Oil Field Pump Unit Hybrid Gear Reducer

An oilfield pumping method comprising the steps of:

• a. providing a pump jack;
• b. modifying a pump jack two-stage transmission gear reducer by:
• i. providing a low speed stage comprising:
• a low speed shaft;
• configuring the low speed shaft to receive motion from an intermediate shaft;
• ii. providing a first gear pair including a low speed shaft double circular arc gear;
• mounting the low-speed shaft double circular arc gear on the low speed shaft;
• and configuring the first gear pair to be driven by an intermediate shaft double circular arc gear mounted on the intermediate shaft;
• and
• iii. providing a high speed stage comprising:
• a high speed shaft;
• configuring the high-speed shaft to receive motion from an intermediate shaft;
• and
• iv. providing a second gear pair including a high speed shaft involute gear mounted on the high-speed shaft;
• and configuring the high-speed shaft involute gear to be driving an intermediate shaft involute gear mounted on the intermediate shaft.