For oil-pumps in small IC engines which gears can be used ?

Explanation:

Oil pump:

• The oil pump is a mechanical device that is used in an engine to circulate oil to the moving parts like bearing, camshaft, and pistons in order to avoid wear and tear of the parts.
• The oil pump is usually a gear-driven from the crankshaft which start pumping oil immediately the engine is running.
• Crossed helical gear are used in oil pump.​
  • ​​Crossed helical gears: The use of crossed helical gears or spiral gear is limited to the light loads. By a suitable choice of helix angle for the mating gear, the two shafts can be set at any angle.

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