US3572975A

US3572975A - Motor compressor resiliently suspended in a case

Info

Publication number: US3572975A
Application number: US819699A
Authority: US
Inventors: Knud V Valbjorn; Bendt Wegge Romer; Bent Melchior Karlsen Holme
Original assignee: Danfoss AS
Current assignee: Danfoss AS
Priority date: 1968-04-27
Filing date: 1969-04-28
Publication date: 1971-03-30
Anticipated expiration: 1988-03-30
Also published as: DE1751259A1; ES366509A1; FR2007115A1; SE352930B; GB1248654A

Abstract

The invention relates to a motor compressor assembly of the type used for small refrigeration machines. The assembly has an outer casing in which a motor compressor unit is suspended by springs. The springs are of the spirally wound type and are disposed, in vertical planes, between the motor compressor unit and the casing.

Description

United States Patent Inventors Appl. No.

Filed Patented Assignee Priority Knud V. Valbjorn Augustenbord;

Bendt Wegge Romer, Nordborg; Bent Melchior Karlsen Holme, Humbaek Pr. Skovby, Denmark Apr. 28, 1969 Mar. 30, 1971 Danfoss A/S Nordborg, Denmark Apr. 27, 1968 Germany MOTOR COMPRESSOR RESILIENTLY [51] Int. Cl F04b 39/00 [50] Field ofSearch 230/235, 232,139, 58; 248/20, 15; 417/363 [56] References Cited UNITED STATES PATENTS 3,182,902 5/1965 Foris 230/235 3,385,542 5/1968 Enemark et al 248/20 Primary Examiner-Robert M. Walker AttorneyWayne B. Easton ABSTRACT: The invention relates to a motor compressor assembly of the type used for small refrigeration machines. The assembly has an outer casing in which a motor compressor R L 2" C38]; unit is suspended by springs. The springs are of the spirally 8 Clalms rawmg wound type and are disposed, in vertical planes, between the US. Cl 417/363 motor compressor unit and the casing.

Patented March 30, 1971 2 Sheets-Sheet 2 EUMPERESSOR RESHJMNTLY SUSllENDlED IN A CASE The invention relates to a motor compressor, particularly for a small refrigerating machine, which compressor is resiliently suspended in a case and has a vertical shaft and spirally wound springs of strip material the ends of which are connected to the motor compressor or the wall of the case and a middle hole in which is fitted over a stud on one of the two parts.

An encased small refrigerating machine is known wherein the spirally wound springs are horizontally disposed, so that their axes extend parallel with the shaft. Secured to the underside of the carrier member are square-headed bolts which engage in the middle hole in the springs, each of these holes being formed by the inside turn being bent to quadratic form. The square-headed bolts are each secured by a lock nut. The outside turn of each spring is extended in a straight line and is screwed onto a retaining tab welded onto the case. With this construction, assembly is difficult since each spring requires two screwed connections and the free end of the spring already attached to the other component is difficult to fit to the associated holding means. Furthermore, difficulties arise as regards the design of the spring: in the peripheral direction of the motor compressor a fairly high degree of resilience is required in order to take up the starting torque in a proper manner. Since, however, the known springs have the same resilient property in the radial direction of the compressor, a relatively large amount of space is required between the com pressor and the wall of the case.

A system is also known wherein the motor compressor is supported by several radially disposed helical springs wound to the shape of a cone. With the help of a special tool, one end-face of such springs is screwed into a complementary thread on the carrier member for the motor, while an appropriateiy shaped turn at the other end-face is sprung into a retaining means, For them to be sufficiently rigid, these springs have to be titted under considerable pretension and this results in further difficulties in assembly.

The object of the invention is to provide a spring suspension means, the resilient properties of which meet all requirements and which can be fitted in a simple manner.

in an above-described motor compressor, this object is achieved by the plane of the helical springs being vertical, the stud being horizontally disposed and the outside turn of the spring being pressed by the force of gravity into a channelshaped holding means corresponding to the shape of this outside turn.

in this construction, the springs are simply mounted on their studs and titted onto one of the components. The two components are then laid one upon the other. This ensures that the springs, held on their studs, pass in a precise manner into the channel-shaped holding means. Conversely, the springs are held in these holding means in such a way that they can no longer slide off their studs. This method of'fitting does not involve any great trouble; it can even be carried out without the use of a tool.

Relatively great rigidity can be imparted to the springs in a direction running roughly radially to the shaft of the motor compressor by appropriate choice of the thickness and width of the spring strip. Conversely, the properties of the springs may be quite different in the peripheral direction, these properties being determined by the use of an appropriate number of turns.

The simplest arrangement is that wherein the holding means is curved and corresponds approximately to a semicircle. A spring of strip material wound in the normal manner can then be used. Moreover, the holding means can be obtained by means of a simple milling operation.

in a preferred embodiment, the holding means is provided on the motor compressor. During assembly the springs are then pushed onto the studs on the case, and the motor compressor is simply suspended therefrom.

in the simplest case, the stud may be cylindrical. in order to hold the spring in the required position and to clamp it more firmly when under load, the cylindrical stud can be flattened on that side opposite the holding means and the inside turn of the spring matched to this flattened portion.

If at least three springs are provided at the three corners of a triangle and their axes extend towards the inside of the triangle, a strong system is obtained for damping movements of the motor compressor in the radially outward direction, and a somewhat softer damping effect is achieved in the case of movement in the peripheral directionzAn optimum damping action is achieved at minimum expense and trouble.

in a further feature of the invention, a carrier supporting the stud and a component fitted with a holding means can together form cooperating transfer lugs. In this construction, no additional components are required for the normal transport lugs. The components can, for example, incorporate an arcuate lug surface which straddles, at a distance, a similarly shaped lug surface on the carrier. This arrangement provides lugs for movement of the motor compressor in both peripheral directions and in the vertical direction.

in another form, the component may have a projection which is held at a distance by a horizontal and a vertical tab on the carrier. When the motor compressor moves in the vertical direction, the projection moves into contact with the horizontal tab and when the compressor moves in a peripheral direction it comes into contact with the vertical tab.

A particularly simple construction results if the component takes the form of extensions of the casting constituting the carrier member for the motor.

The invention will now be described in more detail by reference to an embodiment illustrated in the drawing, wherein:

FIG. 1 is a side view, partly in section, of an encased small refrigerating machine in accordance with the invention,

P16. 2 is a schematic illustration showing a plan view of the machine of FIG. 1, the upper half of the case being removed,

FIG. 3 is a side view of the carrier, and

FIG. 3 shows a section on the line A-A of HG. l.

A motor compressor 4 is resiliently suspended in a case 1, consisting of a lower shell 2 and an upper shell 3. The compressor consists of a motor 5, fitted at the bottom, and a compressor ti disposed at the top, motor and compressor being interconnected by a common carrier member 7. A vertical motor shaft 8 drives the compressor. A cylinder head 9 is connected to a noise-reducing means ll). Further details, such as connecting pipes, oil filling etc. are not. shown for the sake of greater clarity.

The carrier member has three attachments ll, 12 and 13. Associated with these are three carriers lid, l5 and lb welded onto the lower shell 2 of the casing. Between each pair extends a vertical spring l7, lit and i9 of strip material wound to the shape of a helix. As indicated by the arrow l, the middle points of the helical springs form a triangle, the three axes running towards the inside of the triangle. The means for attaching the springs is the same in all three cases. Each carrier has a stud 20, which is flattened on its underside 2i. Each attachment has a semicircular channel 252. The inside turn 23 of the helical spring is angled and lies around the stud 2i and the outside turn 24 of the spring is received in the channel 22.

For purposes of assembly, the three springs merely have to be pushed on to the associated studs. The motor compressor 4 can then be inserted from the top, whereby it lies by the channel 2.2 on the outside turns of the springs.

The attachments l2 and l3 have projections 25. The carriers l5 and is each have a horizontal tab 26 and a vertical tab 27 at a distance from studs 20, as shown more clearly in FIG. 3. The two

tabs

26 and 27, together with the projection 25 form transfer lugs which limit vertical and peripheral movement of the motor compressor d.

As shown in FM. 4, the attachment it has an arcuate lug surface 28 which straddles a similarly shaped lug surface 29 on the carrier M. This again provides a transfer lug which limits vertical and peripheral movement of the motor compressor We claim:

3. A motor compressor assembly for a refrigerating machine comprising a casing unit, a motor compressor unit having a vertical shaft, a suspension assembly including a horizontally extending stud on one of said units and a generally semicircular channel on the other of said units said suspension assembly including a spiral spring having a rectangular cross section nominally equal in width to the width of said channel and being wound in a generally vertical plane, said spring being mounted on said stud in generally concentric relation thereto and being fitted in said channel so as to be transversely restrained by the sides of said channel.

2. A motor compressor assembly according to claim 1 in which said stud is attached to said casing unit.

3. A motor assembly according to claim 1 including a plurality of suspension assemblies like said suspension assembly.

4. A motor compressor assembly according to claim 1 in which said stud has a flattened side on the side thereof opposite said semicircular channel, said spring having its inner end flattened to engage with and conform to said flattened side on said stud.

5. A motor compressor assembly according to claim 1 including at least three suspension assemblies like said susperb sion assembly, said suspensions being at the'comers of a polygon with their axes extending towards the interior of the polygon.

6. A motor compressor assembly according to claim 1 including a carrier upon which said stud is mounted, first lug means on said carrier, second lug means on the other of said units, said first and second lug means cooperating to form transfer lugs.

i. A motor compressor assembly according to claim 6 including spaced apart arcuate surfaces on said first and second lug means with one of said lug means being straddled by the other of said lug means;

8. A motor compressor assembly according to claim 6 wherein each of said lug means has horizontal and vertical spaced relation to each other.

Claims

1. A motor compressor assembly for a refrigerating machine comprising a casing unit, a motor compressor unit having a vertical shaft, a suspension assembly including a horizontally extending stud on one of said units and a generally semicircular channel on the other of said units said suspension assembly including a spiral spring having a rectangular cross section nominally equal in width to the width of said channel and being wound in a generally vertical plane, said spring being mounted on said stud in generally concentric relation thereto and being fitted in said channel so as to be transversely restrained by the sides of said channel.

5. A motor compressor assembly according to claim 1 including at least three suspension assemblies like said suspension assembly, said suspensions being at the corners of a polygon with their axes extending towards the interior of the polygon.

7. A motor compressor assembly according to claim 6 including spaced apart arcuate surfaces on said first and second lug means with one of said lug means being straddled by the other of said lug means.

8. A motor compressor assembly according to claim 6 wherein each of said lug means has horizontal and vertical abutment surfaces, said abutment surfaces being in respective spaced relation to each other.