Wacker Neuson BPU 2440 series Repair Manual

Wacker Neuson BPU 2440 series Repair Manual Manual pdf 18 page image

General Information BPU 2440/2950 Repairwc_tx000264gb.fm 143.8 Theory of OperationSee Graphic: wc_gr000085 and wc_gr001430The vibration required for compaction is produced by the exciter (a)which is firmly joined to the lower mass (b). The exciter contains twoshafts with eccentric weights attached to each shaft. The shafts areconnected by a sleeve gear and rotate in opposite directions. Theexciter is designed as a central vibrator with aligned vibrations. Such aprinciple permits the direction of vibration to be changed by rotating theeccentric weights (c) in relation to one another. In this way, an infinitelyvariable transition between vibration in forward motion, at standstill,and in reverse motion is possible. This process is hydraulicallycontrolled with the operating control handle (d) on the center pole head(e).The drive engine (f) is anchored to the upper mass and drives theexciter. The torque is transmitted by means of a friction connectionthrough the centrifugal clutch (g) and the exciter V-belt (h).The centrifugal clutch interrupts flow of power to the exciter at lowengine speeds and thus permits perfect idling of the drive engine. Thespeed of the drive engine can be infinitely varied by way of the throttlecontrol lever (i).The upper and lower (j) masses are connected to each other by fourvibration-damping shock mounts (k). This damping system preventsthe very high frequencies from being transmitted to the upper mass. Asa result, the functionality of the drive engine is retained in spite of thehigh compaction performance.The drive engine works according to the 4-stroke principle, is startedby way of a recoil starter, draws in combustion air over a dry air filter,(l) and is air-cooled.