Gb 7. maintenance, cleaning and recalibration – WIKA CPB3800 Benutzerhandbuch

Seite 37

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37

WIKA operating instructions model CPB3800

14062232.03 12/2013 GB/D

GB

7. Maintenance, cleaning and recalibration

7.2.6 Hub assembly
1. Unscrew the ram from the spindle. NOTE: left hand thread.
2. Unscrew the spokes from the hub.
3. Knock out the spring pin (1), found at the bottom of one of the tapped spoke holes in

the hub, using a punch 6 mm dia. Pull off hub.

4. The hub locating plate and thrust bearing can now be removed from the spindle.
5. If the flanged bush (2) is to be renewed, it should be pressed out of the locating

plate and a new one pressed in squarely.

6. The thrust bearing (3) is renewed as a complete assembly.
7. The nut, pin and spindle sub-assembly (4) can only be replaced as a matched pair.

Unscrew the nut from the ram, gripping in a soft jaw vice and screw in the new nut.

8. Assemble the thrust bearing, locating plate and hub on to the spindle, lubricating

with molybdenum disulphide grease.

9. Clamp these items together to eliminate end play and re-assemble spring pin. If

using new spindle drill through 6.3 mm diameter to fit spring pin (1).

10. Lubricate the thread with molybdenum disulphide grease and screw into ram nut.

7.2.7 Piston-cylinder unit

As the piston-cylinder unit represents a high proportion of the total value of the pressure

balance, it should always be handled with care and every effort made to keep it clean.

The piston-cylinder unit is made to extremely fine limits of accuracy and it is not

advisable to dismantle it. If it is necessary to clean it, the piston and cylinder bore must

be oiled immediately, in order to protect the high grade finish.

Should the unit become damaged it should be returned complete for replacement or

repair. Parts from different units are not interchangeable as they have to be weighed and

evaluated as a whole.

The serial number of the piston-cylinder unit appears in the certificate of accuracy and

is marked on the body of the unit. This number, as well as the pressure balance serial

number should always be quoted in correspondence concerning the piston/cylinder unit.

The piston-cylinder connections should be blanked if it is removed from the pressure

balance. If the unit is taken off for any reason it should be stored upside-down, resting

on its weight carrier.

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