US2054097A - Harmonic compressor - Google Patents

Description

` sept-15,. 193s.

l.,l. B. REPLOGLE HARMONI C YICOMPRES soR Filed-May 31, 1952 2 Sheets-Sheet 1 :1L/MIM,

' J. B. REPLoGl- E sept. 15, 1.936. 2,054,097

Y HARMONIC COMPRESSOR l Filed May 31, 1932 2 sheetsneet 2 /mA C 60 c; re

Patented Sept. 15, 1936 UNITED sTATEs` PATENT OFFICE The invention relates to electrically driven reciprocating apparatus and more particularly to compressors such, for example, as are adapted for the refrigeration industry.

One of the primary objects of the invention` is to produce an electrically operated reciprocating device free from rotatingparts in which the electrical energy is converted directly into the energy of mechanical reciprocation.

Another important object of the invention is to obtain a compressor of simple design adapted to be produced at low initial cost and to operate at high efliciency.

Other objects will be more apparent upon the consid-eration of the details of construction hereinafter set forth and illustrated in the accompanying drawings, wherein Figure 1 is a side elevation partly in section of an electrical compressor in which the piston of each power unit is shown at the end of its compression stroke;

Figure 2 is an end view of a power ,unit with the cap 21 and spring 22 removed; ,Y

Figure 3 is a transverse section through a power unit on the line 3-3 of Figure l;

Figure 4 is an electrical diagram;

Figure 5 is a sectional elevation of one unit showing the piston starting on the backwardV or intake stroke;

Figure 6 is an enlarged view of a portion of the cylinder and piston shown in Figure 5;

Figure '7 is an enlarged longitudinal section through the electric vibrator 2Q.

The apparatus comprises a base A on which are symmetrically mounted two power units B and C, respectively, connected by an intermediate compressor chamber D. Each of the power units B and C contains a reciprocable element, and the arrangement is such that the movements of the elements are always equal and in opposite directions. The reciprocable element in the particular construction illustr-ated is a cylindrical piston Ill adapted for horizontal movements in a surrounding cylinder I I. The cylinder is arranged centrally of a magnetic housing I2 which has an annular slot I3 therein arranged between the central core I4 and the surrounding wall I5. Within the annular recess is arranged a magnetizing coil I6 which when energized induces a magnetic fiel-d in the housing I2. At the open end of the housing there is preferably arranged an annular pole piece I'I projecting inwardly from the outer wall I5 and forming an annular passage I8 in which the magnetic field is concentrated.

The motive powerV for the device is obtained by placing in the annular space I8 an electric vibrator 2@ consisting of a coiled conductor' through which alternating current is caused to flow. This vibrator is secured to the recipro-Y cable piston IB through the medium of a spider member 2l. The vibrator is also disposedbetween two coiled springs 22 and 23 adapted to normally maintain the vibrator in a central po`si tion within the magnetic eld.

With the arrangement thus far described,

whenever an alternating current of .predetermined frequency is passed through the coil of the vibrator 2B forces are set up in the vibrator tending `to move the vibrator relative vto theV housing alternately in opposite directions jfor each alternation ofthe electric current. It is `an essential feature of my invention that the re'- siliency of the springs 22 and 23 be so propor-` tioned to the mass of the vibrating element that the natural period of vibration of this element corresponds to the frequency of the alternating` current. In other words, assuming that a 60. cycle alternating current is impressed on the coil of the vibrator, it is necessary then that the vibration period of the Vibrator ZilQthe piston II) and the parts connected thereto Ybe exactly 60 cycles per secon-d. With this condition of tuning between the mechanical vibrationl period of the vibrator and the electrical frequency of the current, the amplitude of-Vibration of the vibrator will be built up to an appreciable value determined by the electrical characteristics of the vibrator and the device becomes a reciprocating electric motor vibratingV with true harmonic motion.

As heretofore set forth, there are two power units B and C and Veach of `these units contains identical parts, the arrangement'being such that electric current in any given instant flows oppositely throughthe vibratorswith respect4 to the magnetism in the respective units. Thus the mechanical movements of the vibrating elements are always in opposite directions and by having identical units B and C the power impulses are exactly equal in the opposite directions. This arrangement places the device in balance and eliminates vibration of the machine asa whole.

My invention may be embodied in Yvarious specic constructions dependingfupon the V'character of the work to be performed by the device, but I will now describe more vin detail a preferred construction as illustratedin the drawings.`

The piston I 0 has a longitudinal passageway 25 extending completely through Vthe same ,commu- V'gio the housing I2 for this purpose.

ing portion 46 of the cylinder Il.

Vprovided with a central aperture 4I and is arranged in its entirety within the compressionV nicating at the outer end with the chamber 26 formed within the cap 21. The chamber 26 is in open communication with the sump 28 in the base A, there being a radial port opening 29V in At the inner end of the hollow piston I Vthere is a disk valve 30 which seats against the end face 3l of the piston.

The disk 3U is preferably of polygonal shape andV of a size to t within the f cylinder II and be guided` thereby. The flat portions 32 of the disk provide the necessary clearance for permitting the escape of uid past the valve.Y The valve is assembled to the piston by. means of a link V33 fastened at one end to the center of the disk valve and at the other end to a pin V34 in the piston. The link forms a lost motion connection which, as shown, is due to the looping of the link over the pin with a slight clearance.` The cylinder II is formed with an end shoulder 35 against which a diskV Valve 36 normally rests. This valve as shown has an out-turned annular ange 3'! for guiding the valve spring 38 which in turn is held in position by the cap 39 threaded to the project- The cap is Y p chamber D.

V30 with a Venturi portion 42.

' in'cornmunication withthe downwardly extend-V The central passage 25 in the piston is provided radial bores 43 leading outwardly from thethroat of the venturi to an annular recess 44 on the outer surfaces of the piston. VThis recess is at all times ing passage 45 in the housing from which a'tube 46 leads to the bottom of the sump 28. 41 represents the inlet port to the sump and 48 represents the outlet from the compression chamber D. As shown, this chamber has radial flanges 49 for dissipating the heat'of compression.

The compressor may be used with any suitable medium but where it is to be used for a refriger- Y Vating apparatus afdesirable refrigerant is methyl chloride.

The inlet 41 isconnected to the low pressure side of the refrigerating apparatus and the outlet 48 to the high pressure side. The methyl chloride and lubricant are returned to the sump 28 through the inlet 41 and the lubricant settles tothe bottom of the Vsump while the `Y methyl chloride gas fills the balance of the sump and circulates into each of the units B and C through the radial passages 29, annular recesses I3Y and outer chambers 26. During the reciprocation of the piston I8 the gas inthe cylinder II between the valves 3|! and 36 is compressed by the inward movement of the piston and escapes into theY compressionV chamber D. YIn the outward stroke of the piston the gas is drawn through the Y3l! into the space between said valve and the check valve 36. The aspirating effect of the venturi causes lubricantto be drawn into the venturi from the sump 28 and mixwith the refrigerant. Thus the reciprocation of the piston I0 builds up a pressure within the chamber D.

Figure 4 shows an electrical diagram of the preferred circuits in which50 represents a transformer having a primaryl adapted to operate on'theV ordinary linevoltage such, for example, as 110 volts 60 cycle A. C. The secondary 52 of the transformer is adapted to deliver'the desired voltage for any particular construction and in the example illustrated is wound to deliver 62/3 volts. The Vibrator coils 28h and 29o arey connected in series with the secondary 52 while the center tap 54 of the transformer is grounded and. connected The piston also has intermediate the coils 20b and 20c. In order to obtain a constant magnetic eld for the field coils I6b and |60 a rectifier 55 is connected to the sec Y ondary and this in turn is connected through the coils I6b and |6c to the grounded center tap 54 in such a wayA as to produce opposite magnetic effects. Y

For convenience in passing the current through the coils 20 of the apparatus illustrated in Figure 1 the cap 21 of each power unit is connected to but insulated from the housing I5.: 'Ihis is accomplished by inserting insulation 56 between the Vflanges 51 and 58 which in turn arersecured tothat the outer casing I2 has a conical inner suri face 6I in which is seated the correspondingly shaped end of the core I4. The cylinder. II has an annular flange 62 thereon adapted to abut` the outer face of the housing ,I 2 and has a threadi ed portion'63 for-engaging theV core I4, thus clamping the core and housing together and forming a composite structure. The cuter end of the core I4 is provided with a series of slots 64 for receiving the arms 65 of the spider 2I. This Yspider has a Vhub 66 secured to the outer end of the piston 25 and clamped against a shoulder 61 by the clamping nut 68 threaded on the piston. The spider arms are connected by a continuous ring 69 forming an abutment for the inward end of the conducting coil 10. YThis coil preferably consists of a continuous helix of copper or other suitable conductor, the leaves of which are substantially rectangular in cross section. Between the adjacent convolutions of the helical conductor are inserted steel washers 1I split on one radius to permit following the contour of the helix. These washers are insulated from the copper helix by identical washers Y12 made of insulating material, the steel and insulating washers having an inner diameter such as to bear Von the edges of the spider arms. In order to secure the helix and intermediate washers in one compact Yunit a series of bolts 13 (preferably three in number as shown) are inserted through coincident perforaf tions Vin 'the convolutions. Each bolt 'is insulated from the convolutions byran insulating tube v16. The head 14 of the bolt is inserted in a recess in the flange 69 and insulated therefrom by a suitable washer 15. 11 is a clamping ring to which the bolts 13 are threadedly secured, thereby clamping the helix and intermediate washers into a compact unit. The ring has an annular flange 18 projecting into the inner end of the coil spring 22. It will be observed that the helical coil has one end thereof electrically contacting with the clamping ring 11 and the other electrically contacting with the flange 69 of the spider member. The electric circuit is from the cap 21 through coil spring 22,7clamplng ring 11, helical coil 19, flange 69 and coil spring 23 to the housing I2 which acts as a ground and is suitably connected to the grounded center tap ofthe secondary coil of the transformer. Thus the coil springspserve not only to introduce the required resiliency to mechanically tune the apparatus to the frequency of the alternations but also serve to conduct the alternating current to the reciprocating helical coil 1D. The springs 22 and 23 are always under compression so as to be always held by continuous compression against the insulated surface 21 and the grounded surface of the frame l2 so as to have sufficient pressure to complete the electric circuit through the springs 22 and 23 and the helical conductor 10 at all times. These springs therefore always have non-reversible stresses. In other words, these springs are never subjected to a reverse stress when the device is in operation.

From the foregoing description it will be observed that I have provided an improved form of harmonic compressor which is entirely free from rotating parts and is operable from an ordinary alternating current supply line. While I have described the apparatus in considerable detail, it is to be understood that the invention is capable of being embodied in various other forms.

What I claim as my invention is:

l. 'Ihe combination of a magnetic field element, an element in the field for carrying alternating current, one of said elements being fixed and the other being movable with respect thereto, an oppositely acting alternating current supply of predetermined frequency connected to the second element and constituting the sole actuating current of the device and resilient means interposed between said movable amd fixed elements at separated po-ints and having a predetermined resiliency adapted to impart to said movable element a natural period of vibration corresponding to th frequency of the alternating current.

2. The combination of a magnetic field element, an element in the iield for carrying alternating current, one of said elements being xed and the other being movable with respect thereto, an oppositely acting alternating current supply of predetermined frequency connected to the second element and resilient means interposed between said movable and fixed elements at separated points and having a predetermined resiliency adapted to impart to said movable element a natural period of vibration corresponding to the frequency of the alternating current and a compressor mechanically connected to said movable element.

3. An alternating current electrically operated pumping apparatus comprising a cylinder, a piston reciprocable therein, valves for feeding uid to said cylinder, a helical coil coaxial with said piston, means for passing an alternating current of predetermined frequency through said coil, means for producing a substantially constant magnetic field around said coil and means mechanically connected to said coil for producing a predetermined resiliency adapted to impart to said movable element a natural period of vibration corresponding to the frequency of the alternating current.

4. An alternating current electrically operated pumping apparatus comprising a magnetic housing having an annular gap, a helical coil mounted for reciprocation v'ithin said annular gap, means for energizing said coil with alternating current of predetermined frequency, a coaxial piston connected to said coil to reciprocate therewith, a cylinder for said piston, springs on opposite sides of said coil, the mass of said reciprocating parts being so proportioned with respect to the resiliency of said springs as to impart a natural period of vibration corresponding to the frequency of the alternating current.

5. Electrically operated pumping apparatus comprising a pair of coaxial reciprocating compressors, and separate means for electrically reciprocating the respective compressors always in opposite directions.

6. Electrically operated pumping apparatus comprising a pair of coaxial reciprocating compressors, resilient means connected to each of said compressors adapted to impart thereto a predetermined natural vibration period, and electrical means for urging the respective compressors always in opposite directions in synchronism with said natural vibration period.

7. In an apparatus of the class described, outer and inner magnetic pole pieces having an annular gap therebetween, a vibrator mounted for reciprocation in said annular gap comprising a helical conductor, and magnetic members interposed between the adjacent convolutions of said helical conductor.

8. Electrically operated pumping apparatus comprising a compression chamber, a pair of coaxial cylinders communicating with said compression chamber, pistons in each of said cylinders, an annular vibrator connected to each of said pistons, a magnetic housing surrounding each cylinder and having an annular gap embracing said vibrator, a magnetizing coil for the magnetic housing, resilient means connected to opposite ends of said vibrator and adapted to impart a natural vibration period to said vibrator corresponding to the frequency of alternating current, an electric coil in said vibrator and means for passing alternating current through said coil, the helical coil being so disposed with respect to the magnetic field in the corresponding magnetic housing that each of said vibrators is urged always in the opposite direction from the other vibrator.

9. Electrically operated pumping apparatus, comprising two coaxially reciprocating compressor members of substantially equal mass, separate means for simultaneously reciprocating them in opposite directions at substantially the same speed.

10. Electrically operated pumping apparatus comprising two coaxially reciprocating compressor members, separate actuating means for reciprocating them in opposite directions at substantially the same speed, and a compression chamber located intermediate the compressor members actuating means into which the material acted upon is discharged by the compressor members.

11. Electrically operated pumping apparatus comprising a reciprocating pumping element, electric means for reciprocating said pumping element, a spring associated with said reciprocating pumping element for elastically resisting the reciprocating movement of said element, said spring being under compression Vat all times during the reciprocation of said pumping element, so that it is never subjected to reverse stress when the apparatus is in operation.

12. Electrically operated pumping apparatus comprising a reciprocating pumping element, electric means for reciprocating said pumping element, a spring associated with said reciprocating pumping element for elastically resisting the reciprocating movement of said element, means for preventing a reversal of stress in said spring when the apparatus is in operation.

JAMES B. REPLOGLE.

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