With the fast and aggressive build out of Space, namely the rapidly growing number of LEO constellations orbiting Earth, comes the pervasive need for free-space optical communications that allows space-to-space, space-to-air and space-to-ground connections. Point-to-point use of highly collimated light in high-bandwidth communication is critical to the utility of “mesh networks” connecting each spacecraft with each other and to the ground.

Space-rated gimbals used for Satcom and Optical systems need high torque actuation that allows for decisive move-and-hold positioning and smooth motion for long-range target lock. With size and weight constraints being a design objective for spacecraft, a large aperture, low-profile is ideal for deep integration and desired performance. Zero cogging and high linear torque output inherently come with the slotless architecture.

Multi-axial gimbaling mechanisms, like those used in Coarse and Fine Pointing Assemblies can leverage the benefits of high performance Ring Motors to directly drive movement and maintain position. Frameless motor kits offer the further ability integrate the actuation function as part of optimized systems. Optimized systems offering Size, Weight and Power (SWaP) savings, which is highly desirable in any kind of spacecraft application.

Other Space-systems, like larger gimbal-based Control Moment Gyroscopes (CMG) are used for Attitude Control in larger satellites requiring greater quantities of torque and precision. In some cases, to quickly and precisely move in both azimuth and elevation, and in other cases, to quickly compensate for external “tumbling” disturbances common in orbit.

ThinGap’s LS Series of slotless motor kits is an industry leader for gimbal applications requiring high performance and efficiency. Using a proprietary design, thin wire-wrapped stators and optimized permanent-magnet rotors, ThinGap provides that can match the torque output of slotted motors while avoiding the cogging that plagues them.

ThinGap’s LS line of slotless motor kits range in size from 25 to 267 mm diameter and torque from .1 to 12 N-m continuous. With standard and modified configurations, the product line will cover voltages from 24-400 volts and current from 1 to 100 amps. Hall devices and special configurations are also available.

To learn more about the LS Series, click here.

ThinGap will be participating in the 37th Space Symposium in Colorado Springs on April 4-7, 2022. The company will be represented at the show by CEO, John Baumann, and Lead Applications Engineer, Matthew Panesis. Also present at the show will be members of ThinGap network of sales representatives. Besides meeting with existing and potentially new customers, domestic and international space agencies, and industry partners, a working unit of ThinGap’s H-LSI 75-12 turnkey Direct Drive Motor Assembly (image) based on the company’s slotless motor technology will be demonstrated at the ESI Motion booth (booth #612).

Matthew Panesis, ThinGap’s Applications Engineer commented on the event, “With the recent launch of our new TGR Series of Reaction Wheel Assembly motor kits, the timing is perfect to update our business partners, as well as customers about this new space-rated offering. In addition, we’re proud that our colleagues at ESI Motion will be demonstrating our Direct Drive Motor Assembly being driven by their control electronics.”

ThinGap slotless motors are widely used in many space applications, including Reaction Wheels, Control Moment Gyroscopes, Gimbals, Point-and-Track Satcom, Pumps and other precision actuation functions needed in spacecraft. For vacuum-compatible motor kits, ThinGap can easily provide variants of its commercial off-the-shelf motors. With these modifications, the motor kits can address the need for various program specifications, including low outgassing materials, specialty electronics, and in some cases, redundant stator windings to provide mission-critical assurance.

Space Symposium, held at The Broadmoor in Colorado Springs, Colorado, USA, has brought together space leaders from around the world to discuss, address and plan for the future of space since the inaugural event in 1984. In recent years, the Space Foundation team has welcomed more than 14,000 people from around the world, including speakers, attendees, exhibitors, volunteers, educators, and students. Space Symposium has become widely known as the premier U.S. space policy and program forum for information on and interaction among all sectors of space.

Small form-factor and high inertia-to-weight ratio ideal for microsatellites

Today’s Low Earth Orbit (LEO) satellites, including “SmallSat” and “CubeSat” microsatellites require a range of critical functions to serve their mission as cost-effective spacecraft. One of the most important functions is Attitude Control, which enables high accuracy pointing capabilities.

Reaction Wheel Assemblies (RWA) are used for multi-axis Attitude Control. RWAs use multiple motors that each spin at varying speeds creating a change in kinetic energy in the desired axes. RWAs utilize optimized rotating inertia, speed, and torque to accomplish this.
Motors used in RWAs need to have the optimal balance between torque and inertia, with negligible rotational losses and smooth motion performance. Zero cogging is critical to achieving this smooth motion. Additionally, parts must be made with low-outgassing materials, have flight heritage, and be sourced from suppliers that can support space programs’ stringent requirements.

ThinGap has tuned its product offering of “air core” motors to meet the demands of this application. This moving magnet air-core motor lends itself to very low drag at high operating speeds, and a wide speed range with constant torque. ThinGap’s ironless stator puts all the magnetics (the heaviest part of the motor) in the rotor, maximizing the inertia for a given weight and size requirement. The reaction wheel’s necessary flywheel mass can be reduced, and sometimes fully incorporated into the rotor. The resulting package is lighter weight for the same momentum storage capacity.

Smooth operation is achieved through a zero cogging slotless design that maintains sinusoidal torque versus angle curves with total harmonic distortion of less than 0.5%. The precision wound coil results in a phase-to-phase balance within 1%. Hands down, ThinGap has the highest precision RWA motors available, yielding pure torque vector control, with very low losses and zero cogging.

Motor sizes range from 25mm to 250mm in diameter and axial heights as small as 22 mm, with through holes up to 80% of the outside diameter. Since 2015, ThinGap has shipped thousands of Space-grade or MIL-STD rated motor parts for use in commercial satellites, military and commercial aircraft, and flight-grade NASA programs.

ThinGap Motors Used For RWA Applications

To learn more about the TGR Series of motor kits, click here.

The use of gimbals is becoming pervasive in Low-Earth-Orbit (LEO) Satellites and even ground-based systems. A heavy reliance on gimbal-based systems is an important part of the Defense Agencies’ critical Intelligence, Surveillance and Reconnaissance (ISR) objectives. In addition to defense, there are emerging uses in communications, and remote imaging applications.

Satellites use Gimbals for communication in a similar method for pointing and positioning, with the gimbals acting as the turret and gimbal unit alone, and a device called a fast-steering mirror delivering fine precision control that ensures a reliable optical data connection between satellites, either between low Earth orbit and geostationary satellites and between low Earth orbit satellites.

Multiaxial gimbals require high performance motors to directly drive their movements and to hold position. Advanced space-rated gimbal systems, like those used in Control Moment Gyroscopes (CMG), require a large amount of torque. In some cases, to move in both azimuth and elevation quickly and precisely, and in others to quickly compensate for external “tumbling” disturbances common in orbit.

One of the largest use-cases for ThinGap’s slotless motors are Gimbals, so much so that it considers itself to be the performance leader in Gimbal motors. From handheld applications for action cameras to large platforms designed for satellite-to-satellite communication, the applications of gimbals are endless. By using an array of different sensors and motors to counteract movement, electrically controlled gimbals serve to keep platforms stable and focused. Last summer, ThinGap delivered a series of motor kits to NASA for use in a space-based gimbal application, which serves as a testament to the quality and processes at ThinGap.

Using its proprietary design, thin wire-wrapped stators, and optimized permanent-magnet rotors, ThinGap provides motors with specifications that can match the torque output of slotted motors while avoiding the cogging that plagues them. Ring motors are the perfect form factor for gimbals with their round shape, direct drive mounting capability and empty center.

ThinGap’s motor kits offer a large through hole, usually 65% of more of the device’s outer diameter (OD), due to its efficient mechanical design and optimized components. ThinGap’s LS line of slotless motor kits range in size from 25 to 267 mm diameter and torque from 0.1 to 12 N-m continuous. With standard and modified configurations, the product line will cover voltages from 24-400 volts and current from 1 to 100 amps. Hall devices and special configurations are also available.

To learn more about the LS Series, click here.

ThinGap has made available two new Space-rated frameless motor kits specifically designed for Reaction Wheel Assemblies (RWA) used to control small and miniaturized satellites. The new TGR 29-12 and TGR 45-20 are an extension of the widely used TG Series of aerospace motors supplied by ThinGap for nearly two decades.  The vacuum compatible parts are 29mm and 45mm wide, and 12mm and 20mm tall, respectively.

ThinGap’s patented motor architecture has inherent advantages in RWA and flywheel applications: an efficient ironless core, zero cogging stator, high torque capacity, dynamic responsiveness, and overall weight savings.

The “air core” architecture lends itself to very low drag at high operating speeds and cogless torque. The wave-wound design of the stator produces a sinusoidal Back-EMF with total harmonic distortion of less than 1%. The precision hand wound coil results in a phase-to-phase balance within 1 degree. In combination, these produce the highest precision RWA motors available which yields essentially pure torque vector control with very low losses and zero cogging.

The new TGR’s design puts all the magnetics (the heaviest part of the motor) in the rotor, maximizing the inertia for a given weight and size. The resulting package is lighter weight for the same momentum storage capacity, and because of no iron saturation in the stator, ThinGap’s peak torque capacity is much higher than a similar weight motor. This gives a high dynamic response significantly better than the competition at a lighter weight. The motors are also highly efficient (up to 95%) since the architecture lends itself to very low drag at high operating speeds.

The TGR 29-12’s offers a continuous torque of 0.012 N-m and 0.0054 N-m/√W motor constant. The TGR 45-20 offers a continuous torque of 0.075 N-m and 0.0197 N-m/√W motor constant. This allows the new TGR motor kits to offer more than double the torque of the closest competitor with minimal losses.

Prior TG Series models have been widely used in RWA systems. Sample quantities of the new TGR 29-12 and TGR 45-20 are available with a 12 week lead time.  Additional models of the TGR Series will include a 79 mm and 61 mm OD part set to be released later in 2022.

To learn more, click here.