Trailer Construction; Chassis - PRONAR T669 Operator's Manual

SECTION 3

3.2 TRAILER CONSTRUCTION

3.2.1 CHASSIS

Trailer chassis consists of subassemblies indicated on figure (3.1). Lower frame (1) of the
load box is a structure welded from steel sections. The main support elements are two
longitudinal members connected with crossbars. In the middle section there are sockets (11)
used for mounting of the tipping ram cylinder. In front of the sockets of the ram cylinder is
mounted the load box support (9). In the back of the lower frame there is a rear beam with
tipping lugs. Hydraulic and pneumatic system sockets are mounted on the beam for
connecting a second trailer. The design of the upper frame enables tipping the load box back.
The rear hitch (6) is bolted to the beam to enable coupling the second trailer (biaxial). A pin
with diameter of ∅33 mm is adapted to connecting with drawbar eye of 40 mm. At the rear of
the chassis there is a lights support beam (12), and the rear bumper (5).
Trailer suspension consists of two wheel axles (4), in a tandem arrangement suspended on
taper leaf springs (7) connected by rocker arm (8). Axles are secured to suspension springs
using absorber plates and U bolts. Axles are made from square bars terminated with a pin,
where wheel hubs are mounted on cone bearings. The wheels are single, equipped with
brake shoes activated through mechanical expander cams.
In front there is a drawbar (2) to which shear type drawbar support is mounted (3). Drawbar
with a rotating drawbar eye of 50 mm (14) bolted to the front plate. The optional accessories
also include:
• fixed drawbar eye of
• 40 mm,
• ball drawbar K80.
Tandem chassis can be optionally equipped with a rear steering axle which improves the
tractor and trailer driving comfort on the field. In addition, steering axle facilitates change in
the driving direction, and during sharp turns does not create ruts in the ground and provides
better stability during cornering. When driving forward, the front axle follows the path of the
tractor, because the trailer wheels are directed in the opposite direction than the front wheels
of the tractor.
3.3
Pronar T669