Keep records of storage maintenance procedures and dates.

B. HANDLING

When lifting the unit, be sure to raise it evenly at all four corners to avoid twisting the frame. Attach cable slings, via spreader bar, to the pick-up lugs provided on the H-beam or channel base. If the unit was supplied without a base, use the 3" dia. pick-up hole in the center trunnion gusset above each spring cluster. Check that your lifting equipment is safely sized for the total weight of the equipment to be lifted.

C. Removal From and Re-attachment of Vibrating Frame to Stationary Base or Structure

Should it be necessary to remove the vibrating frame from the base in order to facilitate installation,
be sure to loosen the snubber check arm bolt. The arm should move freely before continuing.

Caution

Failure to loosen bolt may result in breakage to the arm.

After re-assembly of frame to base, snubber check arm bolt must be tight enough so that arm cannot be moved by hand.
It should be torqued to 150 ft./lbs.

Warning

Failure to tighten snubber check arm bolt will result in excessive vibration during shut-down and may result in damage to the feeder as well as the support structure.

 

Allow sufficient clearance in front of the screen at the discharge end or in the rear at the feed end for replacing screen sections. A suggested clearance would be at least one foot longer than longest screen panel.

A minimum vertical clearance of at least five inches should be maintained between the vibrating frame and any stationary structures such as the feed hopper or discharge chutes and bins. Avoid providing places for dust and stones to accumulate and interfere with the movement of the vibrating frame.

Caution

During start-up and shut down the frame may experience a brief period of much larger movement as the vibrating frame passes through the resonant frequency of the support springs. The vibrating frame must not contact any stationary object during this time.

Warning

ALL HOLD DOWN BRACKETS AND SHIPPING STRAPS MUST BE REMOVED BEFORE FINAL LEVELING AND BEFORE START-UP

E. HOPPER CLEARANCE DIAGRAMS

1. Feed End

2. Discharge

F. LEVEL AND DEGREE

If the base is provided, the live frame is set level with the base at the factory before shipping. However, it is very important that the sub-structure supporting the base be level or that the spring pad pedestals be level and located according to Deister drawings. The degree of incline of the unit should be within 1/2 degree of the intended degree in order to assure proper oil gauge readings, bearing lubrication and capacity.

Caution

The unit must be level transversely within 1/4" for seven foot and wider, and 1/8" for less than seven foot wide. Failure to do so can result in premature bearing failures, metal fatigue and uneven material flow. Level should be checked periodically after startup of a new plant or a portable plant in the event that settling has occurred.

G. GRIZZLY SECTION DIAGRAM

H. MOTOR AND DRIVE

1. Direction of Rotation

The direction of rotation of the motor is important to the operation of his unit and should rotate only as shown on the overall (General Arrangement) drawing. Reversing the direction will not affect the vibrating mechanism. If a pivot motor base has been supplied, the direction of rotation may affect belt slippage during start-up. The belts usually grip best when the driven sheave rotates Over and Away From the Motor (OAFM).

2. Motor Location

When Deister does not supply the motor support frames, it is very important that the motor be located as shown on the overall (General Arrangement) drawing. All Deister screen sheaves are specially machined so that, when in operation, there is a point of zero sheave run out. In other words, if a line were drawn from the center of the driven sheave through the center of the motor sheave, there would be no movement towards or away from the motor sheave where that line crosses the outer diameter of the driven sheave. This, of course, means that the center distance is remaining constant and the belts are running smoothly. If the motor is located improperly, the line may not cross at the point of zero run out. This results in belt damage and excessive plant vibration.

3. Belt Tension and Alignment

Proper belt tension is important to machine performance. Belts that are too loose will slip during start-up and may not be able to start the unit. Belts that squeal during start-up or in operation, or whip excessively, may indicate insufficient belt tension.

Caution

Be careful, however: belts that are tensioned too tightly can cause much more serious damage. As belts are over-tightened, the vibrating frame is pulled out of square with the support frame. Operating in this twisted position introduces stresses that can lead to spring failure, metal fatigue, cracking and broken welds in the vibrating frame.

In addition, the twisting will affect the stroke amplitude and character, thus affecting material flow.
Over-tightened belts put an extra load on the mechanism bearings that is unnecessary and may tear up motors and motor bases. Ideally, the belts should only be tight enough that they do not slip during start-up.

After proper tension has been applied to the V-belts, check that the sheave faces have proper angular and parallel alignment.

4. a. Torsion Motor Base (If Applicable)

If not properly operated, the torsion motor base cannot perform its job, which is providing uniform belt tension at all times.

Caution

The top of the base must be parallel to the bottom of the motor base or the base will not have adequate adjustability.

The center of the motor sheave should be located within 30 degrees up or down from the horizontal center of the feeder sheave.

4. b. Pivot Motor Base (If Applicable)

If not properly operated the pivot motor base cannot perform its job, which is providing uniform belt tension at all times.

Caution

The top of the base must be parallel to the bottom of the motor base or the function of the base will be interrupted during start-up and shut down.

The tension spring is always located towards the feeder sheave. The location of the motor on the pivot base is very important as well. By locating the center of the motor one to seven inches horizontally past the center of the motor base, away from the feeder sheave, the weight of the motor actually assists in maintaining belt tension. Final belt tensioning is made by adjusting the compression of the spring in the motor base. Proper spring compression greatly affects belt whip and belt life. The center of the motor sheave should be located within 30 degrees up or down from the horizontal center of the feeder sheave.

Warning

Never adjust belt tension while the feeder is operating and   always replace all guards.

I. SNUBBER ASSEMBLIES

Any vibrating frame that is supported by resilient springs has a resonant or natural frequency at which the frame can jump and lurch very erratically. On Deister equipment this frequency is normally between 120 and 150 cycles per minute. During start-up and shut down the unit must pass through this phase as quickly and as smoothly as possible. That is why Deister equips each unit with snubbers. The snubbers restrict large movements that could damage the vibrating frame and stationary tower yet do not hamper the normal oscillating motion of the unit. Always smear water resistant grease on each side of the check arm against the brass discs. When tightened to approximately 150 FT.- LBS. the snubber assembly should not be moveable by hand or foot. It should be moveable with a medium length pry bar.

Caution

The snubber assemblies should be inspected periodically and worn parts replaced when necessary. See the accompanying drawing.

NOTE:  IMPORTANT PARTS TO CHECK FOR WEAR:

     Friction Spring, Brass Disc, and Spindle Bushing

  J. GEAR TIMING INSTRUCTIONS

  K. RECOMMENDED NUT TORQUE IN FT.- LBS. 

BOLT DIAMETER

	7/16"	1/2"	5/8"	3/4"	7/8"
GRADE 5 BOLT	45	65	125	220	325
GRADE 8 BOLT	55	100	200	375	475

All bolts should be visually checked for tightness after approximately one day of operation. Periodic inspection for loose bolts should be conducted. Replace loose hardware with the appropriate new hardware.

 L. SUPPORT SPRINGS

The quantity and stiffness of the steel coil support springs were selected for your machine's weight and application. The springs are soft enough to minimize the vibration transmitted to the stationary structure but, at the same time, stiff enough to handle moderate feed surges. If the springs are too soft or too stiff, several different stiffness springs are available to fit in the existing spring seats. Consult Deister Machine Company.

If springs are allowed to bottom out, serious damage can be done to the screen frame, tower and springs. Worn paint or bare metal between coils is hard evidence that the spring has been totally collapsed. If this has occurred, an unusually heavy feed surge, plugged chutes, or stalled equipment is most likely to be the cause and should be corrected immediately.

Warning

If the vibrating frame is bottomed out on the springs due to the weight of backed up material, shut down the unit immediately. The back-up should be cleared by hand. Attempting to clear the back-up by running the unit will lead to spring and frame breakage. Clear away dust and stones from the base of the springs daily.

Support springs should be closely inspected at least once a month. In extremely corrosive applications where spring breakage can be more frequent, Deister can supply specialty springs.

M. PREVENTATIVE MAINTENANCE

1. Maintenance Checks

Daily Checks

a.      Oil level (for one week after oil change)

b.      Clear away stones and dust build-up from any moving parts.

Weekly Checks

a.      Screen cloth tension

b.      Wear on screen media and tension plates

c.      Oil level

d.      Even material feed and distribution

e.      Loose bolts

Monthly Checks

a.      Wear on bucker-up rubber wear strips at screen cloth changes

b.      Wear on snubber assemblies

c.      Drive belt tension

d.      Support springs

Semi-Annual Checks

a.      Wear on V-belts and sheaves

b.      Type of oil being used

c.      Wear on cloth support decks

d.      Wear on feed and discharge wear plates (if applicable)

e.      Test oil samples at oil change intervals

2. Housekeeping Practices

Caution

Accumulation of dust and stone around moving parts is one of the largest single causes of part failures. Pivot motor bases, support springs and the vibrating frame are especially susceptible to poor housekeeping. Any sustained impact between the vibrating frame and accumulated material will lead to side sheet and support deck cracking in addition to tower vibrations. Sheaves and belts are susceptible to material jumping over the side sheets and causing damage. Where possible, stationary skirt plates or rubber flaps should be used to deflect airborne material back onto the machine.          Regular housekeeping practices will greatly reduce parts cost and down time.