Page 9 of 11
BA_2005_5_GB_BSB
5.
Principle of operation
Reservoir with wedge plate assy. and scraper
A ratched mechanism (39-43) (section G-H) converts the oscillating motion of the rocker arm (77) (section E-
F) into rotary motion of the feed worm (4) and the scraper (34) attached to it. Irrespective of the direction of
drive of the motor the two parts always rotate clockwise causing the grease to be scraped off the wall of the
reservoir (1) and forced into the housing (17), thus eliminating cavitation and ensuring positive priming of the
pump unit.
Pump insert
The pump insert is secured in the housing (17) by 8 cap screws. It comprises a flange (52) (section A-B) with
an eccentric (74) (section I-K) running on a ball bearing, and the pump element (section I-K) bolted to the
flange.
The eccentric (74) causes a reciprocating motion in the rocker arm (77).(section E-F). The two feeding pistons
(84) are connected to the rocker arm. The double acting pump operates with two pairs of pistons
simultaneously such that, as one pair of pistons is on the suction stroke, the other pair forces the lubricant to
the outlet ports, through the pressure connection. Each of the two feed pistons fitted in the housing (82)
comprises two control pistons (80, 83) in a common bore.
Suction stroke
At the start of the suction stroke, the pistons (80, 83,84) are moving together towards the suction channel
until the spring-loaded control piston (83) is pressed against the stop thus reaching its final position. As the
delivery plunger (84) continues to move, a vacuum is created between the feed plunger (84) and the control
plunger (83). As soon as the feed plunger (84) uncovers the suction port, the vacuum, in conjunction with the
slight overpressure of the lubricant in the pump housing (17), causes lubricant to be sucked into the cylinder.
If the force of the spring (81) is not sufficient enough to enable to move the control piston (83) to the stop into
the final position in the housing (82), the control piston (83) is bound to be positively controlled at the end of
the stroke, by the rocker arm (77) and displaced into its final position mechanically, thanks to a second control
plunger (80) being provided.
Pressure stroke
Now the feed piston (84) moves towards the pressure connection closing the suction channel. The lubricant
enclosed by the feed piston (84) and control piston (83) is moved axially, against the force of the spring (81).
At the moment the annular groove in the control piston (83) is reaching the pressure channel, the axial
movement of the control plunger stops. The lubricant is forded by the feed plunger (84) rotating in axial
direction into the pressure channel. As soon as the two plungers (83, 84) make contact, the stroke of the feed
plunger is terminated.
6. Specifications
Discharge pressure adjustable, max. : ................................................................................................ 400 bar
Discharge rate at : .............................. 88 min
-1
: ............................................... circa 120 cm
3
/min ( 7 l/h )
151 min
-1
: ............................................... circa 235 cm
3
/min ( 14 l/h )
238 min
-1
: ............................................... circa 365 cm
3
/min ( 22 l/h )
Max. rpm :
with geared motor : ............................................................ 250 min
-1
Rotational direction of drive : .......................................................................................................... right or left
Reservoir capacity : ........................................................................................................................ 60 or 100 l
Operating temperature according to design : ...................................................................... - 20
o
C to + 80
o
C
Compatible lubricants : ................................................................................... up to NLGI class 3, DIN 51818
Integral strainer : ................................................... strainer area 40 cm
2
, wire mesh size 0,4 x 0,18 DIN 4189
Integral pressure relief valve : ...................................... adjustable from 0 up to 450 bar, adjusted to 400 bar