Either electric servo actuators or pneumatic cylinders can be used in robotic resistance spot welding; however, there are distinct advantages to going electric.

Lightweight Servo Actuators Lower Robotic RSW Costs

Bill Graber | Tolomatic

Buyers want sturdy, well-built cars, so the quality of welds that hold auto bodies together is crucial to vehicle manufacturers.  Manufacturers want strong welds that are consistently and accurately placed so the finished car looks both durable and attractive.

Welding robots for resistance spot welding (RSW) have been a boon to auto manufacturers because they provide consistent weld placement.  But all welding robots need actuators to carry and power the weld gun. Those actuators have a huge impact on the consistent quality of welds. They can also impact the cost of robotic resistance spot welding.

Either electric servo actuators or pneumatic cylinders can be used in robotic resistance spot welding; however, there are distinct advantages to going electric.  For a thorough review of these advantages, see our white paper.

 

Electric beats pneumatic 

Electric actuators outshine pneumatic systems when it comes to delivering strong welds consistently at a lower lifetime cost. 

  1. Weld quality: Servo actuators apply the right amount of force for just long enough. Weld timing and pressure can be controlled nearly infinitely. Pneumatic cylinders, on the other hand, depend on compressed air systems that deliver fluctuating pressure levels which can mean inconsistent weld quality. 
  2. Repeatability: Because electric actuators are programmable, weld quality is consistent and high.  Speed, force, and other parameters can be locked in. Inconsistent weld quality is a given with pneumatic cylinders because inconsistent pressure is a fact of life with compressed air systems. 
  3. Cost: Even though initially an electric servo actuator may cost more than a pneumatic cylinder, it will last longer (10-20 million welds versus 3 million). Also, electric linear actuators are more efficient, operating at 75-80% efficiency as compared to the 15-25% of pneumatic systems.

Finally, electric actuators can be re-programmed for product changeovers, avoiding the time and expense of making manual changes to pneumatic cylinders.

 

Lower the cost of robotic welding

Welding robots for RSW are expensive. Even the most efficient and effective electric linear actuator can’t get around the fact.  However, if a smaller robot can be used, robotic resistance spot welding costs come down.  A smaller RSW robot will need a lighter actuator.

Our new SWB and SWA servo actuators, part of our ServoWeld® product line, are lightweight, compact RSW actuators that can work with a smaller resistance spot welding robots. The ServoWeld Advanced (SWA) actuator incorporates our highest level of roller screw technology and delivers the maximum number of welds. The ServoWeld Base (SWB) actuator uses an alternate roller screw design to provide long life at a more economical price (better than other electric linear actuators with inverted roller screws or ball screws). The SWA and SWB can produce forces up to 4,000 lbf/17.8 kN, last 10-20+ million welds and hold +/- 3% force repeatability over the life of the actuator.

Find out more about the SWA and SWB by downloading our brochure.

 

 

Comments (0)

This post does not have any comments. Be the first to leave a comment below.


Post A Comment

You must be logged in before you can post a comment. Login now.

Featured Product

ST Robotics Develops the Workspace Sentry for Collaborative Robotics

ST Robotics Develops the Workspace Sentry for Collaborative Robotics

The ST Robotics Workspace Sentry robot and area safety system are based on a small module that sends an infrared beam across the workspace. If the user puts his hand (or any other object) in the workspace, the robot stops using programmable emergency deceleration. Each module has three beams at different angles and the distance a beam reaches is adjustable. Two or more modules can be daisy chained to watch a wider area. "A robot that is tuned to stop on impact may not be safe. Robots where the trip torque can be set at low thresholds are too slow for any practical industrial application. The best system is where the work area has proximity detectors so the robot stops before impact and that is the approach ST Robotics has taken," states President and CEO of ST Robotics David Sands.