Root cause investigation and prevention of dynamic fluctuations in angular-resolved torque measurements of high pressure fuel pumps

In terms of better fuel mixture preparation, both finer atomization and higher system pressure are indispensable. These objectives provoke high mechanical loads on modern injection systems. In particular, the driving torque of the high pressure pump is proportionally linked to the system pressure within the pump cylinder. This article focuses the challenge of measuring angular-resolved torque fluctuations induced by the high pressure pump on a component test bench. After describing a systematic measurement failure consisting of unexpected dynamic proportions within the torque signal, the disturbance is analyzed at steady-state and transient operating conditions of the test bench. Consequently, a method for detecting and analyzing the same within the measurement chain of the signal is suggested. Based on the identification of the root cause of the dynamic fluctuations, enhancement proposals are discussed, realized and validated.