Slant plate type compressor with variable displacement mechanism

Abstract

A slant plate type compressor with a variable displacement mechanism is disclosed. The compressor includes a drive mechanism having a drive shaft rotatably supported in a compressor housing and a coupling mechanism for drivingly coupling the drive shaft to pistons such that rotary motion of the drive shaft is converted into reciprocating motion of the pistons. The coupling mechanism includes a slant plate having an inclined surface. The slant angle changes in response to a change in pressure in the crank chamber and, thus, changes the capacity of the compressor. The drive shaft includes an inner end portion which has a diameter that is smaller than a diameter of the remainder of the drive shaft. A bias spring which has an outer diameter that is greater than a diameter of the remainder of the drive shaft is resiliently mounted on the inner end portion of the drive shaft between the slant plate and the cylinder block. The bias spring restores the slant plate back to its maximum slant angle when the slant angle is decreased below a predetermined angle without the bias spring interfering with the free pivoting motion of the slant plate between various inclination angles. Thereby, the impact forces which act on the internal component parts of the compressor when the compressor is started can be reduced, while at the same time the bias spring still can sufficiently urge the slant plate toward its maximum slant angle if the slant angle decreases below the predetermined slant angle.