Gearbox application expert needs to understand customers specific requirements to be able to recommend a suitable gearbox. Gearbox manufacturer websites often provide pdf catalogues which include guides for correct selection. Some of the key criteria to be considered arespeeds, ratio, torque, powers, external loads, shaft type, mounting, operating conditions, lubrication and service factor.

         Working in a design office for a world leading special purpose machine business, experienced mechanical design engineers would initially select a suitable gearbox for an application using previous knowledge and selection guidelines from gearbox supplier catalogues. These selections would always be verified with the gearbox manufacturers technical engineers and a certified drawing provided to confirm problem free installation.

         If a prime mover or driven equipment cannot be reversed by configuration, there may be a more effective solution to introducing a 1:1 reverse drive arrangement into an application. The drawback here is you have to be careful to understand everything going on in this arrangement since it would be easy to overlook a critical feature and create problems and unnecessary costs. 

         A possible solution involves a pair of spur gears, one on each shaft of the engine and the pump. The axial location of these gears would need to be considered and introduced. Calculations will be needed to determine the correct size and width of gear tooth as well as the resultant overhung shaft loads. Alignment of the shafts needs to be very precise and depending upon operation cycles and operating environment, a method of lubrication will be required and will vary according to the particular setup. Also,a guard would need to be designed and installed correctly to both prevent the ingress of dirt and objects as well as protect personnel from injury. If done right, this method may be perfectly functional and a lot quicker and lower cost to implement than a dedicated gearbox. As always employ an experienced mechanical design engineer to get things right.