Thermostatic valve arrangement

Abstract

A thermostatic valve arrangement includes a stop element disposed at a fixed location on a shaft that extends from and is fixedly connected to a thermostatic element housing. The stop element is located between the housing and a retaining ring which retains a bypass valve disc slidably mounted on and in direct contact with the shaft, and the bypass valve disc is located between the retaining ring and the stop element. An abutment member is slidably mounted directly on the shaft between the housing and the stop member. A bypass spring urges the bypass valve disc into engagement with the retaining ring and an additional spring urges the abutment member into engagement with the stop element. A shoulder of the bypass valve disc engages the abutment member when it is displaced by a predetermined distance along the shaft toward the housing against the bypass spring. The shoulder extends axially along the shaft at a radial spacing therefrom which is sufficient to permit the stop element to move therein. An axial bore is provided in the end of the shaft and a transverse bore is provided adjacent the stop element that communicates with the transverse bore, whereby a minimal coolant bypass flow is provided when the bypass valve disc is in the closed position, and the shoulder forms a seal with the abutment member and blocks the minimal bypass flow when the bypass valve disc is fully open.