Method for forming scroll members used in a scroll type fluid machine

• US 4,696,084 A
• Filed: 02/26/1986
• Issued: 09/29/1987
• Est. Priority Date: 06/14/1985
• Status: Expired due to Fees

• Current Assignee: Mitsubishi Jukogyo Kabushiki Kaisha (Mitsubishi Heavy Industries, Ltd.)
• Original Assignee: Mitsubishi Jukogyo Kabushiki Kaisha (Mitsubishi Heavy Industries, Ltd.)
• Inventors: Mukai, Masatoshi, Sugimoto, Tamio, Itoh, Takuyuki, Ono, Tetsuo, Hirano, Takahisa, Maruiwa, Yasuharu, Fukami, Shoji
• Primary Examiner(s): NOT, DEFINED
• Assistant Examiner(s): Wallace, Ronald S.
• Application Number:
  US06/833,180
• Time in Patent Office: 580 Days
• Field of Search: 29/156.4 R, 29/557, 29/558, 29/156.8 R, 29/156.8 B, 29/DIG. 26, 418/55
• US Class Current: 29/888.022
• CPC Class Codes: F01C 1/0246 Details concerning the involute wraps or their base, e.g. geometry
• CPC Class Codes: Y10S 29/026 Method or apparatus with machining
• CPC Class Codes: Y10T 29/4924 Scroll or peristaltic type
• CPC Class Codes: Y10T 29/49995 Shaping one-piece blank by removing material

Abstract

A scroll type fluid machine comprising a pair of mutually engaged scroll members each including a side plate and a spiral lap uprightly disposed on an inside surface of the side plate; when the scroll members are relatively revolved in solar motion relationship, a fluid volume in sealed chambers defined by the pair of engaged scroll members being varied, so that a pressure of the fluid in the sealed chambers is thereby varied in order to discharge a gas therefrom, characterized by constituting so that stress may not concentrate at stress concentration portions of the scroll members, i.e., at corners of inner end base portions of the laps and the inside surfaces of the side plates in an eddy center section of the scroll members; and a method for forming the scroll members which permit improving productivity, characterized by forming, at the stress concentration portion of each scroll member, a round having a relatively large curvature radius which is enough to provide it with fatigue strength, and then finishing a relatively small round by means of a cutter for finish working.

Claims

1. A method for forming scroll members used in a scroll type fluid machine comprising a pair of engaged scroll members each including a side plate and a spiral lap uprightly disposed on an inside surface of said side plate;

when said scroll members are relatively revolved, a fluid volume in sealed chambers defined by said pair of engaged scroll members being varied, so that a pressure of the fluid in said sealed chambers is thereby varied in order to discharge a gas therefrom, said method being characterized by roughly working each corner of an inner end base portion of said lap and said inside surface of said side plate of said scroll member so as to form a complete round having a relatively large curvature radius which is enough to provide said lap with fatigue strength, by the use of a cutter, and the finishing, at each corner portion, a round having a relatively small curvature radius which does not contact with a tip end portion of said lap of the partner scroll member, by the use of a cutter.