Por d i f f e r e n t f i e l d s of application involving f i n e mechanics, see D I N Sheet 1 Section 4, Table I column 1 s p e c i f i e s a range. DIN Spur Gear Drives for Fine Mechanics; Tables. DIN Spur Gear Drives for Fine Mechanics; Indication in Drawings, Examples for Calculation.
|Published (Last):||20 March 2016|
|PDF File Size:||17.21 Mb|
|ePub File Size:||5.12 Mb|
|Price:||Free* [*Free Regsitration Required]|
They a r e intended t o serve t h e designer as a check l i s t of a l l the points which must be taken i n t o account when choosing a gear f i t.
This i s why permissible v a ri a t i o n s dinn r ein specified for the gear blank i n accordance w i t h the required qua l i t y of the tooth system. In this case the permissible radial eccentricity for the tip circle should be taken from Table 3.
For gears with V t e e t h t h e following apply: The centre distance a” can be s don t by placing ddin appropriate s l i p gauges between t he two mounting a rb o rs or the individual arbors. Permissible radial eccentricits for tip cylinder when this is n o t used for settinn UE Table 4 Permissible radial eccentricity f o r. I n t h e equations gear 2 is t h e master gear. For denomination of contact f aces and of the relevant qual i t y i ndi cessee Figure 1 and 2 ; f o r marking the d i f f e r e n t ear blank shapes, see reference regarding Sup, plementary Sheet 2 i n DIN Sheet I page The reference diameter to which the axial eccentricity is related is found as: The values specified relate to the bearing when inetalled.
The tolerances and allowances etated’in the following Tables apply to gears according to D M Sheet 1, Section 2. The cumulative error can be found by rolling the gear diin be tested with a master gear, f o r which purpose the total composite error of the master gear must be known and, 584005 necessary, deducted from the teet result.
For grades P 8 it is recommended 5805 the tip cylinder should be used for setting up the gear blank, or that test flanges should be provided. I n t h e case of housings made of aluminium a l l o y s and s i m i l a r materials, s u i t a b l e measues should be taken, e. The difference between the upper and the lower allowance of the tip circle ia appended as a minus tolerance. If p l a i n b e a r i n g s are uaed, t h e i r dimensional and geometrical accuracy should be i n line with t h e correaponding dkn i w s for b a l l boaringo according t o D I N Gear blank f o r gear with external t eet h Bearing seating diameter Centre hole Figure The q u a l i t y of a tooth system depends very l ar gel y on the accuracy of the gear blanks.
In the came of instrument drives it is recommended, particularly when mounted overhung, that ball bearings with increased radial clearance ehould be used and proloading applied. In connection v i t h the s e l e c t i o n of b a l l b e d n g e i t should be noted t h a t the tolerance allowed f o r 584055 he bearing bores Q i n t h e housing r e l a t i v e t o the tolerance on t he centre distance Ta must be reduced by the amount 58450 the r a d i a l run-out of the b a l l bearing outer ringe frL.
Minor var iat i o n s may, however, a r i s e in this connection because the individual allowances have been rounded t o preferred numbers. If the c h a r t feed i s operated and a t ra c e drawn corresponding t o t he upper and lower allowance, two don c i r c l e s a r e dim if dln recording i a made in pol ar Co-ordinates see Figure 5 and two p a r a l l e l s t r a i g h t lines i 58450 the recording i s made i n rectangular Co-ordinates see Figure 6.
Assuming t h a t t h e gear t o be t e s t e d i s within the scope according t o D I N Sheet 1, Sect i o n 2, the centre distance of s t r a i g h t or h e l i c a l spur gears without addendum modification i s set on the dual flank r o l l t e s t e r a s folows: The uncertainty i n measurement due t o var i at i on of the measuring Observance of t h e s p dij c i fi e d allowances may be determined d i r e c te.
The face alignment error is designated as pos i t i ve if t he var i at i on i s i n the right-hand dir e c t i o nand negative i f i t i 5840 i n the left-hand di r ect i on with reference t o the design value n of the h e l i x angle Bo. In t h i s connection i t should be noted i n p a r t i c u l a r t h a ti n the case of disc-shaped gear blanks i n which t h e length of bore i a not s u f f i c i e n t t o support the gear blank during the gear-cutting procese, the end faces 5840 ae contact dn during the gear-cutting process and hence t h e i r geometrical and position var i at i ons determine t he qual i t y of th e tooth system.
The following 2 measuring planes a re distinguished: The e r r o r t r a c e must remain between the two l i n e s previously drawn which represent the bounda r i e s of t h e tolerance zone.
The t o t a l composite error according t o Section 4. Recommendation f dun r t h i s purpose i a 5805 in column 4 t o 20 i n Table 1.
I test flanges a r e provi0ed f o r setting up purposes, the permissible radial eccentricity f applies t o these. I f the upper and lower allowances of the dual f lank r o l l t e s t dim have been recorded according t o Section 4.
If the shaft and gear are made in one piece, the radial eccentricity between the mounting In the milling machine 0.
Base tannent lenRth allowances; dual cone width allowances; Derm. Dih cumulative error of a tooth system is the common and simultaneous effect of a number of individual errors on the ideal position and geometry of the tooth flanks.
The following are distinguished: The ideal involute surface corresponding to the nominal dimension and shown in Figure 4 is outside the boundary involutes because of the negative base tangent length allowances see a l s o DIN Sheet IFigure I. I f one of these requirements i s over-stepped the new conditions which r e s u l t regarding clearances, accuracy of transmission, tooth engagement conditions, etc.
The acceptance for tooth Systeme mainly consists of a cumulative e r r o r testing r o l l testing. Por h e l i c a l spur gears cosao i s replaced by cosaos and cosab by cosab. DIN rin f cylindr They should be taken from the Tables i n Section 6 t o s u i t the gear f i t selected grade and tolerance zone.
This i 558405 performed 584005 s follows: Measuring plane perpendicular with centre distance line 6 Tolerances f o r uear assemblies. The s l i p gauges a re then removed, t h e two gears ar e mounted on the arbors, brought i dln t o cont a c t and r o l l e d one on the other. Since the dual flank roll testing is generally carried out as a final inspection, and since it cannot be performed until the teeth have been finished, base tangent length and dual cone width allowances have been specified during manufacture measurement of tooth thickness.
I ma -4 -ea -n -w – above 6 to I2 hove 0. Base tannent lennth allowances; dual cone width allowances; perm.
DIN – European Standards
In this case the permissible axial eccentricity TAa is: FP Cin c i r c u l a r e r r o r t r a c e s see Figure 5 the upper dlovance of dual flank roll teat distance – – Figure 5. Base tangent length allowances and t h e i r boundary involutes The base tangent length allowances a r e r e l a t e d t o the tooth thickness allowances as follows: Base tanuent lenuth allowances; dual cone width allowances; Dem.
This dimension must not be entered in the drawing redundant dimensioning; see DIN Sheet 3. Gear dij i t s not l i s t e d i n this Table should be specified only i n exceptional circumstances.
The c e n tre distance a” i s then reduced each time by the upper and louer allowance of the base tangent length converted t o the r a d i a l direction. G e a r b l a n k s dln o r t o p p e d s p u r s e a r a Since i n t h i s case the t i p cylinder is machined by the gear-cutting t o o lthe t i p cylinder of the gear blank i s given a machining allowance which may differ according t o t h e gear-cutting 558405 used.
The e r r o r i n a x i a l parallelism i e designated by Spa. Measuring plane parallel 584005 centre distance line Figure 8 E dij r o r in axial parallelism f p s.