Sun Gear In Planetary Gear

Planetary gear reducers belong to the epicyclic family of reducers, since the planet gears trace epicycloidal curves in space—very similar to how the popular kid’s toy, the spirograph, works[i]. Simple planetary gears are arranged with a centrally located, externally toothed sun gear that meshes with one or more externally toothed planet gears. As the name implies, the “planet gears” rotate around the “sun gear.” The planet gears also mesh with an internally-toothed ring gear—which encompasses the entire gear set.

CHARACTERISTICS

High torque capacity in a compact package – Due to the load sharing of several planet gears, planetary gear reducers can handle the same torque that a larger parallel axis gear set can take. Although planetary gear sets will likely have more components than a parallel axis gear set, the smaller-size-for-equivalent-torque planetary reducer will be less expensive.

High efficiency – A single stage of planetary gears will likely be over 95 percent efficient.

High reduction ratios – Ratios as high as 11:1 can be achieved in a single planetary gear stage whereas it is difficult to achieve much higher than 5:1 in a single parallel axis stage. However, it is impossible for planetary sets to achieve a ratio much under 3:1 due to geometric interferences. A parallel shaft set is not limited on low ratios as they can be as far down as 1:1 (idler gear).

高扭转刚度 - 由于太阳齿轮可能会接触多个行星齿轮，因此在行星齿轮组中，扭转刚度或对弹性变形的阻力要高于平行轴齿轮集[II]。

润滑柔韧性 - 行星齿轮组可以用油或油脂润滑。行星套件中的齿轮可以防止润滑油逃脱，这与标准的刺齿轮套件不同，并不断重新分配润滑，从而使许多不同的安装方向[iii]。

集成的外壳选项 - 行星套件中的环齿轮可以设计，使其也是整个变速箱的外壳。减少组件的数量会减少组装时间和零件成本，从而增加底线。

同轴旋转的同轴对准和旋转方向 - 行星齿轮组上的输出轴与电动机轴“同轴对齐”，这意味着它们共享相同的轴。行星输出轴也沿与电动机相同的方向旋转，而单级平行轴齿轮组上的输出轴旋转与电动机方向相反。如果需要偏移输出轴，则可以将平行轴齿轮集添加到行星集中，或者可以使用完整的平行轴齿轮集。

Thermal capacity – since the size of a planetary gear reducer is smaller than that of an equal torque capacity parallel axis unit, the thermal capacity will likely not be as high on the planetary gear reducer—making this type of reducer a good fit in intermittent duty applications. Planetary gear reducers can still run continuously, but measures may have to be taken to prevent the gearbox from overheating.

APPLICATIONS

Construction equipment

Door & gate openers

Food & beverage mixers

材料处理设备

Medical devices

Packaging equipment

Power tools

车辆变速器

Wind generation