It's the pits for Renault, Mercedes

A WILLIAMS team mechanic escaped serious injury on Sunday when struck by a flying wheel in the pit lane during the Hungarian Grand Prix.

Two teams were also heavily fined for dangerous decisions following pit stops.

Both Renault and Mercedes were fined $US50,000 ($A55,000) for releasing their drivers, Robert Kubica and Nico Rosberg respectively, without due care during a hectic safety car period.

It was a wheel from Rosberg's Mercedes that flew off and bounced wildly down the pit lane before hitting Williams crewman Nigel Hope.

He sustained slight injuries but was able to continue working and performed his normal job at a later stop after a precautionary visit to the circuit medical centre.

Rosberg's right rear tyre worked loose and careered off his car as he rejoined the pit lane following his stop.

In a separate incident, Kubica was released too soon and without due care into the path of Adrian Sutil's Force India car causing a pit-lane collision.

Sutil was forced to retire from the race but Kubica continued for eight laps before he abandoned.

Kubica was also given a 10-seconds stop-and-go penalty.