Scroll type fluid apparatus having two orbiting end plates linked

Abstract

A scroll type supercharger including first and second orbital spiral elements is disclosed. The supercharger includes a first orbiting scroll having a first orbiting end plate from which a first spiral element extends, and a second oribting end plate fixedly attached to said first orbiting end plate, and from which a second spiral element extends. A hollow portion is formed between the first and second orbiting end plates. The housing includes a first casing further including a first fixed scroll having a first fixed spiral element extending therefrom. The housing also includes a second casing from which a second fixed scroll extends. The first and second casings are fixedly attached to form an operating chamber therein. The orbiting scroll is disposed in the operating chamber such that the orbiting scroll is disposed at an angular and radial offset with said fixed scrolls to form at least one pair of sealed off fluid pockets between interfitting pairs of fixed and orbiting spiral elements. The apparatus further includes a drive shaft having a crank pin disposed about its exterior surface. A longitudinal and radial bore extend through the crank pin, linking central fluid pockets on either side of the orbiting scroll with the hollow portion formed between the first and second orbiting end plates such that the pressure on either side of each orbiting end plate is equalized with the pressure within the outer fluid cavities to prevent bending and warping of the end plates.