Roller bearings

BITZER screw compressors are equipped with fatigue resistant bearings. The bearings are designed for more than 100000 h operation in the central area of the application limits. For this reason, it is generally not necessary to replace them during normal operation (definition Factors influencing the inspection and replacement intervals). However, due to deviations from normal operation, for example due to lack of oil, oil dilution due to wet operation, insufficient suction gas superheat or thermal overload, it may be necessary to replace the bearings.

Checking the roller bearings

Bearing wear is checked by a sound evaluation. Slight bearing damage and slight wear cannot be determined analytically. Defective bearings, however, are easily audible due to a significantly increased noise emission. If this is the case, the bearings must be replaced as quickly as possible.

At bearing change the rotors, the housing and the discharge flange should also be checked visually.In case of severe scores or distinct signs of wear, overhaul or replace the entire compressor!

At bearing change the rotors, the housing and the discharge flange should also be checked visually.

In case of severe scores or distinct signs of wear, overhaul or replace the entire compressor!

For a preventive maintenance the replacement intervals of the bearings are also listed in the table. In case of a normal and fault free operation, however, the full life span potential of the bearings is not utilised.

Inspection and replacement intervals for normal operation (definition Factors influencing the inspection and replacement intervals) and for predominant operation at high condensing temperatures tc>50 °C

Refrigerant

Air conditioning

Inspection interval

Replacement interval

Replacement interval at tc>50°C

R134a / R450A / R513A / R1234yf / R1234ze

10000 h

50000 h

40000 h

R22 / R407A / R407F / R448A / R449A / R404A / R507A / R717

10000 h

40000 h

30000 h

 

Refrigerant

Medium temperature

Inspection interval

Replacement interval

R134a / R450A / R513A / R1234yf / R1234ze

10000 h

50000 h

R22 / R407A / R407F / R448A / R449A / R404A / R507A / R717

10000 h

40000 h

 

Refrigerant

Low temperature

Inspection interval

Replacement interval

Replacement interval at tc>50°C

R134a / R450A / R513A / R1234yf / R1234ze

-

-

-

R22 / R407A / R407F / R448A / R449A / R404A / R507A / R717

10000 h

50000 h

40000 h