Trailer Construction; Chassis - PRONAR PT512 Operator's Manual

CHAPTER 3 Pronar PT512

3.2 TRAILER CONSTRUCTION

3.2.1 CHASSIS

Trailer chassis consists of assemblies indicated on figure (3.1). The lower frame (1) of the
loading case is welded from steel sections. The lower frame construction depends on the
version of a trailer. The main support elements are two longitudinal members connected with
crossbars. In the middle section there is a bracket (2) used for seating the hydraulic tipping
cylinder. In front of tipping cylinder brackets there is a loading case support (9). At the rear of
the lower frame there is a beam (7) with ball pins at the end. The support structure of the
upper frame and the interlocking method allows tipping of the loading case sideways and to
the rear. Brackets for mounting the upper frame are welded to the left and right sides of
a crossbar (8) of the lower frame.
In the rear section of the chassis there is a lights support beam (3) onto which electrical
equipment elements, as well as hydraulic and pneumatic system sockets for connection of
another trailer are installed.
The trailer suspension comprises two axles (4) attached to leaf springs (17) by means of U-
bolts. The suspension is attached the lower frame (1). The axles are made from square bars
ended with pivots onto which wheel hubs (5) are mounted by means of conical bearings. The
wheels are single, equipped with brake shoes which are activated through mechanical
expander cams. The rear wheels are covered by means of fenders (11) attached to trailer
frame brackets. In the front part of the trailer, on the left longitudinal member, wheel chocks
(12) can be found; just behind their supports there is a support for the parking brake crank
mechanism (13).
The hydraulic scissor support (10) is located between the drawbar's longitudinal beams onto
which the drawbar plate (6) is welded. The drawbar can be set in two positions, depending on
the type of a tractor. A drawbar eye (15) is attached to the plate.
3.3