Hydraulic engine mount with pressure relief valve

Abstract

A hydraulic mount assembly includes a pair of mounting members connected to each other through a hollow elastomeric body. The body is closed by a resilient diaphragm so as to form a cavity for damping liquid. A partition is provided to divide the fluid filled cavity into two distinct chambers. A primary chamber is formed between the partition and the interior wall of the body. A secondary chamber is formed between the partition and the interior wall of the diaphragm. The partition includes at least one orifice track connecting the two chambers. There is further provided a pressure relief valve cooperating with the partition and in fluid communication with the two chambers. The pressure relief valve allows damping liquid to pass directly between the chambers when pressure builds to an undesirably high level. This high pressure circumstance can cause the orifice track to choke off, restricting the primary path of fluid flow between the chambers. During operation, the pressure relief valve positively responds to pressure build-up in the primary chamber by allowing the damping liquid to bypass the orifice track and travel directly into the secondary chamber. As the pressure in the primary chamber recedes the pressure relief valve allows damping liquid to return.