Method and device for manufacturing compressor scrolls, compressor scroll, and scroll compressor

A method for manufacturing a compressor scroll, the compressor scroll including

• a first scroll provided on a spiral-shaped first wall portion disposed on a first side of a first end plate,
• a second scroll provided on a spiral-shaped second wall portion disposed on a first side of a second end plate, with the second wall portion meshed with the first wall portion of the first scroll, wherein the second scroll is supported for orbiting movement and prevented from rotating,
• a step portion disposed on the first side of each of the end plates where a height transitions from high on a center portion side of the spiral following the respective wall portion to low on an outer end side, and
• a stepped portion disposed on each of the wall portions where a height transitions from low on the central portion side of the spiral to high on the outer end side, wherein the stepped portions engage with the corresponding step portions, the method comprising the step of:
• water jet peening by jetting cavitation bubbles generated underwater by a water jet at the first side of the end plate of at least one of the scrolls, with a center of the cavitation bubbles being offset from a center of the spiral shape of the wall portion on the end plate and the step portion, and the stepped portion positioned at an outer peripheral portion of the cavitation bubbles,
• wherein the water jet peening step includes moving the cavitation bubbles and the scroll relative to one another to intersect with a straight imaginary line that joins the step portion and the stepped portion and the positions of the cavitation bubbles and the scroll.