I m not sure exactly what these parts do, but the Chinese say they have something to do with the oil pump, but they are pictured with the clutch assembly.  Definitely found on the Tao Tao Rhino but may be found on other makes and models too.  Please check pictures and description before ordering.

Specs:

• 3-hole cover with gasket with spring mechanism on outside
• 3 screws for cover
• Clutch nut
• Curved washer with OUT SIDE printed on it
• Splined housing with 19 splines and (3) 5mm*.80 bolt hole 

• Shipping details:

  Do you need your parts fast?  If you order before 3:00 pm CST, Monday thru Friday, your order goes out the same day.    Buy now!