Komatsu 830E-AC Shop Manual page 680

Operation
Refer to the parts list at right and the pump illustra-
tion in Figure 4-9 for the following description of oper-
ation.
• The driveshaft (38, Figure 4-9) runs through the
centerline of pump housing (40) and valve plate
(51).
• Cylinder barrel (48) is splined to the drive shaft.
• A ball bearing (36) supports the outboard end of
the driveshaft and a (bushing type) bearing (50)
supports the inboard end.
• The pump cylinder barrel is carried in a
polymerous (journal type) bearing (44).
• The valve plate (51) has two crescent shaped
ports (inlet and outlet).
• Pumping pistons (47) in the cylinder barrel are
held against a swashblock (31) by a shoe
retainer (17).
• The shoe retainer is held in position by the
fulcrum ball (43) which is forced outward by
retainer springs (13). The springs act against the
pump cylinder barrel (48) forcing it against the
valve plate (51) while also forcing the piston
shoes against the swashblock.
• The semi-cylindrical shaped swashblock limits
the piston stroke and can be swivelled in arc
shaped saddle bearings (21).
• The cradle is swivelled by the control piston (14).
L4-16
FIGURE 4-9. CUT-AWAY VIEW OF
1. Plug
2. O-Ring
3. Spring
4. Back-Up Ring
5. O-Ring
6. Back-Up Ring
7. O-Ring
8. Piston Ring
9. O-Ring
10. Back-Up Ring
11. Spring
12. Control Piston Stop
Pin
13. Spring
14. Piston
15. Pin
16. Control Piston Stop
Pin
17. Shoe Retainer
18. Pin
19. Retainer Ring
20. Washer
21. Saddle Bearing
22. Roll Pin
23. O-Ring
24. Link
25. O-Ring
26. Gland
27. Jam Nut
28. Maximum Flow Stop
Adjuster
29. Retaining Ring
Steering Circuit
STEERING PUMP
30. Back-Up Ring
31. Swashblock
32. Dowel Pin
33. Saddle
34. Roll Pin
35. Retainer Ring
36. Bearing
37. Shaft Retainer Ring
38. Shaft
39. Seal Retainer
40. Pump Housing
41. Shaft Seal
42. O-Ring
43. Fulcrum Ball
44. Cylinder Bearing
45. Pressure Compensa-
tor
46. Compensator
Adjuster
47. Piston/Shoe Assem-
bly
48. Cylinder Barrel
49. Gasket
50. Bearing
51. Valve Plate
52. Cap Screw
53. O-Ring
54. Cover
55. Piston Ring
56. Cap
57. Unloader Block
58. Unloader Adjuster
L04048