Hydraulic drive for an agricultural sprayer

Claim 2

In an agricultural vehicle with a hydraulic system adapted for use as a liquid dispensing sprayer, a sprayer hydraulic drive comprising: an independent hydraulic source circuit including at least a pump and a reservoir; valve means interconnecting said circuit with a sprayer pump circuit facilitating activation and deactivation of said sprayer pump circuit for various modes of operation; a rotary flow divider operatively connected with said valve means and including a motor rotor linked with a pump rotor via a shaft; said pump rotor hydraulically connected with and driving a sprayer motor; said sprayer motor driving a centrifugal pump of said liquid dispensing sprayer; and pressure relief means for bypassing said sprayer motor and merging with a sprayer pump circuit return line linked with said motor rotor.

Claim 3

The invention in accordance with claim 1, and said return line connected with said sprayer motor and said valve means.

Claim 4

In an agricultural vehicle with a hydraulic system adapted for use as a liquid dispensing sprayer and including a source of hydraulic fluid, a sprayer means including a centrifugal pump for distribution and dispensing said liquid, a sprayer hydraulic drive comprising: a rotary flow divider controllably connectable to said source of hydraulic fluid of said agricultural vehicle; said source being able to operate independently of said divider and said sprayer means; a motor hydraulically connected to said rotary flow divider for driving said centrifugal pump of said liquid dispensing sprayer; a return line hydraulically connected to said rotary flow divider and to said agricultural vehicle hydraulic system; a motor rotor having a first fluid volume capacity; a pump rotor having a fluid volume capacity fractionally and proportionally lesser than said first fluid volume capacity of said motor rotor; a shaft connecting said motor rotor to said pump rotor and driving said pump rotor; said pump rotor sized to match flow rate of said centrifugal pump; said return line is connected to an outlet of said motor and is provided with a one-way check valve allowing fluid flow from said motor and said rotary flow divider to said agricultural vehicle; said motor being equipped with pressure relief means connected to said return line; said pressure relief means comprising; a coast check valve connected in parallel with said motor; a pressure relief valve connected in parallel with said motor and said coast check valve; and a variable orifice in parallel with said motor, said pressure relief valve and said coast check valve.

Claim 5

In an agricultural vehicle with a hydraulic system adapted for use as a liquid dispensing sprayer and including a source of hydraulic fluid, a sprayer means including a centrifugal pump for distribution and dispensing said liquid, a sprayer hydraulic drive comprising: a rotary flow divider controllably connectable to said source of hydraulic fluid of said agricultural vehicle; said source being able to operate independently of said divider and said sprayer means; a motor hydraulically connected to said rotary flow divider for driving said centrifugal pump of said liquid dispensing sprayer; a return line hydraulically connected to said rotary flow divider and to said agricultural vehicle hydraulic system; a motor rotor having a first fluid volume capacity; a pump rotor having a fluid volume capacity fractionally and proportionally lesser than said first fluid volume capacity of said motor rotor; a shaft connecting said motor rotor to said pump rotor and driving said pump rotor; said pump rotor sized to match flow rate of said centrifugal pump; said return line is connected to an outlet of said motor and is provided with a one-way check valve allowing fluid flow from said motor and said rotary flow divider to said agricultural vehicle; said motor being equipped with pressure relief means connected to said return line; said pressure relief means comprising; a coast check valve connected in parallel with said motor; a pressure relief valve connected in parallel with said motor and said coast check valve; and a variable orifice in parallel with said motor, said pressure relief valve and said coast check valve.

Claim 6

The invention in accordance with claim 3, and said rotary flow divider being provided with hydraulic fluid at fluid source pressure and dividing said source fluid into a first fluid volume from said motor rotor and a fractionally smaller amount from said pump rotor; and said fractionally smaller amount of hydraulic fluid from said pump rotor being at a pressure greater than the pressure of said fluid from said motor rotor.