SCARA Robots
The acronym SCARA stands for Selective Compliance Assembly Robot Arm, a particular design developed in the late 1970s in the laboratory of Professor Hiroshi Makino of Yamanashi University, located in Kofu, Japan. The basic configuration of a SCARA is a four degree-of-freedom robot with horizontal positioning accomplished by a combined Theta 1 and Theta 2 motion, much like a shoulder and elbow held perfectly parallel to the ground. The combination of Theta 1 and Theta 2 form the defining structure of the SCARA. The two linked arms comply slightly in the horizontal, but remain rigid in the vertical. Thus the most basic assembly task of putting a peg into a hole is now much easier as the SCARA will comply slightly from side-to-side, but it will not typically tilt or jam the peg in at an angle.
At the end of the Theta 1 and Theta 2 linked arms is the Z-axis, which provides a powerful down and up motion, vertical to the X-Y plane (the table top). In conjunction with the Z is the Roll axis, which orients the end-of-arm to the workpiece. Typically a gripping mechanism or other tool is attached to the end of the Z-axis and it can be raised or lowered, rotated clockwise or counter clockwise, or positioned quickly anywhere within the defined X-Y workspace.
SCARAs are know for their fast cycle times, excellent repeatability, good payload capacity and a large workspace, shaped somewhat like a donut. SCARAs also feature sophisticated motion control with full programmability. With its torso-based, one arm design, the SCARA integrates easily into most applications.
For flexible, high speed parts assembly and handling, consider a SCARA, one of the most useful and flexible automation tools available.
As one of the first manufacturers of SCARA robots in 1981, Sankyo’s SCARAs have been performing precisely and reliably ever since, including more than 3,500 sold through an OEM relationship with IBM Corporation. Now with its seventh generation, the SR84xx Series, Sankyo is proud of the many outstanding features its SCARA have to offer today:
Thousands of Sankyo’s SCARAs have been used in a wide variety of manufacturing environments since 1981, some of which require special features of robot design. Based on this collective experience, Sankyo is proud to offer four different versions of its SR84xx SCARA Series, each version customized to perform reliably in a particular environment.
Industrial: Sankyo’s base SCARA design is for typical industrial environments with an operating temperature of 0 to 40 degrees C, a relative humidty from 8 to 80%, and a general environment conducive to workers without any special protective garb. Sankyo SR84xx SCARAs have performed flawlessly in these types of environments, 24 hours per day, seven days per week, year in and year out.
Cleanroom: For cleanroom, the SR8437C and SR8438C Class 10 (0.30 µm particle size) SCARA versions are available. The Class 10 SCARAs incorporate special seals, finishing, paint, grease, screws and require a vacuum source to evacuate the particulates captured inside the arm. These systems have been well-proven in the disk-drive industry.
Dust Proof: For environments with heavier particulates, the SR8437DP and SR8438DP versions are available. These dust-proof SCARAs incorporate special seals and covers, a Z-axis bellows, and light positive air pressure to keep the particulates out of the interior of the arm. These dust-proof systems meet the International Electrotechnical Commission (IEC) Index of Protection rating of IP5x.
Splash Proof: For environments consisting of splashing water or cutting fluids, the SR8547WP and SR8438WP versions are available. The spalsh-proof SCARAs incorporate special seals and covers and a Z-axis bellows. Many Sankyo splash-proof SCARAs have been incorporated into Sankyo-built machining centers and transfer lines with cutting fluids splashing freely. These splash-proof SCARAs meet IEC’s Index of Protection rating of Ipx4.
A variety of other options, versions and features for Sankyo’s SCARAs have been developed over the years and Sankyo is pleased to make these available as conditions require. This list includes longer versions of the basic SR84xx SCARAs, such as the SR8437 with a 1000 mm reach; longer Z-heads – up to 550 mm for the SR8437 and up to 250 mm for the SR8438; slide-type Z-axes for mounting various types of screw and nut drivers; side-mounted cable interfaces for tighter integration into the workspace; and special paint colors to match specific system designs. Other variations will also be considered on a case by case basis.