Ghana Generator, Diesel Generator Portable, Mobile Generator, Kva Generator Generator Sets,Diesel Generator Co., Ltd. , http://www.generator-china.com
The micro-motor limits the size of the micro-reducer. Not only the micro-gear has a small modulus but also a small number of teeth. In particular, the number of teeth of the planetary gear and the sun gear is generally not more than 15, which is easy to cause interference during meshing. It is difficult. Therefore, the meshing model of the micro gear must take into account the fact that the micro gear itself has a small modulus and a small number of teeth.
In the micro 3K-2 planetary gear reducer, the planetary gears g mesh with the sun gear a and the internal gears b and e, respectively, and the theoretical center distance of the meshing between them is aag=m(Za Zg)/2abg=m(Zb- Zg)/2aeg=m(Ze-Zg)/2(1) where: aag, abg, aeg are respectively ag external meshing, bg internal meshing, and the theoretical center distance of eg internal meshing; Za, Zg, Zb, Ze respectively For the sun gear, the planetary gear, the fixed internal gear, and the number of teeth of the rotating internal gear, it can be obtained by the formula of the gear of the general 3K-2 planetary gear reducer; m is the four-wheel modulus of a, g, b, and e.
Since Za, Zg, Zb, and Ze are different from each other, aag, abg, and aeg are not equal. According to the angle change concentric condition of micro 3K-2 planetary gear reducer design, we must first determine the common center distance of ag, bg, and eg meshing, that is, the actual center distance of the mesh a. Obviously, a is at the theoretical center. The distance between amin and amax is adjusted by the displacement design of each micro gear to obtain the actual center distance.
Therefore, according to the gear meshing characteristics of the micro 3K-2 planetary gear reducer with a gear modulus less than 0.1, the following assumptions are made: (1) In order to facilitate the processing of the micro gear and ensure the meshing coincidence degree, the micro gears The displacements are all positive displacements, that is, the displacement coefficient of each gear is xi≥0.
(2) When the number of teeth modulus has been determined, the number of teeth of the internal gear e is the largest, in order to ensure a compact structure and the smallest size, the displacement coefficient of the e wheel should be the smallest, taking xe=0.
Engagement angle ':'ag=arccos(aag/a')'bg=arccos(abg/a')'eg=arccos(aeg/a') sum of external meshing displacement coefficients: xa-g=(Za Zg) (inva-g-inv)/(2tan) sum of internal meshing displacement coefficients: xb-g=(Zb-Zg)(invb-g-inv)/(2tan)xe-g=(Ze-Zg)(inve -g-inv)/(2tan) displacement coefficient: xe=0, xg=xe-xe-gxa=xa-g-xg, xb=xb-g xg center distance variation coefficient: ya-g=(a'- Aag)/myb-g=(a'-abg)/mye-g=(a'-aeg)/m tooth height variation coefficient: ya-g=xa-g-ya-gyb-g=xb-g- Yb-gye-g=xe-g-ye-g external tooth tip circle diameter: daa=d1 2m(1 xa-ya-g)dag=d2 2m(1 xg-ya-y) internal tooth tip circle diameter :dab=d3-2m(0.75-0.875xb yb-g)dae=d4-2m(0.75-0.875xe ye-g) outer tooth root circle diameter: dfa=d1-2m(1.25-xa)dfg=d2- 2m (1.25-xg) internal tooth root circle diameter: dfb=d3 2m (1.25 xb) dfe=d4 2m (1.25 xe) In the above formula: the pressure angle is generally 20°; d1=mZa, d2=mZg, D3=mZb, d4=mZe are the sun circle, the planetary gear, the fixed internal gear, and the rotating inner gear.
According to the author's design experience, since the displacement coefficient of the micro internal tooth b is the largest, the calculated root circle diameter is outside the intersection of the involute contour of the b tooth, so it must be reduced according to the actual situation; It is calculated that the root of the e tooth is also sharp, making processing difficult.
Therefore, the diameter of the root circle of the b and e teeth should be trimmed on the basis of calculation. The principle is as follows: it is necessary to ensure that the diameter of the root of the micro internal tooth is within the intersection of the involute of the tooth profile, and that it has sufficient The tooth height is to ensure its engagement with the g wheel; in addition, the feasibility of processing must be considered. According to the above modeling and parameter calculation formula, the design of each group with the reduction ratio of 44.2, the number of teeth Za=15, Zg=11, Zb=36, Ze=39, and the modulus m are 0.08, 0.06, 0.04, 0.03 respectively. The calculation, in which m=0.06, has been completed and installed on a 2 mm electromagnetic micromotor; this group of m=0.03 is under development. The main parameters of the above four groups of design, and the foreign reports [4,5] ip = 44.2, Za = 15, Zg = 11, Zb = 36, Ze = 39, the modulus m is 0.08 and 0.04 of the two groups of the main See the design parameters. It can be seen that the calculation results in this paper are in good agreement with the literature [4, 5].