BENDIX MC-12 MODULATOR CONTROLLER ASSY Průvodce řešením problémů stáhnout pdf (Strana 57)

More info: visit www.bendix.com 1-800-AIR-BRAKE (1-800-247-2725)

The Fundamentals of

Compressed Air Brakes

Compressor, Reservoir and Brake Valve

In an air brake system, the compressor supplies the

compressed air for brake operation by taking free

air and compressing it to 100-120 P.S.I. (Maximum

pressure in an air brake system is generally 150 P.S.I.)

The compressed air passes from the compressor into

the reservoir and the air brake system where it (and

its energy) are stored until needed by the driver for a

brake application.

Service Brake System

When the brake valve is operated by the driver, air

ﬂ ows to the chambers where its energy is transformed

into the mechanical force and motion necessary to

apply the brakes.

Braking Forces - Effect of Air Pressure

This control of the braking force by controlling the air

pressure in the chambers is illustrated in Figure 14.

It shows the resulting forces in pounds of various

air pressures with a chamber having an effective

diaphragm area of 24 square inches.

The important point is that the air pressure in a brake

chamber can be controlled so the brake chamber will

develop the required force.

Braking Forces - Effect of Brake Chamber Size

Different sizes of vehicles and different axles of the

same vehicle may require different braking forces,

depending on the weight of the vehicle or the weight

distribution between axles of the same vehicle. These

variations in the braking force are design variations

because the maximum and minimum force required

must be properly provided before good performance

can be obtained throughout the entire braking range.

[Note: Rotochambers are larger, heavier style of brake

chamber typically used on heavier, off-road equipment

where their constant output and longer push-rod stroke

is useful.]

Figure 15 illustrates the developed force in pounds

of each of several different sizes of brake and

rotochambers when supplied with air pressure at 60

pounds per square inch. The effective area of the

different brake chambers generally varies from six

square inches to 36 square inches and their developed

force at 60 pounds air pressure generally varies from

360 pounds to 2,160 pounds. This permits the choice

of a chamber size suitable for properly operating any

size or type of foundation brake.

FIGURE 15 - BRAKING FORCES-EFFECT OF BRAKE CHAMBER SIZE

Clamp Ring Brake Chamber

or Rotochamber

6 9 12 16 20 24 30 36 50*

Effective Area of

Diaphragm (square in.)

6 9 12 16 20 24 30 36 50

Pounds of Force

Developed @ 30 psi

180 270 360 480 600 720 900 1090 1500

Pounds of Force

Developed @ 60 psi

360 540 720 960 1200 1440 1800 2160 3000

Force Developed by Various Size Brake and

Rotochambers at 30 and 60 psi.

FIGURE 14 - BRAKING FORCES-EFFECT OF AIR PRESSURE

Air Pressure

(PSI)

5 10 20 30 40 60 80 100

Developed

Force

(PSI)

120 240 480 720 960 1440 1920 2400

Typical ‘Type-24’

Brake Chamber

Having an

Effective

Diaphragm Area

of 24 Square

Inches.

Compressed Air Brakes

* Rotochamber only

1 2 ... 52 53 54 55 56 57 58 59 60 61 62 ... 69 70

Komentáře k této Příručce

Žádné komentáře

BENDIX MC-12 MODULATOR CONTROLLER ASSY Průvodce řešením problémů Strana 57

Komentáře k této Příručce

Související produkty a manuály pro Modulátor BENDIX MC-12 MODULATOR CONTROLLER ASSY