INSTALLATION & MAINTENACE MANUAL
RCOe2100/03.06
10
2 – Technical Information
This section is dedicated to a general introduction to the machinery. The products this macula refers to are
radial piston hydraulic motors whose series are:
1.
MR/MRE/MRA
(fixed displacement motors – single pistons row)
2.
MRT/MRTE/MRTF/MRTA
(fixed displacement motors– multiple pistons row)
3.
MRD/MRDE/MRDA
(dual displacement motors – single pistons row)
4.
MRV/MRVE/MRVA
(variable displacement motors – single pistons row)
The motors are used to convert the energy generated by working fluid pressure into kinetic energy of a
rotating shaft. The motor provides a torque proportional to the feeding hydraulic pressure and a speed
proportional to the feeding flow rate from the system pump.
The hydraulic radial piston motors object of this manual fall into the range of “Low Speed High Torque”
(LSHT) motors.
One fundamental feature of these motors is the capability to develop a very high starting torque, able to win
high resistant torque and start up the system.
This information represents an initial approach to become familiar with the products object of this manual;
more specific and detailed information on various topics is contained sections to follow.
2.1 – Motor Description
Parker Calzoni motors are the result of an original design aimed to obtain extremely high performances. The
radial driving system consists of telescopic cylinders (1) working against the spherical eccentric cam of the
rotating shaft on one side (2) and against the spherical caps (3) of the cylinder heads (4) on the other side.
The force is transmitted to the rotating shaft directly by means of a pressurised column of hydraulic fluid (a)
without any intermediate connecting rods, pistons, pads and pins; this feature leads to high mechanical
efficiency, thanks to the minimization of friction, and to the reduction of the moving parts wear.
The sealing surfaces of the pistons on shaft and cylinder head caps are perfectly spherical; the sealing surfaces
retain their circular cross section when stressed by pressure so that there is no alteration in the sealing
geometry. The usage of dedicated coating on the motor shaft reduces the friction and prevents any kind of
seizure of the motor’s internal components.
Since the force is transmitted directly toward the centre of the rotating shaft without connecting rods, there is
no transverse component of the thrust (side load) which means no out of round wear of the pistons.
The Parker Calzoni driving system design allows the realisation of motors with limited weight and overall
dimensions.
The timing system is realised by means of a frontal rotary valve (5), that rotates between two fixed plates (6-7),
connected to the main rotating shaft by means of a driving shaft (8).
This timing system design is hydraulically balanced and self compensated for wear and temperature variation.
