Claims:We claim:

1. A Power Take Off (PTO) unit for a rear-wheel driven, east-west configuration transaxle driven by the input shaft of the gearbox, wherein the PTO unit comprises:

• a front housing having a flange thereof cooperating with the flange of a transaxle,
• a rear housing fastened to the front housing and carrying a companion flange,
• an input shaft securely connected to an extended input shaft of the transaxle and carrying an input bevel gear thereon,
• an output shaft carrying an output bevel gear at the one end thereof, the PTO output shaft being connected to the companion flange at the other end thereof to operate any implement by the PTO unit,
• a disengagement device for engaging or disengaging the PTO unit to the transaxle input shaft as required for operating the connected implement,

wherein the power is transferred by the input bevel gear to the output bevel gear which is disposed at 900 with respect to the input bevel gear, the bevel output gear being splined on the PTO output shaft at the end adjacent the input bevel gear and carrying the companion flange splined at the other end thereof.

2. Power Take Off (PTO) unit as claimed in claim 1, wherein the extended input shaft of the transaxle is connected to input shaft of the PTO unit by means of suitable fasteners.

3. Power Take Off (PTO) unit as claimed in claim 1, wherein the PTO input shaft is supported within the extended input shaft of the transaxle at one end and supported on a PTO support at the other end thereof and in alignment with the extended input shaft supported on a bearing thereof.

4. Power Take Off (PTO) unit as claimed in claim 3, wherein the PTO input shaft carries the input bevel gear, which is supported on a bearing on the PTO front housing side and also by the bearing on transaxle side.

5. Power Take Off (PTO) unit as claimed in claim 1, wherein the PTO output shaft is supported on a second bearing substantially at the center thereof.

6. Power Take Off (PTO) unit as claimed in claim 5, wherein an oil seal is provided on the companion flange side mounted between the PTO rear housing and the companion flange.

7. Power Take Off (PTO) unit as claimed in claim 1, wherein the disengagement device comprises an operating lever connected to one end of an arm passing through the PTO front housing for engaging or disengaging the other end of the arm with or from the PTO input bevel gear.

8. Power Take Off (PTO) unit as claimed in anyone of the claims 1 to 7, wherein the connected implement is a generator for generating electrical power, a pump used for irrigation applications or a freezing device used during transportation of goods.

9. A method for transferring power from a gear box via an extended input shaft of a rear-wheel driven, east-west configuration transaxle to operate an implement connected to a Power Take Off (PTO) unit, wherein the method comprises the steps of:

• taking off power from the extended input shaft of the transaxle and delivering it to the PTO input shaft carrying the input bevel gear of the PTO unit,

• engaging the PTO unit for receiving the power at the input bevel gear of the PTO unit,

• transferring the power by the input bevel gear to the output bevel gear disposed transverse thereto or disposed at 900 with respect to the output bevel gear splined on the PTO output shaft carrying the companion flange splined thereon,

• taking off power from PTO input shaft to the companion flange with an output at 900 thereto, and

• providing output to any implement by means of the companion flange connected thereto.

Dated: this day of 30th August, 2016. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention relates to the transaxle of light commercial vehicle. In particular, the present invention relates to a power take-off unit of a Light commercial vehicle. More particularly, the present invention relates to a power take-off unit for a rear axle rear-wheel driven motor vehicle.

BACKGROUND OF THE INVENTION

The power take-off or power take-off (PTO) is one of the methods used for taking power from a power source, such as an internal combustion engine, and transmitting it to an application such as an attached implement or separate machines. Most commonly, it is a PTO system comprising a splined output shaft on a tractor or truck, which is configured for easily connecting and disconnecting a PTO-shaft, and a corresponding input shaft to or from the end of any such attached application. Therefore, any power take-off system allows the attached implements to draw energy, e.g. from IC engines of a tractor or truck.

PRIOR ART

US4793430A discloses a tractor and implement drawn thereby, which includes a hitch and drive structure for power take-off (PTO) driven, semi-integral implement. A hutch adapter is used to couple a PTO-driven implement to a three-point hitch arrangement of a towing tractor. The implement includes a transaxle housing mounted for rotation about an upright axis that passes through a ball connection effected between a drawbar of the hitch adapter and the implement tongue. The tractor PTO-shaft is connected by a telescopic drive shaft to an input shaft supported by the transmission housing for rotation about an axis extending perpendicular to and intersecting said upright axis provided for steering the transmission housing for maintaining the input shaft disposed in parallel relationship to the tractor PTO shaft is a steering assembly including a pair of steering arms depending from the housing and engaging diametrically opposite locations of a cylindrical guide surface of a guide member fixed to the drawbar with the guide surface arranged concentrically to an axis located in a plane containing the previously mentioned axes and intersecting the upright axis at the ball connection.

Tractor PTO-shaft disclosed in US4793430A is connected by a telescopic drive shaft to an input shaft supported by the transmission housing for rotation about an axis extending perpendicular to and intersecting said upright axis. Here, the PTO is connected to the engine and PTO output is connected to the transmission input shaft.

CN203570942U discloses an angle transmission transfer case. The angle transmission transfer case comprises a case body, wherein an input shaft, an output shaft and a power takeoff shaft are arranged in the case body, the input shaft and the output shaft are arranged in a coaxial mode, the power takeoff shaft is arranged perpendicular to the input shaft, the input shaft is sleeved with a power takeoff driving gear, the power takeoff shaft is sleeved with a power takeoff driven gear, the power takeoff driving gear is meshed with the power takeoff driven gear, and the power takeoff driving gear and the power takeoff driven gear are spiral bevel gears. According to the angle transmission transfer case, due to the fact that a pair of spiral bevel gears are used for carrying out transmission, the power takeoff shaft and the input shaft are arranged in a 900 mode, the original position of a gas compressor can be changed by 900, gas inlet and heat dissipation of the gas compressor are facilitated, it is ensured that the gas compressor can work for a long time, ventilation performance is good, the temperature in a vehicle body is lowered, and a steel cylinder set cannot be influenced by hot gas flow.

However, the angle transmission transfer case disclosed in CN203570942U comprises a case body, wherein an input shaft, an output shaft and a power take-off shaft are arranged in the case body, the input shaft and the output shaft are arranged in a coaxial mode, the PTO-shaft is arranged perpendicular to the input shaft. Here, the PTO application is for a inline configuration (North-South, Rear-wheel drive PT). Therefore, the abovementioned concept is applicable for North South Automatic configuration gearbox only.

DISADVANTAGES WITH THE PRIOR ART

The problem with the existing power take-off units is that they are configured for specific purposes. Moreover, the conventional PTO units do not provide a constant rpm at the PTO output. PTO is connected to Engine and PTO output is connected to the transmission input shaft.

DEFINITIONS

Front-wheel-drive or Front Engine-Front Drive (FF) layouts are the ones in which the front wheels of the vehicle are driven. This layout is typically chosen for its compactness. Since the engine and the driven wheels are disposed on the same side of the vehicle, there is no need for a central tunnel through the passenger compartment to accommodate a propeller shaft running between the engine and the driven wheels. The weight of the engine mounted over the front driven wheels also improves vehicle road-grip in normal conditions. However, in this FF layout, due to weight transference under acceleration, the weight on the front wheels is reduced and so their traction is also reduced, thereby limiting the torque that can be utilized. FF layout also restricts the size of the engine that can be placed in modern engine compartments, as FF configurations usually have Inline-4 and V6 engines, while longer engines such as Inline-6 and 90° V8 engines will rarely fit therein.

A transverse engine or "east-west" configuration is commonly used in such FF layouts, which is in contrast to FR layouts using longitudinal engine.

Rear-wheel drive (RWD) typically places the engine in the front of the vehicle and the driven wheels are located at the rear, a configuration known as front-engine, rear-wheel drive layout (FR layout). Most of rear-wheel-drive vehicles use a longitudinally-mounted engine in the front of the vehicle, driving the rear wheels via a driveshaft linked via a differential between the rear axles. Some FR layout vehicles place the gearbox at the rear, though most attach it to the engine at the front.
FR layout is often chosen for its simple design and good handling characteristics. Placing the drive wheels at the rear allows ample room for the transmission in the center of the vehicle and avoids the mechanical complexities associated with transmitting power to the front wheels. For performance-oriented vehicles, the FR layout is more suitable than front-wheel-drive designs, especially with engines that exceed 200 horsepower. This is because weight transfers to the rear of the vehicle during acceleration, which loads the rear wheels and increases their grip.

Rear Engine Rear wheel drive layouts (RR) are those which places both engine and drive wheels at the rear of the vehicle.

Placing the engine near the driven rear wheels allows for a physically smaller, lighter, less complex, and more efficient drivetrain, since there is no need for a driveshaft, and the differential can be integrated with the transmission, commonly referred to as a transaxle. Since the engine is typically the heaviest component of the car, putting it near the rear axle usually results in more weight over the rear axle than the front, commonly referred to as a rear weight bias. The farther back the engine, the greater the bias. Typical weight bias for an FR (front engine, rear drive), is 55/45 front/rear; for MR, 45/55; for RR, 35/65. Rear weight bias reduces forward weight transfer under braking, and increases rear weight transfer under acceleration. The former means that traction is more evenly distributed among all four wheels under braking, resulting in shorter stopping times and distances. The latter means that the driven wheels have increased traction when accelerating, allowing them to put more power on the ground and accelerate faster.

DESCRIPTION OF THE PRESENT INVENTION

The present invention relates to a Power Take-off (PTO) Unit for the East-West configuration transaxle of a rear engine rear wheel drive vehicle driven by the input shaft of the gearbox. Here, the PTO-unit includes a set of bevel gears. The output of the PTO-unit is at 900 to the axis of the crankshaft. PTO-unit takes the drive from the input shaft of the gearbox. PTO-unit is operable during the stationary condition of the vehicle as well while in motion. The PTO-unit in accordance with the present invention is configured as an add-on unit to the gearbox, the output of which can be indexed at any angle. The PTO-unit also includes a selector mode lever for disengaging PTO-unit from transaxle.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide an East-west configuration transaxle gearbox.

Another object of the present invention is to provide a Rear-wheel vehicle driven vehicle.

A further object of the present invention is to provide a multipurpose Power take-off (PTO) unit for a Light Commercial Vehicle.

Still another object of the present invention is to provide a Power take-off (PTO) unit, which generates power at constant rpm.

Yet another object of the present invention is to provide a Power take-off (PTO) unit drawing output from the input shaft of the transaxle gearbox.

Yet further object of the present invention is to provide a PTO-unit, which includes a selector mode lever for disengaging the PTO-unit from the transaxle gearbox.

These and other objects and advantages of the present invention will become more apparent from the following description when read with the accompanying figures of drawing, which are, however, not intended to limit the scope of the present invention in any way.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a Power Take Off (PTO) unit for a rear-wheel driven, east-west configuration transaxle driven by the input shaft of the gearbox, wherein the PTO unit comprises:

• a front housing having a flange thereof cooperating with the flange of a transaxle,

• a rear housing fastened to the front housing and carrying a companion flange,

• an extended input shaft of the transaxle and carrying an input bevel gear thereon,

• an output shaft carrying an output bevel gear at the one end thereof, the PTO output shaft being connected to the companion flange at the other end thereof to operate any implement by the PTO unit
• a disengagement device for engaging or disengaging the PTO unit to the transaxle input shaft as required for operating the connected implement,

wherein the power is transferred by the input bevel gear to the output bevel gear which is disposed at 900 with respect to the input bevel gear, the bevel output gear being splined on the PTO output shaft at the end adjacent the input bevel gear and carrying the companion flange splined at the other end thereof.

Typically, the extended input shaft of the transaxle is increased length at the end of basic manual transaxle.

Typically, the PTO input shaft is supported within the extended input shaft of the transaxle at one end and supported on a PTO support at the other end thereof and in alignment with the extended input shaft supported on a bearing thereof.

Typically, the PTO input shaft carries the input bevel gear, which is supported on a bearing on the PTO rear housing side.

Typically, the PTO input bevel gear is supported on a bearing disposed between the PTO front housing and the center portion of the input bevel gear.

Typically, the PTO output shaft is supported on a first bearing at the output bevel gear side and on a second bearing substantially at the center thereof.

Typically, an oil seal is provided on the companion flange side mounted between the PTO rear housing and the companion flange.

Typically, the disengagement device comprises an operating lever connected to one end of an arm passing through the PTO front housing for engaging or disengaging the other end of the arm with or from the PTO input bevel gear.

Typically, the connected implement is a generator for generating electrical power, a pump used for irrigation applications or a freezing device used during transportation of goods.

In accordance with the present invention, there is also provided a method for transferring power from a gear box via an extended input shaft of a rear-wheel driven, east-west configuration transaxle to operate an implement connected to a Power Take Off (PTO) unit, wherein the method comprises the steps of:

• taking off power from the extended input shaft of the transaxle and delivering it to the PTO input shaft carrying the input bevel gear of the PTO unit,

• engaging the PTO unit for receiving the power at the input bevel gear of the PTO unit,

• transferring the power by the input bevel gear to the output bevel gear disposed transverse thereto or disposed at 900 with respect to the output bevel gear splined on the PTO output shaft carrying the companion flange splined thereon,

• taking off power from PTO input shaft to the companion flange with an output at 900 thereto, and

• providing output to any implement by means of the companion flange connected thereto.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings (Figs. 1- 4 courtesy Wikipedia), which include:

Figure 1 shows a conventional front-wheel driven automobile with transversely disposed engine mounted in front of the front-axle thereof.

Figure 2 shows a conventional rear-wheel driven automobile with longitudinally disposed engine mounted on the front-axle thereof.

Figure 3 shows a conventional rear-wheel driven automobile with longitudinally disposed engine mounted behind the rear-axle thereof.

Figure 4 shows a conventional four-wheel drive automobile with longitudinally disposed engine mounted on the front-the rear-axle thereof.

Figure 5 shows an automobile provided with a rear-wheel driven automobile with an engine mounted in an East-West configuration which is equipped with a Power Take-off (PTO) Unit for the transaxle in accordance with the present invention driven by the input shaft of the gearbox (Figure 6).

Figure 6 shows an enlarged view of another embodiment of the Power Take-off (PTO) Unit for the transaxle configured in accordance with the present invention.

DETAILED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the following, different embodiments of the present invention will be described in more details with reference to the accompanying drawings without limiting the scope and ambit of the present invention in any way.

Figure 1 shows a conventional front-wheel driven automobile with transversely disposed engine mounted in front of the front-axle thereof.

Figure 2 shows a conventional rear-wheel driven automobile with longitudinally disposed engine mounted on the front-axle thereof.

Figure 3 shows a conventional rear-wheel driven automobile with longitudinally disposed engine mounted behind the rear-axle thereof.

Figure 4 shows a conventional four-wheel drive automobile with longitudinally disposed engine mounted on the front-the rear-axle thereof.
Figure 5 shows an automobile provided with a rear-wheel driven automobile with an engine mounted in an East-West configuration which is equipped with a Power Take-off (PTO) Unit for the transaxle configured in accordance with the present invention driven by input shaft of gearbox (Fig.6).

Figure 6 shows a typical layout of the first embodiment of the Power Take-off (PTO) Unit 500 for the transaxle 550 configured in accordance with the present invention. The figure illustrates the transaxle side 550 on the left side and the PTO unit 500 disposed on the right side of the dotted lines Y–Y. The rear transmission housing 552 for the transaxle 550 includes an extended input shaft 560 joined with the PTO unit 500 at mutually cooperating flanges respective 570 and 510 by means of suitable fasteners (not shown). This extended input shaft 560 is supported on bearing 562 and configured to be in alignment with the PTO, which in turn is supported on another bearing 524. PTO sleeves for engaging the gears 526 are disposed in the front housing 528 of PTO 500. PTO shaft 520 also carries a PTO sleeve 526 for mounting the bevel gear 534. This bevel gear 534 drives a PTO output shaft 530 with integrated bevel gear. The bevel gear integrated output shaft is driven by PTO input shaft bevel gear 534 is supported by bearing 538 on housing 528. An oil seal 544 is provided on the side of a companion flange 546 mounted on the other end of the PTO output shaft 530.

A disengagement device 548 is also provided in the upper region of the front housing 528 of the PTO 500 and adjacent the companion flange 546. This device 548 engages the PTO 500 as and when required and disengages when not required. This feature allows the base transmission to run at high efficiency.

WORKING OF THE INVENTION

The PTO unit in accordance with the invention can be operated as under:

- Taking off power from the input shaft and delivering it to the PTO output, which may be a generator to generate power, a pump for irrigation applications or a freezer during transportation and the like,

- Receiving the power at the bevel input gear after PTO is engaged,

- Transferring the power by the input gear to the bevel output gear which is at 900 with respect to the bevel output gear, wherein the bevel output gear is splined on the output shaft which also has the companion flange splined thereon,

- Taking off power from input shaft to the companion flange with a 900 output, and

- Providing output to any device by means of the companion flange which can be connected to any device.

TECHNICAL & ECONOMIC ADVANTAGES OF THE INVENTION

The PTO Unit configured in accordance with the present invention has the following advantages:

- Flexibility of connecting any device to the PTO.

- Direct control of the output speed/power of the PTO by means of the engine / input shaft speed.

- Indexing of the output shaft at any angle for a multipurpose application.

- Output fluctuations are very little due to use of the bevel gears

- Ideal for power generation when a generator is connected.

- Output of PTO is directly behind the vehicle, thereby ease of operation by connecting to any other deice.
- Transfer of power from input shaft to PTO is available via angled transmission set-up.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments.

The embodiments herein and the various features and advantageous details thereof are explained with reference to the non-limiting embodiments in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein.

It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Although the embodiments presented in this disclosure have been described in terms of its preferred embodiments, the skilled person can easily make innumerable changes, variations, modifications, alterations and/or integrations in terms of materials and method used to configure, manufacture and assemble various constituents, components, subassemblies and assemblies as well as in terms of the size, shapes, orientations and interrelationships thereof without departing from the scope and spirit of the present invention.

The numerical values given of various physical parameters, dimensions and quantities are only approximate values and it is envisaged that the values higher or lower than the numerical value assigned to the physical parameters, dimensions and quantities fall within the scope of the disclosure unless there is a statement in the specification to the contrary.

Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

While considerable emphasis has been placed on the specific features of the preferred embodiment described here, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiments without departing from the principles of the invention. These and other changes in the preferred embodiment of the invention will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the invention and not as a limitation.

List of Reference Numerals

1. Transaxle side 550
2. Rear transmission housing 552
3. Extended input shaft of the rear transmission housing 560
4. Bearing supporting the extended input shaft 562
5. Flange of the rear transmission housing 570
6. Power Take-off (PTO) Unit 500
7. Flange of the PTO Unit 510
8. PTO input shaft 520
9. Bearing for the PTO shaft 524
10. PTO sleeve carried by the PTO shaft 526
11. Front housing of the PTO unit 528
12. PTO output shaft 530
13. Bevel input gear 534
14. Bevel output gear 536
15. Oil seal 544
16. Companion flange mounted on the PTO output shaft 546
17. Disengagement device 548