The basis of Cone Drive's capabilities in Precision Gearing lies with the inherent characteristics of Double Enveloping worm gearing geometry. Double Enveloping geometry, which puts more teeth in contact at the gear mesh than traditional worm gearing, provides a much larger contact area that yields higher torque carrying capacities and enhanced precision. Cone Drive produces gearing with transmission accuracy better than .3 milli-radians (1 arc minute). This gearset is ideal for those applications requiring extremely high rates of accuracy in positioning and repeatability. Where absolute zero backlash is required, Cone Drive offers a unique two-piece worm gearset which can provide that level of precision.
Servo Drives & Gearheads | AccuDrive Products
Servo drives from Cone Drive benefit from the expertise and innovation of our more traditional brands. Available in both right angle and inline configurations, coupled with the availability of multiple precision levels, you are sure to find the right product for your application.
Worm Gear Reducers & Gear Sets
Worm Gear Reducers from Cone Drive set the industry standard for dependability. With innovative technologies such as Conex Helicoidal and our true double-enveloping geometries, these worm gear speed reducers and worm gear motors cannot be beat for compactness and shock load.
Double Enveloping Worm Gear Technology
There are three different types of worm gearing: non-throated, single-throated, and double-throated, see Figure 1. In non-throated worm gearing, neither the worm nor the driven gear is throated. In single-throated worm gearing, one element (usually the driven gear) is throated. In double-throated worm gearing, both the driven gear and the worm are throated.
Double-enveloping worm gearing possesses several key advantages over other types of worm gearing. In a cylindrical worm gearset, only one to two gear teeth are in contact with the worm.
In a double-enveloping worm gearset, three to eleven gear teeth are typically in contact with the worm, depending upon the ratio. The increased number of driven gear teeth that are in contact with the worm significantly increases torque capacity, and also raises shock load resistance.In addition to increasing the number of driven gear teeth in contact with the worm, double-enveloping worm gearing also increases the contact area on each gear tooth. The actual areas of instantaneous contact between the worm threads and the driven gear tooth are lines. These lines of contact move across the face of the gear tooth as it progresses through its total time of mesh with the worm. The lines of contact in double-enveloping worm gearing are configured to increase the power transmission capability and reduce the stress on each gear tooth.
Figure 2 shows a cylindrical worm gearset where two gear teeth are in mesh with the worm. Each meshed gear tooth has a single line of contact extending across half of its width. As a gear tooth is rotated through its arc of contact with the worm, the line of contact sweeps from the tip of the gear tooth to its root. The line of contact is approximately aligned with the worm thread's sliding direction.
As the gear tooth is rotated through its arc of contact with the worm, the line of contact sweeps from the tip of the gear tooth to its root. Figure 3 shows the same analysis for Cone Drive double-enveloping worm gearing. Between three and eleven gear teeth (five in this example) are in mesh with the worm at any moment. During a significant portion of the mesh cycle, the geometry of the double-enveloping worm gear creates two lines of contact on each gear tooth instead of one. As a gear tooth is rotated through its arc of contact with the worm, one line of contact is maintained at the center of the tooth. The other contact line sweeps from the left (entering) side of the tooth toward the center. During the end of the tooth's movement through the contact arc (positions 4 and 5), the two lines of contact converge into a single line at the center of the tooth. The lines of contact are roughly perpendicular to the worm thread sliding action.