Designed calculation of helical gear

Purpose of calculation: assessment of interaxial spacing and other parameters of gear, excluding chipping of teeth surface of operating gear.

Estimate value of interaxial spacing

, мм

where – torque at the wheel, Н m;

– ratio for uneven load spread along contact line – ratio of relative wheel width for any wheels under symmetrical position in relation to supports.

Calculated value (мм) should be rounded to nearest big figure according to GOST 2185-66.

1^st row

2^nd row

–

–

Note: values of the 1^st row are preferable.

Further calculation is recommended to be done in the following sequence:

Gearing module is to be set as , mm,
with rounding up to nearest standard value.

Standard row (selection) of modules

	1^st row		1,25	1,5		2,5
2^nd row			1,75	2,25	2,75	3,5	4,5	5,5

In order to set linear dimensions – diameters, lengths, heights etc the standards define rows as specified in Table 6.

Table 6.

Normal linear dimensions (GOST 6636-69)

Ra 20	Ra 40	Ra 20	Ra 40	Ra 20	Ra 40	Ra 20	Ra 40
1,0	1,00	5,6	5,6
	1,05		6,0
1,1	1,10	6,3	6,3
	1,15		6,7
1,2	1,20	7,1	7,1
	1,30		7,5
1,4	1,40	8,0	8,0
	1,50		8,5
1,6	1,60	9,0	9,0
	1,70		9,5
1,8	1,80	10,0	10,0
	1,90		10,5
2,0	2,00	11,0	11,0
	2,10		11,5
2,2	2,20	12,0	12,0
	2,40		13,0
2,5	2,50	14,0	14,0
	2,60		15,0
2,8	2,80	16,0	16,0
	3,00		17,0
3,2	3,20	18,0	18,0
	3,40		19,0
3,6	3,60	20,0	20,0
	3,80		21,0
4,0	4,00	22,0	22,0
	4,20		24,0
4,5	4,50	25,0	25,0
	4,80		26,0
5,0	5,00	28,0	28,0
	5,30		30,0

Note. From rows (Ra5, Ra10, Ra20, Ra40) as set by the standards the rows Ra20, Ra40 are also indicated with smaller gradation

All catching parameters are expressed via the following module

Width of the wheel is defined by the following equation:

, мм.

Width of the pinion is set as , мм.

Calculated dimensions should be verified with standard ones as per GOST 6636-69 (Table 6).

Helix angle to be set as follows: .

Minimum helix angle is to be .

Then the following parameters shall be defined:

- total number of gear teeth , taking as whole part of integer ;

- number of pinion teeth , rounding up to whole integer ;

- number of wheel teeth .

Helix angle value is to be refined .

Actual gear ratio shall be refined and its deviation from the set value:

, .

Then calculation of geometrical parameters of toothed wheels is to be done according to formulas as specified in Table 7

Table 7

Calculation of geometrical parameters of toothed wheels

Parameter	Symbol	Formula
1. Reference diameter, mm	pinion
wheel

Extension of Table.

Дата добавления: 2015-10-31