LATERAL DRIVE UNIT FOR ROTARY CULTIVATORS

Abstract: The invention is a new lateral drive unit (C) to be applied to agricultural machines, comprising four gearwheels meshing mutually in pairs, and wherein the first gearwheel (1) receives motion from the horizontal shaft (E) connected to the reduction gear operated by the power takeoff of the agricultural machine and transmits it to the second, bigger gearwheel (2) with which it meshes, said second gearwheel (2) being connected, through a common shaft (5), to the third, smaller gearwheel (3), said third gearwheel (3) meshing with and transmitting motion to the fourth, bigger gearwheel (4), which in turn is connected to the knife-carrying shaft (b). Due to the diameters of the various gearwheels and to the reduction ratios of the various gears, the ratio between the motion received from the power takeoff of the agricultural machine and the final motion of the rotary cultivator shaft improves the efficiency of the cardan shaft.

Description: TITLE LATERAL DRIVE UNIT FOR ROTARY CULTIVATORS DESCRIPTION The present invention concerns the sector of agricultural machinery and in particular it concerns rotary cultivators with horizontal shaft. At present rotary cultivators with horizontal shaft receive motion from the agricultural machine that, through a suitable drive unit, transfers the rotary motion to the rotor or horizontal shaft equipped with teeth, knives or hoes. In the rotary cultivators available at present the transmission of motion from the agricultural machine to the rotary cultivator takes place through a centre reduction unit and a lateral reduction unit comprising three gears or a chain whose reduction ratio is approximately 1 ,7:1. The reduction unit is positioned laterally and comprises a single intermediate gear, positioned between the propeller shaft gear and the knife-carrying shaft gear, or a chain with two gears. In order to eliminate the drawbacks mentioned above, a new type of rotary cultivator has been designed and implemented, which ensures improved performance levels. In its main parts the new rotary cultivator comprises a frame, one or more hoe or knife-carrying shafts, one or more drive and reduction units and a suitable connection system for the connection with the agricultural machine. The knife-carrying shaft is constituted by a known type of horizontal rotary shaft, on which the knifes for the tillage are installed. The drive and reduction unit is applied to the side of the frame and connects the knife-carrying shaft to the shaft that receives motion from the reduction gear operated by the power takeoff of the tractor. The drive and reduction unit is constituted by a series of gears that transmits motion from the reduction gear operated by the tractor power takeoff to the knife-carrying shaft, reducing the number of revolutions. In particular, the lateral drive and reduction unit comprises four gearwheels that mesh mutually in pairs. The first gearwheel receives motion from the reduction gear operated by the tractor power takeoff, through a shaft that is parallel to the knife-carrying shaft, and transmits it to the second, bigger gearwheel with which it meshes. The second gearwheel is connected, through a common shaft, to the third, smaller gearwheel, so that the number of revolutions of the second and third gearwheels is exactly the same. The third gearwheel transmits motion to the fourth, bigger gearwheel, with which it meshes. The fourth gearwheel transmits the motion received to the knife-carrying shaft of the new rotary cultivator. Due to the diameters of the various gearwheels and to the reduction ratios of the various gears, the ratio between the motion received from the power takeoff of the agricultural machine and the final motion of the rotary cultivator shaft improves the efficiency of the cardan shaft. The ratio is approximately 3:1 , but this value must not be considered binding for the purposes of this patent. The new rotary cultivator, implemented as described above, offers the considerable advantage that it can be used even in models with different dimensions, with no need to use the additional reduction gears that have been necessary up to now. In the known rotary cultivators the torque transmitted to the cardan shaft is on average 2700 Nm. With the new drive unit the torque transmitted is reduced to approximtately 1700 Nm. Therefore, the double reduction applied to the lateral drive unit of the rotary cultivator makes it possible to make the input shaft rotate with more revolutions and consequently with reduced torque in Nm and reduced power absorption. In the solution adopted the horizontal cardan shaft of the lateral drive unit has higher rotation speed, thus reducing the torque transmitted and improving the efficiency of the drive unit. In fact, to obtain greater operating efficiency of the rotary cultivator, it is sufficient to have an agricultural machine capable of supplying approximately 90-100 HP at 800-1000 rpm. The following is just an example among many of a practical embodiment of the invention in question, illustrated in the enclosed drawings, wherein: Figure 1 is a general view of the new rotary cultivator, in which it is possible to observe the frame (A), a knife-carrying shaft (B), a propeller shaft (E), a reduction gear (C) and a connection element (D2) for the connection to the agricultural machine of the new rotary cultivator, for the transmission of motion from the agricultural machine to the new rotary cultivator. Figures 2a and 2b show two schematized sectional views of the drive and reduction unit, in which it is possible to observe the various gearwheels. The first gearwheel (1 ), which receives motion from the propeller shaft (E) connected to the power takeoff of the agricultural machine, meshes with the second, bigger gearwheel (2). The second gearwheel (2) is applied to the same shaft (5) as the third gearwheel (3), which is smaller than said second gearwheel (2). The third gearwheel (3) in turn meshes with the fourth, bigger gearwheel (4) connected to the knife-carrying shaft. Therefore, with reference to the above description and the enclosed drawings, the following claims are put forth.

Claims: CLAIMS 1. Lateral drive unit to be applied to agricultural machines, characterized in that it comprises four gearwheels meshing mutually in pairs, and wherein the first gearwheel receives motion from the horizontal shaft connected to the reduction gear operated by the power takeoff of the agricultural machine and transmits it to the second, bigger gearwheel with which it meshes, said second gearwheel being connected, through a common shaft, to the third, smaller gearwheel, said third gearwheel meshing with and transmitting motion to the fourth, bigger gearwheel, which in turn is connected to the knife-carrying shaft.

Inventors: VALENTINI ANTONIO, VALENTINI, ANTONIO
Applicants: VALENTINI ANTONIO, VALENTINI, ANTONIO
Application year: 2001
Main classification: A01B33
IPC codes: A01B33