초록 ▼

An accurate and low cost sensing apparatus for a swash or wobble plate compressor that requires no modifications in compressor design or operation, and which provides a repeatable and accurate measure of compressor speed and stroke. The apparatus includes a sensor module and a stroke sensing circuit

An accurate and low cost sensing apparatus for a swash or wobble plate compressor that requires no modifications in compressor design or operation, and which provides a repeatable and accurate measure of compressor speed and stroke. The apparatus includes a sensor module and a stroke sensing circuit. The compressor has an outer housing formed of aluminum or other non-magnetic material, as is customary in automotive air conditioning systems. The sensor module includes a magnetic field responsive sensor such as a Hall Effect or magneto-resistive (MR) sensor, and is attached to the periphery of the housing in proximity to a reciprocating ferrous element such as a bushing shoe on the swash or wobble plate assembly. The sensor produces a quasi-sinusoidal output voltage signal having a frequency proportional to compressor speed, and the stroke sensing circuit determines the compressor stroke by band-pass filtering, amplifying, and peak detecting the signal. The output of the stroke sensing circuit is substantially insensitive to noise, and the relationship between it and the compressor stroke is substantially linear, resulting in a reliable, accurate and inexpensive sensing apparatus.

대표청구항 ▼

[ What is claimed is:] [1.]1. A variable stroke refrigerant compressor including a non-magnetic housing, a non-rotary plate tiltable to determine a stroke of said compressor, said non-rotary plate being supported within said housing and having a peripheral ferrous element that is constrained to reci

[ What is claimed is:] [1.]1. A variable stroke refrigerant compressor including a non-magnetic housing, a non-rotary plate tiltable to determine a stroke of said compressor, said non-rotary plate being supported within said housing and having a peripheral ferrous element that is constrained to reciprocating movement in proximity to said housing, the compressor further comprising:a sensor module including a magnetic field responsive sensor mounted on an exterior surface of said housing so as to detect a magnetic flux passing through said ferrous element and said housing, the sensor producing a quasi-sinusoidal voltage corresponding to the reciprocating movement of said ferrous element; anda stroke sensing circuit for filtering and amplifying said quasi-sinusoidal voltage, and for detecting peak values of the filtered and amplified voltage as an indication of the compressor stroke.