Specifications

VC 5000 (PDF FORMAT) 2 ©Copyright Eaton Corp., 2010. All rights reserved.
1.0 INTRODUCTION
Throughout this manual there are a number of HAZ-
ARD WARNINGS that must be read and adhered to in
order to prevent possible personal injury and/or dam-
age to equipment. Three signal words “DANGER”,
“WARNING” and “CAUTION” are used to indicate the
severity of a hazard, and are preceded by the safety
alert symbol.
Denotes the most serious hazard, and is used
when serious injury or death WILL result from
misuse or failure to follow specific instruc-
tions.
Used when serious injury or death MAY result
from misuse or failure to follow specific
instructions.
Used when injury or product/equipment
damage may result from misuse or failure to
follow specific instructions.
It is the responsibility and duty of all personnel
involved in the installation, operation and maintenance
of the equipment on which this device is used to fully
understand the:
procedures by which hazards can be avoided.
1.1 Description
1.1.1 The Airflex
®
air-actuated VC element assembly is
specifically designed and manufactured for severe
clutch or brake applications on heavy equipment
where high starting loads or sustained slippage would
normally lower clutch or brake efficiency and reduce
operating life. Constricting action and ventilated con-
struction make high torque capacity and rapid heat
dissipation possible.
1.1.2 All Airflex VC element assemblies are supplied with
long wearing, NON-ASBESTOS friction material.
1.1.3 Airflex element assemblies are available for drum
diameters from 11.5 inches through 76 inches. The
element size designation indicates the nominal drum
diameter in inches, the clutch model and the width of
the friction material. For example, size “38VC1200”
indicates the element operates on a drum having a
nominal diameter of 38 inches, is an Airflex “VC”
series clutch or brake (the scope of this manual) and
has friction material which is 12 inches wide.
1.1.4 Where diameter space is limited, or the torque
required is greater than a single element can transmit,
all sizes of Airflex VC elements can be supplied as
dual units.
1.2 How It Works
1.2.1 Referring to Figures 1 and 2, the neoprene and cord
actuating tube is contained within a steel rim which is
drilled for mounting to the driving component (or reac-
tion bracket in the case of a VC brake application). As
air pressure is applied to the air actuating tube, the
tube inflates, forcing the friction shoe assemblies uni-
formly against the drum, which is attached to the
driven component. The friction shoe assemblies,
which consist of friction blocks attached to aluminum
backing plates, are guided by torque bars which are
secured to side plates. In the case where the VC ele-
ment is being used as a clutch and is attached to the
driving shaft, the torque flow is from the driving shaft,
through the element mounting component (typically
an iron spider), through the rim/side plate structure,
through the torque bars to the backing plates and fric-
tion material, where the torque is transmitted through
the friction couple to the components mounted on the
driven shaft (clutch drum and drum mounting compo-
nent). As actuating air is exhausted, release springs
and centrifugal force assure positive disengagement.
1.3 Element Adjustment
1.3.1 Airflex VC elements are completely self-adjusting and
automatically compensate for lining and drum wear.
Lubrication is not required. The torque developed is
dependent upon rotating speed and applied air pres-
sure. By limiting the applied pressure, the element will
act as a torque limiting device and provide overload
protection.
1.3.2 To accomplish regulated or cushioned engagement of
the element, a flow control valve may be installed in
the element air supply line and adjusted to restrict air
flow to the element while allowing free flow away from
the element for rapid disengagement. By adjusting the
flow, the rate of engagement may be varied. Note that
the flow control valve does not regulate air pressure.
The supply pressure must always be adequate to
transmit the maximum required torque. Refer to the
OPERATION section of this manual for air piping con-
figurations.