Vibration isolation for a transversely mounted compressor

BACKGROUND OF THE INVENTION

A hermetic compressor, such as that in a window room air conditioner, is conventionally contained within a generally cylindrical shell secured in some fashion to the unit housing and connected to other elements in the system through a suction and a discharge line. The axis of the shell, the motor rotor and stator, and the portion of the shaft carrying the rotor are all, nominally, coaxial. If the compressor is vertically oriented, the center of gravity would tend to be quite close to the axis of the shell. The forces produced by the motor and pump structure during operation of the compressor will tend to cause rotational movement of the shell which will tend to produce movement through the suction and discharge lines.

If the compressor is placed in a horizontal orientation, the oil sump will shift from a position centered on the axis of the shell to the side of the shell and at a distance which is a significant percentage of the shell radius. So, the location of the center of gravity will be changed as well as the direction in which it acts. U.S. Pat. No. 5,810,322 discloses a horizontal compressor which is secured at its bottom to one leg of each of two L-shaped brackets and is integral therewith. The other legs of the two L-shaped brackets are secured to a support through a pin and grommet. Thus, the entire support of the integral L-shaped brackets and compressor is through the pins which are, nominally, aligned with the axis of the compressor. The L-shaped brackets can serve as linkages relative to the exertion of forces produced during operation of the compressor and the support provided by the pins. The pins are rectangular, as is the pin socket, so as to resist rotation.

U.S. Pat. No. 6,132,183 discloses a vertical compressor and a number of mounting configurations. In each configuration most, if not all, of the weight is supported by a vibration isolator. Torsion isolation is provided through a plurality of torsion isolators which are located radially with respect to the axis of the compressor shell.

SUMMARY OF THE INVENTION

A pin located as close as practical to the center of gravity extends radially downward from the shell of a horizontally mounted compressor. The radial pin is received in an isolator which supports most of the weight of the compressor. The bottom isolator is suitably supported and/or secured to the base pan of the room air conditioner. Pins extend from each end of the shell as close as is practical to the axis of the compressor shell and are supported by isolators secured in suitable supports. The compressor may be located in a shell-type enclosure which supports the isolators while providing sound insulation.

It is an object of this invention to eliminate the need for a compressor baseplate and its accompanying sound emission.

It is another object of this invention to facilitate grommet installation.

It is a further object of this invention to reduce grommet failure. These objects, and others as will become apparent hereinafter, are accomplished by the present invention.

Basically, a horizontally mounted compressor is supported from below by a vibration isolator located as close as practical to the vertical projection of the center of gravity of the compressor and this isolator supports most, if not all, of the weight of the compressor. The ends of the compressor are supported by isolators located as close as practical to the axis of the compressor.

BRIEF DESCRIPTION OF THE DRAWINGS

For a fuller understanding of the present invention, reference should now be made to the following detailed description thereof taken in conjunction with the accompanying drawings wherein:

FIG. 1

is a side view of a compressor mounted according to the teachings of the present invention;

FIG. 2

is a partially sectioned view of a portion of

FIG. 1

;

FIG. 3

is a sectional view of a modified grommet;

FIG. 4

is an exploded view of the bottom mounting structure;

FIG. 5

is an exploded view of a modified end mounting structure;

FIG. 6

is an exploded view of a modified mounting arrangement;

FIG. 7

is a partially sectioned view of a compressor supported by the mounting arrangement of

FIG. 6

;

FIG. 8

is a partial view of an alternative attachment structure for the

FIG. 6

embodiment;

FIG. 9

is an exploded view of a second alternative bottom mounting structure; and

FIG. 10

is a partially sectioned view of a third alternative bottom mounting structure.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

In

FIGS. 1 and 2

, the numeral

10

generally designates a window room air conditioner of which only compressor

12

and base pan

14

are illustrated. Compressor

12

will have suction and discharge lines connected thereto as well as an electrical supply connection and these will be specific to the design of air conditioner

10

and will dictate the specifics of where compressor

12

can be supported. Their illustration would only complicate an understanding of the present invention. Referring to

FIGS. 1 and 2

, vibration isolator

30

is located beneath compressor

12

and is received in bore

16

-

1

of isolator mounting

16

which is illustrated as a separate member suitably secured to base pan

14

but may be integral with base pan

14

. Pin, or stud,

12

-

1

is secured to compressor

12

and extends radially downward from compressor

12

. Pin

12

-

1

is snugly received in bore

30

-

1

of vibration isolator

30

. The location of pin

12

-

1

and of its supporting isolator

30

should be as close as possible to the vertical projection of the center of gravity of compressor

12

. The maximum deviation from the vertical projection should never exceed 25% of the axial length of compressor

12

. Vibration isolator

30

supports most, if not all, of the weight of compressor

12

. Referring to

FIG. 3

, vibration isolator

130

is illustrated which may be used in place of vibration isolator

30

. Vibration isolator

130

differs from vibration isolator

30

in that it has a throat

130

-

1

rather than a uniform bore

30

-

1

. Vibration isolator

130

has a relatively high stiffness in the vertical direction and a much lower stiffness in the transverse directions to ensure a sufficiently low natural frequency for the torsional mode. The different stiffnesses are due to the fact that in vertical support the isolators

30

and

130

are essentially an annular cylinder whereas only throat

130

-

1

of isolator

130

coacts with pin

12

-

1

in the transverse directions but the entire bore

30

-

1

which is coextensive with pin

12

-

1

coacts therewith. As a result of only throat

130

-

1

of isolator

130

coacting with pin

12

-

1

, the throat

130

-

1

can act as a fulcrum relative to pin

12

-

1

thereby permitting some transverse movement of compressor

12

.

Compressor

12

is supported at its ends by vibration isolators

32

which are smaller than vibration isolators

30

and

130

and are supported by brackets

20

and

21

. Other than being of a larger size, vibration isolator

130

of

FIG. 3

illustrates an alternative to isolator

32

. Pins, or studs,

12

-

2

and

12

-

3

extend in axial directions from respective ends of compressor

12

. Preferably pins

12

-

2

and

12

-

3

are coaxial and located along the axis A—A of compressor

12

. The location of compressor structure which is not illustrated will dictate the location of pins

12

-

2

and

12

-

3

as well as their support brackets

20

and

21

. The displacement of pins

12

-

2

and

12

-

3

from the axis A—A of compressor

12

should be as small as practical but no more than 66% of the radius of the shell of compressor

12

. Pins

12

-

2

and

12

-

3

are received in identical vibration isolators

32

which are received in and supported by brackets

20

and

21

, respectively. Isolators

32

have a much lower stiffness in all directions than isolators

30

and

130

. Isolators

32

may have a uniform bore

32

-

1

, as illustrated, or may have a throat portion corresponding to throat

130

-

1

of vibration isolator

130

. If pins

12

-

2

and

12

-

3

are coaxial, brackets

20

and

21

will be identical. If pins

12

-

2

and

12

-

3

are not coaxial, the brackets

20

and

21

will differ so as to accommodate the different distances between pins

12

-

2

and

12

-

3

and the base pan

14

and any interfering structure (not illustrated) but will otherwise be the same.

FIG. 4

illustrates an isolator mounting

114

-

1

which is integral with base pan

114

. Mounting

114

-

1

has a bore

114

-la which receives vibration isolator

130

. Pin

12

-

1

of compressor

12

is received in throat

130

-

1

of vibration isolator

130

.

Referring now to

FIG. 5

which is specific to pin

12

-

3

and bracket

121

but which will also apply to pin

12

-

2

and its corresponding bracket (not illustrated), pin

12

-

3

is received in isolator

32

. Isolator

32

is, in turn, received in and supported by bracket

121

. Bracket

121

has a semi-cylindrical recess portion

121

-

1

preferably extending at least 180° for receiving isolator

32

and an end wall portion

121

-

2

for limiting axial movement of isolator

32

and thereby compressor

12

. Cover

123

coacts with bracket

121

to hold isolator

32

in place. Bracket

121

is integral with or suitably secured to base pan

214

. Isolators

32

may have a uniform bore

32

-

1

, as illustrated, or may have a throat portion corresponding to throat

130

-

1

of vibration isolator

130

.

In operation, the rotation of the rotor, crankshaft and pump structure within the shell of compressor

12

tends to produce a rotary motion of compressor

12

about axis A—A. If pins

12

-

2

and

12

-

3

are coaxial, the motion will tend to be about their common axis and within isolators

32

. If pins

12

-

2

and

12

-

3

are not coaxial, the specific geometry of the pins and forces will tend to produce rotary movement of one pin with respect to the other and a tendency to move the one of isolators

32

associated with the rotary movement of one pin. Pin

12

-

1

coacting with isolator

30

or

130

tends to resist all rotary and axial movement of compressor

12

. As noted above, the resistance to rotary and axial movement will be greater for isolator

30

then for isolator

130

. Because isolator

30

or

130

supports most of the weight of compressor

12

, the deformation of isolator

30

or

130

tends to cause pin

12

-

1

to be more securely gripped thereby enhancing resistance to axial and rotary movement of pin

12

-

1

and thereby compressor

12

.

Referring to

FIGS. 6 and 7

, a shell-type of enclosure

40

can be employed to support compressor

12

on base pan

14

and permit the elimination of brackets

20

,

21

and

121

while attenuating sound radiation. Enclosure

40

is made up of an upper half

41

and a lower half

42

. The openings in enclosure

40

for the suction and discharge lines and the electrical supply connection have not been illustrated since they will be specific to the compressor. Lower half

42

has a radially extending collar

42

-

1

at its bottom for receiving isolator

30

which, in turn, receives pin

12

-

1

of compressor

12

. Half tube portions

42

-

2

and

42

-

3

are formed at each end of lower half

42

for receiving isolators

32

. The outer ends of tube portions

42

-

2

and

42

-

3

define wall portions

42

-

2

a

and

42

-

3

a

, respectively, which keep isolators

32

axially in place. Half tube portions

41

-

1

and

41

-

2

are formed at each end of upper half

41

and coact with half tube portions

42

-

2

and

42

-

3

, respectively, for keeping isolators

32

axially and radially in place. The location of collar

42

-

1

and half tubes

41

-

1

,

41

-

2

,

42

-

2

, and

42

-

3

will depend upon the location of pins

12

-

1

,

12

-

2

and

12

-

3

as in the embodiments of

FIGS. 1-4

. Lower half

42

of enclosure

40

is supported by legs

43

and

44

which can be integral with half

42

and suitably secured to base pan

14

, may be integral with base pan

14

, or may be separate pieces secured to base pan

14

. Legs

43

and

44

will be located in accordance with the room available for a specific compressor design. While two legs,

43

and

44

, are illustrated, one or three or more legs may also be used where necessary, or desired. Upper half

41

and lower half

42

of enclosure

40

are held together by clamps

46

, bolts

47

and nuts

48

with clamps

46

encircling half tube portions

41

-

1

and

42

-

3

as well as

41

-

2

and

42

-

3

.

Referring specifically to

FIG. 7

, compressor

12

is illustrated within enclosure

40

. Insulation

50

is located within enclosure

40

and surrounding compressor

12

. The use of insulation

50

is optional, but preferred, since it reduces sound transmission. If the space between enclosure

40

and compressor

12

is filled with insulation, the insulation will resist movement of compressor

12

and the attendant sound generation.

FIG. 8

illustrates attachment structure which is integral with the enclosure

140

and replaces clamp

46

, bolt

47

and nut

48

. Enclosure

140

includes an upper half

141

having a tab

141

-

1

with an opening

141

-

2

therein. Lower half

142

of enclosure

140

has a projection

142

-

1

which is received in opening

141

-

2

to secure halves

141

and

142

together. Structure corresponding to tab

141

-

1

, opening

141

-

2

and projection

142

-

1

will also be located at the other ends (not illustrated) of halves

141

and

142

.

In the embodiments of

FIGS. 1

,

2

,

4

,

6

and

7

most, if not all, of the weight of the compressor

12

is supported by vibration isolator

30

or

130

. However, it is only the weight of compressor

12

acting on vibration isolator

30

or

130

. If necessary, or desired, the vibration isolator located beneath the compressor may be subjected to compressive or tensile forces in addition to those forces supplied by the weight of the compressor acting on the vibration isolator.

In

FIG. 9

, compressor

112

has a nut

112

-

1

or corresponding structure suitably secured thereto or integral therewith at a location corresponding to a radially downward direction when compressor

112

is in place in a room air conditioner or the like. Pins

118

and

119

are coaxial and axially separated and extend from vibration isolator

230

with threaded portion

118

-

1

being threaded into nut

112

-

1

and threaded portion

119

-

1

passing through bore

314

-

1

in base pan

314

and has nut

148

threaded thereon. Unlike other embodiments, vibration isolator

230

is not circumferentially supported. The tightening of nut

148

on threaded portion

119

-

1

will draw vibration isolator

230

and compressor

12

towards base pan

314

. This permits vibration isolator

230

to be placed in tension even though it is being acted on by the weight of compressor

112

and this results in a greater resistance to movement of compressor

112

and a corresponding reduction in noise generation.

The embodiment of

FIG. 10

is a combination of the embodiments of

FIGS. 4 and 9

. As in the case of the

FIG. 4

embodiment, pin

212

-

1

is secured to compressor

212

and isolator mounting

414

-

1

is integral with base pan

414

. As in the case of the

FIG. 9

embodiment, pin

212

-

1

has a threaded portion

212

-

1

a

which extends through bore

414

-

1

b

and is received in nut

248

. Vibration isolator

30

is received in bore

414

-

1

a

. Pin

212

-

1

serially extends through bore

30

-

1

in isolator

30

, bore

414

-

1

b

in base pan

414

, bore

34

-

1

in neoprene washer

34

into nut

248

. The tightening of nut

248

on threaded portion

212

-

1

a draws compressor

212

towards base pan

414

and can squeeze vibration isolator

30

more than would be due to just the weight of compressor

212

acting on vibration isolator

30

. The clearance between pin

212

-

1

and bore

414

-

1

b

and the placing of resilient material washer

34

between base pan

414

and nut

248

eliminates any metal to metal path between compressor

212

and base pan

414

.

From the foregoing it should be clear that the present invention teaches the supporting of a compressor by three isolation mounts which have or receive pins therein. The isolation mounts are made of neoprene or other suitable elastomeric materials. One of the vibration mounts is located beneath the compressor and supports most, if not all of the weight of the compressor and, in some embodiments is further compressed, or placed in tension, by tightening a nut. A pin extends from each end of the compressor. Ideally the axis of the compressor and that of the pins would be coaxial. Realistically, the axes will be parallel but as close as possible to being coaxial with the compressor. To the extent that the pins are not coaxial, the support structure will be modified to accommodate the different locations relative to the base pan but the basic structure supporting the pin at each end of a compressor will be the same.

Although preferred embodiments of the present invention have been illustrated and described, other changes will occur to those skilled in the art. It is therefore intended that the scope of the present invention is to be limited only by the scope of the appended claims.