US2351878A - Controlling means - Google Patents

Description

June 20, 1944. s. ss 2,351,878

CONTROLLING MEANS Filed April 26, 1941 INVENTOR M A. M

Patented June20, 1944 Philip S. Russel,

corporation of Mic Detroit, their, assignor to Detroit Lubricator Company,

higan Detroit, Mich., a

Application April 26, 1941, Serial No. 390,473 11 Claims. (Cl. 230-114) This invention relates to novel means for controlling the supply or feeding of a fluid medium and which among other uses is particularly useful in connection with fuel burning apparatus.

One object is to provide novel means for actuating the controlling means.

Another object is to provide a new and novel means for regulating the output of the fluid supplying means.

Another object is to provide means; whereby the output regulating means is actuated by the.

fluid supplying means.

Another object is to provide novel nieans for a fan inlet damper. Another object is to provide in a fan having an inlet damper, an automatic means to allow convection air flow through the fan housing upon control .-failure of predetermined air supply of the fan.

Another object is to provide a multi-speed motor operable to propel a fan at multi-speeds and to actuate a damper upon change of voltage to the fan driving motor. I I

Another object is to provide a fuel burning apparatus in which means is provided to supply combustion air at substantially constant rates in accordance with'the rates of fuel supply to the burner and in which provision is made for convection air flow upon failure of the air supply means.

Another object is to provide a means for maintaining a substantially constant reduced volume of air deliveryto a fuel burning apparatus irrespective of natural variations in the combustion chamber pressure.

Another object is to provide a means for supplying air at either of two substantially constant rates to a fuel burner irrespective of natural changes in absolute combustion chamber pressure within the fuel burning apparatus.

This invention consists in the improved construction of and combination of parts, to be more fully described hereinafter and the novelty of which will be particularly pointed out and distinctly claimed.

In the accompanying drawing, to be taken as a part of this specification, there is fully and clearly illustrated a preferred embodiment of the invention, in which drawing:

Figure 1 is a partial view of an oil burning apparatus embodying the invention;

Fig. 2 is a view partly in elevation and partly in central vertical section means of Fig. 1 showing the invention;

Fig. 3 is a view similar to Fig. 2 but showing the parts in a second position, and

of the air supplyin to the portion I3 as by means of failure of the means casing or'housing 1 Fig. 4 is a partial view showing a modified form of damper.

Referring to the drawing by characters of reference, the numeral I represents generally a constant level fuel supplying means such as that shown, described and claimed in a copending application of Walter S. Landon and Philip S. Russel, Serial No. 368,367, filed October 29, 1940 for Control apparatus. The means I has its outlet connected by means of a conduit 2 to the inlet pipe 3 leading to the fuel burning apparatus 4 which preferably is of the well known pot or hydroxylation type burner. Air is supplied to the apparatus 4 by a fan means generally designated 5 having secured to a wall thereof a safety switch 6 which is connected into the burner system (not shown) in a manner to place the system in pilot or low fire operation upon 5 to supply sufficient air.

The means 5 is shown in more detail in Figs. 2 and 3 and comprises the usual scroll shaped enclosing a centrifugal type An electric motor 9 is carried by the housing on one wall 9' thereof and is secured thereto as by means of bolts I 0. The motor 9 has a wound stator I I and a rotor I2 which is journaled in a bearing I2 of the motor 9. The rotor I2 has a portion I3 which profan or fan wheel 8.

jects through an aperture extending through the wall 9 and carries the fan 8 which is secured screws I4. The rotor I2 has a shaft portion I5 which extends through the bearing I2* and has adjacent its end portion a thrust washer it which is securely fastened thereto and which acts due to its engagement with an end wall I 6 of the bearing I! to limit longitudinal movement of the rotor I2 toward the right, see Figs. 2 and 3. A spring I! comprising a pair of leaf springs positioned at substantially right angles relative to each other have at their intersecting portion a hardened plate member I 8. A pin member I8 is received within a central aperture in the end wall of the shaft portion I5 and has a hardened spherical head portion which engages the plate member I8. The end portion of the leaf of spring I1 are bent to form curved surfaces whichengage the bottom wall of a cup shaped member I8 which is secured rigid with the motor 9. The spring I! is flexed nearly into a flat position so that movement of its curved end sur-- springs It will be Jacent the side wall of the member l8 so that they act to properly position the member l8 for engagement with the pin member l8. The spring |1 acts to urge the rotor |2 outward from the cup shaped member is and the washer l8 into engagement with the end wall It. The position of the washer II on the shaft portion I8 is such that upon engagement of the washer l8 and end wall I8 the rotor I2 is displaced a predetermined distance out of magnetic alignment with the stator II.

The casing 1 has a wall 28 which is opposite to and substantially. parallel to the wall 8*. The wall 28 has an aperture 2| in concentric and axial alignment with the rotor l2 and fan wheel 8 and which aperture 2| serves as the inlet for air to the casing 1 which has a tangentially extending outlet 22 secured to an inlet 28 of the fuel burning apparatus 4. damper 24 having a contour substantially corresponding to and having an area slightly less than that of the aperture 2| has a pair of perpendicularly extending tabs or ears 28. The tabs 28 have horizontally aligned apertures which are displaced from the plane of the damper 24 and receive a horizontally extending shaft 28 which is ionrnaled in apertures within tabs or ears 21 extending upward from a plate member 28. The member 28 is secured to the outer face of the wall 28 and has an aperture therethrough congruent with aperture 2|. The damper 24 is supported by the shaft 28 so that the lower area of the damper 24 is greater than the upper area so that a low pressure within the casing 1 will act to rotate the damper 24 toward closed position and into engagement with a stop member 28 carried by the wall 28.

noted that due to the displaced position of the damper 24 relative to its fulcrum or hinged point the damper 24 will swing toward. the position as shown by the dotted lines in Fig. 2. The upper area of the damper 24 is bent inwardly as at 88. to provide for a predetermined minimum flow opening to the fan means 8 and it also acts to balance the damper 24 toward the partially open position as shown by the dotted line position thereof in Fig. 2 to allow for natural draft flow of air through the casing 1.

The upper area of the damper 24 is slotted as at 8| so that the damper 24 will not be limited in its opening movement due to its engagement with an operating thrust rod 82 to be hereinafter more fully described. Adjacent the edge portions of the slot 8| are upstanding fingers 88 which are secured to the damper 24 above the rod or shaft 28 so that a thrust exerted thereon in a direction toward the wall l-will cause the damper 24 to be rotated in a counterclockwise direction, see Figs. 2 and 3.

The fingers 88 have aligned apertures through which is positioned a stub shaft 84. Secured to the shaft 84 and positioned between the nugers 88 is a rectangular shaped member 88 which extends downward therefrom toward the bottom of the slot 8|. The bottom of slot 8|, it is noted, is slightly below a straight line drawn between the apertures in the tabs 28. The shaft 28 has a downwardly extending-offset V-shaped portion 88 so that the shaft 28 will not obstruct the slot 8| and which also allows the damper 24 to be secured more positively to the shaft 28.

A tubular member 81 has one end portion secured to the rotor portion |8 with its axis concentric with the rotor l2. The other end A plate-like portion of the member 81 extends toward the wall 28 and has an apertured transverse wall 88 spaced from the end of the rotor portion l8. The rod 82 has a head or enlarged portion of suflicient size such that it will not pass through the aperture in wall 88 positioned within the member 81 and cooperates therewith to form a rotary slip connection. The rod 82 extends through the wall 88 and through the slot 8|. If desired, a suitable bearing material such as oil impregnated bronze maybe positioned with the member 81 and against the wall 88 to provide a more suitable bearing surface for the head portion of the rod 82. The end of the rod 82 which extends through the slot 8| is clamped in adjusted position to the rectangular member 88 by a screw 88. The wall 88 is positioned relative to the end wall of the rotor portion l8 so that during the periods when the fan 8 is not rotating, as for example, in case of failure of the source of electrical energy therefor and there is no appreciable difference in pressure between that within and without the casing 1, the head of the rod 82 will have suflicient movement prior to engagement with the end wall of the portion l8 to allow the damper 24 to rotate into the dotted line position of Fig. 2 to allow enough air to flow by natural draft through the casing 1 to support pilot fire combustion. The length of the rod 82 is so adjusted that during operation of the fan 8 by the motor 8 at reduced voltage, i. e. under the condition shown in Fig. 2, with the damper 24 against stop member 28, the head portion of the rod 82 will be substantially at but will not engage the wall 88 with any substantial force. With this adjustment of the rod 82 there will be substantially no frictional loss at reduced voltage motor operation due to a pull being exerted on the rod head portion by the wall 88.

In Fig. 2 a schematic simplified wiring diagram is shown. The numeral 48 represents generally a transformer having its primary coil 4| connected by lead wires 42 to a suitable source of electrical energy supply. The transformer 48 has a secondary coil 48 which has its end turns connected to terminal posts 44, 48 and has an intermediate tap leading to a terminal post 48. The terminal posts 48 and 48 are connected respectively to contact members 41, 48 of a single pole double throw switch 48 having a contact member 88 operable to engage either the member 41 or 48 but not both simultaneously. A lead wire 8| connects the contact member 88 to one terminal of the motor 8 and a lead wire 82 connects the other terminal of the motor 8 to .the terminal post 44.,

As. shown in Fig. 2, the motor 8 is being supplied with a reduced voltage which in the case of a motor having a volt 60 cycle electrical rating may be for example, 65 volts.. Under this 65 volt operation the spring |1 will maintain the rotor |2 displaced from alignment with the stator II as shown. In Fig. 3 the motor is being supplied with full rated voltage or in the instant ,case 110 volts. The rated voltage im pressed on the stator acts to draw the rotor |2 into alignment with the stator l| compressing the spring l1 and acting through the rod 82 to move the damper 24 to the position as shown in Fig. 3.

In Fig. 4 there is shown a modified form of the damper means arrangement in which form the numeral 88 designates a damper hinged to the wall 28 of thehousing 1 in a manner similarly to the damper 24.

. are, however, sufficient 24. Because the fan assure The damper 55 does not have its upper area bent inwardly but isall in one plane. Because there is no inwardly bent portion on the damper 55 the slot 3| may be omitted and the rectangular member 85 may be placed within an aperture (not shown) in a manner similar to the positioning of the member 35 within the lower end of the slot ll. A screw 58 damper 55 engages the stop member 29 upon closure of the damper I and acts to limit its closing movement thereby to determineits closed or restricted flow position and to regulate the rate of air supplied by the fan means 5. The damper I55 will operate in substantially the same manner as does the damper 24 and which will be presently described.

The operation of the device is as follows: Electrical energy is supplied to the transformer 40 through the lead wires 42. Assume that the contact members 48 and 50 are in engagement as shown in Fig. 2 and the motor 9 is being supplied with 65 volts. The 65 volts are not suflicient to move the rotor I2 into alignment with the stator ll against the force exerted by the spring I! but to insure positive rotation of the rotor l2 and are sufllcient to start rotation thereof from a standstill. The speed of rotation of the rotor l2 while being lower than the rotating speed when full voltage is supplied to the stator II is too great to provide the low air flow desired to the fuel burning apparatus 4 unless the inlet opening is restricted. Should the voltage to the motor 9 be reduced sufiiciently to provide the correct air fiow to the apparatus 4 with an inlet opening of the size necessary to supply high fine air, it would be necessary to reduce the voltage to such an extent that the motor 9 would not start from a standstill and would be subject to stalling. The rate of flow of air thr ugh the fan means 5 is restricted by the damper 24 to that which may be drawn through the slot 3| and through the space provided by the bent upper portion of the damper 8 has a relatively high available static pressure due to its speed of rotation the rate of air delivery to the combustion chamber is so slightly afiected by normal variation in chimney draft including negative draft as to make a burner of the class described practically independent of chimney draft.

Should the heat output from the apparatus 4 not be sufficient to supply the demand and an increased heat output is desired, the fuel supplying means I will be actuated to increase the rate of flow of fuel to the apparatus 4. The switch 49, which is a part of the means I as shown in said Landon and Russell application, Serial No. 363,367, wilrpart the contact members 48 and 50 and close contact members 41 and 50 to increase the voltage on the stator II to 110 volts or full rated voltage. stator H ,causes the rotor I 2 to be moved in a direction toward alignment with the stator ll compressing the spring l1. Movement of the rotor 12 toward alignment with the stator II will cause the end wall 38 to pull the rod 32 thereby rotating the damper 24 against the air pressure acting thereon and into the position shown in Fig. 3 to allow an increased air flow with less restriction to the fan means 5 so that proper air is supplied to the apparatus 4 to compensate for the increased fuel flow.

It may now be seen that there is provided a means for supplying air to a burner at two different rates of flow for two different rates of fuel threaded to the lower edge portion of the.

This increase in voltage on the flow. The rate of air flow in each instance will be maintained substantially constant irrespective of failure of of absolute throughout pressure within the apparatus 4 means 5 will act to allow a natural draft flow of air to the burner at a sufilcient rate for pilot or low fire operation.

What is claimed and desired to be secured by Letters Patent of the United States is: l

1. In a structure for supplying air under pressure, a housing having an inlet and an outlet, a fan positioned within and for propelling air through said housing, an electric motor associated with and for driving said fan and having a rotor and a stator, said rotor being magnetically movable axially of said stator, a pressure resaid lost-motion connecting means to move said damper means toward open position and against the air pressure force exerted on said damper means.

exerted on said said increased voltage is supplying air under presan inlet and an outlet, a

any normal range which might be caused by changes in stack draft. In the event the power to the motor 9 the fair to reduce restriction to 4 said rotor axially out of alignment with said stator, thrust means connected to said damper means, lost motion means connecting said thrust means and said rotor, said rotor being operable upon axial movement into alignment with said stator to move said damper means toward open position, and means to supply electrical energy to said motor, said supply means being operable to furnish said motor with a reduced electrical voltage for operation of said motor and with an increased electrical voltage for operation of said motor, said resilient means being of sufllcient strength to hold said rotor against axial movement into alignment with said stator and to hold said damper means against movement toward open position when said reduced voltage is being supplied to said motor, said resilient means exerting a suiliciently small force resisting axial movement of said rotor so that said rotor will be moved axially into substantial alignment with said stator and said damper means will be moved toward open position against the pressure force exerted on said damper means when said increased voltage is being supplied to said motor, said damper means being biased for movement toward open position and operable to move toward open position upon a predetermined reduction in pressure diilerence between that within said housing and that surrounding said housing flow through said inlet.

4. In an air supplying means tor an oil burning apparatus, a tan housing having an outlet communicable with the apparatus and having an inlet, a tan rotatable within said housing and operable to supply air ior combustion under pressure through said outlet to the apparatus, a motor for rotating said Ian, damper means controlling air flow to said fan through said inlet and having an open position to allow sufilcient combustion air flow for high fire operation of the apparatus, means'ior moving said damper means toward closed position for reduced flow of com-- bustion air to the apparatus for a low fire operation of the apparatus, and automatically acting means overcome by said closing means and operable upon failure of said fan to supply air to the apparatus to move said damper means to an open position intermediate said high fire opened position and closed position to allow natural draft flow of combustion air to the apparatus to maintain suiiicient air flow to the apparatus for said low fire operation.

5. In a fan control, a fan housing having an axial inlet and a tangential outlet, a tan wheel in said housing having its axis aligned with said inlet, a damper plate positioned in said inlet and horizontally pivoted, said plate having an inturned upper portion !or predetermined air admission, an electric motor having its armature axially displaced from magnetic alignment and axially aligned with said wheel axis, a thrust member having one end secured to said plate to pull said plate toward open position, and a rotary slip connection securing the other end or said thrust member to said armature so that said armature can rotate relative to said plate, said armature being movable into magnetic alignment upon energization thereby to move said plate toward open position.

6. In an apparatus oi the character described, a housing, an electrical motor having a stator and having an axially movable rotor, means urging said rotor out of magnetic alignment with said stator, said rotor being rotatable upon the application or a reduced voltage to said motor,

said urging means being operable to hold said rotor out magnetic alignment with said stator against the magnetic pull exerted by said stator at said reduced voltage, said rotor being rotated upon the application 0! increased voltage to said motor, said urging means being operable to allow movement 0! said rotor substantially into magnetic alignment with said stator under the influence oi the magnetic pull exerted by said stator at said increased voltage, fluid impelling means positioned within and operable to impel a fluid through said housing, iluid controlling means controlling the ilow oi fluid through said housing and responsive to fluid pressure, means supporting said controlling means for free automatic movement between an open and a closed position by changes of fluid pressure in said housing when said rotor is held out of magnetic alignment, and means to move said controlling means to a further opened position by the axial movement or said rotor relative to said stator.

7. In a structure for supplying air under pressure, a housing having an inlet and an outlet, a tan positioned within and for propelling air through said housing, an electric motor associated with and for driving said tan and having a rotor and a stator, a pressure responsive normally open damper means controlling flow through said inlet, force-exerting means urging said damper means to its normally open position, resilient means urging said rotor axially relative to said stator, means operatively connecting said rotor and said damper means for movement of said damper means toward open position upon magnetic axial movement of said rotor, and means to supply electrical energy to said motor at a reduced voltage to provide a smalldiiierentialoi air pressure, said supplying means being operable to supply electrical energy to said motor at a relatively increased voltage to provide an increased differential or air pressure, said resilient means being of sufllcient strength to hold said rotor against magnetic axial movement when the reduced voltage is supplied to said motor, said damper means being actuated by said small difterential or air pressure at said reduced voltage to overcome said force exerting means and to move to a flow restricting position, and said resilient means exerting a suiilciently small force resisting axial movement of said rotor so that said rotor will be magnetically moved axially to move said damper means toward open position against the increased differential of air pressure exerted on said damper means when said increased voltage is supplied to said motor.

8. An apparatus for supplying air under pressure, comprising a scroll fan housing having a side wall inlet and a tangential outlet, a blower wheel in said housing having its axis or rotation concentric with said inlet, an electric motor secured to said housing and having its rotor alined with and secured to said wheel, a pull rod extending through said wheel concentric with said inlet, a rotary bearing means securing said rod to said rotor for rotation 01 said rotor relative to said rod, a damper plate controlling flow of air through said inlet into said housing, said plate being formed for predetermined minimum iiow of air in the closed position of said plate, means eccentrically mounting said plate for movement 0! said plate toward closed position by diilerential of air pressures,-means securing said rod to said plate for movement of said plate toward open position upon inward movement of said rod, said rotor being axially movable in the motor stator by magnetic attraction, means resisting magnetic axial movement of said rotor below a predetermined voltage applied to said motor, said resisting means being overcome at a voltage above said predetermined voltage thereby to pull said rod inwardly by axial movement of said rotor, means operable to urge said plate toward open position upon stoppage of said wheel, and means providing lost motion for diflerential air pressure movement of said plate relative to said rotor.

9. A device for supplying air under pressure, comprising a housing having an inlet and an outlet, a fan positioned within and for propelling air through said housing, an electric motor for driving said fan at low speed and at a higher speed, fluid pressure responsive damper means controlling said inlet and movable by fluid pressure to restrict said inlet, means urging I said damper means toward open position and overcome by fluid pressure established by low speed operation of said fan, said motor having a rotor movable axially out or magnetic alignment with its stator, means holding said rotor out of magnetic alignment upon low speed operation of said fan, said holding means being overcome by the magnetic force resulting from the increased motor voltage required for the higher speed operation of said fan so that said rotor is moved axially toward magnetic alignment with its stator, and means operable by axial magnetic movement of said rotor to move said damper means toward open position against fluid pressure.

10. An apparatus for supplying air under pressure, comprising a fan housing, a fan in said housing, an electric motor carried by said housing and'having an axially movable rotor connected to said tan, a damper plate controlling 5 admission of air to said housing and eccentrically mounted for swinging movement by differential 01' air pressure, means operable upon stoppage or said fan to swing said plate to an open position, means to supply current to said motor to drive said fan so that said plate is moved by differential of air pressure toward a closed position from said open position, means operable to hold said rotor against axial movement upon operation of said motor, means to supply an increased current to said motor so that said rotor is moved axially against the force of said rotor holding means by the magnetic attraction of the motor stator, a rod operable to transmit axial movement of said rotor to said damper plate, and means connecting said rod to said plate at one side of the plate axis so' that axial movement of said rotor will swing said plate to an open position against the diflerential of air pressure on said plate. Y 11. In an air supplying apparatus, a motor having a casing and having a rotor and a stator, a fan housing having an opening throughwhich said rotor extends, means directly to said casing, a fan wheel laterally shiftable in said housing and secured to and supported by said rotor, said rotor being axially movable in said stator and into and out of magnetic alignment therewith, a spring in said casing and urging said rotor toward said housing and out of said magnetic alignment, a damper plate controlling the inlet of said housing, and a pull rod secured to said rotor and operatively coni neoted to said plate to pull said plate to open position upon movement of said rotor toward magnetic alignment with said stator.

PHILIP s. RUssEL.

securing said housing

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