Electric motor and compressor construction

Claim 2

In a hermetic compressor the improvement comprising an electric induction motor having a stator and a rotor, first and second run windings wound on said stator and disposed to form electrical field poles generally opposite one another diametrically of said rotor, said run windings having end turns projecting beyond both of the axially opposite ends of said stator, said end turns of said first and second windings being arranged in a horseshoe configuration at each of said ends of said stator so as to extend circumferentially of said stator adjacent one another and such that the end turns of both said first and second windings traverse one of said field poles and respectively define first and second gaps therein each exposing a portion of the adjacent surface of the associated end of said stator, said gaps being located in the vicinity of the other of said field poles, a piston-type compressor mounted on at least one of said exposed surface portions of said stator so as to be nested in the associated one of said gaps, means supporting said rotor for rotation in said stator, and means drivingly connecting said rotor to the piston of said compressor.

Claim 3

In the compressor as set forth in claim 1 the further improvement wherein said compressor has a cylinder block constructed of nonmagnetic material, said block being secured to said stator in the portion thereof axially between said gaps to support said compressor on said stator.

Claim 4

In the compressor as set forth in claim 2 the further improvement wherein said cylinder block has an inboard bearing bracket cast integrally therewith to form part of said rotor support means, the sides of said cylinder block and said inboard bearing bracket facing said stator having an annular notch therein, and wherein sAid rotor has an axial projection at the end thereof adjacent said block disposed for rotation through said annular notch.

Claim 5

In the compressor as set forth in claim 2 the further improvement wherein said rotor support means comprises an outboard bearing bracket made of nonmagnetic material and disposed in said second gap on the side of said stator opposite said cylinder block, and said outboard bearing bracket and cylinder block are clamped to said stator by fastening means extending axially through said stator to connections with said outboard bearing bracket and said block.

Claim 6

In the compressor as set forth in claim 1 the further improvement wherein said stator comprises a plurality of laminations of magnetic material secured to one another by an adhesive.

Claim 7

In the compressor as set forth in claim 1 the further improvement wherein said compressor is secured to said stator in said first gap by a plurality of fastener means disposed in said second gap and extending axially through said stator to connections with said compressor to thereby clamp said compressor against said one exposed surface portion, and means electrically insulating said fastener means from said stator and insulating said fastener means from one another at the ends of said fastener means located in said second gap.

Claim 8

In a hermetic compressor, the combination comprising a single phase alternating current induction motor having a stator and a rotor, first and second run windings and first and second start windings wound on said stator and having end turns projecting beyond the axially opposite ends of said stator, said end turns of said first run winding extending circumferentially of said stator adjacent the end turns of said second run winding, said end turns of all of said windings forming a horseshoe configuration at each of said ends of said stator defining first and second axially aligned gaps in said windings, each of said gaps exposing a portion of adjacent surface of the associated end of said stator, a piston-type compressor mounted on at least one of said exposed surface portions of said stator, and means drivingly connecting said rotor to the piston of said compressor, said run winding being arranged on a common axis extending diametrically of said rotor, said start windings being disposed generally opposite one another diametrically of said rotor and laterally of said common axis of said run windings and offset toward the portion of said stator diametrically opposite said gaps.

Claim 9

In a hermetic compressor, the combination comprising a single phase alternating current induction motor having a stator and a rotor, first and second run windings and first and second start windings wound on said stator and having end turns projecting beyond the axially opposite ends of said stator, said end turns of said first run winding extending circumferentially of said stator adjacent the end turns of said second run winding, said end turns of all of said windings forming a horseshoe configuration at each of said ends of said stator defining first and second axially aligned gaps in said windings, each of said gaps exposing a portion of adjacent surface of the associated end of said stator, a piston-type compressor mounted on at least one of said exposed surface portions of said stator, and means drivingly connecting said rotor to the piston of said compressor, said run winding being arranged on a common axis extending diametrically of said rotor, said start windings being disposed generally opposite one another diametrically of said rotor and laterally of said common axis of said run windings and offset toward the portion of said stator diametrically opposite said gaps.

Claim 10

In the compressor as set forth in claim 7 the further improvement wherein said stator has a circular row of axially and radially extending winding slots arranged in a circular row therearound through a circumferential extent of approximately 300* with the ends of said row terminating on opposite sides of said gaps, said windings each comprising a plurality of coils each distributed in pairs of said slots.

Claim 11

In the compressor as set forth in claim 8 the further improvement wherein said plurality of slots consist of 20 slots numbered herein for identification consecutively one through 20 and spaced at equal angular intervals around said stator adjacent the inner periphery thereof with slots numbers one and 20 bounding said gaps, and wherein each of said windings consists of four coils, said four coils of said first run winding being wound through said slots numbered one through four and 17 through 20 and with the two runs of each coil of said first run winding disposed opposite one another on a line perpendicular to said common axis, said four coils of said second run winding being wound in like manner through said slots numbered five through eight and 13 through 16, said four coils of said first start winding being wound through slots one through four and seven through 10 and said four coils of said second start winding being wound through slots 11 through 14 and 17 through 20.

Claim 12

In an electric motor and pump unIt having a stator with an annular core having a plurality of winding slots disposed in a circular row around the inner periphery of said core, the improvement wherein said stator core has an unslotted portion disposed between the ends of said row of slots, a series of field windings wound through said slots and having end turns projecting beyond each of the axially opposite end surfaces of said core, said end turns being arranged in a horseshoe configuration whereby a gap is formed in each of said end turns exposing a portion of each of said end surfaces axially aligned with said unslotted portion of said core, a pump unit mounted on said stator including a cylinder block secured to said unslotted portion of said core and disposed with its cylinder axis perpendicular to the axis of said stator, bearing means secured to the unslotted portion of said core and extending radially inwardly therefrom, a rotor shaft journaled in said bearing means coaxial with said stator and carrying a rotor thereon, and means forming a driving connection between said rotor and a piston received in said cylinder for imparting reciprocation to said piston in response to rotation of said rotor.

Claim 13

In an electric motor and pump unIt having a stator with an annular core having a plurality of winding slots disposed in a circular row around the inner periphery of said core, the improvement wherein said stator core has an unslotted portion disposed between the ends of said row of slots, a series of field windings wound through said slots and having end turns projecting beyond each of the axially opposite end surfaces of said core, said end turns being arranged in a horseshoe configuration whereby a gap is formed in each of said end turns exposing a portion of each of said end surfaces axially aligned with said unslotted portion of said core, a pump unit mounted on said stator including a cylinder block secured to said unslotted portion of said core and disposed with its cylinder axis perpendicular to the axis of said stator, bearing means secured to the unslotted portion of said core and extending radially inwardly therefrom, a rotor shaft journaled in said bearing means coaxial with said stator and carrying a rotor thereon, and means forming a driving connection between said rotor and a piston received in said cylinder for imparting reciprocation to said piston in response to rotation of said rotor.

Claim 14

The motor-pump unit as set forth in claim 10 wherein said cylinder block and bearing means are constructed of nonmagnetic material.

Claim 15

The motor-pump unit as set forth in claim 11 wherein said stator core comprises a plurality of laminations of magnetic material secured to one another by an adhesive.

Claim 16

The motor-pump unit as set forth in claim 11 wherein said cylinder block has an inboard bearing bracket cast integrally therewith to form at least part of said bearing means, the side of said cylinder block and said inboard bearing bracket facing said core having an arcuate notch formed therein, and wherein said rotor has an axial projection at the end thereof adjacent said block disposed for rotation through said arcuate notch.

Claim 17

The motor-pump unit as set forth in claim 11 wherein said bearing means comprises an outboard bearing bracket disposed on the side of said core opposite said cylinder block and said outboard bearing bracket and cylinder block are clamped to said core by fastening means extending axially through said core to connections with said outboard bearing bracket and said cylinder block.

Claim 18

The motor-pump unit as set forth in claim 10 wherein said fastening means comprises a plurality of steel fasteners extending axially through said unslotted portion of said core, each fastener having at one end a threaded connection to said cylinder block and at the other end thereof a clamping connection with said core, and means electrically insulating said fasteners from said core and from one another at said other ends thereof.

Claim 19

In a hermetic compressor having a hermetic casing with an alternating current single phase electric motor and pump unit resiliently supported therein, the improvement comprising an annular laminated stator core having a plurality of winding slots disposed in a circular row around the inner periphery of the stator, said stator core having an unslotted portion disposed between the ends of said row of slots, a pair of run windings and a pair of start windings wound in a distributed manner through said slots, said windings having end turns projecting beyond the axially opposite end surfaces of said core and together forming a horseshoe configuration at each of the axially opposed ends of said core to thereby define axially aligned gaps in said end turns registering with said unslotted portion of said core, said pump unit including a cylinder block secured to said unslotted portion of said core and disposed with its cylinder axis perpendicular to the axis of said stator, inboard and outboard bearing means mounted respectively to the axially opposite surfaces of said unslotted portion of said stator and extending radially inwardly therefrom, a rotor shaft journaled in said bearing means coaxial with said stator and carrying a rotor therein, and means forming a dRiving connection between said rotor and a piston received in said cylinder for imparting reciprocation to said piston in response to rotation of said rotor.

Claim 20

In a hermetic compressor having a hermetic casing with an alternating current single phase electric motor and pump unit resiliently supported therein, the improvement comprising an annular laminated stator core having a plurality of winding slots disposed in a circular row around the inner periphery of the stator, said stator core having an unslotted portion disposed between the ends of said row of slots, a pair of run windings and a pair of start windings wound in a distributed manner through said slots, said windings having end turns projecting beyond the axially opposite end surfaces of said core and together forming a horseshoe configuration at each of the axially opposed ends of said core to thereby define axially aligned gaps in said end turns registering with said unslotted portion of said core, said pump unit including a cylinder block secured to said unslotted portion of said core and disposed with its cylinder axis perpendicular to the axis of said stator, inboard and outboard bearing means mounted respectively to the axially opposite surfaces of said unslotted portion of said stator and extending radially inwardly therefrom, a rotor shaft journaled in said bearing means coaxial with said stator and carrying a rotor therein, and means forming a dRiving connection between said rotor and a piston received in said cylinder for imparting reciprocation to said piston in response to rotation of said rotor.

Claim 21

In a hermetic compressor having a hermetic casing with an electric motor and pump unit supported therein, the improvement comprising a stator core having an unslotted portion disposed between windings wound on said core and having first end turns projecting beyond one end of said core and second end turns projecting beyond the axially opposite end of said core, said end turns being arranged to define first and second gaps in said first and second end turns respectively, said gaps registering with said unslotted portion of said core, said pump unit including a cylinder block secured to said unslotted portion of said core at said one end thereof and disposed with its cylinder axis perpendicular to the axis of said stator, inboard bearing means cantilever connected to said block and extending radially inwardly from said cylinder block and terminating short of the portion of the inner periphery of said core radially opposite said unslotted portion, a rotor shaft journaled in said bearing means coaxial with said stator and carrying a rotor thereon and means forming a driving connection between said rotor and a piston received in said cylinder for imparting reciprocation to said piston in response to rotation of said rotor.

Claim 22

In a hermetic compressor having a hermetic casing with an electric motor and pump unit supported therein, the improvement comprising a stator core having an unslotted portion disposed between windings wound on said core and having first end turns projecting beyond one end of said core and second end turns projecting beyond the axially opposite end of said core, said end turns being arranged to define first and second gaps in said first and second end turns respectively, said gaps registering with said unslotted portion of said core, said pump unit including a cylinder block secured to said unslotted portion of said core at said one end thereof and disposed with its cylinder axis perpendicular to the axis of said stator, inboard bearing means cantilever connected to said block and extending radially inwardly from said cylinder block and terminating short of the portion of the inner periphery of said core radially opposite said unslotted portion, a rotor shaft journaled in said bearing means coaxial with said stator and carrying a rotor thereon and means forming a driving connection between said rotor and a piston received in said cylinder for imparting reciprocation to said piston in response to rotation of said rotor.

Claim 23

The compressor as set forth in claim 17 wherein said inboard bearing means comprises a hub having a bore concentric with said rotor shaft and a main journal insert secured in said hub bore and coaxially dependent therefrom, said insert having a bore in which said rotor shaft is journaled.

Claim 24

The compressor as set forth in claim 18 wherein said insert has a sleeve extending axially from said hub and terminating between said ends of said core, said rotor having a sleeve secured to said rotor shaft between said sleeve of said insert and said opposite end of said core, said rotor axially overlapping and encircling said sleeve of said insert and defining therewith an annular cavity for collecting lubricant and supplying the same to said rotor shaft between said insert sleeve and said rotor sleeve.

Claim 25

The compressor as set forth in claim 19 wherein said main journal insert has a radially projecting external flange adapted to abut said hub on the side thereof facing said rotor, and said hub bore and said insert have mating threads whereby said insert may be screwed into said bore to bring said flange into abutment with said hub.

Claim 26

The compressor as set forth in claim 20 wherein said insert has a bearing surface at the end thereof opposite said sleeve of said insert and disposed in a plane perpendicular to the axis of said rotor shaft, and said rotor shaft has a head radially overlapping said end bearing surface of said insert, said head having a bearing surface seating on said insert bearing surface to form an axial thrust bearing for said rotor shaft.

Claim 27

The compressor as set forth in claim 21 wherein said one end of said insert has a slot extending between the bore of said insert and the exterior of said insert, said slot being covered by said head of said rotor shaft and serving to feed oil to said insert bore, said hub having a surface encircling said insert generally flush with said slot to feed oil to said slot.

Claim 28

The compressor as set forth in claim 18 wherein said block and hub are cast integrally as a unit from a structural aluminum alloy and said insert is made of steel.

Claim 29

The compressor as set forth in claim 17 further including an outboard bearing means cantilever connected to said unslotted portion of said core at said opposite end thereof and extending radially inwardly therefrom, said outboard bearing means having a hub portion coaxial with said rotor shaft and spaced axially from said inboard means, said rotor shaft being journaled in said inboard and outboard bearing means, said rotor being secured to said rotor shaft intermediate said inboard and outboard bearing means.

Claim 30

The compressor as set forth in claim 24 wherein said cylinder block and said outboard bearing means are clamped to said unslotted portion of said core by fastener means extending axially through said unslotted portion of said stator core and having connections with said block and said outboard bearing means.

Claim 31

The compressor as set forth in claim 25 wherein said fastener means comprise a plurality of steel studs each threaded at one end into said cylinder block, and including means electrically insulating said studs from said core and from said outboard bearing means.