US3169737A

US3169737A - Vibration isolation system

Info

Publication number: US3169737A
Application number: US214388A
Authority: US
Inventors: David S Wilson
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 1962-08-02
Filing date: 1962-08-02
Publication date: 1965-02-16
Anticipated expiration: 1982-02-16

Description

Feb. 16, 1965 D. 5. WILSON 3,169,737

VIBRATION ISGLATION SYSTEM Filed Aug. 2, 1962 2 Sheets-Sheet l INVENTOR.

DAVID s. WILSON.

BWJ7%W ATTORNEY.

Feb. 16, 1965 D. 5. WILSON 3,169,737

VIBRATION ISOLATION SYSTEM 2 Sheets-Sheet 2 Filed Aug. 2, 1962 FIG. 2

INVENTOR.

DAVID s. wlLsou.

ATTORNEY.

United States Patent 3,1695 37 RATEON ESOLA'HON SYSTEM David S. Wilson, East yracuse, N.Y., assignor to Carrier Corporation, Syracuse, N.Y., a corporation of Delaware Filed Aug. 2, 1962, Ser. N 214,388 1 Claim. (U. 243-18) The invention relates to an air conditioning unit and particularly to a means for mounting the fan and motor assembly within the unit.

Conventional air conditioning apparatus is by its very nature a source of noise and vibration. The primary sources of noise and vibration emanating from air conditioning apparatus include the fan or fans, the drive motor or motors therefor and the compressor and its drive motor. Since the air conditioning apparatus or a portion thereof may be within the enclosure being conditioned, noise and vibration attributable to the air conditioning apparatus, particularly noise and vibration emanating from that portion located within the confines of the enclosure, is objectionable and hence is to be avoided or isolated in so far as practicable.

For purposes of description, an air conditioning unit may be divided into a condenser section and an evaporator section. In an air-to-air type of unit, the condenser section communicates with the out-of-doors either through physical placement outside or by means of suitable duct work. The evaporator section communicates with the enclosure being conditioned either through physical placeinent therein or by means of suitable duct work. In this type of unit both the condenser section and the evaporator section rely on the circulation of air for their operation and accordingly both sections normally are provided with a fan. A suitable power means, for example, a motor and a suitable drive means between the motor and fan, for example, a belt and pulley arrangement, are provided to within the confines of the enclosure or, if not within,

, communicating therewith by suitable duct Work which it is understood may transmit noises originating in the evaporator section into the enclosure, the evaporator fan and drive motor therefor are 'of particular concern as a source of noise and vibration. V

Heretofore, the evaporator fan has been driven by a relatively low speed four-pole electric motor rigidly attached to the air conditioning unit structure within the evaporator section. A typical four-pole motor speed is 1,750 rpm. Recent practice, however, employs a twopole electric motor operating at approximately twice the rpm. of the heretofore mentioned four-pole motor, typically 3,500 r.p.m., to drive the evaporator fan. As in the case of the four-pole motor, a rigid attachment of the two-pole motor to the air conditioning unit structure is provided.

' Vibration resulting from unbalance in the rotating parts of the evaporator fan motor and the drive between the motor and fan, heretofore not particularly significant at the relatively low speed of the four-pole motor, is magnified by the doubled rotational speed of the two-pole motor. This vibration, now at a higher frequency, more closely approaches the natural resonance of the various structural parts and panels of the air conditioning unit. As may be understood, panels of a given area are more efficient noise radiators at higher frequencies resulting in an increased noise level. An increase in the number of resonating parts and panels increases the noiselevel. The-noise itself is more disturbing because of the sensitivity of the human ear'to higher frequency noises. Further, because of the rigid attachment of the evaporator fan motorto the unit, vibration originating in the motor and drive may be transmitted in varying degrees to other ilfihflli? Patented Feb. 16, 1965 ice parts of the air conditioning unit with deleterious effects. Particularly susceptible to vibration induced fatigue are the various refrigerant piping connections. 1

With these considerations in mind, it is a principal 5 object of this invention to provide an improved means for supporting a fan assembly in an air conditioning unit.

It is a further object of this invention to provide a novel mounting structure for the fan assembly of an air conditioning unit effective to resiliently yet accurately position the fan assembly in operative relationship with respect to the unit.

It is an additional object of this invention to provide a unique mounting structure effective to position the fan and motor assembly within an air conditioning unit so that vibrations emanating from the fan and motor assembly are absorbed to thereby prevent transfer thereof to the air conditioning unit.

This invention relates to an air conditioning'urlit including a housing, a compressor, a condenser section ineluding a fan, an evaporator section including a fan, the evaporator fan being rotatably mounted on an auxiliary frame, a drive motor on said auxiliary frame operatively connected to the evaporator fan, and means to position a plurality of mounting brackets fixedly attached to the enclosure and adapted to receive the mounting rods therethrough, a resilient spacer for each of the fan mounting brackets adapted to receive a mounting rod therethrough, one end of the spacerbeing adapted to abut its respective bracket, a spring adapted to surround a portion of each of said resilient spacers, one end of the spring abutting a portion of each spacer adjacent said one end thereof, a retaining member adapted to receive each of said mounting'rods therethrough and to abut the opposite end of each spring and an adjustable locking device on each of the mounting rods adapted to contact the opposite side of the retaining member to adjust spring tension.

The attached drawing illustrates'a preferrred emb0di merit of the present invention, in which:

FIGURE 1 is a plan View, partially in section, il-1ustrating an air conditioning unit embodying the present invention;

FIGURE 2 is a cross-section taken along line II-II of FIGURE 1 showing applicants novel mounting means; and

FIGURE 3 is an enlarged sectional view of applicants novel mounting structure. i t Referring to the drawings, numeral- 1 designates generally an air conditioning unit. Preferably, the unit comprises an indoor compartment 2 and an outdoor compartment 3 separated by a partition 4. Partition 4'is provided with 'a' suitable insulation 7 whereby indoor compartment '2 is thermally isolated from outdoor compartr'nent 3.. g I

Outdoor compartment 3 includes a compressor 8 positiond therein. A suitable motor 9 is provided therefor.

Outdoor'coils 11, 1-2 are positioned adjacent openings the openings 13, M across coils ll, 12. Theair ex hauststo the atmosphere through opening 21in the top panel'zd.

' The indoor compartment 2 includes an indoor coil 30- positioned adjacent opening 31 in end panel 32. A fan 7 described hereinafter.

a scroll 36 is fixedly positioned adjamnt coil 30 in the indoor compartment 2 by suitable means (not shown). A diffuser 37, rigidly attached to fan scroll 36, communicates with the area to be conditioned. A fan 35 is positioned within the scroll 36. A drive motor 39 is operatively connected to fan 35. The construction and mounting of fan 35 and. motor 39 will be more particularly Scroll 36 is provided with suitable inlets 40.

Air is drawn through opening 3-1 across the indoor coil 30 which serves to condition the air. The conditioned air then passes into inlets 40 of scroll 36. Fan 35 discharges the conditioned air through diffuser 37 into the area to be conditioned.

Diffuser 37 may communicate directly with the area to'be-conditioned or indirectly by means of suitable duct work. The'inlet opening 31 may communicate with the atmosphere whereby fresh air is introduced into the compartment 2 for conditioning or it may communicate with a the area conditioned either directly or by means of suitable duct work whereby air. from the area conditioned is'introduced into the compartment 2 for conditioning. Adjustable dampers (not shown) may be provided to permit va-rying mixtures of indoor and outdoor air to be introduced into inlet opening 31 for conditioning.

Coils 11, 12 and Slland compressor 8 are operatively A suitable expansion device is included in the refrigerant circuit.

If the unit 1 functions to cool the area to tioned, indoor coil 30 serves as the evaporator and outdoor coils 11, 12 serve as the condenser. If the unit 1 functions to heat the area to be conditioned, indoor coil 30 serves as the condenser and outdoor coils 11, 12 serves as the evaporator. Motors 9, 19 and 3-9 are suitablyconn'ected to a source of electric power. Suitable controls for the unit 1 are also provided.

Fan 35 and drive motor 39 therefor are includedrin subassernbly 34 attached to diffuser 37 and partition 4 within the indoor compartment 2 ina manner to' be more fully explained; In the embodiment shown, fan 35 includes two

fans

45 and 46 fixed to a common drive shatt,47. As may be understood, fan 35 may comprise one or more fans. 47 are rotatably supported in bearings 49, 50 fixedly attached to the

sidemembers

51, 52 respectively ofan auxiliary or sub-frame 55. .lnfthe embodiment shown, the auxiliary frame 55 is generally. U-shaped with a base member 56 rigidly attached to the

aforementioned side members

51, 52 to, iormthe U-shape. Itis understood that auxiliary frame 55 may be of any desired configuration, for example,

' V trapezoidal. Brace members 59 are fixedly attached between each of the

side members

51, 52 respectively and the base member 56.

;A motor base plate 61 having fan motor 39 rigidly attached thereto is provided. Pivot means 620m each Q side of the rnotor base plate filcooperate with brace be condi- 7 connected to provide a closed circuit for a suitable refrigerant.

mentof the tension of belt 71. A suitable threaded looking means, for example, a'nut (not shown) is adapted to. cooperate with the threaded portion of bolt 67 to fixedly position bolt 67 relative to slotted support member 65 whereby an adjusted belt tension may be main: tained.

In order to position the subassembly 34- within the unit, mounting rods 75 are suitably fixed to the auxiliary frame 55 at each of the corners thereof. Ends 90 of rods 75 are suitably threaded. Mounting brackets or

plates

74, 76 are provided. Brackets 74 are fixedly attached by suitable means (not shown) to the outside casing of diffuser 37. As noted heretofore,dilfuser 37 is rigidly'attached to fan scroll 36; The fart scroll and diffuser unit, is rigidly positioned within indoor compartment 2 by suitable means (not shown); Brackets 76 are similarly fixedly attached to partition 4 of en closure 1. Mounting

brackets

74, 76 are each provided with a cylindrical boss or protuberance'95, theend of which is open at 77. Mounting rods 75 are adapted to extend through openings 77 whereby the sub-frame V 55 may be positioned withinthe enclosure 1.

Referring particularly to FIGURE 3 of the drawings, resilient spacers 80 each having a centralbore 81 therethrough adaptedto receive rods 75 are provided. Spacers 8th may be composed of rubber or other suitable resilient material. .Acylindrical recess 84 is provided in one end 79 of each of the spacers Stl. Spacers Stlmay be of a generally cylindrical construction having a stepped portion 92 of a radius slightly greater than the main portion 93. A second stepped portion 94 including the end 79 The opposite ends of drive shaft adjoins-stepped portion 92 and is of a greater radius. The surface 83 between the stepped

portions

92, 94 constitutes an abutment or land against which one end of spring 85 bears. As may be understood, end 79 of resilient spacers Btlis adapted to abut its

respective'mounting plate

74 or 76, cylindrical recess 84- receiving the mounting plate protuberance 95. The'resilient portion of spacer 8% between surface83 and end 79 provides high frequency vibration isolation. a a V A spring 85 adapted to surround each resilient spacer 80' is provided. One end of spring 85 abuts surface 83 of spacer 8i). Retaining member 86 having a hole 87 therein adaptedto receive mounting rod 75' abuts the 1 compartment '2 to fixed diffuser 37 and partition 4 by inserting mounting rods 75 into holes 77 of

brackets

74, 76. -Resilient spacers 80 are .nextplaced oneach of the mounting rods 75 so that'the end 79 of each spacer abuts its'respective mounting

bracket

74, 76; As noted the 1 protuberance 95 of each of the brackets 74;, 76 is remember 59 and auxiliary support 68 to pivotally'mou'nt motor base plate 61 on the auxiliary supporting frame 55. support member is pivotally attachedto brace memberf59 so as to exte'nd outwardlytherefrom A slot 66 is provided in the remote end of supportmember 65. .A bolt 67 slidably receivable in the slot 66 is attached to the edge ofplate 6-1 remote from the aforesaid pivotal attachment, The portion of bolt 67 extending beyond slot 66is suitably-threaded. p

The'shaft of motor 39'is'provided with a pulley 69 fixedly attached thereto. A cooperating pulley 'is fixed on fan shat-t 47. Belt 71 drivingly'interconnects the motor pulley 69 with the shaft pulley 70.

It is'understood that the pivotal mounting of motor" plate 6 1on auxiliary frame 55 permits adjustment of the center to center distance between the motor pulley ceived in the cylindrical recess 84 of its respective spacer to thereby locate and position spacer 8i). Spring is positioned over each'spacer 80 so that one end thereof 1 the fan scroll 36.

' tain-ing member 86 with spacer 80. a

Springs 85 are selected to 'providea proper degree of static deflection. The amount of static deflection'selected' is unusually large, .for example, approximately one-half inch, This large amount of'initialjstaticfdeflection permits applicants unique mounting toi-a-bsorb all but the very lowest vibrational frequenciesof the subassem-bly 34.;

As rnaybe" understood; excessive displacements of the suhassemblyGd are absorbed through contact of the r.

That portion of spacer 80' between eachspring 85 and its respectivemounting bracket 74-, 75 prevents metal 'to' e 3 metal contact between each bracket and its respective spring and provides high frequency vibration isolation. The spacer also prevents metal to metal contact between each mounting rod 75 and its

respective bracket

74, 76. Thus, noise due to relative movement between the bracket and spring and between the mounting rod and the bracket is eliminated.

Resilient spacers 80 are located against lateral movement through the cooperation of mounting plate protuberance 95 with cylindrical recess 84. The cooperation of bore 81 of resilient spacer 80 with its respective mounting rod 75 limits lateral movement of the subassembly 34 relative to the indoor compartment 2. As may be noted in the drawings, the bore 81 of each resilient spacer 80 is of slightly larger diameter than its respective mounting rod 75 so as to provide a clearance therebetween,

This clearance between bore 81 and its respective mounting rod 75 permits relative movement between the resilient spacer 30 and the rod 75 in a vertical direction but limits lateral movement of mounting rod 75 relative to the resilient spacer.

It may also be noted that the resiliency or strength of the various springs 85 may vary dependent upon the weight supported by each spring in order that all mounting points have the same degree of deflection to insure movement of the fan and motor subassembly in a single plane. Movement of the subassembly 34 in a single plane,

unit in an air conditioning apparatus housing comprising a rod-like member secured to said fan and motor unit, a plate-like bracket having a generally cylindrical outwardly projecting bracket part and an opening therethrough secured to said air conditioning apparatus housing, said bracket opening being coaxial with said projecting bracket part and dimensioned to permit free movement of said rod-like member therethrough, a generally cylindrical resilient member engaging said bracket, the 10 portion of said resilient member engaging said bracket having a generally cylindrical recess for snugly receiving said bracket projecting part to inhibit lateral movement between said resilient member and said bracket, said resilient member having an opening therethrough coaxial with said recess and dimensioned to permit free movement of said rod-like member therethrough, said cylindrical resilient member having a first stepped portion and a second stepped portion spaced therefrom, the second stepped portion being adjacent the bracket and having an 2 outer dimension greater than the outer dimension of the first stepped portion, the portion of the resilient member between said first and second stepped portions forming an abutment, a spring around said resilient member first stepped portion in engagement with resilient member abutment, and adjustable connecting means between said rodlike member and said spring for selectively controlling the dampening response of said support.

that is a direction perpendicular to the axis of the fan scroll 36 obviates the possibility of contact between the revolving

fans

45, 46 and the stationary scroll 36. Lateral movement of the subassembly 34 is restricted through the cooperation of openings 81 in resilient spacers with rigid mounting rods 75. It is appreciated that the resilient spacers 80 are firmly positioned against lateral movement through contact of bracket protuberance with spacer recess 84.

\Vhile I hate described a preferred embodiment of the present invention, it will be understood that the invention is not limited thereto since it may be otherwise embodied within the scope of the following claims.

I claim:

A support for resiliently positioning a fan and motor References Cited by the Examiner ROBERTA. OLEARY, Primary Exmninen. WILLIAM J. WYE, Examiner.