PSI - Issue 12

Francesco Mocera et al. / Procedia Structural Integrity 12 (2018) 213–223 Author name / Structural Integrity Procedia 00 (2018) 000–000

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Fig. 3: Mechanical architecture of a self propelled feed mixer wagon.

from high stock blocks. The case study machine of this work is a self propelled vertical feed mixer wagon, equipped with a hydraulic milling head for silage cutting Fig. 2 and a hydraulic transmission which actuate the rear wheels. The only pure mechanical users are the augers, directly connected to the machine gearbox through a hydraulic clutch as shown in Fig. 3. In Tab. 1 the main features of the feed mixer wagon considered in this study are summarized.

Table 1: Self propelled vertical feed mixer wagon main characteristics

Features

Description

Mass

11800 kg

Mass max load

16000 kg

Engine power

125 kW

21 m 3

Tank volume

Augers

n° 2, vertical type, two speed Power Shift

Driveline

hydrostatic transmission, Rear Wheel Driven

3. Working cycle description

To evaluate the e ffi ciency of a machine it is important to consider the ratio between the work done and the amount of energy required for it. Considering as an example a car, the main result expected is to move people and objects between points away from each other. The e ffi ciency of such a task can be defined as the ratio between the obtained results (number of travelled kilometers) and the required energy in terms of fuel liters. In the case of a working machine, the same power unit must satisfy the power request of several users. The e ffi ciency must be evaluated considering the overall work done and the amount of fuel required by each task. Sometimes, the same NRMM can be used in several application fields: a construction application would emphasize loading operations while an agricultural application would be mainly characterized by handling and pulling operations. In both cases, the manufacturer must ensure the machine operability, addressing its e ffi ciency to lower the costs related to fuel consumptions for the final user. When evaluating performance of an industrial working machine it is necessary to consider the overall results achieved by the machine during its nominal working day / year. To do that it is necessary to define the Working Cycle of the machine as shown in Fig. 4 and addressed by (Mocera, 2017).