In agricultural hydraulic pumps, some gears may be intentionally exposed for several reasons.

The first aspect is the ease of maintenance. Exposed gears allow for easy inspection, lubrication, and replacement when necessary. In agricultural applications, pumps are often exposed to harsh environmental conditions that can cause gear wear. Exposed gears simplify maintenance and help reduce downtime.

Exposed gears help to dissipate the heat that hydraulic pumps generate during operation. By being exposed to the surrounding air, the gears transfer heat more efficiently, reducing the risk of overheating and damage to the pump. Exposed gears experience less friction and heat buildup than gears enclosed in a housing. Reducing friction increases efficiency, which improves pump performance and reduces energy consumption.

Lastly is cost reduction - exposed gears are less expensive to manufacture than enclosed gears. This can reduce the cost of pumps and make them more affordable for farmers and other agricultural users.