, Description:SINGLE SHAFT INTEGRATED SHIFTING SYSTEM FOR A 5-SPEED MANUAL TRANSMISSION
FIELD OF INVENTION:
[001] The present subject matter described herein, relates to manual transmission system for gear shifting, and, in particular, to a single shaft integrated shifting 5 system for shifting gears in five speed forward and one speed reverse gear manual transmission.
BACKGROUND AND PRIOR ART:
[002] Generally, in manual transmission gearbox, three rail/shifting shafts are used to shift the gears. On the three shifting shafts, low speed gears, high speed 10 gears, and 5th and reverse gear selection mechanism is enabled. Further, the gearbox has a reverse idler assembly for engaging the vehicle in reverse gear. Generally, the reverse idler assembly has a reverse input gear driven by the input shaft, a reverse output gear driven by the output shaft, and a reverse idler gear which is selectively movable into meshed engagement with the reverse input gear 15 and the reverse output gear for driving the output shaft in a second direction. The reverse idler gear is a gear used to change the direction of the rotation of the shafts.
[003] Figures 1 & 2 show existing three shaft shifting system used in the five (5) speed manual transmission systems. In the figure 1, the three shaft shifting system 20 100 has a low speed shaft set 101, high speed shaft set 102, and 5th and reverse gear shaft set 103. On the each of the shifting shaft sheet metal fork and yoke is mounted or welded. Based on the selection of the gear, the corresponding shaft moves and performs the action. In the figure 2(a), the low speed shaft set 101 is explained. In the low speed shaft set 101, a fork 202 and yoke 203 is mounted on 25 the low speed shaft 201. The fork 202 and the yoke 203 are positively mounted, such as welded on the low speed shaft 201.
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[004] Similarly, in the high speed shaft set 102 (as shown in figure 2(b)), a fork 206 and yoke 205 is mounted on the high speed shaft 204. The fork 206 and the yoke 205 are positively mounted, such as welded on the high speed shaft 204.
[005] As shown in figure 2(c), the 5th and reverse gear shaft set 103 has a shaft 207, a fork 208, a yoke 209 and a reverse gear arm 210. The fork 208, yoke 209, 5 and the reverse gear arm 210 are positively mounted on the shaft 207. Once all the shaft sets are ready, the multiple shifting shafts are arranged to make a multi shaft shifting system as illustrated in figure 1.
[006] In the existing three shaft system, a big space is required for fitting and arrangement of the multiple shafts in the gearbox which increases the size of the 10 gearbox and ultimately creates space constraint problem in the vehicle. Further, multiple shaft of the shifting system adds extra weight and cost on the vehicle.
[007] Further, single shaft shifting systems are known in the prior art for example Japanese Patent Application JP4232072B2, Chinese Patent Application CN202937796U, and German Patent Application DE102014204290A1, which 15 disclose the features of using fewer parts, utilizing single moving shaft, and more economically feasible system, and less space requirement.
[008] In the known prior arts, reverse gear mechanism is a separate system apart from the forward gears system. Therefore, a separate system is required for reverse gear mechanism. In the prior arts, a separate yoke with lever system is 20 required for reverse gear mechanism. Further, in order to operate with separate system, a second shift finger on the shift tower is used for shifting the reverse gear.
[009] Though these prior arts discuss about the single shaft shifting systems, but each has its own drawbacks and limitations. These known systems are costly and 25 have several special parts and extra parts which are very complex. Further, this complexity makes the serviceability of the system difficult and costly. Therefore, a simple and inexpensive single shaft shifting system is required which is effective for reverse gearing along with forward gear mechanism.
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OBJECTS OF THE INVENTION:
[0010] The principal objective of the present invention is to provide a single shaft integrated shifting system for five speed manual transmission.
[0011] Another object of the present subject matter is to use single shift shaft to mount all the fork and yoke of all the gears. 5
[0012] Another object of the present invention is to mount reverse gear arm on the single shift shaft for reverse gear mechanism.
[0013] Another object of the present invention is to provide simple structure to eliminate complexity of separate reverse gear system in the gearbox.
[0014] Another object of the present invention is to provide a small, simple, and 10 effective single shift shaft system which consume less space in the vehicle.
[0015] Yet another object of the present invention is to provide light weight and low cost system for manual transmission.
SUMMARY OF THE INVENTION:
[0016] The present subject matter disclosed herein relates to a single shaft 15 integrated shifting system for shifting gears in five forward and one reverse gear manual transmission in vehicles. The present single shaft integrated shifting system has one shifting shaft acting as a support and guide-way to three (3) sets of gear shifting forks and yokes. The present single shaft integrated shifting system is capable of shifting 6 gears, i.e., five (5) forward gears and one (1) reverse gear 20 in the manual transmission. In the present system, shift fork and yoke of low speed gears and high speed gears are coaxially mounted on the single shift shaft using sliding bearings. Further, shift fork and yoke of the fifth (5th) gear and reverse gear arm are positively mounted on the single shift shaft. The shift fork of the low speed gears and high speed gears floats/slides on the single shift shaft 25 with the help of sliding bearings. Accordingly, the single shift shaft does not move during gear shift of the high speed and low speed gear. Further, shift fork of the fifth (5th) speed gear and the reverse gear arm is fixed on the single shift shaft. Accordingly, the single shift shaft moves during shifting of fifth (5th) speed gear
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and reverse gear where shift forks of high speed and low speed gear does no move and keep floating over the single shift shaft with the help of sliding bearings.
[0017] In order to further understand the characteristics and technical contents of the present subject matter, a description relating thereto will be made with reference to the accompanying drawings. However, the drawings are illustrative 5 only but not used to limit scope of the present subject matter.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter and are therefore not to be considered for limiting of its scope, for the invention may admit to other equally 10 effective embodiments. The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system or methods in accordance with 15 embodiments of the present subject matter are now described, by way of example, and with reference to the accompanying figures, in which:
[0019] Fig. 1 illustrates three shifting shaft system for five (5) speed manual transmission system as known in the art;
[0020] Fig. 2 (a), (b), and (c) illustrate each shaft of the three shifting shaft 20 system for five (5) speed manual transmission system in detail as known in the art;
[0021] Fig. 3 illustrates mounting of plurality of gear comps over a single shift shaft, in accordance with an embodiment of the present subject member;
[0022] Fig. 4(a), (b), and (c) illustrate structure of each component of the single 25 shift shifting system in detail, in accordance with an embodiment of the present subject matter;
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[0023] Fig. 5 illustrates the single shaft integrated shifting system for manual transmission, in accordance with an embodiment of the present subject matter; and
[0024] Fig. 6 and 7 illustrates the arrangement of reverse gear arm with the reverse gear system in the single shaft integrated shifting system, in accordance 5 with the present subject matter.
[0025] The figures depict embodiments of the present subject matter for the purposes of illustration only. A person skilled in the art will easily recognize from the following description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles 10 of the disclosure described herein.
DESCRIPTION OF THE PREFERRED EMBODIMENTS:
[0026] The subject matter disclosed herein relates to a single shaft integrated shifting system for shifting gears in five forward and one reverse gear manual transmission in vehicles. The present single shaft integrated shifting system has 15 one shifting shaft acting as a support and guide-way to three (3) sets of gear shifting forks and yokes. The present single shaft integrated shifting system is capable of shifting 6 gears, i.e., five (5) forward gears and one (1) reverse gear in the manual transmission. In the present system, shift fork and yoke of low speed gears and high speed gears are coaxially mounted on the single shift shaft using 20 sliding bearings. Further, shift fork and yoke of the fifth (5th) gear and reverse gear arm are positively mounted on the single shift shaft.
[0027] The shift fork of the low speed gears and high speed gears floats/slides on the single shift shaft with the help of sliding bearings. Accordingly, the single shift shaft does not move during gear shift of the high speed and low speed gear. 25 Further, shift fork of the fifth (5th) speed gear and the reverse gear arm is fixed on the single shift shaft. Accordingly, the single shift shaft moves during shifting of fifth (5th) speed gear and reverse gear where shift forks of high speed and low
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speed gear does no move and keep floating over the single shift shaft with the help of sliding bearings.
[0028] Conventionally, a separate system apart from the forward gears system is required for the reverse gear shifting. In this system, a separate yoke with lever system is required for reverse gear mechanism. Further, in order to operate with 5 separate system, a second shift finger on the shift tower is used for shifting the reverse gear. Accordingly, the known systems are costly and have several special parts and extra parts which are very complex. Further, this complexity makes the serviceability of the system difficult and costly.
[0029] According to present subject matter, shift forks of all the gears are 10 mounted on the single shift shaft. Further, the reverse gear arm is also mounted on same the single shift shaft to avoid the requirement of a separate system for reverse gear mechanism. In the present system, shift fork and yoke of low speed gears and high speed gears are coaxially mounted on the single shift shaft using sliding bearings. Further, shift fork and yoke of the fifth (5th) speed gear; and 15 reverse gear arm are positively mounted on the single shift shaft. The shift fork of the fifth (5) gear and the reverse gear arm is fixed on the single shift shaft. Accordingly, only the single shift shaft moves during shifting of the fifth (5th) speed gear and the reverse gear where shift forks of high speed and low speed gear does no move and keep floating over the single shift shaft with the help of 20 sliding bearings. In the present system, no separate mechanism for reverse gear shifting is required. Through the present system, requirement of an extra system for reverse gear is eliminated.
[0030] It should be noted that the description and figures merely illustrate the principles of the present subject matter. It should be appreciated by those skilled 25 in the art that conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present subject matter. It should also be appreciated by those skilled in the art that by devising various arrangements that, although not explicitly described or shown herein, embody the principles of the present subject 30
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matter and are included within its spirit and scope. Furthermore, all examples recited herein are principally intended expressly to be for pedagogical purposes to aid the reader in understanding the principles of the present subject matter and the concepts contributed by the inventor(s) to furthering the art, and are to be construed as being without limitation to such specifically recited examples and 5 conditions. The novel features which are believed to be characteristic of the present subject matter, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. 10
[0031] These and other advantages of the present subject matter would be described in greater detail with reference to the following figures. It should be noted that the description merely illustrates the principles of the present subject matter. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the 15 principles of the present subject matter and are included within its scope.
[0032] Fig. 3 illustrates mounting of plurality of shaft comps over a single shift shaft, in accordance with an embodiment of the present subject. As shown in figure 3, a single shaft integrated shifting system 300 includes a single shift shaft 301, low speed gear comp 304, high speed gear comp 303, fifth (5th) speed gear 20 comp 302, and reverse gear arm 305. The low speed gear comp 304, the high speed gear comp 303, the fifth (5th) speed gear comp 302, and the reverse gear arm 305 (collectively referred as components/comps or individually referred as component/comp) are coaxially mounted on the single shifting shaft 301. Every component has through bore or hole to receive the single shift shaft 301. All the 25 components are arranged in a sequence like, first the fifth (5th) speed gear comp 302, second the high speed gear comp 303, third the reverse gear arm 305, and fourth the low speed gear comp 304 on the single shift shaft 301. Once the single shift shaft 301 passes through bores of all the components, the fifth (5th) speed gear comp 302 and the reverse gear arm 305 is positively mounted on the single 30
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shift shat 301. The positive mounting can be any positive mounting like CO
2 welding and butt welding. Where the low speed gear comp 304 and the high speed gear comp 303 are coaxially mounted on the single shift shaft 301 using sliding bearings. A sliding bearing is provided between the bores of the low speed gear comp 304 and the high speed gear comp 303 and the single shifting shaft 301. 5
[0033] Fig. 4(a), (b), and (c) illustrate structure of each component of the single shift shifting system in detail, in accordance with an embodiment of the present subject matter. Figure 4(a) illustrates structure of a low speed gear comp 304 in accordance with an embodiment of the present subject matter. The low speed gear comp 304 comprises a semicircular shift fork 304a at one end and a circular 10 through bore 304c at other end. Further, both the ends are connected with a rectangular metal sheet 304d which has an integrated yoke 304b. The shift fork 304a is integrated with yoke 304b. At the upper side of the shift fork 304a a circular bore 304c is present to receive the single shift shaft 301. The present low speed gear comp 304 is a single or unitary structure having the shift fork 304a, 15 two bores 304c, and the yoke 304b. Further, the low speed gear comp 304 is made of single sheet metal which has high strength and stress holding capability. The low speed gear comp 304 is coaxially mounted on the single shift shaft 301 through the circular bore. The low speed gear comp 304 is slid-ably mounted on the single shift shaft 301 using sliding bearings. In the low speed gear comp 304, 20 two sliding bearings are used. One sliding bearing at one bore 304c which is near the yoke 304b and another sliding bearing at another bore 304c which is above the shift fork 304a. The bore 304c near the yoke 304b provides support to the yoke 304b and avoids hanging of the yoke 304b on the single shift shaft 301.
[0034] Figure 4(b) illustrates structure of a high speed gear comp 303 in 25 accordance with an embodiment of the present subject matter. The high speed gear comp 303 comprises a semicircular shift fork 303a, a yoke 303b and a circular through bore which is not visible in the figure. The circular through bore is below the base of the yoke 303b and above the semicircular shift fork 303a to receive the single shift shaft 301. The present high speed gear comp 303 is a 30
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single or unitary structure having the semicircular shift fork 303a, a circular bore, and the yoke 303b. The shift fork 303a is integrated with yoke 303b. Further, the high speed gear comp 303 is made of single sheet metal which has high strength. The high speed gear comp 303 is coaxially mounted on the single shift shaft 301 through the circular bore. The high speed gear comp 303 is slid-ably mounted on 5 the single shift shaft 301 using sliding bearing. In the high speed gear comp 303, one sliding bearing is used at the circular bore which allows the movement of the shift fork 303a upon selection of the gear.
[0035] Figure 4(c) illustrates structure of a fifth (5th) speed gear comp and reverse gear arm mounted on the single shift shaft 301, in accordance with the present 10 subject matter. The fifth (5th) speed gear comp 302 has semicircular shift fork 302a at one end and a circular through bore (which is not visible in the drawing) at other end. Further, both the ends are connected with a rectangular metal sheet 302d which has an integrated yoke 302b. At the upper side of the shift fork 302a a circular bore (which is not visible in the drawing) is present to receive the single 15 shift shaft 301. The shift fork 302a is integrated with yoke 302b. The present fifth (5th) speed gear comp 302 is a single or unitary structure having the shift fork 302a, two bores, and the yoke 302b. Further, the fifth (5th) speed gear comp 302 is made of single sheet metal which has high strength. The fifth (5th) speed gear comp 302 is coaxially mounted on the single shift shaft 301 through the circular 20 bores. After receiving the single shift shaft 301 through the bores, the fifth (5th) speed gear comp 302 is fixed or positive mounted on the single shift shaft 301. The positive mounting can be any positive mounting like CO2 welding and butt welding. Further, the fifth (5th) speed gear comp 302 is restricted about its circular movement over the single shift shaft 302. After the circular bore near the yoke 25 302b, reverse gear arm 305 is coaxially fixed mounted on the single shift shaft 301. The reverse gear arm 305 is also restricted about its circular movement over the single shift shaft 301. The reverse gear arm 305 is manufactured by forging or lost wax process.
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[0036] Fig. 5 illustrates the single shaft integrated shifting system for manual transmission, in accordance with an embodiment of the present subject matter. In the figure 3 and 4, details about the structure of the system and its components has been defined. Figure 5 is equivalent to figure 3 for which explanation is given above. As shown in figure 5, a single shaft integrated shifting system 500 includes 5 a single shifting shaft 501 (same as 301 in figure 3), low speed gear comp 504 (same as 304 in figure 3), high speed gear comp 503 (same as 303 in figure 3), 5th gear comp 502 (same as 302 in figure 3), and reverse gear arm 505 (same as 305 in figure 3). All the above mentioned components are arranged in a pre-defined sequence as explained in figure 3. Once the single shifting shaft 501 passes 10 through bores of all the components, the fifth (5th) gear comp 502 and the reverse gear arm 505 is positively mounted on the single shifting shaft 501. The positive mounting can be any positive mounting like CO2 welding and butt welding. Where the low speed gear comp 504 and the high speed gear comp 503 are coaxially mounted on the single shifting shaft 501 using sliding bearing. 15
[0037] Further, all the components are manufactured in manner that their yokes come in line with proper support from both the ends. The low speed gear comp and the fifth (5th) speed gear comp has two bores to support the comps over the single shift shaft. As explained above, the shift fork of the low speed gear comp 504 and the high speed gear comp 503 floats/slides on the single shift shaft 501 20 with the help of sliding bearings. Accordingly, the single shift shaft 501 does not move during gear shift of the high speed and low speed gear. On the other hand, the shift fork of the fifth (5th) speed gear comp 502 and the reverse gear arm 505 is fixed on the single shift shaft 501. Accordingly, the single shift shaft 501 moves during shifting of fifth (5th) speed gear and the reverse gear arm 505 where shift 25 forks of high speed gear comp and low speed gear comp does no move and keep floating over the single shift shaft with the help of sliding bearings
[0038] Fig. 6 and 7 illustrates the arrangement of reverse gear arm with the reverse gear system in the single shaft integrated shifting system, in accordance with the present subject matter. In the figure 6, reverse gear arm 605 is coaxially 30
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fixed mounted on the single shift shaft 605. The shape and configuration of the reverse gear arm 605 is such that it does not restrict or obstruct movement of the shift fork of the low speed gear comp. Further, the reverse gear arm 605 is engaged with the reverse gear assembly 606 which has an idler gear assembly for putting the gears in reverse direction. The reverse idler gear is a gear used to 5 change the direction of the rotation of the shafts. When the selection for reverse gear is made, the reverse gear arm 605 mounted on the single shift shaft 601 moves and pushes the reverse idler gear to engage in between input and out gears. Further, working of the reverse gear with respect to input and output gear is well known. In the present system, there is no requirement of separate yoke and lever 10 system for reverse gear. From the present system, yoke of fifth (5
th) speed gear comp is used to give input or selection for the reverse gear. In the present system, reverse gear arm receives the selection from yoke of the fifth (5th) speed gear comp where the yoke receives the selection from the same finger/lever of shift tower shaft. In the present system is very simple system in which selection of 15 reverse gear can be made directly from the single shift shaft. The present system is very simple and cost effective.
[0039] Although embodiments for the present subject matter have been described in language specific to structural features, it is to be understood that the present subject matter is not necessarily limited to the specific features described. Rather, 20 the specific features and methods are disclosed as embodiments for the present subject matter. Numerous modifications and adaptations of the system/device of the present invention will be apparent to those skilled in the art, and thus it is intended by the appended claims to cover all such modifications and adaptations which fall within the scope of the present subject matter.

Claims:We claim:
1. A single shaft integrated shifting system (300, 500) for selection and engagement of gears in five (5) speed manual transmission along with reverse gear, the single shaft integrated shifting system (300) comprising:
a single shift shaft (301, 501, 601) which is sliding along its axis 5 about its axis;
a low speed gear comp (304, 504) and a high speed gear comp (303, 503) are coaxially mounted on the single shift shaft (301, 501, 601) using sliding bearings; and
a fifth (5th) speed gear comp (302, 502) and a reverse gear arm (305, 10 505, 605) are positively mounted on the single shift shaft (301, 501, 601).
2. The single shaft integrated shifting system (300, 500) as claimed in claim 1, wherein shift fork (304a) of low speed gear comp (304, 504) is integrated with a yoke (304b). 15
3. The single shaft integrated shifting system (300, 500) as claimed in claim 1, wherein shift fork (303a) of high speed gear comp (303, 503) is integrated with a yoke (303b).
4. The single shaft integrated shifting system (300, 500) as claimed in claim 1, 20 wherein the low speed gear comp (304, 504) and the high speed gear comp (303, 503) have through bore(s) (304c) to receive the single shift shaft (301, 501, 601) coaxially.
5. The single shaft integrated shifting system (300, 500) as claimed in claim 1, 25 wherein shift fork (302a) of the fifth (5th) speed gear comp (302) is integrated with a yoke (302b).
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6. The single shaft integrated shifting system (300, 500) as claimed in claim 1, wherein the low speed gear comp (304, 504), the high speed gear comp (303, 503), and the fifth (5th) speed gear comp (302, 502) are made of single sheet metal.
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7. The single shaft integrated shifting system (300, 500) as claimed in claim 1, wherein each of the low speed gear comp (304, 504), the high speed gear comp (303, 503), and the fifth (5th) speed gear comp (302, 502) is unitary structure.
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8. The single shaft integrated shifting system (300, 500) as claimed in claim 1, wherein the low speed gear comp (304, 504) and the high speed gear comp (303, 503) are axially slid-able on the single shift shaft (301, 501, 601) along axis of the single shift shaft (301, 501, 601).
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9. The single shaft integrated shifting system (300, 500) as claimed in claim 1, wherein the reverse gear arm (305, 505, 605) is directly engaged with reverse gear system (606) having idler gear.
10. The single shaft integrated shifting system (300, 500) as claimed in claim 1, 20 wherein the low speed gear comp (304, 504) and the fifth (5th) speed gear comp (302, 502) has support from both the ends on the single shift shaft (301, 501, 601).