Hydraulic pump drive

A hydraulic pump drive is mounted to the tongue of an agricultural implement. Connecting components between the pump and the drawbar extender of the towing tractor aim the pump input shaft toward the tractor. A short telescoping PTO assembly connects the pump shaft to the tractor PTO shaft using conventional PTO components operating in a nominal equal angle configuration.

BACKGROUND OF THE INVENTION

The present invention relates generally to agricultural machines and, more particularly to an improved hydraulic pump drive for a pull-type agricultural implement.

Most commonly, the various implements used in farming operations are pulled by, and powered by, an agricultural tractor. The implements normally have a pivoting tongue of some sort affixed at one end to the tractor drawbar, and to the implement at the other. A power-take-off shaft (PTO) of the tractor typically provides mechanical power to the implement. The PTO may provide direct drive to the mechanical components of the implement, or may power a hydraulic pump that, in turn, provides hydraulic power to the various components of the implement. In the latter arrangement, the most common the structure has the PTO supporting a pump and gearbox assembly or a direct drive pump and coupler assembly. A PTO-supported pump may encounter several problems, such as, for example, spline fit is critical and difficult to control, unacceptable pump vibration and PTO shaft failures occur if not corrected, and the weight and bulk of a high capacity pump are difficult to handle manually. All of these identified problems either result in high warranty costs or complaints by operators.

It would advantageous to have a hydraulic pump drive that overcomes the problems identified above.

SUMMARY OF THE INVENTION

Accordingly, it is an object of the present invention is to provide an improved hydraulic pump drive for an agricultural implement.

Another object of the present invention is to provide an improved hydraulic pump drive for an agricultural implement that pivotally mounts the hydraulic pump to the implement tongue.

It is another object of the instant invention to provide a hydraulic pump drive for a towed agricultural implement that continually aims the pump drive shaft toward the towing vehicle regardless of the tongue angle.

It is yet another object of the instant invention to provide a hydraulic pump drive for a towed agricultural implement that is durable in construction, inexpensive of manufacture, carefree of maintenance, facile in assemblage, and simple, versatile and effective in use.

These and other objects are attained by providing a hydraulic pump drive mounted to the tongue of an agricultural implement. Connecting components between the pump and the drawbar extender of the towing tractor aim the pump input shaft toward the tractor. A short telescoping PTO assembly connects the pump shaft to the tractor PTO shaft using conventional PTO components operating in a nominal equal angle configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Many of the fastening, connection, processes and other means and components utilized in this invention are widely known and used in the field of the invention described, and their exact nature or type is not necessary for an understanding and use of the invention by a person skilled in the art, and they will not therefore be discussed in significant detail. Also, any reference herein to the terms “left” or “right” are used as a matter of mere convenience, and are determined by standing at the rear of the machine facing in its normal direction of travel. Furthermore, the various components shown or described herein for any specific application of this invention can be varied or altered as anticipated by this invention and the practice of a specific application of any element may already by widely known or used in the art by persons skilled in the art and each will likewise not therefore be discussed in significant detail.

When discussing or describing the relative rotational movement between the implement tongue and the tractor, it is common to refer to the freedom of rotation about the vertical axis as “yaw”, the horizontal as “pitch” and fore and aft as “roll”.

FIGS. 1 and 2show an agricultural tractor T, identified further inFIG. 1by tractor tire10and inFIG. 2by tractor tires10,12. Tractor T includes a PTO shaft20and a drawbar22with a drawbar extender24affixed to the end thereof to increase the length of the drawbar and thereby improve the operational characteristics of the drawbar/implement interface. Drawbar extender24includes an opening26therethrough adjacent the rearward end thereof.

An implement tongue30extends rearwardly, relative to the normal direction of travel of tractor T, and supports an implement, not shown, such as a mower-conditioner, baler, or the like. Tongue30includes a horizontal tongue pivot plate32rigidly affixed thereto and extending forwardly therefrom and including a vertical hole34therethrough. An elongate tongue pivot pin36, having a vertical axis, extends through holes26and34in drawbar extender24and horizontal tongue pivot plate32.

An hydraulic pump40is supported on tongue30by a flange-like support assembly comprised of a pair of parallel side support plates (only one of which,42, is shown inFIG. 1) with a lower support pivot plate44. Pump40includes a flange-like support assembly comprised of a pair of parallel pump support plates (only one of which,48, is shown inFIG. 1), with an upper support pivot plate46affixed to the pump body and maintaining it in a fixed position relative to upper support pivot plate46. A pump support pivot pin50, having a vertical axis, extends through holes in the lower and upper pivot plates44,46(in the alternative, pin50could be affixed to plate44, as by welding). The components of the support assembly and the drawbar extender are arranged such that the vertical axes of the tongue pivot pin36and the pump support pivot pin50are coextensive, i.e., pins36and50have a common vertical axis38. Further, support plates42and pivot support plate44could be formed of a single piece of formed steel.

Forwardly of pivot pins36and50is an alignment pin60extending through the lower and upper pivot plates44,46and drawbar extender24. Pin60is maintained in position by any suitable means, such as a cotter pin or spring clip62. Pin60keeps the pump shaft64, to be discussed further below, parallel to PTO shaft20.

The tractor PTO shaft20is connected to the pump shaft64by a telescoping equal angle PTO assembly66. As shaft20is rotated, the hydraulic pump40pumps oil through hoses68to and from the operational components of the implement.

The benefits of the instant invention are attained by pivotally mounting the hydraulic pump40to the implement tongue30. Connecting components between the pump40and the drawbar extender24aim the pump input shaft64toward tractor T at all times. In fact, some later model tractors have provisions to extend the drawbar to a length that generally equals the standard drawbar length plus an extender, thus eliminating the need for the extender for turning or PTO provisions—the alignment pin60could be pivotally affixed to an attachment on the drawbar as well as the extender.FIG. 2shows, in phantom, the tongue in a normal implement operating position70and in the maximum turn angle position72. A short telescoping PTO assembly86connects pump shaft64to the tractor PTO shaft20using conventional PTO components, and operates in a nominal equal angle configuration. The telescoping is needed to accommodate elevation differences between the pump and tractor shafts, and to allow for tractor pitching. Since the pump40is aimed toward the tractor regardless of the tongue angle relative to the drawbar, no additional telescoping or joint angle allowances are needed for turning. The drive action is similar to that shown in patent publication no 2-2/0047246, dated Apr. 25, 2002. Flexible hoses68are used to connect pump ports to hydraulic lines that are secured to the tongue30.