Scroll type fluid machine having intermittent oil feed to working chamber

A scroll type fluid machine, comprising:

• a sealed casing;
• a first scroll disposed within said sealed casing, said first scroll having a first end plate, and a first spiral ridge provided on a front side of said first end plate;
• a second scroll disposed within said sealed casing, said second scroll having a second end plate, and a second spiral ridge provided on a front face of said second end plate;
• said first and second spiral ridges being interleaved with each other;
• said second end plate having a back face supported by a support member secured to said sealed casing, said support member having an oil sump provided therein;
• working chambers formed between said first and second spiral ridges, said working chambers varying from a low-pressure range on a peripheral side to a high-pressure range on a center side as volumes of said working chambers are decreased due to revolution of said second scroll relative to said first scroll;
• a back side chamber formed between said back face of said second end plate and said support member;
• a cylinder member disposed within said back side chamber such that said back face of said second end plate makes sliding contact with an end face of said cylinder member;
• a center side chamber formed inside said cylinder member within said back side chamber;
• an oil feed chamber provided on said end face of said cylinder member so as to open to said back face of said second end plate;
• an oil passage provided in said cylinder member for introducing oil from said oil sump into said oil feed chamber;
• and
• communicating means provided in said second end plate, said communicating means being in intermittent flow communication with said oil feed chamber, such that intermittent flow communication is provided from said oil feed chamber to said working chamber through said communicating means as said second scroll revolves.