Brochure

159
IDH1-1/2-IDR1-11/2
TableNo.2 LoadRatings-IdlerBushings
IdlerBushings
Browning Idler Bushings provide Idlers in the following
products:
Sheaves
FHP
Multiple
Poly-V*
358
Gearbelt
®
Pulleys
Gears
Furnished complete with:
Ball bearings, cap screws, stud bolts and nuts
Table No. 1 Specifications
Correct operating tension is an important factor in the
satisfactory performance and life an any V-belt or chain drive.
As V-belts wear they seat themselves deeper in the sheave
grooves. This sealing, along with belt stretch, lessens the
initial tension. The result is slippage and loss in horsepower
capacity unless some form of take-up is used to restore and
maintain original tension.
As chains wear they elongate, which results in sway or slop
and increased vibration. This puts undue shock into the drive
and increases bearing wear.
Both V-belt and chain drives wear at an increased rate if
allowed to run with insufficient tension. Adjustment of center
distance is the best method of maintaining proper tension. In
cases of fixed centers, Browning Drive Tighteners and Idlers
provide the necessary means of take-up. The Browning Drive
Tighteners also provide a means of obtaining extra belt or chain
wrap frequently needed for extremely high ratios, multiple shaft
or serpentine drives.
Careful consideration must be given to the following when
using idlers:
1. Too much tension in a drive causes excessive belt, chain
and bearing wear.
2. Too little tension in a drive allows belt slippage or chain
vibration, resulting in loss of power and additional wear.
3. All idlers should be used on the slack side of the drive.
4. V-belt drive idlers should be used on the inside of the
belt. Allowance should be made for horsepower loss due
to the reduced arc of contact.
5. Where necessary to use V-belt drive idlers on the outside
of the belt, the reverse bending will reduce belt life.
6. Flat face pulley idlers can be used on either inside or
outside of the belt.
7. Sprocket idlers should be used on the outside of chain
drives and with at least three teeth engaged in the chain.
8. Idlers used on the inside of a drive should be located
approximately 1/2 of the center distance from the large
sheave, pulley or sprocket.
9. Idlers used on the outside of a drive should be located
approximately 1/2 of the center distance from the small
sheave, pulley or sprocket.
* These sizes fit H, P, Q and Q1 Drive Tighteners shown on pages 155-157.
Note : Mount stud bolt in either direction.
BrowningDriveTightenersandIdlers
AverageLifeFactors
Radial load capacities shown for Needle Bearing Idlers and Idler
Bushings are based on 2500 hours average life. If another average
life is desired, these ratings must be modified by factors as follows:
500 Hours - 1.71 4000 Hours - .85 9000 Hours - .65
1000 Hours - 1.36 5000 Hours - .79 10000 Hours - .63
1500 Hours - 1.19 6000 Hours - .75 15000 Hours - .55
2000 Hours - 1.07 7000 Hours - .71 20000 Hours - .50
3000 Hours - .94 8000 Hours - .68
Available for H, P1, Q1 and R1 bore items.
Part
No.
DIMENSIONS
(inches)
Tapped
Holes
Approx.
Wt.
Lbs
O.D. O.L. No. Size
*IDH1 - 1/2 2 1/2” 2 9/16” 2 1-4” - 20” .9
*IDP1 - 5/8 3 3 41/64 2 5/16 - 18 1.9
*IDQ1 - 3/4 4 1/8 4 7/32 2 3/8 - 16 5.5
*IDQ1 - 1 4 1/8 4 39/64 2 3/8 - 16 5.9
*IDR1 - 1 1/2 5 3/8 6 1/2 2 3/8 - 16 14.1
Part
No.
Radial Load Capacity in Pounds Based on 2500
Hours average Life at rpm Shown
100 500 1000 1500 2000 2500 3000 3500
IDH1 - 1/2 1518 1016 854 772 718 678 648 624
IDP1 - 5/8 1518 1016 854 772 718 678 648 624
IDQ1 - 3/4 3320 2222 1868 1688 1568 1486 1420 1366
IDQ1 - 1 3554 2378 2000 1806 1680 1590 1518 1462
IDR1 - 1 1/2 8326 5570 4684 4232 3936 3726 3560 3424
* Poly-V is believed to be a trademark and/or trade name of Veyance Technologies, Inc.,
and is not owned or controlled by Emerson Power Transmission Corp.