J&M 220 Operating And Maintenance Manual - page 11
MODEL 220
HYDRAULIC
IMPACT HAMMER
I. GENERAL
INFORMATION
B. MAJOR COMPONENTS (CONTINUED)
Controls
The hammer is controlled by a remote electric/hydraulic system in the power unit
which allows for both manual single blow operation or automatic continuous stroke
operation. The stroke of the ram can be varied between 12” (.3M) and 48” (1.2M),
on-the-fly, allowing control of the hammer energy to suit various types of piling and
soil conditions. Under continuous operation, the hammer will operate at 45 blows
per minute at the maximum energy setting. The blow rate will increase at lower
energy settings. Control of the continuous cycling of the hammer is fully hydraulic
(non-electric), operated by valves contained within the actuator assembly. No
maintenance of adjustment of these valves is normally required. The hammer can
be operated from the control panel at the power unit, the remote pendant control or
the radio remote control unit
Interconnecting Hoses
Hydraulic power is transmitted from the power unit to the hammer through 100 ft.
(30M) of steel braid reinforced hydraulic hoses (4). High pressure, threaded type,
quick disconnects on these hoses facilitate connection to the power unit without oil
loss. Dust covers are provided to keep disconnects clean when the hammer is
disconnected.
Power Unit
Power for the hammer is normally provided by a free-standing, Model 325, diesel-
hydraulic power unit. The Model 325 is powered by a Caterpillar 3306 engine which
develops 325 Hp at 2100 rpm. The totally enclosed power unit is mounted on a skid
type fuel tank sub-base, and has lockable doors. Central lifting of the power unit is
facilitated by an integral lifting bale. A control panel at the side of the unit contains
all the operating gages and controls. A common reservoir supplies hydraulic oil to
the main pump and the stroke control pump. Filtration and cooling means for the
hydraulic oil are incorporated within the power unit. Electro/hydraulic valves are
provided for hammer start/stop and stroke control. Pressure limiting valves are
included for all systems. Four hydraulic hoses connect the power unit to the Model
220 hammer. This power unit can also be crane mounted for ease of operation.
If the crane is capable of providing the required flow, pressure, cooling and filtration
to the hammer, it is possible to adapt it for hammer operation and eliminate the
power unit
I-3