I. MARCO CONTEXTUAL DE LA INVESTIGACIÓN
1.3. PROBLEMA DE INVESTIGACIÓN
Symptom Cause Remedy Remarks There is play.
(See Table 4.2 (b).)
Loose screws or pins. Tighten and apply LOCTITE as specified.
Defective reducer. Replace the reducer. Refer to section 6.
There is play. (See Table 4 2 )
Incorrect gear adjustment. Adjust the gears. Refer to section 5.4. (See Table 4.2.)
Worn gears. Replace the gears. Refer to section 6.
Worn bearings. Replace the bearings. Contact the service repre-
sentative.
Cracked casting, etc. Replace cracked parts. Contact the service repre- sentative.
Unusual noise Insufficient gear or reducer
lubrications.
Lubricate. Refer to section 3.
Foreign matter in gears or re- ducer.
Clean and lubricate. Refer to section 3. Excessive pressure on bear-
ings.
Reduce the pressure on the bearings.
Contact the service repre- sentative.
Defective reducer. Replace the reducer. Refer to section 6.
Incorrect gear adjustment. Adjust the gears. Refer to section 5.4.
Worn gears. Replace the gears. Refer to section 6.
Worn bearings. Replace the bearings. Contact the service repre-
sentative.
Incorrect servo adjustment. Adjust the servo. Contact the service repre- sentative.
Insufficient lubrication to the inside of balancer
Lubricate (900 cc) Refer to section 3.2.
Unusual heating Insufficient gear or reducer
lubrication.
Lubricate. Refer to section 3.
Specified grease not used. Replace with the specified grease.
Refer to section 3. Excessive pressure on bear-
ings.
Reduce the pressure on the bearings.
Contact the service repre- sentative.
Excessive load. Reduce the load/restrict
movement conditions.
Incorrect gear adjustment. Adjust the gears. Refer to section 5.4. Incorrect time constant. Revise the time constant. Refer to the parameters. Drops when the power
supply is off
Brake gap too large. Replace the motor. Refer to section 6 and Table 4 3 (*)
supply is off
Fused brake drive relay. Replace the relay. 4.3 (*). Grease leakage Deteriorated O--ring, oil seal
or packing.
Replace the O--ring, oil seal or packing.
Cracked casting, etc. Replace cracked parts. Contact the service repre- sentative.
Loose screws. Tighten.
(1) Method
1 Move the robot to the designated posture(Refer to table 4.3(a), and Fig 4.3 (b) ).
2 Release the brake control (Refer P85).
3 Apply pressure on each axis as Fig 4.3 (a).
4 Measure the moving distance.
Apply pressure on each axis 3 times, and measure the moving distance at 2nd and 3rd attempt. The backlash is calculated by the average of them.
Home Position 0 +10kg --10kg +10kg +10kg --10kg --10kg
1st attempt (Dont measure)
2nd attempt (B2= L1+ L2) L2 L1 L3 L4 3rd attempt (B3= L3+ L4)
Fig.4.3 (a) How to measure the backlash
The backlash is calculated as B=B2+ B3
2 .
(2) Measuring posture and position.
1 For iF, iF/2.85, iW, iW/175, iW/285, iS, iL,
Table4.3 (a) Posture for measuring backlash Measuring axis Posture axis J2 J3 J4 J5 J6 J1 70_ 0_ --- --- --- J2 0_ 0_ --- --90_ --- J3 50_ --90_ --90_ --90_ 90_ J4 50_ --90_ 90_ 90_ --90_ J5 70_ 0_ 90_ 90_ --180_ J6 70_ 0_ 90_ 90_ --90_
4.3
THE MEASUREMENT
OF THE BACKLASH
Fig.4.3 (b) Posture for measuring backlash
Table4.3 (b) Position for measuring backlash
Item A B C D E F S--420iF 2193 1190 1300 233 233 250 S--420iW 2193 1190 1300 251 251 323 S--420iW/175 2193 1190 1300 220 220 298 S--420iW/2.85 2655 1190 1752 251 251 323 S--420iS 2043 1190 1150 377 377 350 S--420iL 2795 1190 1902 408 408 360 S--420iF/2.85 2655 1190 1752 233 233 250 2 For iR,iR/120
Table4.3 (c) Posture for measuring backlash Measuring axis Posture axis J2 J3 J4 J5 J6 J1 0_ 30_ --- --- --- J2 --- --- --- --- --- J3 --20_ 0_ --- --- --- J4 --20_ 0_ --90_ 90_ --90_ J5 --30_ 0_ 180_ 30_ 0_ J6 --30_ 0_ --90_ 30_ 0_
Fig.4.3 (c) Posture for measuring backlash
NOTE
In the case of S--420iR and iR/120, the backlash of J2 can’t measure. Because the gravity acts on the direction of J2, constantly.
(3) Allowable backlash tolerances
Table4.3 (d) Allowable backlash tolerances (S--420iF)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 3.1 1.45 0.89 11.98 4.79 14.18
Displacement conversion (mm) 1.98 0.5 0.33 1.51 0.6 1.03
Distance (mm) 2193 1190 1300 433 433 250
Table4.3 (e) Allowable backlash tolerances (S--420iW)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 3.1 1.45 0.89 11.04 4.42 11.89
Displacement conversion (mm) 1.98 0.5 0.33 1.45 0.58 1.12
Table4.3 (f) Allowable backlash tolerances (S--420iW/175)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 3.1 1.45 0.89 11.6 4.64 11.98
Displacement conversion (mm) 1.98 0.5 0.33 1.48 0.59 1.04
Distance (mm) 2193 1190 1300 440 440 298
Table4.3 (g) Allowable backlash tolerances (S--420iW/2.85)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 2.78 1.45 0.98 11.04 4.42 11.89
Displacement conversion (mm) 2.15 0.5 0.5 1.45 0.58 1.12
Distance (mm) 2655 1190 1752 451 451 323
Table4.3 (h) Allowable backlash tolerances (S--420iS)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 3.34 1.45 1 6.74 2.7 7.24
Displacement conversion (mm) 1.98 0.5 0.33 1.13 0.45 0.74
Distance (mm) 2043 1190 1150 577 577 350
Table4.3 (i) Allowable backlash tolerances (S--420iL)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 2.38 1.45 0.6 8.5 3.4 9.57
Displacement conversion (mm) 1.94 0.5 0.33 1.5 0.6 1
Distance (mm) 2795 1190 1902 608 608 360
Table4.3 (j) Allowable backlash tolerances (S--420iF/2.85)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 2.78 1.45 0.98 11.98 4.79 14.18
Displacement conversion (mm) 2.15 0.5 0.5 1.51 0.6 1.03
Distance (mm) 2655 1190 1752 433 433 250
Table4.3 (k) Allowable backlash tolerances (S--420iR,iR/120)
J1 J2 J3 J4 J5 J6
Angle conversion (arc--min) 2.21 --- 0.98 14.37 4.79 11.35
Displacement conversion (mm) 2 --- 0.5 1.81 0.6 0.83
5
ADJUSTMENTS
Each part of the mechanical unit is carefully adjusted at the factory before shipment. Therefore it is usually unnecessary for the customer to make adjustments at the time of delivery. However, after for a long period of use or after parts are replaced, adjustments may be required.
Axis limits define the motion range of the robot. The operating range of the robot axes can be restricted because of:
D Work area limitations
D Tooling and fixture interference points D Cable and hose lengths
There are three methods used to prevent the robot from going beyond the necessary motion range. These are
D Axis limit software settings D Axis limit switches -- optional D Axis limit hardstops
WARNING
Do not use axis software limits as the only method for restricting robot motion. Change the hard stops to match the software modifications, otherwise injury to personnel and damage to equipment can occur.
Axis limit software settings are upper and lower motion degree limitations. The limits can be set for all robot axes and will stop robot motion if the robot is calibrated. If the robot is not calibrated,
overtravel limit switches or hardstops are contacted two to three degrees beyond the software limits. Overtravel switches for axis 1 are available as an option.
Axis limit switches are overtravel switches that, when tripped, cut power to the servo motors. These are located about 0.5 degrees beyond the software limits. Overtravel switches for J1--axis are available as an option.
Axis limit hardstops are physical barriers that are located two or three degrees beyond the overtravel limit switch or software setting on the three major axes. The robot cannot move beyond a hardstop. Setting the axis limits software settings changes the motion range of the robot. The axis limit screen displays the current upper and lower axis limits, for each robot axis, in degrees.