WycoTool Hydraulic Paving Vibrators - Manual (Page 4)

2
Wyco Tool Company
CHAPTER 2
VIBRATOR DESIG FU DAME TALS
a) Rotor
The rotor is the component that generates
vibration. A vibration impulse is generated
every revolution. It is essentially a shaft with
material removed from one side to create an
unbalance. The greater the unbalance, the
greater the centrifugal force that can be gener-
ated. The following lists the potential cen-
trifugal forces generated by the rotor at differ-
ent speeds:
Speed VPM Force 2000# 2500#
5,000………… 448 562
6,000………… 677 809
7,000………… 877 1,101
8,000………… 1,145 1,438
9,000………… 1,450 1,820
10,000………… 1,790 2,247
10,800………… 2,088 2,621
b) Bearing and Bearing Cups
Two bearings are located on each end of the
rotor. Each bearing is individually sealed and
lubricated with high temperature grease. The
bearings are separated from each other by a
shim, which prevents interaction between the
bearing outer races. The bearing inner races
and shims are clamped together on both ends
of the rotor using threaded components. The
bearings fit into high precision ground bearing
cups. The clearance between the bearing
outer diameters and the bearing cup inner
diameters is extremely small. A hardened cup
is permanently pressed into the head housing.
The other cup is slotted to prevent rotation
and it mates with the motor housing.
c) Hydraulic Motor
Forcing hydraulic oil through it operates the
Hydraulic Motor. The oil passes between two
gears, causing the output shaft to turn. The
output shaft is centered on the motor. A gear
is internally mounted on the output shaft and
mates with an idler gear. A lip seal assembly
is used to seal between the aluminum
hydraulic motor housing and the output shaft.
Controlling the oil flow through the motor can
control the motor speed.
d) Square Head Housing
The Square Head Housing has four flat sides
which are beneficial for transmitting vibration
to the mix. It supports the rotor through the
bearings and bearing cups. The external sur-
faces are case hardened for wear resistance.
e) Oldham Style Drive Components
The components that transmit rotation from
the hydraulic motor to the rotor are of a
design known as Oldham drive. These com-
ponents allow for a slight misalignment
between motor and rotor axes of rotation. The
output shaft from the hydraulic motor has two
flat parallel surfaces. These flat surfaces mate
with a slot in the driver. The driver also has
flat surfaces, which mates with the slot in the
driver sleeve. The driver sleeve screws on to
the end of the rotor. The drive slots are
located 90 degrees from each other. Small
amounts of misalignment are compensated for
with a small amount of relative motion
between the flats and the slots.
f) Vibration Isolator
The rubber vibration isolator is used to
reduce transmission of vibration to the mount-
ing bar of the paver. It allows for a small
amount of relative motion required to create
vibration while maintaining support for the
vibrator.
g) Hydraulic Hoses and Quick Disconnects
Two hydraulic hose connections are required.
The pressure hose is the smaller diameter hose
and it supplies hydraulic oil to the vibrator.
The return hose is the larger diameter hose
and hydraulic oil exits through it. Quick
disconnects are used on the end of each
vibrator hose. Generally, the female quick
disconnect is attached to the pressure line.