Key Coupling and Scroll Compressor Incorporating Same

Abstract

A scroll compressor includes a movable scroll compressor body and a fixed scroll compressor body that are arranged for relative orbital movement relative to one another to facilitate compression of refrigerant. To guide the orbital movement, a Oldham key coupling is provided that may include four keys spaced in separate quadrants for guiding movement of the scroll compressor body along a linear translational path along a lateral axis. Additionally, running clearances may be unequally and non-symmetrically arranged so as to prevent unwanted rotation of one of the scroll compressor bodies and thereby prevent unwanted edge loading.

1 . A scroll compressor, comprising:
 a housing;   scroll compressor bodies including a first scroll compressor body and a second scroll compressor body, the second scroll compressor body being moveable relative to the housing, the scroll compressor bodies having respective bases and respective scroll ribs that project from the respective bases and which mutually engage, the scroll ribs generally surrounding a central axis, wherein the scroll compressor bodies are movable relative to one another along first and second lateral axes, the first and second lateral axes and the central axis being generally mutually perpendicular; and   a key coupler acting upon the second scroll compressor body, the second scroll compressor body being movable relative to the key coupler along the second lateral axis, the key coupler having a first pair of cooperating sliding contacts with the second scroll compressor body including first and second contacts that act on a same side of the first lateral axis and on opposite sides of the second lateral axis, respectively, and wherein different keys provide said different first and second contacts.   
     
     
         2 . The scroll compressor of  claim 1 , wherein the first and second contacts are confined to only on the same side of the first lateral axis. 
     
     
         3 . The scroll compressor of  claim 2 , further including a second pair of cooperating sliding contacts between the key coupler and the second scroll compressor body, including third and fourth contacts that act only upon an opposite side of the first lateral axis relative to the first pair, the third and fourth contacts acting on opposite sides of the second lateral axis, respectively. 
     
     
         4 . The scroll compressor of  claim 3 , wherein the second scroll compressor body includes first and second guide flanges, and wherein the key coupler includes a ring body and four keys projecting from the ring body to provide the first, second, third and fourth contacts, each key being in a separate one of the four quadrants defined by the first and second lateral axes, wherein the first flange slides along the second axis between the first and second keys, and wherein the second flange slides along the second axis between the third and fourth keys. 
     
     
         5 . The scroll compressor of  claim 4 , wherein the key coupler is slidable relative to the first scroll compressor body along the first axis, the key coupler including fifth and sixth keys projecting from the ring body, the fifth and sixth keys being received in first and second keyway slots defined by the first scroll compressor body, respectively, the fifth and sixth keys and the first and second keyway slots being aligned on the first lateral axis. 
     
     
         6 . The scroll compressor of  claim 1 , wherein the first and second contacts are provided along projecting keys provided by one of the second scroll and the key coupler, and wherein the keys engage along a surface that is not a slot. 
     
     
         7 . The scroll compressor of  claim 6 , wherein the keys are part of the key coupler and project from a ring body, and wherein the movement along the second lateral axis is guided free of slots and free of ear structures on the second scroll compressor body. 
     
     
         8 . The scroll compressor of  claim 1 , wherein the first scroll compressor body is fixed relative to the housing and wherein the second scroll compressor body is moveable about an orbital path relative to the housing and the first scroll compressor body. 
     
     
         9 . A scroll compressor, comprising:
 scroll compressor bodies including a first scroll compressor body and a second scroll compressor body, the first and second scroll compressor bodies having respective bases and respective scroll ribs that project from the respective bases and which mutually engage;   a key coupler acting upon the second scroll compressor body, the second scroll compressor body being linearly movable relative to the key coupler by a contact interface between the key coupler and the second scroll compressor body, wherein the contact interface includes at least four keys.   
     
     
         10 . The scroll compressor of  claim 9 , wherein the second scroll compressor body includes first and second guide flanges, and wherein the key coupler includes a ring body with the at least four keys projecting from the ring body toward the second scroll compressor body, wherein the first flange slides along the second axis between the first and second keys, and wherein the second flange slides along the second axis between the third and fourth keys. 
     
     
         11 . The scroll compressor of  claim 10 , wherein the key coupler is linearly slidable relative to the first scroll compressor body, the key coupler including fifth and sixth keys projecting from the ring body, the fifth and sixth keys being received in first and second keyway slots defined by the first scroll compressor body, respectively, for facilitating relative linear movement. 
     
     
         12 . The scroll compressor of  claim 9 , wherein the at least four keys are not received in slots. 
     
     
         13 . The scroll compressor of  claim 9 , wherein the first scroll compressor body is fixed relative to a housing and wherein the second scroll compressor body is moveable relative to the housing and the first scroll compressor body about an orbital path. 
     
     
         14 . A scroll compressor, comprising:
 a housing;   a drive unit contained in the housing having a rotary output on an output shaft that rotates about a central axis, the shaft including an offset drive segment that is offset relative to the central axis;   scroll compressor bodies in the housing including a fixed scroll compressor body and a movable scroll compressor body, the scroll compressor bodies having respective bases and respective scroll ribs that project from the respective bases and which mutually engage, the scroll ribs generally surrounding the central axis, wherein the fixed scroll compressor body is fixed relative to the housing; and wherein the movable scroll compressor body has a drive hub projecting from the base slidably receiving the segment wherein rotation of the drive shaft is operative drive the moveable scroll member along an orbital path;   a key coupler between the second scroll compressor body guiding movement of the moveable member along first and second lateral axes, the first and second lateral axes being generally mutually perpendicular with the central axis, wherein the moveable scroll compressor body includes first and second guide flanges, and wherein the key coupler includes a ring body and four keys projecting from the ring body toward the movable scroll compressor body to provide first, second, third and fourth contacts, each key being in a separate one of the four quadrants defined by the first and second lateral axes, wherein the first flange slides along the second axis between the first and second keys, and wherein the second flange slides along the second axis between the third and fourth keys, and wherein the key coupler including fifth and sixth keys projecting from the ring body, the fifth and sixth keys being received in first and second keyway slots defined by the fixed scroll compressor body, respectively, for facilitating relative linear movement along the first lateral axis.   
     
     
         15 . The scroll compressor of  claim 14 , wherein the first, second, third and fourth keys are not received in slots. 
     
     
         16 . The scroll compressor of  claim 15 , further comprising a non-symmetrical running clearance between the four keys and the movable scroll compressor body, the non-symmetrical running clearance arranged to correct key clearance backlash and minimize edge loading wear. 
     
     
         17 . The scroll compressor of  claim 16 , wherein the non-symmetrical running clearance is accomplished through offset placement of pairs of keys relative to the second lateral axis. 
     
     
         18 . The scroll compressor of  claim 17  wherein the non-symmetrical running clearance is accomplished through offset placement of the guide flanges relative to the second lateral axis.