Electrodynamic Linear Motor Operated Gas Compressor

Abstract

The resilient armature centering mechanism surrounds the compressor cylinder rather than being positioned in axial series with the armature and cylinder structure. This arrangement results in a particularly compact structure for use as a hermetic refrigerator compressor.

Description

BACKGROUND OF THE INVENTION

Linear motor operated gas compressors of the type wherein the reciprocating armature is power operated in both directions form a null position, the resilient means, conventionally helical springs, for yieldingly urging the armature to null position, is arranged in axially spaced series relation with the armature and compressor cylinder. With such an arrangement, the machine is of substantial length, making it unsatisfactory for some uses such as, for example, a hermetic refrigerator compressor.

SUMMARY OF THE INVENTION

A cylinder structure is mounted on a frame member and includes a cylinder and a wall extending radially outwardly from the cylinder and spaced from the frame member in a direction axially of the cylinder. The cylinder is surrounded by a control member disposed intermediate the frame member and the wall of the cylinder structure. A piston in the cylinder and the control member are connected to the reciprocating armature. The control member is acted upon by resilient means, yieldingly opposing reciprocation of the armature from its null position. The resilient means may be in the form of springs arranged in a circular series above the cylinder and engaging opposite sides of the control member.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a vertical sectional view of a gas compressor embodying the invention; the orientation of the view is indicated by the line 1-1 FIG. 2.

FIG. 2 is a view taken on line 2--2 FIG. 1.

FIG. 3 is a view taken on line 3--3 FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The compressor unit consists of spaced apart frame end members 20, 21. These members are formed with aligned circular shoulders to receive the ends of an annular stator member 23.

The upper frame member 21, referring to FIG. 1, is formed with an annular flange 25 extending radially inwardly in axial spaced relation to the stator 23.

A cylinder structure is mounted upon the end member 21 and consists of an outer wall 26 and an inner wall 27. These walls are arranged in concentrically spaced apart relation. The lower end portion of the outer wall 26 is formed with an annular flange 28 formed with a circular shoulder engaging the end member 21. The flange 28 is formed with threaded apertures to receive tie bolts 30 which extend through the flange 31 of the lower end member 20, and threaded into flange 28. The bolts 30 serve to clamp the cylinder structure against the frame end member 21, and to clamp the stator 23 between the end members 20, 21.

The inner wall 27 forms the cylinder portion having a cylinder bore in which there is mounted for reciprocation a piston 33. A control member, acted upon by the resilient positioning means, consists of a cup-shaped member having a bottom wall 34 formed with a hub 35. The periphery of bottom wall 34 merges with an upstanding circular flange 37 terminating in a radial flange 38.

The piston 33 is formed with a tubular projection 40, the lower end of which is positioned in a circular recess formed in the wall 34 of the control member. A piston rod 41 is provided at its upper end with a nut 43. The piston rod extends through the piston 33, the bottom wall 34 of the control member, through an armature 45, and terminates in a circular member 46, to which it is secured by a nut 47 threaded on the lower end of the piston rod, as shown in FIG. 1.

The stator 23 is provided with coils 50, 51. The armature 45 is formed of solid, ferrous material and is provided with short circuiting rings 53 of conductive material located in groups of laminations 55. The outer groups 55 at the upper end of the armature are retained by a washer like member 57, clamped between the upper end of the armature and the control member. A similar washer member 58 is clamped between the armature and a spacer sleeve 60 engaged by the nut 47.

In the coil arrangement illustrated in FIG. 1, the coils 50 are connected to a source of alternating current and the coil 51 is connected to a DC supply. When the coils are so energized, they effect axial reciprocation of the armature 45 and accordingly, the piston 33. It will be understood by those familiar with the linear motor art that other forms of coil arrangements may be employed. The electrical operating functions of the device form no part of this invention.

A circular series of helical compression springs 65 is arranged between the cylinder structure walls 26, 27 and are interposed between the annular flange 38 of the control member and an annular end wall 67 connecting the walls 26, 27. A like series of springs 68 are arranged between the flange 25 of the frame end piece 21 and the flange 38 of the control member. These springs, as will be apparent, function to yieldingly oppose reciprocation of the armature 45 and piston 33. The springs 65, 68 are formed and dimensioned to effect reciprocation of the armature 45 in resonance. The cylinder portion 27 of the cylinder structure is provided with a valve plate 70 containing a discharge valve 71 and an intake valve 72 communicating with an intake passage 73. A cylinder head 75 is attached to the upper end of the cylinder by threaded connection. The head 75 is formed with a cylindrical flange abutting against the valve plate 70 forcing the valve plate against a shoulder 77 formed in the cylinder bore. The compressed gas discharged through the valve 71 passes through a conduit 79 connected to a discharge passage 80 by a flexible connection 81.

The compressor structure is yieldingly supported within a casing 83. A bracket 85 is fixedly attached to the inner surface of the casing 83 as by welding. A stud 86 is fixed to the bracket. The compressor is supported by a pair of spring members formed of resilient rods. These rods are formed intermediate their ends with a loop 87 mounted on the stud 86. One spring member is formed adjacent the loop 87, see FIG. 2, and with upwardly extending leg portions 90, the upper ends of which merge with arcuate extensions 91 provided at their ends with apertured terminals 92. Screws 93 extend through the terminals 92 and are threaded into radially extending bores formed on the flange 21.

The other spring member is formed with depending leg portions 95 similar to the leg portions 90 and the legs 95 in like manner terminate in arcuate portions 96 attached to the inner surface of flange 31 of the lower end member 20. The flange 31 is formed with a notch 97 for the admission of a tool to tighten the nut 98 on stud 86. Subsequently, the end closure 99 is hermetically sealed to the casing 83.

Gas is conveyed to the interior of the casing 83 through a conduit 100. If the end member 20 is formed solid, it is provided with openings 101 for the passage of the gas upwardly between the stator 23 and the armature 45 and about springs 65, 68 to the inlet passage 73. When the compressor unit is employed in a refrigeration system, the passage of the refrigerant vapor in contact with the stator and armature and springs 65, 68 effects cooling of those components.

The lower end member 20 is formed with a cylindrical hub 102 in which the member 46 is mounted for reciprocation. The piston 33 and member 46 serve to maintain the armature 45 in concentrically spaced relation to the stator 23.

Claims

I claim:

1. An electrodynamic linear motor operated gas compressor comprising a stator formed with a passage extending axially therethrough, a first end member positioned on one end of said stator, a second end member positioned on the opposite end of said stator, means operable to clamp said end members against said stator, a cylinder structure including inner and outer concentrically spaced apart walls, connecting means connecting like ends of said inner and outer walls, the opposite end of said other wall being attached to said first end member, said inner wall forming a cylinder portion having a cylinder bore and including intake and exhaust valve assemblies, an armature arranged for reciprocation in the passage in said stator, a piston fixed to said armature for reciprocation in said cylinder bore, a control member fixed to said armature and having a wall portion extending axially therefrom and encircling said inner wall and terminating in a radially outwardly extending resilient means between said radial flange and said connecting means in a second resilient means intermediate said first member and said radial flange, said resilient means yieldingly opposing reciprocation of said armature having means slidably engaging said second end member and serving in conjunction with said piston to maintain said armature in spaced concentric relation to said stator, and electrical driving coils mounted in said stator member and operable when energized to effect reciprocation of said armature.

2. A gas compressor as set forth in claim 1 wherein the clamping means clamping the end members to the stator are disposed externally.