3 Product description
3.1 Functional description
The operating principle of the roots pump is based on 2 synchronous pistons that rotate in a housing
without touching. The pumping effects arise as a result of the opposing rotation of the 2 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 op-
posing yet synchronised movement of the rolling pistons is achieved by means of a pair of gears mount-
ed 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 capable of compressing
against atmospheric pressure, the roots pump must be operated in conjunction with a backing pump
connected upstream.
Roots pumps of the M series are equipped with a magnetic coupling.
1
4
2
3
9
8
10
11
12
14
13
15
5
6
7
Fig. 2:
Design, construction
1 Vacuum flange
9
Lubricant drain plug
2 Measurement connection vacuum side
10
Fore-vacuum flange
3 Motor
11
Optional fore-vacuum connection
4 Oiler for version with RSSR
12
Sealing gas connection motor side
5 Overflow valve
13
Measurement connection fore-vacuum side
6 Eye bolt
14
Sealing gas connection bearing side
7 Cardboard cover disk
15
Sight glass, gearbox side
8 Lubricant filling plug
3.2 Identifying product
To ensure for a clear identification of the product when communicating with Pfeiffer Vacuum, always
keep all of the information on the rating plate to hand.
The following information is shown on the rating plates:
● Pump model
● Model number
● Type and quantity of the lubricant
● Max. allowable pump rotation speed
● Date of manufacture
● Input voltage range (motor rating plate)
Product description
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