| 摘要 |
An evaporable foam pattern assembly for casting a housing for a rotary engine. The pattern assembly includes a central rotor chamber pattern section and a pair of end pattern sections which, in the cast engine, are mounted on either side of the central section. The cental pattern section is provided with a central chamber of epitrochoidal shape and the end sections are each formed with a central opening. The outer portion of each central opening is cylindrical in shape, while the inner portion is elliptical and separated from the outer portion by a relief groove. Each end pattern section is provided with an air passage that communicates through the relief groove with the elliptical opening, so that in the assembled cast engine, air introduced into the passage of one of the end sections flows into the rotor chamber of the central section and is discharged from the other end section. The central pattern section is formed of two compounds which are joined along a parting line disposed normal to the axis of the rotor chamber, while each end outer pattern section is formed of two components joined along a parting line that extends through the relief groove and is disposed normal to the axis of the openings in the end section.
|
