A limiter device is provided in a variable displacement compressor capable
of varying a discharge displacement per revolution and compressing a
fluid in a cycle. The limiter device includes an operating characteristic
acquiring means for acquiring a predetermined characteristic during a
compression operation of the compressor, and a varying means for varying
the discharge displacement of the compressor to a minimum side when the
predetermined characteristic obtained by the operating characteristic
acquiring means exceeds a predetermined value. Thus, the limiter device
can prevent the compressor from being brought into trouble such as
locking and can protect a driving belt and other auxiliary equipment on a
side of an engine, while it is unnecessary to provide a pulley with a
limiter function.