Noise Control of Hydraulically Powered Vehicles

For many industrial vehicles, hydrostatic drive systems offer advantages over standard combustion engine or electrical drive systems. This includes high torque at low speeds, elimination of complicated gears and belts, and increased efficiency. Many times these vehicles have hydraulically powered implements, so using a hydraulic drive system simplifies the vehicle design. Acoustically, hydrostatic drives and hydraulic power systems have unique noise control considerations. The sound produced by the hydraulic pumps can be tonal leading to operator and/or spectator annoyance, even at relatively low sound pressure levels. Sound levels produced by the pumps can high and vibration isolating the pump and lines can be difficult. This can lead to high in-cab and exterior sound pressure levels. This paper presents an overview of hydraulic power systems and several case studies for the noise control treatment development of hydraulically powered machines.