BETRA RING Rubber Isolator
Natural frequency :7 to 22 Hz
The BATRA® ring comprises a rubber ring bonded to two metallic washers one with a circular groove, the other with a mating circular ridge which allows BATRA® rings to be mounted one on top of another.
APPLICATIONS
BATRA® rings may be used :
➤ for making suspensions that are very flexible vertically and also damped by the natural properties of the rubber (road and rail vehicles);
➤ for making very effective anti-shock buffers (wagons, cars, gantries).
➤For special applications, where the quantities would justify custom manufacture, it is possible to supply Special BATRA® rings either with only one bonded lower armature or “all rubber”.
➤For special cases of shock, there are Special BATRA® rings with overlapping, non-bonded, armatures.
The design of the BATRA® ring gives the following basic characteristics :
➤ behaviour identical to that of a metallic spring plus damper;
➤ robustness : - well behaved under shock; - removal of the risks of suspension collapse;
➤ flexibility easily tailored by stacking BATRA® rings;
➤ transverse creep limited by the two bonded armatures.
OPERATING CHARACTERISTICS
The instantaneous deflection indicated in this table is approximate as it depends on the impact speed.
| Reference | Static compression | Dynamic compression | |||
|
Nominal
load
(daN)
|
Deflect (mm) |
Nominal
load
(daN) |
Deflect (mm) |
Max Φa |
|
| 541050 | 50-200 | 0,8 | 600 | 3,5 | 57 |
| 541083 | 90-360 | 3 | 1100 | 7 | 90 |
| 541082 | 125-500 | 3 | 1500 | 7 | 100 |
| 541100 | 175-700 | 3 | 2100 | 7 | 115 |
| 541112 | 210-850 | 3 | 2500 | 7 | 130 |
| 541145 | 325-1300 | 3,5 | 4000 | 9,5 | 150 |
| 541144 | 375-1500 | 3 | 4500 | 7 | 158 |
It is possible to use a metallic cushion for this application.
ASSEMBLY
The rings are centred using the grooves and ridges. To avoid play under no-load conditions, the
stack should be pre-compressed by 3 to 10% of its height. It is also necessary to leave sufficient
room around the stack for the sideways expansion under load.
| Reference |
φA (mm) |
B (mm) |
φC (mm) |
G (mm) |
H (mm) |
J (mm) |
R1 (mm) |
R2 (mm) |
Weight (g) |
| 541050 | 50 | 11 | 14 | 32 | 4 | 5 | 2,5 | 1,5 | 45 |
| 541083 | 80 | 27 | 41,5 | 61 | 4 | 6 | 3 | 3 | 220 |
| 541082 | 86 | 27,5 | 32 | 65 | 5 | 7 | 4 | 2 | 300 |
| 541100 | 100 | 28,5 | 32 | 65 | 5 | 7 | 4 | 2 | 415 |
| 541112 | 115 | 30 | 50 | 85 | 10 | 10 | 5 | 3 | 540 |
| 541145 | 140 | 35 | 55 | 100,5 | 10 | 10 | 5 | 3 | 890 |
| 541146 | 146 | 20 | 55 | 100,5 | 10 | 10 | 5 | 3 | 750 |
| 541144 | 146 | 35 | 55 | 100,5 | 10 | 10 | 5 | 3 | 980 |
| 541175 | 170 | 35 | 60 | 115 | 10 | 10 | 5 | 3 | 1360 |
| 541174 | 170 | 50 | 60 | 115 | 10 | 10 | 5 | 3 | 1680 |
| 541185 | 185 | 40 | 95 | 140 | 10 | 10 | 5 | 3 | 1510 |
| 541249 | 250 | 50 | 70 | 160 | 10 | 10 | 5 | 3 | 2600 |
| 541250 | 250 | 59 | 70 | 160 | 10 | 10 | 5 | 3 | 4400 |
