Gas distribution mechanism. Engine M30
1 Camshaft
2 Key
3 Bolt
4 Copper sealing ring
5 Adapter
6 Cylindrical pin
7 Nut
8 Bolt
9 Chain sprocket
10 Cylindrical pin
11 Spring washer
12 Flange
13 Guide plate
14 Bolt
15 Tension bar
16 Drive chain
17 Guide bar
18 Plug
19 Sealing ring
20 Pressure spring
21 Ball
22 Piston
23 Support finger
24 Lock washer
25 Lock washer
26 Support finger
27 Spacer washer
28 Bushing
29 Oil pipeline
30 Hollow bolt
31 Sealing ring
32 Bracket
(The original source of the article is on the website BMWman)