Linear Positioning

ServoBelt™ Linear Drive

Go the distance with limitless travel lengths

From short stroke precision applications under a meter to long travel transfer robots over 50 meters, ServoBelt™ Linear actuators redefine the classic belt drive. ServoBelt puts belts to work in an entirely new way that reduces the positioning errors and speed limitations of conventional belt drives.

  • High Performance, Low Cost. With speeds up to 4 m/s, accuracy to ± 4 µm per meter and bi-directional repeatability of ± 1 encoder count, ServoBelt Linear compares favorably to high-end linear motor drives costing thousands more.
  • Limitless Scalability. With a chassis based on standard Bosch-Rexroth T-slot extrusions, ServoBelt Linear can be engineered for travel distances up to 50 meters or more to create large-format motion systems—such as Cartesian transfer robots, material handling systems and large gantry systems.
  • Multiple Independent Carriages and Axes. A single ServoBelt Linear axis will support multiple, independently-controlled carriages for complex motion control tasks over any travel distance.

Operating Principles

ServoBelt Linear operates very differently from a conventional single-belt drive. It has two mating sets of gear teeth—a “static” set molded into a tray affixed to ServoBelt’s structural aluminum chassis and an “active” set provided by a toothed, steel-reinforced polyurethane belt. The molded static gearing runs the length of the axis, acting much like a gear rack. In operation, a motorized pinion in ServoBelt’s moving carriage rides between the two sets of gearing to move the carriage along the axis.

There are two different drive styles that define how the carriage interacts with the gearing:

SBL Standard Drive

  • Standard Carriage

ServoBelt Linear Standard Drive is our compact original design in which the “active” belt runs the length of the ServoBelt axis. It travels over the carriage’s drive pinion and through a set of idler rollers fixed inside ServoBelt’s moving carriage.

SBL LoopTrack Drive

  • LoopTrack Carriage

SBL LoopTrack Drive features a shorter upper drive belt that loops continuously within the carriage itself. Without an active belt running the length of the axis, it avoids the possibility of belt sag in inverted or cantilevered applications and allows multiple independent carriages to operate on the same axis. This carriage style is suitable for most applications.

With both drive styles, the belts are under tension only around the pinion, which minimizes belt stretch and makes driveline stiffness constant along the entire travel length of the motion axis. What’s more, both designs preload the belt mesh on either side of the pinion for backlash-free carriage movement in either direction, contributing to ServoBelt’s linear-motor-class accuracy and precision.

ServoBelt Linear in Action

ServoBelt Linear In Action

With its limitless travel length and ability to support multiple independent carriages on a single motion axis, ServoBelt shines in a wide variety of complex motion control systems, including:

Cartesian Robots. ServoBelt Linear Cartesian robots with custom end-of-arm tooling (EOAT) and advanced sensing capabilities excel at tending multiple machines and at transfer operations — at a lower cost, with less complexity and with a smaller footprint than automation systems built around 6-axis articulated arm robots.

Gantry Systems, Large and Small. From small lab automation systems to large packaging lines, ServoBelt Linear actuators are the backbone of gantry systems with best-of-class performance to cost.

Long Travel Linear Motion Axes. ServoBelt Linear scales to any stroke or travel length requirement, with shipped systems currently exceeding 50 meters. This long travel capability results partly from ServoBelt’s moving motor design and partly from proprietary joining techniques that allow multiple chassis sections to be combined into a single long linear motion axis. Add multiple carriages to that long axis, and it becomes possible to cost-effectively perform many independent operations along a single long axis.

ServoBelt Linear Applications

  • Warehouse Automation
  • Lab Automation
  • LED Panel Manufacturing
  • Machine Building

ServoBelt Linear Featured Video

SBL Technical Specifications


Technical Specifications Light Duty Medium Duty  Heavy Duty
Type Rotary Drive Linear, NEMA 23 or user motor Rotary Drive Linear, NEMA 23, 34 or user motor Rotary Drive Linear, NEMA 34 or user motor
Maximum Linear Force (lbs)
Recommended | Ultimate
50 | 100 100 | 200 500 | 1000
Linear Travel
Per pinion revolution time (mm) | Pitch Diameter
75 | 0.940 200 | 2.506
Bearing Type Preloaded 4-row recirculating ball, standard or corrosion resistant
Maximum Length 5.5 m with single-piece chassis.
Virtually limitless travel distances with chassis splices.
Motor Type 3-phase brushless servo or user supplied of any type
Uni-Directional Repeatability (µm)
Achievable under ideal conditions.
±10.0 ±15.0
Bi-Directional Repeatability (µm) ±25 to ±125 depending on deceleration profile ±80 to ±130 depending on deceleration profile
Angular Deviation (±arc-sec)
Yaw angle maximum in the plane of the base. Most chassis are flexible enough that this value is generally the achievable number when the unit is straightened on user surface.
Encoder Type and Resolutions: Linear (μm), Rotary (CPR) (µm)  16 KCPR (NEMA 23) rotary motor encoder; 1 μm magnetic linear; 1 μm, 0.5 μm, 0.2 μm, 0.1 μm optical linear 16 KCPR (NEMA 23), 16 KCPR (NEMA 34) rotary motor; 1 μm magnetic linear; 1 μm, 0.5 μm, 0.2 μm, 0.1 μm optical linear 16 KCPR (NEMA 34) rotary motor encoder; 1 μm magnetic linear; 1 μm, 0.5 μm, 0.2 μm, 0.1 μm optical linear
Speed (m/sec)  4
Max Shear for 106 m @ 2m/sec (N) 840 2028 (single rail), 4057 (double rail)
Max Pitch and Yaw Moment for 106 m @ 2 m/sec (N-m) 5.6 110 (single rail), 220 (double rail)
Max Roll Moment for 106 m @ 2 m/sec (N-m)1 5.6 25 (single rail) 183, 365, 232 (-180, -270, -90S) 25 (single rail) 183, 365 (-180, -270)
Ultimate Dynamic Belt Life
Out-and-back cycles to belt failure at load in Newtons.
50 M cycles @ 13 lb
25 M cycles @ 25 lb
18 M cycles @ 38 lb
9 M cycles @ 50 lb
50 M cycles @ 25 lb
25 M cycles @ 50 lb
18 M cycles @ 75 lb
9 M cycles @ 100 lb
25 M cycles @ 300 lb

Configure and CAD

© 2024 Bell-Everman, Inc.