GB2400831A

GB2400831A - Tractor floor and split transmission arrangement

Info

Publication number: GB2400831A
Application number: GB0309061A
Authority: GB
Inventors: Richard Heindl
Original assignee: AGCO GmbH and Co
Current assignee: AGCO GmbH and Co
Priority date: 2003-04-22
Filing date: 2003-04-22
Publication date: 2004-10-27
Also published as: GB0309061D0

Abstract

A tractor comprises a driver platform and a transmission arranged so that the highest point of the transmission is below the driver's seat 18 and level with a front portion 15 of the platform. The transmission is hydrostatic and mechanical. Its hydraulic path comprises a hydraulic motor 8 and pump 7 in a pivoting body 10. Its mechanical path and hydraulic path both receive torque from an input shaft 4 via a splitter 3 and supply torque to a summer 5 which provides combined torque to a common output shaft 6. The transmission housing 1 comprises a step 13 corresponding to a step 17 between two parts 15,16 of the platform. The platform does not have a tunnel which could obstruct the operator's feet.

Description

240083 1

A TRACTOR

The invention is directed to a tractor to be used for agriculture and/or forestry purposes comprising a drive including an engine and a travelling transmission gear having an input shaft which is driven by an engine. The cabin of the tractor is arranged above the housing of the travelling transmission gear. The bottom of the cabin is positioned approximately at the height of the input shaft and in the region of the feet of the driver. This part of the bottom is located deeper as the bottom part supporting the driver's seat which is arranged above that part of the housing of the gear which has the highest positioned height.

Vehicles of the kind mentioned above have been designed to have short overall dimensions to be used for special cases in narrow environments or on extreme inclined fields. Especially if it is necessary to drive at inclined hills perpendicular to the direction of inclination, it is necessary to have vehicles having a centre of gravity arranged as low as possible, and with limited height, to minimize the danger of the vehicle falling over. Often, when entering doors, height is restricted. Consequently, there also is the need to have vehicles with limited height. To have the desired limited height of the vehicle is necessary to arrange the cabin if the vehicle also as low as possible. Furthermore, the body of the vehicle has to be arranged as low as possible, however, the necessary ground clearance has to be maintained as well as the room to locate the engine and the drive gear. In known vehicles the bottom of the cabin supporting the driver's seat is arranged at as low a height as possible above the transmission gear. In the neighbourhood of the seat of the driver the transmission gear is enclosed by a tunnel providing only little room for the feet of the drive which are arranged about at the place where the crank shaft of the engine is positioned. This tunnel in the cabin is of no comfort to the driver. The driver has to work with an inconvenient position of his feet.

Furthermore, he is hindered to move his feet, for example when watching working equipment behind or beside to the vehicle.

Consequently, it would be desirable to increase driver comfort.

In know vehicles having a common drive gear a lot of room is needed to position this drive gear. According to the invention the known drive gear is replaced by a hydrostatic- mechanical torque split gear which only needs little room and can be positioned below the driver's seat. Consequently, the region of the driver's seat up to the region above the input shaft may be designed free of elements extending in the upward direction. This is the condition permits the arrangement of the bottom of the cabin in front of the driver's seat at the level of the input shaft of the torque split gear. The bottom of the cabin in this region must be extended over the width of the vehicle in a substantially planar manner, or with the substantial part of the front part of the base arranged below the input shaft with a raised part over the input shaft. It is of advantage of the flexibility of the vehicle that the overall length of the vehicle remains unchanged although the gear is positioned with distance to the engine.

The invention will be explained with respect to the drawing attached. The drawing shows that travelling transmission gear and part of the cabin located above.

The dewing shows the housing I of the travelling transmission gear of a tractor. A hydrostatic-mechanical torque split gear 2 - know per se - is arranged within the housing 1.

The torque split gear comprises a split means to split the power of an input shaft 4 in a mechanical path and a hydraulic path. The input shaft 4 is driven by an engine not shown.

Means 5 for adding up the power of the hydraulic path and the mechanical path to an output shaft 6 are provided. The hydraulic path includes two hydrostatic elements of the kind swivel-mounted in a pivotal body, i.e. a hydraulic pump 7 and a hydraulic motor 8. Pivotal bodies 10 being pivotal about vertical axis 9 are supporting the hydrostatic elements and provide inn nitely variable revolutions of the output shaft 6 with respect to the amount of the pivotal movement of the pivotal bodies 10 for driving the differential gear 11 of the rear wheels.

The pivotal bodies 10 in a position according to a middle pivotal movement are directed to the front in longitudinal direction of the tractor defining a flare of the contour of the torque split gear 2. The housing 1 of the travelling transmission gear with its part above the pivotal bodies 10 is positioned with short distance in a manner so that the wall 12 of the housing, directed to the front is designed as a step 13. The input shaft 4 enters the housing I in the region of this step 13 and is directed to the rear up to the split means 3.

A cabin 14 is arranged above the housing 1. The cabin includes a base composed of a front part 15 and a rear part 16 separated by a step 17 having the same form and size as the step 13.

The cabin 14 is adapted to the longitudinal direction of the vehicle in a manner so that the step 1 7 is positioned above step 13 of the housing I of the gear. The rear part 16 supports a seat 18 for the driver while the front part 15 provides an area allocated for the driver's feet.

The front part 15 of the base is arranged with short distance above the input shaft 4 and is planar for the full width of the cabin 14. It is understood to fall within the scope of the invention solution if the front part 15 on both sides of the input shaft 4 is designed to extend below the input shaft 4. In this case a tunnel is provided bridging the input shaft 4 but this is of no relevance as to the comfort of the driver.

Claims

I. A tractor comprising a drive line, and an operator's platform, wherein the drive line is arranged in a transmission housing and includes an engine having an output shaft and a transmission having an input shaft, wherein the transmission input shaft is driven by the said engine output shaft, and wherein the operator's platform comprises a base including a front part, a rear part, and step therebetween, the front part of the base being situated in a substantially horizontal plane close to a horizontal plane of the input shaft and below the rear part of the base, wherein the rear part of the base is located above a highest point of the transmission housing and mounts an operator's seat, and wherein said transmission includes a hydrostatic-mechanical torque split drive mechanism arranged in said transmission housing, the torque split drive mechanism comprising: a splitter means (3) to split the power of the input shaft (4) into a mechanical path and hydraulic path; at least one hydraulic pump (7) swivel-mounted in a pivotal body (10); at least one hydraulic motor (8) swivel-mounted in a pivotal body, and means for summing up the power of the hydraulic and mechanical path at an output shaft (6), wherein a wall (12) ofthe transmission housing includes a step (13), and wherein the step in the operator's platform is positioned above the step in the transmission housing.
2. A tractor according to Claim I, wherein the pivotal bodies ( 10) are mounted in the front part of the transmission housing below said step.
3. A tractor according to Claim I, wherein said operator's platform is part of an operator's cabin.
4. A tractor substantially as shown in, and described with reference to, the drawings.