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Title:
RACK GEAR CONTINUOUSLY VARIABLE TRANSMISSION (RG.CVT)
Document Type and Number:
WIPO Patent Application WO/2020/053704
Kind Code:
A1
Abstract:
The (RG.CVT) is a continuously variable transmission. This mechanism consists of an input, output shaft, two gear disks that fixed on main shaft, two interface rods, two rack gear, number of gears and one actuator set. In this invention, the rotation of gear disks convert to liner motion to the two rack gears through the two interface rods and the liner motion of rack gears convert to rotation of output shaft through a number of gears and bearings. The connection point of the interface rods on the gear disks controlled through the actuator set. By changes the connection point of the interface rods, the speed of liner motion of the rack gears and also the rotational speed of the output shaft will be changed. Because shift connection point by is continuously, variations of the output shaft rotational speed will be continuously.

Inventors:
ROSTAMLOU ALIREZA (IR)
ROSTAMLOU AYDIN (IR)
ROSTAMLOU ARASH (IR)
Application Number:
PCT/IB2019/057421
Publication Date:
March 19, 2020
Filing Date:
September 03, 2019
Export Citation:
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Assignee:
ROSTAMLOU ALIREZA (IR)
International Classes:
F16H15/04
Foreign References:
CN103573957A2014-02-12
KR20100122601A2010-11-23
Download PDF:
Claims:
Claims

1. The Rack Gear Continuously Variable T ransmission (RG.CVT) is a mechanism for converting torque to rotation speed, without limitation in the amount of torque transfer value. This mechanism consists of one input shaft with a gear is fixed on it and one main shaft with two gear disks are fixed on it and two parallel keys and two slider sets and two slider parts and one actuator set and two rods and two rack gears (two side tooth) and four guide rods and six gears and four one way free bearings and two shafts (upper and lower) and one output shaft with a gear is fixed on it and a number of sensors. The rotary motion enters through the input shaft and is transmitted to the gear disks and main shaft, the rotational motion of two disks convert to liner motion in the two rack gears (first and second) through the two interface rods (one end of each interface rods connected to a slider part that placed inside of the groove on the gear disks and other end of each interface rods connected to a rack gears). Each one of two rack gears(first and second) placed between two gears and also engaged with these two gears, and each rack gears are mounted on two guide rods. One of two gears that engaged with first rack gear and one of two gears that engaged with second rack gear are mounted on the upper shaft through the two one way free bearings, and also a gear is fixed on the end of upper shaft. Other gear of two gears that engaged with first rack gear and other gear of two gears that engaged with second rack gear are mounted on the lower shaft through the two one way free bearings, and also a gear is fixed on the end of the lower shaft. The two gears that are mounted on end of the two shafts (upper and lower) are engaged with the gear that is fixed on the output shaft:

2. The RG.CVT of claim 1 , wherein an input shaft with a gear is fixed on it:

3. The RG.CVT of claim 1 , wherein an output shaft with a gear is fixed on it':

4. The RG.CVT of claim 1 , wherein a main shaft:

5. The RG.CVT of claim 1 , wherein two gear disks:

6. The RG.CVT of claim 1-5, wherein each gear disks have one liner groove in direction of the disk radial:

7. The RG.CVT of claim 1 , wherein two slider parts:

8. The RG.CVT of claim 1 , wherein two parallel keys

9. The RG.CVT of claim 1 , wherein two slider sets:

10. The RG.CVT of claim 1-8, wherein each slider sets comprising of:

A cylindrical slider part;

A ball bearing; and

A retainer part.

1 1. The RG.CVT of claim 1 , wherein an actuator set:

12. The RG.CVT of claim 1-10, wherein an actuator set comprising of:

A number actuator;

A number guide shaft;

A number slider; and

Two number interface rods.

13. The RG.CVT of claim 1 , wherein two interface rods:

14. The RG.CVT of claim 1 , wherein two rack gears (two side tooth):

15. The RG.CVT of claim 1 , wherein four guide rods:

16. The RG.CVT of claim 1 , wherein six gears:

17. The RG.CVT of claim 1 , wherein two shaft:

18. The RG.CVT of claim 1 , wherein four bearing (one way free bearing):

19. The RG.CVT of claim 1 , wherein a number of sensors for automating the mechanism:

Description:
RACK GEAR CONTINUOUSLY VARIABLE TRANSMISSION

TECHNICAL FIELD

[0001] The present application relates generally to transmissions, and more particularly, to a variable diameter shaft continuously variable transmission (VDS. CVT) for producing high torque output, high power transmission and efficiency of the transmission.

BACKGROUND

[0002] Transmissions are used in transportation, agricultural and construction equipment to transmit power from power sources, such as internal combustion engines to equipment for accomplishing a desired task. For example, transmissions are used to properly transmit power to the wheels of a vehicle, or to a vehicle implement. Various industries use gear mechanisms for transmission and conversion of engine power.

[0003] Various gearbox types such as, for example, gearboxes with constant or variable transmission rates are used. Gearboxes have multiple advantages such as capability of transmission of high torques, low depreciation rate, constant transmission for a selected rotation rate, and high efficiency.

[0004] However, despite of multiple advantages, the gearboxes have disadvantages such as, for example, limited number of transmission rates, and stepwise (non-linear) transmission rates, which can lower efficiency and cause difficulty in selection of a suitable torque.

[0005] Continuously variable transmission (CVT) can be used to overcome the above mentioned disadvantages of gearboxes. A continuously variable transmission (CVT) is a transmission that can change through an infinite number of effective gear ratios between a minimum and a maximum range. In contrast, non-CVT transmissions offer a fixed number of gear ratios.

[006] Specifically, hydrostatic CVTs may use a variable displacement pump and a hydraulic motor and transmit power using hydraulic fluid. A swash plate may be used within the variable displacement pump to vary the output of the hydrostatic CVT by adjusting the fluid flowing into the hydraulic motor. Thus, the swash plate may enable the hydrostatic CVT to be continuously variable.

[0007] Some hydrostatic CVTs may be combined with gear assemblies, drive shafts, and clutches to create a hydro-mechanical CVT. It may be appreciated that in certain applications, such as in construction equipment, a high torque output may be utilized by implements of the construction equipment. Further, a high torque output may be beneficial for low speed movement of vehicles, such as construction vehicles or agricultural vehicles.

[0008] In CVTs, transmission rate between an input shaft and an output shaft can be changed continuously in a linear manner such that infinite number of transmission rates is available between predefined lower and upper limits. In a CVT, transmission is provided by friction between parts of the CVT. in this mechanism the highest power is transmitted through hydraulic fluid.

[0009] For example, in a V belt driven CVT, friction between a belt and a pulley and in a toroidal CVT, friction between a toroidal and disks of the CVT cause the transmission. In the both mechanism, the friction between driver and driven and also between V belt and pulley is very low.

[0010] However, using the low friction mechanism in CVTs cause problems such as limited transmission capability, high depreciation, low efficiency and also using hydrostatic CVTs need hydraulic sets. Hence there is a need for a RG.CVT to produce efficient transmission with continuous linear variation and high torque output and high power transmission.

SUMMARY

[001 1] The disclosed subject matter relates to a rack gear continuously variable transmission (RG.CVT). This invention is based on the power transfer (torque- rotation speed) from the input shaft to the output shaft through disk sets and rack gear and two intermediate bars and two gear sets.

[0012] Power enters the RG.CVT through input shaft. Power exits the RG.CVT through output shaft. A gear is fixed on the input shaft and the input shaft placed on the fixed bearing, the gear on the input shaft is involved with the first gear disk and the first gear disk is fixed on the main shaft and also the second gear disk is fixed on the main shaft, and main shaft placed on the fixed bearing.

[0013] One liner groove created on the each gear disks (first and second) which they are along of the disks radii. One slider part placed inside the each liner groove of the gear disks and the slider parts can have liner motion inside the liner grooves(along of the disks radii).

[0014] Two slider sets are placed on the main shaft of the gear disks and these two slider set can have liner motion on the main shaft and along of the shaft axis, each one of slider sets connected by a bar to the one slider part that placed inside the liner grooves on the gear disks (bar connection with slider set and slider part are hinge connection). Other side of each slider parts connected by a ball bearing with one end of a rod. [0015] Two other end of the each rods, connected with two rack gears (two side have teeth), and each rack gear is placed between the two gears and involved with two gears (one of the two gears involved with the upper side of rack gear and the other gear involved with the lower side of rack gear).

[0016] In this case, the rotational motion of the gear disks convert to the liner motion in the rack gears and the liner motion of the rack gears convert to the rotational motion in the four gears.

[0017] The two gears that involved with the upper side of two rack gears are placed on the upper shaft by two one way free bearings and the other two gears that involved with the lower side of two rack gears are placed on the lower shaft by two one way free bearings (engage direction with shaft in the all one way free bearings are same), the two upper and lower shafts mounted on the fixed bearings.

[0018] By liner motion of two rack gears to the forward or backward, the four gears that are involved with two rack gears will have rotational motion, by liner motion of two rack gears to the forward, only two gears involved with one shaft from two shafts (upper or lower), (for example, upper shaft) and only upper shaft has rotation and lower shaft will be free with gears.

[0019] By liner motion of two rack gears to the backward, the lower shaft has rotation and upper shaft will be free.

[0020] Two other gears fixed on the end of the upper and lower shafts. A gear is fixed on the output shaft and this gear involved with two gears that fixed on the end of two upper and lower shafts in this way, the rotation of two gears transfer to the output shaft output shaft is mounted on the fixed bearings.

[0021] By creating continuously variable liner motion in two slider sets (non-directional) through actuator set, the two slider parts have continuously variable liner motion in directional of gear disks radii, as a result the rack gears will have continuously variable liner motion and the output shaft will has continuously variable rotational speed.

BRIFE DISCREPTION OF THE DRAWING

[0022] FIG 1 configuration of mechanism and components include:

A) One number input shaft 1 and the gear 2 is fixed on the shaft and the shaft is placed on the fixed bearing;

B) Two numbers gear disks 3, 4 that are fixed on the main shaft 5 and the main shaft is placed on the fixed bearing, and the gear disk 3 involved with the gear 2. crated a liner groove on the each gear disks 3, 4 in direction of gear disks radii, (ninety degrees difference between the direction of two grooves on two gear disks 3, 4); C) Two numbers slider part 6 placed inside the grooves on the gear disks 3, 4, and the slider pats can have liner motion inside of the grooves in direction of the gear disks radii;

D) Two numbers parallel key 7 that mounted on the main shaft 5

E) two numbers slider set 8,9 are mounted on the main shaft 5, and the slider sets can have liner motion on the shaft 5 in direction of shaft axis;

F) Two numbers rod 10, one of two rods 10 is interface between the part 8 (from one of the two slider sets 8,9) and one of two slider parts 6 which is placed on the gear disk 3. Other rod of two rods 10 is interface between the part 8 (from the other slider set of two slider sets 8,9) and other slider part of two slider parts 6 which is placed on the gear disk 4. the rods connection type with the slide sets and the slider parts are hung connection;

G) Two numbers rod 1 1 , one of the two rod 1 1 is interface between the part 9 (from one of the two slider sets 8,9) and one side of part 12, and other one of the two rod 1 1 is interface between the part 9 (from other one of the two slider sets 8, 9) and other side of the part 12;

H) A part 12 is placed on the guide shaft 13, and the parte 12 connected to the actuator 14. The part 12 can has liner motion on the shaft 13 in direction of the shaft axis by the actuator 14;

I) Two numbers rod 15, one end of the a rod is connected with the slider 6 which is placed on the gear disk 3, and other end of the rod is connected with the rack gear 16. One end of second rod is connected with the slider 6 which is placed on the gear disk 4, other end of the second rod is connected with the rack gear 17. All connection of rods 15 with the slider sets and rack gear are by ball bearings;

J) Four numbers gear 21 , 22, 23 ,24 (the gears 23, 24 not shown);

K) Two numbers shaft 24, 25 (the shaft 25 not shown);

L) Four numbers bearing (one way free bearings) 28 (not shown);

M) Two numbers gear 26, 27 (the gear 27 not shown);

N) One gear 29, is fixed on the shaft 30;

O) One number output shaft 30 and is placed on the fixed bearing; and

R) One number body 31.

[0023] FIG 2 rack gear 16 is placed on two guide shafts 18 and it can has liner motion on the guide shafts 18 in direction of guide shafts axes, and the rack gear 16 is located between the two gears 20, 22 and also involved with these two gears (rack gear is double side gears). In this figure the back parts are not shown.

[0024] FIG 3 rack gear 17 is placed on the two guide shafts 19 and it can has liner motion on the guide shafts 19 in direction of guide shafts axes, and the rack gear 17 is located between the two gears 21 , 23 and also involved with these two gears (rack gear is double side gears). In this figure the back parts are not shown.

[0025] FIG 4 two gears 20, 21 are mounted on the upper shaft 24 by two bearings 28 (one way free bearings), and a gear 26 is fixed on the upper shaft, and the upper shaft mounted on the two fixed bearings. Two gears 22, 23 are mounted on the lower shaft 25 by two ball bearing 28 (one way free bearings), and a gear 27 is fixed on the lower shaft, and the lower shaft mounted on the two fixed bearings.

[0026] One gear 29 is fixed on the output shaft 30 and the output shaft is placed on the fixed bearing, and the gear 29 involved with the two gears 26, 27.

[0027] FIG 5 as shown in this figure, there are two slider sets with parts 8,9, the cylindrical slider 8 is connected by a bearing to the retainer part 9. The cylindrical slider 8 has an inner hole and the diameter of the hole is equal to the diameter of the main shaft 5 (with further tolerance) and has one groove in side surface of the hole in direction of the hole axis.

[0028] FIG 6 the graph w1 at the top of the page is the ratio of rotational speed of the upper shaft 24 to the angular velocity (radians per second) of the gear disk 3, and the middle graph w2 of the page is the ratio of rotational speed of the upper shaft 24 to the angular velocity (radians per second) of the gear disk 4, and the bottom graph of the page is the ratio of rotational speed of the upper shaft 24 to the angular velocity (radians per second) of two gear disks 3, 4 (combination of two graphs w1 and w2).

[0029] FIG 7 the graph ώ1 at the top of the page is the ratio of rotational speed of the lower shaft 25 to the angular velocity (radians per second) of the gear disk 3, and the middle graph ώ2 of the page is the ratio of rotational speed of the lower shaft 25 to the angular velocity (radians per second) of the gear disk 4, and the bottom graph of the page is the ratio of rotational speed of the lower shaft 25 to the angular velocity (radians per second) of two gear disks 3, 4 (combination of two graphs ώ1 and ώ2).

[0030] FIG 8 the graphs (w1 ,w2, ώ1 ,ώ2) are combined of rotational speeds of two shafts 24, 25 on the output shaft 30.

DESCREPTION OF EMBODIMENTS

[0031] Power (torque-rotation speed) enters the RG.CVT through the input shaft 1 and power transmittal from the gear 2 to the gear disk 3 and to the main shaft 5 and gear disk 4.

[0032] As describe in the figure 1 , by moving through the actuator 14, the part 12 has liner motion on the shaft 13, and moving of part 12 causes the liner motion of two slider sets 8,9 through the two rods 11 on the main shaft 5 in the shaft direction axis.

[0033] The slider set 8, 9 can have linear motion on the main shaft 5 and along shaft axis. The bearing between the cylindrical slider 8 and the retainer part 9 of the slider set 8, 9 causes the retainer part 9 does not following the rotation movement of the cylindrical slider 8, and also by the parallel key 7 between the cylindrical slider 8 and the main shaft 5, the rotational speed of cylindrical slider 8 is the same with the rotational speed of the main shaft 5.

[0034] By liner motion of two slider sets 8, 9, two slider parts 6 have liner motion inside of the liner grooves on the two gear disks 3, 4, through the two rods 10.

[0035] The slider part 6 from gear disk 3 connected to the rack gear 16 through the rod 15 and the rack gear 16 is mounted on the two guide shafts 18, and the

[0036] The slider part 6 from gear disk 4 connected to the rack gear 17 through the rod 15, and the rack gear 17 is mounted on the two guide shafts 19.

[0037] By rotation of the two gear disks 3, 4, the two rack gears 16, 17 will have liner motion through the two rods 15, on the guide shafts.

[0038] The rack gear 16 is located between the two gears 20, 22 and also involved with these two gears. The gear 20 fixed on the bearing (one way free bearing) 28 and the bearing (one way free bearing) is fixed on the shaft 24. The gear 22 is fixed on the bearing (one way free bearing) 28, and the bearing 28 is fixed on the shaft 25.

[0039] The rack gear 17 is located between the two gears 21 , 23 and also involved with these two gears. The gear 21 is fixed on the bearing (one way free bearing) 28 and the bearing 28 is fixed on the shaft 24. The gear 23 is fixed on the bearing (one way free bearing) 28 and the bearing 28 is fixed on the shaft 25.

[0040] The free direction or engage direction of the four bearings (one way free bearing) 28 on the two shafts 24, 25 are the same.

[0041] When the rack gear 16 moves forward, two gears 20, 22 will have rotation, and the gear 20 with shaft 24 will be engaged through the bearing (one way free bearing) 28, and the gear 22 will be released with shaft 25. When the rack gear 16 moves backward, the gear 20 will be released with shaft 24 and gear 22 with shaft 25 will be engaged through the bearing (one way free bearing) 28.

[0042] When the rack gear 17 moves forward, two gears 21 , 23 will have rotation, and the gear 21 with shaft 24 will be engaged through the bearing (one way free bearing) 28, and the gear 23 will be released with shaft 25. When the rack gear 17 moves backward, the gear 21 will be released with shaft 24 and gear 23 with shaft 25 will be engaged through the bearing (one way free bearing) 28.

[0043] The direction of rotation in the two shafts 24, 25 are the same. [0044] Since the angle between direction of the two grooves that created on the two gear disks 3, 4 is ninety degree, so when the speed of one rack gears is zero (the return point of rack gear), the speed of other rack gear will be maximum, this is shown in the graphs.

[0045] Because of the properties of the one way free bearing, each one of the two gears 20, 21 that has more rotation speed, it will be engaged with the shaft 24, and this is true in the two gears 22, 23 with shaft 25.

[0046] So, in the all positions of rack gears movement, at least, one of the two shafts 24, 25 will has rotation.

[0047] Two gears 26, 27 that are fixed on the two shafts 24, 25 are involved with the gear 29, so the rotation of two shafts will transfer to the output shaft 30.

[0048] As described above, the two slider parts 6 can have move within two grooves on two gear disks 3, 4 by actuator 14. When the main shaft 5 has a rotation, by moving two slider parts 6, the liner speed of the two rack gears will be change, and accordingly, the rotational speed of four gears 20, 21 , 22, 23 and the two shafts 24, 25 and finally the rotational speed of the output shaft 30 will change.

[0049] Since the motion generated by the actuator 14 is continuous, the rotational speed changes in the output shaft will also be continuous.

[0050] By installing the a number of sensors on the mechanism and controlling the actuator through the sensors, this invention will be automatic.

[0051] Because the parts used in this invention are simple, so making this invention with the available facilities is possible.

[0052] This invention applicable to all industries that need to convert rotation speed to torque or vice versa, including: automotive, shipbuilding, machine tools.

[0053] While the foregoing has described what are considered to be the best mode and/or other examples, it is understood that various modifications may be made therein and that the subject matter disclosed herein may be implemented in various forms and examples, and that the teachings may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim any and all applications, modifications and variations that fall within the true scope of the present teachings.

[0054] Unless otherwise stated, all measurements, values, ratings, positions, magnitudes, sizes, and other specifications that are set forth in this specification, including in the claims that follow, are approximate, not exact. They are intended to have a reasonable range that is consistent with the functions to which they relate and with what is customary in the art to which they pertain.

[0055] The scope of protection is limited solely by the claims that now follow. That scope is intended and should be interpreted to be as broad as is consistent with the ordinary meaning of the language that is used in the claims when interpreted in light of this specification and the prosecution history that follows and to encompass all structural and functional equivalents. Notwithstanding, none of the claims are intended to embrace subject matter that fails to satisfy the requirement of Sections 101 , 102, or 103 of the Patent Act, nor should they be interpreted in such a way. Any unintended embracement of such subject matter is hereby disclaimed.

[0056] It will be understood that the terms and expressions used herein have the ordinary meaning as is accorded to such terms and expressions with respect to their corresponding respective areas of inquiry and study except where specific meanings have otherwise been set forth herein. Relational terms such as first and second and the like may be used solely to distinguish one entity or action from another without necessarily requiring or implying any actual such relationship or order between such entities or actions. The terms "comprises," "comprising," or any other variation thereof, are intended to cover a non exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "a" or "an" does not, without further constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0057] The Abstract of the Disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. In addition, in the foregoing Detailed Description, it can be seen that various features are grouped together in various implementations for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed implementations require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed implementation. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separately claimed subject matter.