10
Product description
4.2
Function
The operating principle of the Roots pumps is based on two synchronous pistons which
rotate in a housing without touching. The pumping effects arise as a result of the oppos-
ing rotation of the two figure-of-eight shaped rolling pistons. While suction chambers are
formed between the rolling pistons and the housing, the rolling pistons continuously form
a mutual seal without touching each other or the housing. This opposing yet synchro-
nised movement of the rolling pistons is achieved by means of a pair of gears mounted
on the extended shaft ends. Lubrication is limited to the two bearing and gear chambers
which are arranged separately from the suction chambers. As the Roots pump is not ca-
pable of compressing against atmospheric pressure it needs to be operated in conjunc-
tion with an upstream backing pump.
A bypass valve that is either cast into or bolted to the housing protects the pump against
overheating.
Fig. 3:
Roots pump Okta 18000
1
Vacuum flange
2
Fore-vacuum flange
15
Lubricant filler screw (2x)
16
Lubricant drain screw
(2x)
17
Sight glass (2x)
18
Oiler
18.1 Finned tube cooler (only for
the Okta 25000)
33
Blank flanges for mounting
the overflow valve (option)
18 18.1
1
15
16
2
33.1/33.2
SG
SG
17
