Operation Limit Of Main Parts - Mitsubishi Electric UM 5t Instruction Manual

・ Operation Limit of Main Parts
Part
When the depth of wear on the surface
Hoist gear reaches 10% of the tooth thickness
(Fig. 3)
When the depth of wear on the surface
Traversing gear
reaches 20% of the tooth thickness
When the wear reaches 1% of the original
Gear shaft
diameter
When the wear reaches 2% of each
Other shafts
original diameter
Gear shaft:
2% or less of the original diameter
Motor pinion:
Clearance
1% or less of the drum shaft original
between shaft
diameter.
and bearing
Other shafts:
4% or less of the original shaft
diameter
Damage, harmful flaws, or abnormal
Rolling bearing
noise
Harmful flaws on the lip or the shaft
surface with which the lip gets into
Oil seal
contact
Brake mechanism Abnormal operation
Wear of 5% of the original size
Traversing
Difference between left and right wheel
wheel tread
diameters of 1% (Fig. 5)
Traversing
50% of the original thickness (Fig. 4)
wheel flange
Wear on the groove bottom
Sheaves
30% of the wire rope diameter
Key spline Deformation, significant backlash, and
serration abnormal wear
Wear of hole and shaft
Joints
(pins and holes)
20% of the nominal diameter
conditions.
Hook dimensions
(Reference dimensions)
Unit: mm
a
5 t 135
10 t 150
* Reference dimensions are shown in the above table. Before using a new
hook, be sure to measure the actual dimension
Limit
b
63
90
(Double rail type)
- 38 -
Part
10% of the number
Strand
of strands in one
breakage
twisted wire
7% of the nominal
Wear
diameter
Deformation Significant deform-
and corrosion ation and corrosion
Breakage
Rope end
When the contact thickness reaches
Contactor contact
0.5 mm
Hoisting brake disk For a detailed description of the
replacement standards, refer to
"Maintenance and Inspection of Brake".
Traversing brake
disk
When there is no clearance between the
Electromagnetic
center legs of the movable and stationary
cores which have been fitted to each other.
brake cores
(New core: Approx. 0.3 mm)
Current collector
When the center diameter reaches 35 mm
(New wheel 45 mm in diameter)
wheel
When the cable has deteriorated due to
external flaws, especially when the ground
Cable
wire is breaking
200 V class; 0.2 M Ω
Insulation of all
400 V class; 0.4 M Ω
circuits
The traversing rail and metallic push-
button pendant must have been grounded
Ground
properly.
Ground resistance; 100 Ω or less
Apparent gap, large flaws and wear
Hook
(Fig. 2)
* The service life greatly depends on the use
Punch mark
Fig. 2
Wear
Fig. 4
Limit
Reference
replacement
schedule:
* Approx. 40,000
cycles
Tooth thickness
Amount of gear
Pitch circle
.
Fig. 3
Wear
(Monorail type)
Fig. 5