Vibration motors

Eccentric Rotating Mass (ERM) motors represent the original technology for generating vibration. They are simple to use and are available in a wide range of sizes. That translates to a wide range of vibration amplitudes and frequencies to match any application. They can be found in everything from the smallest smart watch to truck steering wheels.

We can design and manufacture these type of vibration motors using a range of motor technologies, including iron core, coreless and brushless, in both cylinder and coin form factors.

Benefits are that the motors are simple to use and understand. DC motors in particular are easy to control and if long life is necessary, then brushless vibration motors can be used.

Compromises are that the amplitude is tied geometrically to the frequency and the speed, for example it’s not possible to alter the amplitude and frequency independently.

We produce these motors with three different motor constructions and technologies. Iron core for lower cost, coreless for medium cost and medium performance and brushless for the highest performance and longest life.

Solenoid actuators are similar to LRAs but are typically much larger. With a construction similar to a solenoid, a large coil is formed though which a mass can slide.

In some cases the mass is tied at each end by springs that prevent it from hitting the outer case or end stop. This construction arrangement is therefore similar to a large LRA.

In other designs it is intended that the inner mass will hit and end stop built into the motor enclosure which will create more of an impact.

A third type of solenoid actuator is attached via a lever to a touch surface which is suspended via haptic suspension mounts. This solenoid is used to jog the surface when touched which the brain interprets as a button push.

Solenoids actuators require a custom driver to control them and so are a more expensive alternative to ERMs. The use cases for solenoids are quite specific and often ERMs are a more reasonable and worthy substitute.

Vibration alerting is used to interrupt a users attention with a tactile alert. A pager or phone vibrating to indicate an incoming message.

A fireman’s radio indicating an incoming call. A respiratory aid indicating that it’s filter needs changing, and a pace-maker indicating that it’s battery needs changing, are all examples of using vibration to augment or replace sound or visual-based indicators or warnings.

Case study | pacemaker patient notifier

Our customer required an ultra reliable vibration alerting motor for their implantable pacemaker.

They also called upon us to perform all the value-add engineering and quality control services required, to reliably produce a class III FDA approved medical product.

Over the past decade, we have delivered over 1 million brushless vibration motors with very high quality and performance consistency.

Screen haptics is where a vibration motor is used to simulate the tactility of a push-button when a user presses a flat screen.

Signals from the screen’s touch sensors trigger a haptics driver that sends impulse drive signals to the vibration motor(s) attached to the screen. The motors operate vibrating the screen so that the user feels the sensation of pressing a physical button.

We have a wide range of vibration motors and Linear Resonant Actuators optimised for screen haptics applications. We also have a new range of heavy-duty haptic actuators designed for larger screen (such as point of sale) haptics.

Case study | thermal imaging camera

Our customer was updating their range of thermal imaging cameras by integrating touch screens, to enable more complicated user-interfaces without increasing physical button count.

We produced a linear resonant actuator (LRA) solution that provided crisp haptic feedback to the screen, despite a ruggedised enclosure.

Precision Microdrives vibration motors can also be used to add haptics to non-screen user interfaces. These include capacitive touch-surfaces which do not have a screen (e.g. capacitive switch panels), and other user-interfaces such as machine control sticks / levers. Information can be fed instinctively back to the machine operator by vibration motors embedded into the control columns / handles. This is a more refined version of Vibration Alerting, where more information than just an alert needs to be conveyed to the user.

Many items can be turned into haptic user interfaces, for example, shoes that vibrate directions to one foot at a crossroads, or steering wheels that vibrate as part of a lane departure warning system.

Case study | industrial barcode reader

Our customer was designing a ruggedised barcode reader for use in a food distribution warehouse.

The scanner would regularly see very rapid temperature changes between ambient and sub-zero (frozen foods) sections. We designed and manufactured a motor that could withstand these environmental challenges as well as deliver long-life, crisp, haptic feedback to the scanner handle.

Vibration is used in industrial processes, vending machines and lab equipment to aid the movement of materials through a process.

For example, ice-cubes through the chute of a crusher, wires through the hopper of a wire crimping machine, or the mixing / emulsification of fluids and powders.

If you have powders, small items, wires, or other materials that are prone to getting stuck or won’t mix, try freeing them with a source of vibration. We offer a wide range of motors for this application, including super-long-life brushless vibration motors for constant operation.

Case study | vibrating hopper for automated wire crimping

Our customer manufactures complex automatic wire crimping machines. In one of their processes, they required pre-cut wires to be fed through the machine, and found that they needed to vibrate the wire hopper to reliably funnel the wiresets which were sticking.

Our solution was a brushless vibration motor with a precise speed controller set to the hopper resonant frequency.

A more unusual use of our vibration motors is within instrumentation and material analysis markets. Some seismometers and vibration monitoring sensors integrate our vibration motors to operate as part of their self-testing algorithms.

This reduces the chances of false-negative readings within the instruments. Also, some instruments deliberately send vibration through a material under test, measuring how the vibration signals propagate through the medium. We can customise our range of vibration motors to precisely target a specific frequency range or amplitude.

Case study | portable medical instrument

Our customer was designing a new portable neurothesiometer instrument, that could be used to quick-test for type II diabetes in patients.

The requirements were for a very precise frequency output of 128 Hz. Since the frequency had to be controlled and longevity was critical, we chose a brushless vibration motor solution with a customised controller that ran the motor at a precise 7680 (+/- 10) RPM.

An obvious use of vibration motors is in the application of ‘good vibrations’ for adult toys and consumer massager applications.

However, vibration motors are also used in the application of pain relief to sore joints and the trigger-point release of fatigued and overtrained muscles.

For healthcare applications, the precise application of frequency and amplitude is often required. At Precision Microdrives we can tailor the performance characteristics of our motors to deliver an exact vibration, as well as tuning vibration systems to take advantage of or avoid completely system resonant frequencies.

Case study | tennis elbow vibration therapy pain relief

Our customer designed a new consumer healthcare device to offer pain relief to ‘tennis elbow’ injuries.

The product was launched with an aggressive pricing strategy but required a precise vibration frequency and amplitude profile.

We designed a cost-effective iron core vibration motor and improved the product’s accuracy by individually calibrating and marking each motor during manufacture.