2.Old SumitomoType............................................................................. 2/4

Swing Unit

PageNo. 4 /12 First Edition ：03/2006

2. Maintenance Reference Table (1) Worn Out Parts Replacement Standards

If the parts are worn and exceed the below standards, replace or readjust. However, if they are extremely damaged judging from the external appearance, replace with the appropriate part.

Table 4 Worn Out Parts Replacement Standards

Item

Clearance between piston and cylinder bore (D-d) Standard dimensions (mm) Recommended replacement value (mm) Treatment

0.032 0.062 Replace piston or cylinder

Backlash of piston and shoe caulking part (d) 0 0.3 Replace piston shoe assembly

Shoe thickness (t) 6 5.8 Replace piston shoe assembly Assembled height of press plate and spherical bush(H-h) 7 6.5 Replace set of the press plate and spherical bush Friction plate thickness 4.0 3.6 Replace

Backlash of Piston and Shoe ( δ ) Shoe Thickness (t) Assembled Height of Press Plate and Spherical Bush (H-h)

(2) Sliding Surface Modification Standards

If the surface roughness of each sliding parts is exceed the below standards, modify or replace.

Table 5 Sliding Surface Modification Standards Part name Standard surface roughness Surface roughness requiring modification Shoe 0.8-Z (Ra = 0.2) (Lapping) 3-Z (Ra = 0.8) Shoe plate 0.4-Z (Ra = 0.0) (Lapping) 3-Z (Ra = 0.8) Cylinder 1.6- Z (Ra = 0.4) (Lapping) 12.5-Z (Ra = 3.2) Valve plate 0.8-Z (Ra = 0.2) (Lapping) 6.3-Z (Ra = 1.6) Note:1. By lapping to each sliding parts, the surface roughness should be below the standard. 2. Replace both the press plate and the spherical bush as a set if a rough surface is observed on the sliding areas of them.