.25. Find Xz, φf, Xf, X and α listed in table 9 respectively.
Let: Xa=K·na+X, when na=0, X=6.76817959
Then, Xa=X=6.76817959
Let: n′a=0.25, Xa=5.499145918. The interval of na and n′a is: 0.25.
Then: 5.4499145918=0.25·K+6.76817959
So: X=6.76817959−5.076134688·na
X=h/tan α, h=10.5 mm, X=10.5/tan α
1. Calculation of Shut Transmission Efficiency
In combined transmission of planetary gear used in the “Gear/Cam Continuously Variable Transmission”: (See
So, power transmitted by nb is a half of the total power.
P=Pa−Ph=0 (see II, 4 Calculation of additional rotation angles). Moreover, in basic transmission: gear part 15/gear part 4=1, slope part 8, angle α is more than 45° (α>45°). Axial force of the push rod part 13 is less than radial force. (See tables 8 and 9 as well as
ηf=1−(X2+0.04−1)/2 (B)
2. Calculation of Combined Transmission Efficiency of Planetary Gear:
Calculation of efficiency input by H and b and output by a (See
Formula: ηa=1−|(na−nh)/na|Ψ (C)
Let: nh=600 r/min, na=6000×0.276=1656 r/min
η value of combined planetary gear input of other gears is shown in table 11.
3. Transmission Efficiency of “Gear/Cam Continuously Variable Transmission”
Formula: η1=ηf·ηa (η value of each gear is shown in table 12)
1. Bearing Selection and Speed Calculation
Member with the maximum rotation speed in the “Gear/Cam Continuously Variable Transmission” is: gear part 4 (See
Let: the input rotation speed nh=7000 r/min
(1) Gear R, Xz=1.09734=Xzmax
(2) Gear 3, Xz=1.03782
The limit rotation speed of 7009C angular contact ball bearing lubricated with “grease”: ng=7500r/min, and the limit rotation speed of 7009C angular contact ball bearing lubricated with “oil”: ng=10000r/min.
Since: nmax=7681.38<10000 r/min, n=7264<7500 r/min
Bearing is selected, and design is reasonable.
2 Planetary gear assembly condition and transmission ratio check:
3. Verification of linear speeds of cam and push rod:
1. Safety and Reliability
As illustrated by the calculation and proof above, the “Gear/Cam Continuously Variable Transmission” is safe and reliable based on the mathematics or structural principles.
Through use of “meshed coupler”, load stepless speed change mechanisms and planetary gear mechanisms can be set into six groups. For example, the safety and reliability of a helicopter transmission are more outstanding. If one or two groups of load stepless speed change mechanisms and planetary gear mechanisms in the transmission are worn out or damaged, e.g., by bullets, the “Gear/Cam Continuously Variable Transmission” can continue working under load.
2. Fuel Efficiency and Environmental Protection
In over 90% of the running time, automobiles are driven between gear 3 to gear 5. It can be known from the calculation above that the mesh type transmission efficiency of gear 3 is 95.6%, the mesh type transmission efficiency of gear 4 is 97%, and the mesh efficiency of gear 5 is 97.2%. Fuel saving is reliable in load stepless speed change in comparison to the existing automobile transmission which saves fuel by about 30%.
Calculation is carried out by using percentage intermediate values of the abovementioned petroleum economization proportions: the intermediate proportions of petroleum economization of “Gear/Cam Continuously Variable Transmission” automobile in comparison to the existing continuously variable automobile are calculated as follows (see Background of the Invention above):
1) Petroleum economization in item 1: (10%+15%)/2=12.25%
2) Petroleum economization in item 2: (100−12.25)[(5+15)/2]%=8.775%
3) Petroleum economization in item 3: (100−12.25−8.775)[(10+15)/2]%=9.7%
4) Items 1+2+3=12.25%+8.775%+9.7%=30.725%
Therefore, “Gear/Cam Continuously Variable Transmission” automobile saves 30.725% petroleum than the existing continuously variable automobile; thus it would also reduce emission pollutants and waste gas by about 30.725%. For similar reasons, emission reduction for about 30% is also reliable.
Particularly in environmental protection: in case of running out of petroleum, since the damage degree of “biofuel” to the environment is 3-5 times higher than that of petroleum, the environmental protection advantage of the “Gear/Cam Continuously Variable Transmission” becomes even more significant.
3. Economy
The “Gear/Cam Continuously Variable Transmissions” of the present invention have numerous advantages over the existing technologies, for example, they are easy and reliable for controlling the stepless speed change mechanism and convenient for intelligent speed adjustment with very low costs; and meanwhile, the types of their parts are less than those in the existing automobile transmissions, thus convenient for batch production, and their manufacturing costs and applied resources are equivalent to those of the existing automobile transmissions. However, the excellent performance of the “Gear/Cam Continuously Variable Transmissions” highlights its superior economy.
4. Conclusions:
The “Gear/Cam Continuously Variable Transmissions” of the present invention could contribute to saving about 30% of energy and reducing about 30% of emission, and thus benefit the mankind greatly.
The foregoing examples and description of the preferred embodiments should be taken as illustrating, rather than as limiting, the present invention as defined by the claims. As will be readily appreciated, numerous variations and combinations of the features set forth above can be utilized without departing from the present invention as set forth in the claims. Such variations are not regarded as a departure from the spirit and script of the invention, and all such variations are intended to be included within the scope of the disclosure.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application No. 61/746,618, filed on Dec. 28, 2012, which is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US13/77749 | 12/26/2013 | WO | 00 |
| Number | Date | Country | |
|---|---|---|---|
| 61746618 | Dec 2012 | US |
