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Idler Pulleys »
Small Nylon Pulleys - Bearing Mounted
General Information
SAVA’s Bearing Mounted Nylon Pulleys are primarily engineered and designed for use with small cables and cords. They offer greatly increased mechanical efficiency over plastic pulleys and are considerably less expensive than bearing mounted pulleys now available. SAVA pulleys are being used on recorders, metering equipment, indicators, control mechanisms, drive systems, etc.
Two basic types of bearing mounted pulleys are offered. The SP series is used where a more precise shielded bearing is required and the UP series where a commercial type bearing is adequate. These are described in more detail with the charts. In addition to the pulleys shown, SAVA can manufacture special diameters and shapes to fit your requirements.
In all cases where “CABLE SIZES TO” are noted, it should be understood that this includes the coating, if any.
SP Series Pulleys
The SP series pulleys below incorporate a precision, double shielded, lubricated single row ball bearing which is ABEC3 precision built to give all the accuracy needed to satisfy the load, speed, and life expectancy requirements of many applications now using more expensive ultra-precise bearings.
Please note that pulleys with extended inner races are more expensive than those without extensions.
SAVA
Item |
REF. Old
Part No. |
Dimensions |
Cable
Sizes
To |
Load*
(Lbs) |
A
+-.0005 |
B
+-.020 |
C
+-.020 |
D
+-.010 |
E
+-.010 |
F1
+.000
-.005 |
R
REF. |
SP2031
SP2031E |
SP-231
SP-231-E |
.125 |
.310 |
.375 |
.110 |
.093 |
N/A
.141 |
.015 |
1/32 |
10 |
SP2044
SP2044E |
SP-243
SP-243-E |
.125 |
.437 |
.500 |
.156 |
.125 |
N/A
.188 |
.025 |
3/64 |
10 |
SP2050
SP2050E |
SP-250
SP-250-E |
.125 |
.500 |
.625 |
.156 |
.125 |
N/A
.188 |
.015 |
1/32 |
10 |
SP2063
SP2063E |
SP-263
SP-263-E |
.125 |
.625 |
.750 |
.156 |
.156 |
N/A
.188 |
.025 |
3/64 |
10 |
| SP3050E |
SP-248-E |
.1875 |
.500 |
.625 |
.125 |
.125 |
.156 |
.015 |
1/32 |
10 |
| SP3088 |
SP-387 |
.1875 |
.885 |
1.070 |
.250 |
.219 |
N/A |
.025 |
3/64 |
90 |
| SP3106 |
SP-310 |
.1875 |
1.063 |
1.250 |
.250 |
.219 |
N/A |
.035 |
1/16 |
90 |
SP4088
SP4088E |
SP-487
SP-487-E |
.250
.250 |
.885 |
1.070 |
.281
.188 |
.219
.188 |
N/A
.219 |
.025 |
3/64 |
90 |
| SP4125 |
SP-613 |
.250 |
1.250 |
1.500 |
.281 |
.281 |
N/A |
.050 |
3/32 |
90 |
| SP4138 |
SP-614 |
.250 |
1.375 |
1.750 |
.281 |
.281 |
N/A |
.065 |
1/8 |
90 |
|
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Bearing Life
The load ratings shown on the dimensional tables give the approximate dynamic capacity of the bearings under normal operating conditions of constant load and speed of 2500 hours average life. These figures assume that the bearings are properly mounted, operate under clean conditions, and are properly lubricated. For load ratings at speeds other than 500 PM shown in the dimensional table, multiply the rating at 500 RPM by the following factors:
50 RPM
––––––––
2.50 |
100 RPM
–––––––––
1.90 |
300 RPM
–––––––––
1.23 |
800 RPM
–––––––––
.83 |
1000 RPM
–––––––––
.76 |
It is frequently necessary to determine what life a bearing will have when operating under a known or mean radial load at some constant or average speed. The Load-Life Formula may be written as follows:
|
Life (Unknown) @ =
|
Load Rating at 2500 hours
–––––––––––––––––––––––
Actual Radial Load |
The above figures are estimates based on statistical evidence and are intended to serve as a guide.
The nylon pulley is a press fit over the bearing. Improper alignment of cable or cord may cause premature failure of the bearing or in certain installations cause the pulley sleeve to come off. Since there is considerable variation in application, we recommend actual life tests for your intended use.
NOTE: Most pulleys can be supplied with metric bearings; please inquire. Pulleys can be manufactured out of other plastics for an additional cost.
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