Warner Electric Garden Tractor Clutch User Manual

Garden Tractor Clutch
P-1097-6 819-0458
Troubleshooting and
Installation Guide
Contents
Coil Springs
Field
Rotor
Top V iew from Pulley
Armature Assembly
Sleeve
Armature
Face
Armature/Brake Plate Contact Surfaces
Brake Plate
Airgap Preset at Factory
Airgap Adjustment Nuts
Armature/Spring Rivet joints are located in line with the bearing stakes
Three, equally spaced, bearing staking punch marks
Failure to follow these
instructions may result in product damage,
Troubleshooting Checklist . . . . . . . . . . . . . . . . 3
Electrical Evaluation. . . . . . . . . . . . . . . . . . . . . 4
Airgap Adjustment . . . . . . . . . . . . . . . . . . . . . . 6
Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
Antirotation . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Antirotation Requirements . . . . . . . . . . . . . . . 13
Warranty . . . . . . . . . . . . . . . . . . . . . . Back Page
equipment damage, and serious or fatal injury to personnel.
Bearing Mounted Electric Clutch/Brake Assemblies and Operation
Components
An electric clutch/brake or clutch consists of three primary components:
1. Field Assembly
The clutch's "power" source contains the coil which generates magnetic force. Most common applications require a 12 volt DC coil, although other voltages are available.
2. Rotor Assembly
Generally, the input of the clutch. Includes a keyed hub which mates with the keyway in the drive shaft. The rotor transmits torque from the drive shaft to the output, or armature assembly.
3. Armature Assembly
Generally, the output of the clutch. Also contains the mechanical brake in a clutch/brake assembly. The armature transmits torque from the rotor to the driven load.
The sleeve is a secondary component. This sleeve serves as a spacer between the rotor and the field assembly, and is also a support for the field assembly bearing.
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Bearing Mounted Clutch/Brake Assembly
Troubleshooting PTO Clutches and Clutch/Brakes
A. Clutch Symptom: Clutch will not Engage
Problem Possible Causes
Low voltage supply • Defective battery
• Faulty charging system
• Bad wiring or connectors Rotor/armature airgap too large • Rotor/armature wear, readjust airgap Zero voltage • Broken lead wire
• Open clutch coil, check coil resistance
• Faulty switch
• Blown Fuse
B. Clutch Symptom: Clutch Slips
Problem Possible Causes
Low voltage supply • Defective battery
• Faulty charging system
• Bad wiring or connectors Overloaded clutch • Improperly sized clutch Contaminated friction surfaces • Engine oil leak on clutch Clutch loose on shaft • Loose mounting bolt
• Mounting bolt too long and bottoms
in shaft before clamping clutch
• Mounting washer too thin and deforms
when bolt is tightened
Clutch not mounted square • Mounting shoulder not square
• Clutch integral key hitting end of keyway
• Chamfer too small on spacer or ground
drive pulley
Broken rivet joints • Loose mounting, replace clutch
C. Clutch Symptom: Noisy Clutch
Problem Possible Causes
Failed bearing • Loose mounting
• Operating Temperature above 250° F
• Bearing Preloaded Axially
Adapter plate rattles against • Some noise is normal: to reduce noise antiorotation pin level, isolate antirotation pin from
frame with rubber
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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A
C
DB
Meter
Meter
Instructions for Evaluating VX Series Clutches
Windows
Bearing Mounted Field Clutches (self-contained clutch/brake package)
Clutch to be at room temperature - 70° F - for this check.
Step 1. Measure Clutch Coil resistance
1. Turn engine and PTO switch off.
2. Disconnect clutch wire connection.
3. Select meter to check ohms.
4. Connect meter lead wires to the wires in the clutch connector. (Figure 1)
5. If meter reads below 2.40 ohms or above
2.90 ohms, then the clutch has failed and needs to be replaced.
Figure 1
If the meter reads between 2.40 and 2.90 ohms, proceed to step 2.
Step 2. Measure Clutch Current Draw - 12 Volt System
1. Turn engine off.
2. Disconnect clutch wire connection.
3. Select meter to check amps (10 amp scale).
4. Connect one meter lead wire to one wire in clutch connector at A. (Figure 2)
5. Connect the other meter lead wire to the corresponding wire in the mating connector at C. (Figure 2)
6. Connect a short wire from D to B in both connectors. (Figure 2)
Figure 2
Figure 3
7. Turn PTO switch on.
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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8. If meter reads below 4.0 amps, the problem would be in the electrical system leading to the clutch (battery, relay, switch, etc.).
Burnishing Procedure for Electric Clutch/Brake to be performed with mower deck attached.
If the meter reads 4.0 amps or above, proceed to Step 3.
Step 3. Check Air Gap Setting
1. Turn engine and PTO switch off.
2. Locate the three "windows" or "notches" where the air gap is checked. (Figure 3)
3. With feeler gauge check gap at all three locations (minimum of two).
4. Factory air gap setting is .005" - .023".
5. If gap doesn't fall between .005" - .023" then reset using a .012" feeler gauge.
Changing the air gap is achieved by tightening and/or loosening the three nuts.
If you find after completing Steps 1, 2 and 3 that:
1. Run at 50% throttle.
2. Engage and disengage the clutch 5 times. (10 seconds on/10 seconds off).
3. Increase to 75% throttle.
4. Engage and disengage the clutch 5 times. (10 seconds on/10 seconds off).
Note: All values taken at room temperature. Voltage at 12 VDC. As temperature increases, nresistance increases, and current decreases.
1. The resistance falls between 2.40 and 2.90.
2. The amp draw is 4.0 or above.
3. The air gap is between .005" and .023" or reset to .012". Then the electric clutch is within factory specifications and is not the source of the problem.
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Airgap Adjustment
Top View from Pulley
Armature/Spring Rivet joints are located on line with the bearing stakes.
Airgap Adjustment Nuts
Three, equally spaced, bearing staking punch marks.
Windows
Brakeplate
Window
.012" Feeler Gauge (3) Required
Adjustment
Nut
G. Procedure for Airgapping Bearing Mounted PTO Clutch/Brakes
Airgaps are preset at the factory and do NOT require initial adjustment.
Bench setting:
1. Remove clutch from tractor.
2 Orient the clutch so it is viewed from the field
side.
3. Locate the three rivet joints in the armature assembly which fasten the leaf springs to the armature.
Figure 17
Location of Windows — Three Per Brakeplate
7. Insert a .012" feeler gauge through each window, being careful to position the feeler gauge between the rotor face and the armature face.
Positioning Rivet Joints for Airgap Adjustment
4. Rotate the pulley until these three rivet joints
5. Do not disturb the orientation of the armature
6. Locate the three windows in the brakeplate,
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Figure 16
are located midway along the edge of the triangular adapter, or halfway between each stud. This prevents measuring the airgap over a rivet joint.
assembly with respect to the field.
one at each stud.
Figure 18
Setting the Airgap
8. With all three feeler gauges in place, begin
to alternately tighten each nut an equal amount.
9. Tighten each nut until the feeler gauges
begin to feel snug. Each gauge should require an equal amount of force for insertion and extraction.
10. Remove the feeler gauges. Turn the rotor
assembly to check for rotor/armature drag. The rotor should turn freely.
11. Due to dimensional variations, the airgap between the rotor and armature may vary on a clutch from .023/.005", even though the gap at the three windows was set at .012". This is an acceptable condition.
12. Using feeler gauges, check the airgap through the three windows. If the airgap does not fall between .023/.005", repeat the above procedure. Remember: Never check the airgap directly over a rivet joint.
Option 1: Setting on the engine crankshaft.
13. To help set the airgap, mount the unairgapped unit directly to the engine crankshaft, securing it to the shaft with the appropriate bolt and washer with a minimum thickness of .250". When going from an unclamped state to a clamped state, the clearance between the rotor and armature is reduced about .002". A .012" feeler gauge should still be used in the clamped state. If a 3/8" diameter bolt is used, tightening torque on the bolt should be 340-45 lb.ft. Grade 8 bolt. If a 7/16" diameter bolt is used, tightening torque on this bolt should be 50-55 lb.ft. Grade 5 or 8 bolt.
14. As an alternative to mounting directly to the crankshaft in setting the gap, an assembly fixture consisting of a stub shaft with a shoulder can also be used. This stub shaft should duplicate the crankshaft dimensions. Secure the clutch to this shaft as noted above in Step 13.
Note: Care must be exercised when setting
the airgap with the clutch secured to the shaft, as it is difficult to detect rotor/armature drag when the engine is running.
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Airgap Adjustment
Top View from Pulley
Armature/Spring Rivet joints are located on line with the bearing stakes.
Airgap Adjustment Nuts
Three, equally spaced, bearing staking punch marks.
Windows
Brakeplate
Window
.012" Feeler Gauge (3) Required
Adjustment
Nut
Locating the Rivet Joints
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Locating the Windows
Inserting the Feeler Gauges
Crankshaft
Ground drive pulley or spacer must be chamfered to clear this radius on the crankshaft shoulder.
1.0"
Minimum shaft
engagement
1.340 Min Diameter x .250 Min Thick Washer
Ground
drive
pulley
Engine Face
Crankshaft Shoulder
Note 2
Note 2
Failure to torque bolt to requirements will degrade clamping and can allow the clutch to separate from the shaft, causing risk of personal injury.
Thread size Torque required N-m
3/8-24" UNF* 40-45 lb.ft. 54-61 7/16-20" UNF** 50-55 lb.ft. 67-75 M 10 X 1.50 55-60 N-m 55-60
Note: All values are for dry (unlubricated) plated bolts, please consult fastener manufacturer if any type of locking element (thread lock compound, patch etc.) is to be used.
* 3/8 -24 UNF Grade 5 bolt is unacceptable ** 7/16-20 UNF Grade 5 or 8 bolt is acceptable
Mounting the Clutch/Brake
NOTE:
1. Proper bolt torque is critical.
2. Always bottom the clutch against a flat surface; never against a radius.
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Antirotation Brackets Suggested Configurations
(Figure 11)
1/4" x 5/8" Bent Flat
Steel Field Restraint
(Figure 13)
1/4" x 3/4" Rubber Stop
Field Restraint
(Figure 12)
5/16" Diameter Bent Steel
Rod Field Restraint
Wheel clearance between brake/ clutch and steel restraint 1/16” required here.
(Figure 14)
1/8" x 3/4" Bent Flat
Steel Restraint
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Antirotation Requirements
Axial motion parallel to the shaft must not be restricted.
Field Bearing
Warning:
If axial motion is restricted, this bearing will be improperly loaded and may be subject to failure.
Crankshaft Centerline
Rotational Motion about the centerline of the shaft must be restricted, to prevent tearing the lead wires out, but not held rigidly.
Crankshaft Centerline
Field restraint slot
Do Not Restict the Field Assembly Some movement is required to prevent field bearing failure.
Warner Electric • 800-825-9050 P-1097-6 • 819-0458
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Warner Electric LLC
31 Industrial Park Road 815-389-3771
Fax: 815-389-2582
New Hartford, CT 06057
www.warnerelectric.com
P-1097-6 819-0458 8/11 Printed in USA
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