Field of the Invention:
The present invention generally relates to the rotavator’s multispeed Gear Box Assembly, particularly a lever operated Two-Speed Rotavator Gear-Box; wherein the instant disclosure provides an improved gear box assembly used on Rotavator with shift lever incorporated on gear box. The said gear box particularly comprises shifting mechanism (Constant Mesh Arrangement) for gears inside gear box to achieve different speed of rotor assy.
Firstly, the current invention is basically lever-operated shifting mechanism for gear box, through which different speed of the output shaft can be achieved on Rotavator. The mechanism is based on basic principles of employing constant mesh arrangement in Rotavator gear box. Prior art/technology of gear box for rotavators does not have this kind of arrangement for change of speed.
Secondly, the extension of counter shaft in gear box is to achieve reverse rotation of the rotor assembly. The prior art/technology of gear box does not have this kind of extension of counter shaft.
With this arrangement following benefit can be achieved:
1) Easy and quick change of speed;
2) In comparison to the available prior arts, Fuel & time saving for speed change requirement.
Background of the present invention:
Rotavator is an agricultural implement. It is well known amongst the farmers across the globe, which is generally applied for mixing and breaking of soil. The number of RPM required of rotor varies for different soil working applications. The prior art of changing the speed includes dismantling of gear box and change the position of gears or removal and replacement of gears to achieve the different speed.
But still this equipment has certain drawbacks in its operation, leading to practical change of speed.
Drawbacks of conventionally Multispeed Gear Box:
• Farmer has to manually change the gear of the gear box to obtain the required speed which is very cumbersome and time consuming activity, apart from these farmers also need to be aware about the change procedure.
• As the procedure is time consuming, most of the times farmer does not change the gears which cause poor yielding or more fuel consumption.
• As there is no option for the removal of mud or soil from the rotavator’s rotor. This can only be removed manually which is a cumbersome activity. Therefore, in most of the cases, these will always mud get stick to the rotor of the machine which cause rusting and ultimately factor of safety gets reduced
• Sometimes tractor remain idle while changing the gears in gear box due to which loss occurs
Conventional multi speed gear construction and Working Principle:
Conventional multispeed gear box consists of an input shaft by which power goes to the spur gear, which is in mesh with another gear. There from, this power is transferred to pinion gear and after that transferred to bevel gear and finally transferred to rotor assembly with the help of side gear train. Figure-1 shows the picture view of the existing technology gear box.
In view of the above mentioned background and drawbacks associated with conventional practice, the present invention is intended to provide a lever operated Two-Speed Rotavator Gear-Box, which basically incorporates a lever-operated shifting mechanism (Constant Mesh Arrangement) for gear box, through which different speed of the output shaft can be achieved on Rotavator.
Prime object of the present invention is to provide a lever operated Two-Speed Rotavator Gear-Box, which basically incorporates a lever-operated shifting mechanism (Constant Mesh Arrangement) for gear box, through which different speed of the output shaft can be achieved on Rotavator.
Another object of the present invention is to provide the rotavator’s multispeed Gear Box Assembly, particularly a lever operated Two-Speed Rotavator Gear-Box, wherein it provides an improved gear box assembly used on Rotavator with shift lever incorporated on gear box.
Another object of the present invention is to provide the extension of counter shaft in gear box to achieve reverse rotation of the rotor assembly.
Another object of the present invention is to provide such an improved gear box assembly with shift lever incorporated on gear box, which is effectively customized to be used on Rotavator and which addresses drawbacks of conventionally Multispeed Gear Box.
Another object of the present invention is to provide a lever operated Two-Speed Rotavator Gear-Box, which achieves following benefits:
• Easy and quick change of speed
• Fuel & time saving for speed change requirement (wrt prior art)
Short description of the drawings, incorporated herein for discussing the invention:-
Figure 1: Gear Box (Prior Technology)
Figure 2(a): Top schematic view (Section View) of the Shifting Gear Box with Extended Counter Shaft
Figure 2(b): Schematic representation of two spur gears B1 and B2 which are also in mesh with two spur gears A1 and A2, wherein said Gears B1 and B2 have half spline hub as shown therein;
Figure 3: Schematic representation of the inventive feature relating to the one sleeve, which consists of same spline as of gear B1 and B2 hub, wherein this sleeve is in continuous contact with the gear B1 and B2.
Figure 4: Schematic representation of inventive features relating to the one coupling, having the internal spline must exactly match the external spline of the gears B1 and B2 and the sleeve is mounted in such a way that half portion is on gear hub and the other half will be on sleeve.
Figure 5: Schematic representation of the mounting and design of the rail shaft, wherein one rail is inserted in gear box housing, and three grooves are cut on the rail shaft, first and third having different speeds and the second one with neutral position.
Figure 6: Another schematic representation of the mounting and design of the rail shaft.
Figure 7: Represents schematic view of the mounting of the fork and assembly of spring, ball and screw with fork; wherein this figure 7 indicates that a fork is assembled with the coupling and is mounted on the rail shaft for the easy change of the speed. A ball, spring and round Allen head bolt are inserted inside the fork.
Figure 8: Another schematic representation of the mounting of the fork and assembly of spring, ball and screw with fork.
Figure 9: Schematic representation of a shaft together with a flat is connected to the fork, wherein the flat is attached to the shaft for the movement of the fork and finally for the movement of the gear.
Figure 10: Represents complete schematic design of the gear box of the invention, wherein finally a pinion gear is mounted on the pinion shaft which is in mesh with another bevel gear.
Figure 11: Represents schematic view of the improved gear box assembly with shift lever incorporated on gear box, which is effectively customized to be used on Rotavator; wherein it particularly indicates that a ttransmission shaft is connected to the bevel gear which transmits the power to the gear C1 which is in mesh with the idler gear C2 which is further in mesh with the gear C3 (already Existing Method).
Figure 12: Schematic representation of the cardan shaft connection within the lever operated Two-Speed Rotavator Gear-Box, wherein it indicates that reverse rotation is also possible by changing the cardan shaft position.
Towards illustrating the inventive features, drawings are labeled with certain numeric references, as under:
Structural/operational feature, involved within the assembly of a lever operated Two-Speed Rotavator Gear-Box, to be used with rotavator Numeric reference
Housing Gear Box Existing Design 1
Main PTO shaft 2
Pinion Shaft 3
Pinion Gear Z15 4
Bevel Gear Z24 5
Gear Z16 A1
Gear Z14 A2
Gear Z17 B1
Gear Z19 B2
Splined Hub 6
Sleeve 7
coupling 8
RAILSHAFT 9
FORK 10
Ball 11
Bolt 12
Spring 13
Shaft 14
Rotating Flat 14
Shaft 15
Gear Z20 T C1
Gear Z35 T C2
Gear Z28 T C3

Description of the present invention:
The present invention generally relates to lever operated rotavator two speed gear box with constant mesh arrangement and particularly to the rotavator’s multispeed Gear Box Assembly, wherein the invention discloses an improved gear box assembly used on Rotavator with shift lever incorporated on gear box. The said gear box particularly comprises shifting mechanism (Constant Mesh Arrangement) for gears inside gear box to achieve different speed of rotor assy.
Firstly, the current invention is basically lever-operated shifting mechanism for gear box, through which different speed of the output shaft can be achieved on Rotavator. The mechanism is based on basic principles of employing constant mesh arrangement in Rotavator gear box. Prior art/technology of gear box for rotavators does not have this kind of arrangement for change of speed.
Secondly, as indicated in the Shifting Gear Box with Extended Counter Shaft (Figure 2(a)), the extension of counter shaft in gear box is to achieve reverse rotation of the rotor assembly. The prior art/technology of gear box does not have this kind of extension of counter shaft.
With the help of current invention of multispeed gearbox this requirement can be fulfilled.
Major inventive features included in the present invention are as follows: -
• Rotavator gear box lever with operated gear shifting mechanism, capable of changing the speed without opening the gear box cover.
• The reverse rotation possible of counter shaft.
New concept of the present invention for two speed gear box is as follows:-
Construction:
• Two spur gears A1and A2 are mounted on single input shaft.
• Two another spur gears B1 and B2 which are also in mesh with gear A1 and A2, are mounted on pinion gear shaft.
• Two needle roller bearings are mounted on two spline bushes mounted on pinion shaft with the help of spline.
• Gears B1 and B2 have half spline hub (6) as shown in Figure -2(b)
• One sleeve (7) consists of same spline as of gear B1 and B2 hub (6), this sleeve (7) is in continuous contact with the gear B1 and B2.The fig -3 shows the attached arrangement as describe.
• One coupling (8) having the internal spline must exactly match the external spline of the gears B1 and B2 and the sleeve (7) is mounted in such a way that half portion is on gear hub and the other half will be on sleeve (7). Fig-4 is shown for the better understanding.
• One rail is inserted in gear box housing, and three grooves are cut on the rail shaft (9), first and third having different speeds and the second one with neutral position’ Fig-5 and Fig-6 shows the mounting and design of the rail shaft (9) respectively.
• A fork (10) is assembled with the coupling (8) and mounted on the rail shaft (9) for the easy change of the speed. A ball (11), spring (13) and round Allen head bolt are inserted inside the fork (10). Fig-7 and Fig-8 shows the mounting of the fork (10) and assembly of spring (13), ball (11) and screw with fork (10).
• A shaft (15) together with a rotating flat (14) is connected to the fork (10). The flat (14) is attached to the shaft (15) for the movement of the fork (10) and finally for the movement of the gear. Fig-9 is attached for the better understanding.
• Finally a pinion gear is mounted on the pinion shaft which is in mesh with another bevel gear (5).Fig-10 shows the complete design of the gear box.
• A Transmission shaft is connected to the bevel gear (5) which transmits the power to the gear C1 which is in mesh with the idler gear C2 which is further in mesh with the gear C3 ( already Existing Method). Fig-11 is attached for the clear understanding of the whole concept.
Working:
• The power is transferred to the input shaft with the help of the cardan shaft.
• After the power is transferred to both spur gears A1 and A2 which in turn rotate another spur gears B1 and B2.
• Gears B1 and B2 rotate freely at the needle roller bearing.
• As we shift the lever coupling (8) from neutral position to engaged position (ie from the second position of the groove of the rail to the first or third position of the same) its one half will reside on gear hub and the other half will be on the sleeve (7). As the gear B1 or B2 rotates, it will cause rotation in the coupling (8) due to which the sleeve (7) will rotate and consequently leading to the rotation in the pinion shaft (3) and thereafter creating rotation in the pinion gear and finally rotating the bevel gear. After that power goes to gear C1 which transmits the power to the idler gear C2 and thereafter the power is transmitted to the gear C3 and finally we get the power at rotor assembly. Same procedure is also done to obtain another level of speed. Below is the current speed chart, which we obtained with gear pair.
RPM Chart
Sr.no I/P RPM Gear (A1,A2) Gear (B1,B2) Pinion Gear Bevel Gear Gear O/P(Rpm) side Gear C1 Idler Gear C2 Idler Gear C3 rotor rpm
1 540 14 19 15 24 249 20 35 28 178
2 540 16 17 15 24 318 20 35 28 227

However we can obtain various speeds with another pair of spur gears.
Reverse Rotation Working: Reverse rotation is also possible by changing the cardan shaft position .Figure shows better understanding of the principle.
RPM chart of the speed is described below:RPM Chart
Sr.no I/P RPM Pinion Gear Bevel Gear Gear O/P(Rpm) side Gear C1 Idler Gear C2 Idler Gear C3 rotor rpm
1 540 15 24 338 20 35 28 241

It is to be noted that the present invention is susceptible to modifications, adaptations and changes by those skilled in the art. Such variant embodiments employing the concepts and features of this invention are intended to be within the scope of the present invention, which is further set forth under the following claims:-

CLAIMS:

We Claim:

1. Rotavator’s multispeed Gear Box Assembly, particularly a lever operated Two-Speed Rotavator Gear-Box assembly with shifting mechanism (Constant Mesh Arrangement) to achieve different speed of rotor assy, characterized in:
• Rotavator gear box lever with operated gear shifting mechanism, capable of changing the speed without opening the gear box cover; and
• Provision of performing Reverse rotation by changing the cardan shaft position.
2. Rotavator’s multispeed Gear Box Assembly, as claimed in claim 1, wherein the construction of the two speed gear box includes the following:-
• Two spur gears A1 and A2 are mounted on single input shaft.
• Two another spur gears B1 and B2 which are also in mesh with gear A1 and A2, are mounted on pinion gear shaft.
• Two needle roller bearings are mounted on two spline bushes mounted on pinion shaft (3) with the help of spline.
• Gears B1 and B2 have half spline hub (6) as shown in Figure -2(b)
• One sleeve (7) consists of same spline as of gear B1 and B2 hub (6), this sleeve (7) is in continuous contact with the gear B1 and B2.The fig -3 shows the attached arrangement as describe.
• One coupling (8) having the internal spline must exactly match the external spline of the gears B1 and B2 and the sleeve (7) is mounted in such a way that half portion is on gear hub and the other half will be on sleeve (7). Fig-4 is shown for the better understanding.
• One rail is inserted in gear box housing, and three grooves are cut on the rail shaft (9), first and third having different speeds and the second one with neutral position’ Fig -5 and fig-6 shows the mounting and design of the rail shaft (9) respectively.
• A fork (10) is assembled with the coupling (8) and mounted on the rail shaft (9) for the easy change of the speed. A ball (11), spring (13) and round Allen head bolt are inserted inside the fork (10). Fig 7 and Fig -8 shows the mounting of the fork (10) and assembly of spring (13), ball (11) and screw with fork (10).
• A shaft (15) together with a rotating flat (14) is connected to the fork (10). The flat (14) is attached to the shaft (15) for the movement of the fork (10) and finally for the movement of the gear. Fig -9 is attached for the better understanding.
• Finally a pinion gear is mounted on the pinion shaft (3) which is in mesh with another bevel gear. Fig-10 shows the complete design of the gear box.
• A Transmission shaft is connected to the bevel gear (5) which transmits the power to the gear C1 which is in mesh with the idler gear C2 which is further in mesh with the gear C3 ( already Existing Method). Fig-11 is attached for the clear understanding of the whole concept.
3. Rotavator’s multispeed Gear Box Assembly, as claimed in claim 1-2, wherein the working of the two speed gear box includes the following:-
• The power is transferred to the input shaft with the help of the cardan shaft.
• After the power is transferred to both spur gears A1 and A2 which in turn rotate another spur gears B1 and B2.
• Gears B1 and B2 rotate freely at the needle roller bearing.
4. As we shift the lever coupling from neutral position to engaged position (ie from the second position of the groove of the rail to the first or third position of the same) its one half will reside on gear hub and the other half will be on the sleeve (7). As the gear B1 or B2 rotates, it will cause rotation in the coupling (8) due to which the sleeve (7) will rotate and consequently leading to the rotation in the pinion shaft and thereafter creating rotation in the pinion gear and finally rotating the bevel gear. After that power goes to gear C1 which transmits the power to the idler gear C2 and thereafter the power is transmitted to the gear C3 and finally we get the power at rotor assembly. Same procedure is also done to obtain another level of speed.
5. Rotavator’s multispeed Gear Box Assembly, as claimed in claim 1, wherein the Rotavator gear box lever with operated gear shifting mechanism, capable of changing the speed without opening the gear box cover.
6. Rotavator’s multispeed Gear Box Assembly, as claimed in claim 1, wherein for the preferred embodiment of the two speed gear box, the exemplary speed chart obtained is as under:
RPM Chart
Sr.no I/P RPM Gear (A1,A2) Gear (B1,B2) Pinion Gear Bevel Gear Gear O/P(Rpm) side Gear C1 Idler Gear C2 Idler Gear C3 rotor rpm
1 540 14 19 15 24 249 20 35 28 178
2 540 16 17 15 24 318 20 35 28 227

7. Rotavator’s multispeed Gear Box Assembly, as claimed in claim 1, wherein said two speed gear box is provisioned for reverse rotation by way of changing the cardan shaft position.