Патент USA US2405474код для вставки
Aug. 6, 1946. ‘ T. c. VAN DEGRIFT ' BALANCING MACHINE Filed Nov. 27, 1942 _ 2,405,474 , I I 2 Sheets-“Sheet 1 3a ' Summon: Aug- 65 1946- 'rQc. VAN DEGRIF‘T 2,405,474 BALANCING MACHINE Filed Nov. 27, 1942 513 2 Sheets-Sheet 2 Patented Aug. 6, 1946 v 2,405,474 fUNlTiED ' STATES ‘ PATENT OFFICE ‘ r 72,405,474 . > . , - - Thomas (3..' Van BALANCING Degrift, Detroit, Mich, a'SSignOr to General Motors Corporation, Detroit, Mich“ a corporation of Delaware ~ Application November 27, 1942, Serial No. 467,113 -11 Claims. (cilia-.66) .27 1 l This invention relates to ‘balancing means and more‘speci?cally'to means for dynamically bal ancing, a rotating part at substantially the speed at which it will normally operate in service; ter of the‘top cross membersB'and Ill are‘sup ported'a pair of 'spaced'?e'xible leaf spring mem bers ‘l2 ‘and I6 ‘on'e'ach side. These resilient leaf . spring ’ members » extend "down I to. approxi Dynamic forces applied to a rotating body occa sion ‘various vibrations which cannot be antici ' mately the ‘center offithe'framefformed IbyIthe side members and-support upon their lower-‘ends an open bearing member'IB, the upper surface ofv which is‘grooved to form a substantiallysemi circular portion ‘20,1'into which‘ may be insertedv the ends of ‘a ‘cradle assemblyiincluding the'p'ort pated by statically balancing the device and it is therefore necessary in many instances and espe ciallywhere the rotative speedis high to care fullybalance bodies dynamically so that they maycoperatesatisfactorily and ‘not be subject to vibrations-set up'by dynamic forces therein. tobe-tested. ’ This assemblyicomprises a pair of It’ is therefore an’ objectof my invention to . provide a- means for dynamically balancing a rotating part. I side plates formed of aiseries of radiating arms‘ 22 which extendoutwardly from a center hollow’ hub 24 which is cylindrical and has upon its 15 outerf'end -'a smaller cylindrical member 26. 'The .It is a further object of; my invention to pro vide an assembly of driving means and a part to ends of‘ the radiating arms ‘22 are connected'to be dynamically balanced, which maybe easily ber byspacing connecting means‘ 28. 'This 'as inserted into supporting means. sembly' therefore'forms a'hollowdrum-like frame I V _, thelopposite frame arms on the other side mem It is a still ‘further object of my invention 20 into which maybe inserted ‘the device to be to provide a‘resiliently mounted supporting "as sembly into which a previously assembled driv in the transverse members'28 to lift one frame ing and driven means may be easily inserted. member from the other. It is a still further object of my invention to tested simply ‘by removing'the securingfme'ans ' ' ' ‘ ' “Fixedly secured to one‘ of the central "cylin-e provide a balancing machine for rotative parts drical members 24 is a motor ?eld stator winding which is simple and rugged in construction. With these and other objects in view which will become apparent as the speci?cation pro 3!] capableof creating a rotating ?eldiwhen‘ener gized. The cylindrical ‘members 26 each carry adjacent their ends where they enlarge into' the portions 24 a’bearin'g member 32 which is adapted ceeds, the embodiments ‘of my invention will‘ be best understood by reference to the following 30 to support the shaft '34 ‘of a rotor 36 to be tested speci?cation and claims and the illustrations ‘in which has laminations vin the manner of conven-' the accompanying drawings, in which: _' tional squirrel cage induction rotors. The end Figure 1 is a vertical section taken through a‘ of the rotor ‘shaft projects into the hollow space machine embodying my invention; ' Figure 2 isan enlarged detail sectional view taken on line 2-2 of Figure 1; Figure 3 is an end view of the angular index ing device; _ . ‘ Figure 4 is an end view of ‘the mechanism taken on line 4-4 of Figure 1, parts being broken away and shown in section; “ ' Figure 5 is a schematic wiring diagram of the indicating means associated with the vbalancing machine; ' Figure 6 is‘a schematic circuit diagram show ing the 'pick-p-up unit connected to the indicating left in'the cylindrical'portion 26 in each instance 35 and on one end ‘has‘forced thereover a‘press-e ?tted coupling "38 'which'isj supported upon a transverse shaft 4!],‘th'e latter being trunnioned in bearing '42 carried by upright'M on the base‘ 2. On ‘the opposite side of the bearing“ a disc 40 46' is ‘applied to the shaft and is" adapted to rotate therewith. This disc ‘is formed of insu lating material'and at- one po-rtion'adjacent ‘its periphery-carries an axial pin 1580f conductive material. Also ‘mounted ‘on the ‘upright 44 is '-an electromagnetic coil 50 having a U-shaped core‘terminating in two projecting pins‘52 and means; and 54 which extend toward each other leaving an air gap therebetween' in which the disc 46 ‘and axial pin '48‘ rotate. Thus once each revolution’ of 50 the shaft " the pin 48 ‘will lie normally between Referring vnow -more specifically to' Figure 1, the members 52 and 54 and decrease ‘the reluc there is “shownltherein a base 2 upon which is tance of the'magnetic circuit to cause the coil mounted a pairiofvertical frame ‘members 4 and as to ‘provide-an impulseand in this manner 6 :which; are connected.‘ together : by horizontal give an angular impuise or index-for the rotating ' Figure’T-is-"a detailed sectional view showing a different (type of vibration condenser pick-up means. top _ V ‘ ,Ymembersj and-rill; Adjacent the ‘Gen-a member ‘ ' 2,405,474 3 .There is provided a small pin 56 which is an chored in the lower portion ofthe cradle mem ber 18 and which projects through an opening 58 in the cylindrical portion 28 of the frame to prevent the frame per se from turning. Thus on an application of power to the stator wind ing 38' through the terminals 68 the rotor 35 may be ‘caused to rbtate about‘its axis ,on its , shaft SQ-in'bearin'gs "32'which rotation‘will also 4 two frequencies are the same and by knowing the frequency of the oscillator the rotative speed of the test part will be known. An adjustable capacitor 88 is provided to vary the frequency of the known oscillator. In order to ascertain the amplitude of the vibrations which are picked up by the condenser pick-upmeans ‘formed of the1 two plates 12-456, the latter ‘are connected'by lines 98' andv 92 with cause the shaft 49 and index disc 46 to rotate, 10 the vertical displacement circuit of the oscillo the remaining portion of the frame being held > graph and therefore as the capacity varies be ‘ tween these plates the potential across the ver stationary by pins 55. As the rotor rotates at tical oscillograph plates will vary and cause ver its given speed, if there are forces of unbalance tical displacement of the cathode beam to give which are brought into play by such rotation, the members I8 supported on the resilient‘stri'ps i2; 15 1a direct reading of‘ the amplitude of these hori and IE will be caused to move in a horizontal ‘ " 7zontal vibrations. —' I' have thus provided a means plane by such force. 1_ h. _;> '3 -, . In order to pick up this vibration, I have pro forimpressing a potential indication of the am plitude of said vibrations and also an angular in dexing means to determine the angular position vided a bracket 62 which extends from the'side frame members 4 or 6 and which supports upon 20 of the maximum vibration forces since the num ber~of;;angular degrees from the starting poin its outerend a hollowcylindrical casing 64 with: can;;be?guredfromlthe oscillograph. -; _» _- _ in onezend'of which :is insulatedly; mounted a -~-Referring to ‘Figure 7, there is therein shown disc‘S? connected by a suitable line 68 with indie a modi?ed pick-up form inwhich a stud-94 is eating apparatus to be described. , The oppositev end of the cylindrical casing 64 Jmovably supports 25. threaded intoi'one side‘ of the cradle member !8 and carries an insulating washer 96 and a a rod'lll upon one end of which is secured a smaller insulating washer 98. Mounted between second spaced-disc 12 which is brought into jux these two insulating parts and having an-open taposition with the ?rst disc 66. This rod also ing Hi0 therethrough of larger diameter than carries a small disc 14 between which and a por tion of the casing there‘ is mounted a concentric 30 the'stud is a resilient lever or bar I02 which is ?rmly clamped to the stud but insulated there‘ spring 16 to spring bias the rod outwardly. The from. The projectingend of the .bar carries a end of- this rod is brought into ‘juxtaposition and weight Hi4 which projects to within a short dis bears against a face of the cradle member 18 tance of a member I06 connected to the cradle and is therefore moved back and forth by any 58. A conductor I08 is connected tov one end of horizontal vibration thereof. . This movement the member V102 and a second conductor H0 is thus alters the distance between the two discs connecteddirectly to the stud and therefore to 12 and 66 which form a condenser and therefore the remainder of the apparatus; Upon vibration varies the capacity of-the same to give‘ indica the weight 104 will therefore move back and tions. One of these 'units is provided adjacent forth relative to the member I06 and the capacity each bearing member. In order to maintain the thereby formed will be varied in much the same hearing or :cradle member against‘the end of the manner. as the capacity pick-up formerly de rod ‘H! a spring 18 is provided which has one scribed. However, this construction is consider end secured to the cradle member and the oppo ably simpler and in some instances it maybe site end adjustably secured to the frame through desirable to use this instead of the former de thumbscrew 80.‘ ‘ ~ ' ’ ’ .4 In operating the balancing machine therefore the two frame members ‘are taken apart, the stator winding 39 remaining secured to one and the ‘rotor to be tested is inserted with one end of vice. . Its function in the system would however be the same. I claim: . - a - > V - . 1., In a machine for balancing rotating parts, its shaft in bearing 32 on the frame member car 50 a base, a pair of spaced open bearing members resiliently mounted on. the base,’ a. driving stator rying the stator. The other frame member is‘ ?eld assembly for. supporting a driven rotor to then applied, the other end of the rotor shaft extending through the second-bearing 32 and the spacing means 28 is secured at the'ends of 'arms be .tested adapted to be slung in the bearing members, and pickup means mounted on the base 22. This assembly is then laid in the'open bear ings [8, the pins 56 preventing the assembly from, turning. The coupling 38 is pressed onto the end of the rotor shaft to drive the angular indexing adjacent each bearing member’, having a‘ por tion extending into contact therewith to pick up the Vibration of the bearing member due to ‘the means and the-condenser pick-up means are then - 2.;In a machine-for‘balancing'a~rotating part, of course remain stationary indicating that the tially semi-cylindrical groove in the bearing mem rotation of the rotor. r ' - adjusted so that the spring-biased rods ‘I0 con 60 a base, a plurality of spaced uprights mounted'on the base, a pair of resilient strips supported from tact the cradle members I8. The machine is the uprights on each side, an open bearing mem then in readinessfor testing the rotor. ber secured to the lower end of each pair of The ‘disc 45 and its associated electromagnet 59 strips, a cradle mounted in the open- bearing provides the angular index, the latter being con members, astator driving ?eld supported by the nected through line 82 with an oscillograph 84 cradle, said rotating part being rotatably sup and is so connected as to trigger the horizontal ported in juxtaposition to and driven by the sweep circuit of the same so that at the instant stator on the cradle and vibration pick-up means the pins 48 passes between the pins 52 and 54 mounted on the base and contacting the bear the sweep circuit is'caused to start, thus giving this point as the beginning of the wave on the 70 ing members. 3. In a machine for balancing rotating part oscillograph. In order to ascertain the speed, an a'base, a plurality of spaced upright supports, oscillator of known frequency 86 may be con a pair of spaced bearing members resiliently nected to the oscillograph and when the two fre supported from said upright supports, a substan quencies coincide the wave appearing thereon will 5 2,405,474 6 bers, cradle means to enclose and rotatably sup port a part to be balanced comprising a pair of side members having radial arms detachably tested, means for securing the ends of the arms together in de?nite spaced relation, a driving stator ?eld winding rigidly mounted within the enclosure formed by the spaced cradle members in juxtaposition to the rotor to rotate the same, said hollow cylindrical cradle portions being non rotatably mounted in the resiliently mounted connected together at their outer ends and cen tral hollow shafts, which latter shafts are trun nioned in the spaced bearing members, and means for locking the shafts against rotation in the bearing members. bearing members, and angular indexing means 4. In a machine for balancing rotating parts, secured to and driven by the rotor shaft. a base, a plurality of spaced upright supports, 10 8. In a machine for balancing rotating parts, a pair of spaced bearing members resiliently sup resiliently mounted spaced aligned bearing mem ported from said upright supports, a substan bers, spaced cradle members comprising hollow tially semi-cylindrical groove in the bearing mem cylindrical central portions and radially extend bers, cradle means comprising a pair of spaced ing arms for rotatably supporting a rotor to be separable side members having radial arms con 15 tested, means for securing the ends of the arms nected together at their outer ends and central together in de?nite spaced relation, a driving hollow shafts for rotatably Supporting a rotat stator ?eld winding rigidly mounted within the able part to be balanced having shafts, said cradle enclosure formed by the spaced cradle members shafts being trunnioned in the spaced bearing in juxtaposition to the rotor to rotate the same, members, means for locking the cradle shafts 20 said hollow cylindrical cradle portions being non against rotation in the bearing members, a driv rotatably mounted in the resiliently mounted ing stator coil ?xedly mounted within the cradle bearing members, a transfer shaft connected to in juxtaposition to the rotatable part, a trans the rotor shaft and means for generating an fer shaft coupled to the rotor shaft, and angular . electric pulse once per revolution connected to indexing means driven by the transfer shaft. 25 and driven by said shaft. 5. In a machine for balancing rotating parts, 9. In a balancing machine for balancing ro a base, a plurality of spaced upright supports, tating parts, a supporting frame, a plurality of a pair of spaced bearing members resiliently spaced aligned open bearing members resiliently supported from said upright supports, a substan slung from the frame, a driving stator ?eld as tially semi-cylindrical groove in the bearing sembly for mounting a driven rotor to be bal members, cradle means comprising a pair of anced supported in the bearing members, and spaced separable side members having radial means whose electrical capacity will be changed arms connected together at their outer ends and by relative movement between parts thereof central hollow shafts for rotatably supporting a mounted adjacenteach bearing member and sub rotatable part to be balanced having shafts, said 35 ject to the vibrations thereof caused by the rota cradle shafts being trunnioned in the spaced tion of the rotor. , bearing members, means for locking the cradle 10. In a balancing machine for balancing ro shafts against rotation in the bearing members, tating parts, a supporting frame, a plurality of a driving stator coil ?xedly mounted within the spaced aligned open bearing members resiliently cradle in juxtaposition to the rotatable part, a 40 slung from the‘frame, a driving stator ?eld as transfer shaft coupled to the rotor shaft, angular sembly for mounting a driven rotor to be bal indexing means driven by the transfer shaft, said . anced supported in the bearing members, a plate angular indexing means comprising a disc ?xed mounted in insulated relation with respect to to the transfer shaft, a pin carried by the periph the frame, a second spaced plate mounted in ery of said disc and magnetic means mounted contact with the open bearing members whereby adjacent the disc periphery whose ?eld is altered ‘ a condenser is formed by the two plates and vi by the passing of the pin to give an angular index bration of the bearing members due to rotation point. ' 6. In a machine for balancing rotating parts, resiliently/mounted spaced aligned bearing mem bers, spaced cradle members comprising hollow cylindrical central portions and radially extend ing arms for rotatably supporting a rotor to be tested, means for securing the ends of the arms together in de?nite spaced relation, a driving sta tor ?eld winding rigidly mounted within the en closure formed by the spaced cradle members in juxtaposition to the rotor to rotate the same, said hollow cylindrical cradle portions being non-ro tatably mounted in the resiliently mounted bear ing members. 7. In a machine for balancing rotating parts, resiliently mounted spaced aligned bearing mem bers, spaced cradle members comprising hollow cylindrical central portions and radially extend ing arms for rotatably supporting a rotor to be of the rotor will cause capacity variation and provide an indication of such vibration. 50 11. In a balancing machine for balancing r0 tating parts, a supporting frame, a plurality of spaced aligned open bearing members resiliently slung from the frame, a driving stator ?eld as sembly for mounting a driven rotor to be bal 55 anced supported in the bearing members, an arm projecting from each open bearing member, a stud threaded into the bearing members, a ?ex ible arm insulatably mounted on each stud, a weight on each ?exible arm projecting in juxta 60 position to the ?rst named arms and forming an electrical condenser therewith whereby vibration, . of each bearing member will cause relative move- ' ment between the arms and therefore capacity change to indicate vibration caused by rotation 65 of the rotor. ' \ THOMAS C. VAN DEGRIF'I‘.