Circular irrigation system with worm gear drive

Abstract

A worm gear drive assembly for driving the wheeled support assemblies for an elongated irrigation pipe including a motor having an output controlled in response to bending or deflection of the pipe and a forwardly and rearwardly extending shaft with a drive worm gear on each end thereof engaged with a worm wheel for driving the supporting wheels. Each supporting wheel is connected to the frame structure in such a manner that it may be oriented for driving the pipe in a direction transverse to the longitudinal axis thereof or in a position perpendicular thereto to enable the irrigation pipe to be towed or pulled in a direction parallel to its longitudinal axis to facilitate movement from one area to be irrigated to another.

I claim: 
     
       1. In an irrigation system having a boom movable over a relatively large land area and including an elongated pipe receiving water for discharge through a plurality of sprinkler heads, that improvement comprises a plurality of support assemblies for the boom, each support assembly including an elongated frame member generally in perpendicular relation to the boom, a wheel journalled at each end of the elongated frame member for engaging the ground surface, a drive motor supported from the frame member, and a driving connection between said motor and .[.each of.]. said wheels for driving the wheels and propelling the support assembly thus propelling the elongated boom, said drive connection including a worm pinion and worm wheel to provide positive driving connection between the motor and wheels to prevent free wheeling of the wheels in the event of traversal of a downgrade, each wheel including a spindle, means connecting the spindle to the frame member, a wheel hub journalled on said spindle, a wheel .[.and pneumatic tire.]. secured to the hub, said worm wheel being secured to said hub for rotation therewith .Iadd.about a common axis.Iaddend. whereby rotation of the worm wheel will drivingly rotate the wheel.Iadd., said means connecting the spindle to the frame means including means enabling the spindle to pivot approximately 90° whereby the axes of rotation of the wheels may be parallel to the axis of the boom or perpendicular thereto, and means disengaging the drive connection between the motor and wheels to enable the boom to be towed..Iaddend. 
     
     
       2. The structure as defined in claim 1 wherein said driving connection includes an elongated drive shaft extending from the motor, and extending toward each of the wheels, a worm pinion engaged with each worm wheel and drivingly connected to the outer ends of said shaft. 
     
     
       3. The structure as defined in claim 2 wherein said worm pinions are detachably connected to the drive shaft with the worm pinion and worm wheel being disposed in a housing, means connecting the housing and the frame member to prevent rotation of the housing and enable torque to be exerted on the worm wheel and wheel connected therewith for driving the wheel. 
     
     
       4. The structure as defined in claim 3 wherein said means connecting the spindle to the frame member includes releasable fastening means to retain the spindle in a position substantially perpendicular to the frame member for rotation of the wheels about axes substantially parallel to the longitudinal axis of the elongated boom and orientation of the spindle in a transport position for orientating the wheels in a transport position having rotational axes substantially perpendicular to the longitudinal axis of the elongated boom thereby enabling the elongated boom to be towed axially when all of the wheels on all of the supporting assemblies have been oriented in the transport position thereby enabling the irrigation system to be moved from one area being irrigated to another without disassembly and reassembly of the components of the irrigation system. 
     
     
       5. The structure as defined in claim 4 together with a curved guard rod extending outwardly from means connecting the spindle to the frame member and curving in front of the wheel to protect the wheel and deflect crops from out of the path of the wheel. 
     
     
       6. The structure as defined in claim 4 wherein the detachable connection between the drive shaft and worm pinion is automatically disconnected when the means connecting the housing and frame member is disconnected and the wheel is disposed in transport position to enable free wheeling of the wheel and rotation of the housing therewith. 
     
     
       7. In an irrigation system having a boom movable over a relatively large land area and including an elongated pipe receiving water for discharge through a plurality of sprinkler heads, a plurality of support assemblies for the boom, each support assembly including an elongated frame member generally in perpendicular relation to the boom, a wheel journalled at each end of the elongated frame member for engaging the ground surface, a drive motor, that improvement comprising a worm drive connection between the drive motor and a ground-engaging wheel to provide positive drive for the wheel and prevent free-wheeling of the wheel when traversing a downgrade, said worm drive connection including a worm wheel connected with the ground-engaging wheel, and a worm pinion meshing with the worm wheel and drivingly connected with the motor, and means disengaging the drive connection between the drive motor and .[.ground-engaging wheel.]. .Iadd.worm pinion.Iaddend. to enable towing of the boom when moving the irrigation system from one area to another. .Iadd. 8. The structure as defined in claim 7 wherein each of said wheels includes a supporting member defining an axis of rotation for the wheel, and means mounting the supporting member from the frame member for pivotal movement between a boom towing position in which the axis of rotation is perpendicular to the boom and a position in which the axis is parallel to the boom for movement of the boom in a circular path, and means releasably securing said supporting member in both positions..Iaddend..Iadd. 9. The structure as defined in claim 7 wherein said supporting member includes a housing for the worm drive connection, and means securing the housing to the frame member for orientation in both positions..Iaddend..Iadd. 10. In an irrigation system, an elongated water distribution pipe, a plurality of support means supportnig said pipe, each of said support means comprising an elongated, horizontally disposed frame means which is disposed transversely to the longitudinal axis of said pipe, a wheel assembly at each end of said frame means, power means including a drive shaft drivingly connected to at least one of said wheel assemblies, the rotational axis of each of said wheel assemblies being generally parallel to the longitudinal axis of said pipe when distributing water, and means for selectively pivoting said wheel assemblies with respect to the frame means to a tow position so that the rotational axis of each of said wheel assemblies will be transversely disposed with respect to the longitudinal axis of said pipe to permit said pipe and said support means to be towed, said driven wheel assembly comprising a drive wheel, a gear housing having gear means therein connected with a positive drive output member, said drive wheel being mounted on said output member for rotation therewith, and means for disengaging the drive shaft from the gear means so that said drive wheel may freely rotate when said wheel assembly has been pivoted to said tow position..Iaddend. .Iadd. 11. The structure as defined in claim 10 wherein said gear housing includes a plate disposed horizontally thereon, said frame means including a plate disposed horizontally thereon, said means for selectively pivoting said wheel assemblies includes pivot bolt means extending through said plates, and lug means interengaging said plates to retain the plates in two perpendicular positions about the pivot bolt for retaining the wheel assemblies in water distributing position and tow position.