PK264-03BOriental Motor
$90.001 in stockAsk for a quote
Manufacturer
Oriental Motor
- Condition: New old stock, open stock
Oriental Motor is a Japanese maker of small motors and motion control products, and Vexta is the brand name it puts on its stepping and brushless lines. The two have been printed together on the front of so many machines that people use them interchangeably: a shop will say it has a Vexta on the axis and mean an Oriental Motor stepper, and everyone understands. Vexta is a brand rather than a company, so the stock is filed here under the maker, and a search for either name finds it.
What they are known for. Selling a motor as a system rather than as a part. Oriental Motor built its business around the idea that a customer wants a shaft to turn at a known speed under a known load, not a set of specifications to reconcile, so the catalog is organised around matched combinations: a motor, a gearhead that bolts to it, and a driver or controller sized to suit. That is why so much of this stock arrives already assembled, and why a Vexta gearmotor tends to have documentation giving the output torque rather than leaving you to derive it.
Reading the numbers. The motor and the gearhead are separate part numbers even when they arrive bolted together. On the PK264-03B with a 4GN25KA gearhead, PK is the two phase stepping motor series, the digits describe the frame and body length, and the suffix identifies the winding. The gearhead number is where the useful figure hides: in 4GN25KA, the 25 is the reduction ratio, so twenty five turns of the motor make one turn of the output. The frame is NEMA 23 at the motor end with a larger housing at the gearhead, worth measuring before you commit to a mounting plate.
What a gearhead does to the deal. It multiplies torque by the ratio and divides speed by it, less efficiency, and it multiplies resolution the same way, so a 1.8 degree step becomes 0.072 degrees at the output. What it adds is backlash, and backlash is why a geared stepper is right for a lift, a feed or an indexer and wrong for anything that has to reverse direction and land accurately. It also holds the grease that suffers most in storage: a reduction stage that has stood still for years will feel stiff, and if the application needs accuracy it is worth opening and repacking.
Questions about Oriental Motor
Is Vexta a different company from Oriental Motor?
No. Vexta is the Oriental Motor brand name for its stepping and brushless motor products, so a motor marked Vexta is an Oriental Motor product and the two names appear together on most labels. The stock is filed under Oriental Motor, which is the maker, and the Vexta name is stated on every listing that carries it.
What does 4GN25KA mean?
It is the gearhead, not the motor. The GN series is a parallel shaft gearhead line, and the 25 is the reduction ratio, so twenty five motor turns give one output turn. The leading digit and the trailing letters describe the frame and the mounting and output shaft configuration. The motor in front of it has its own part number and its own specification.
Can I take the gearhead off and use the motor on its own?
On most of these, yes, and it is a normal thing to do. The motor and gearhead are separate products that bolt together, so removing the gearhead leaves a standard frame stepper with its own shaft. Check what shaft the motor has underneath before you plan around it, because a motor sold as part of a combination sometimes carries a pinion rather than a plain shaft.
How much backlash should I expect?
Enough to matter if you are reversing direction and expecting to land in the same place, and not enough to matter if you are driving in one direction under load. Published figures for a parallel shaft gearhead of this class are typically in the region of one degree at the output, and a unit that has been in storage may measure slightly worse until the grease redistributes. If your application cannot tolerate it, do not gear the motor, size it up instead.
What driver do these need?
A two phase stepper driver matched to the winding current and inductance, which are in the spec table. Oriental Motor sold matched drivers alongside the motors and those are the easy answer where one comes with the unit. If you are pairing it with a generic driver, send us the driver model and the motor part number and we will tell you whether the current rating and the winding suit each other.