Miki Pulley Co., Ltd. In-House Facilities ① | Hiring Companies
2026/06/15
Now that we can conduct spring constant evaluation tests in-house, we can confidently provide our products to customers!
Miki Pulley Co., Ltd. Engineering Department
〉Challenges
We cannot verify whether the required specifications have been met unless the unit is installed on the customer’s machine
〉Objective
We want to evaluate high-speed couplings in-house
〉Benefits
We can now verify and evaluate the coupling’s performance in-house!
We want to evaluate the coupling internally!
Spring constant testing, which is essential for product development and the evaluation of existing products
[What Is a Coupling?]
A coupling is a component that connects the shafts of a machine. Specifically, it connects the drive shaft—such as a motor that powers the machine—to the driven shaft—such as a ball screw that moves when power is
transmitted—to transfer power (torque). Click here
for more details ↓ An Easy-to-Understand Explanation! What Is a Coupling?
[What Is a Spring Constant Test?]
This test is performed before and after the torsional vibration test. Specifically, the torsional vibration test is used to verify durability, while the spring constant tester is used to check whether there has been any change in stiffness (the degree to which the coupling deforms under torsion) before and after the test.
Miki Pulley offers a wide range of couplings, which
are shaft joints. We carry over 25 different types! We offer various types of couplings to suit our customers’ specific applications. Among
these, the Servoflex Series—Miki Pulley’s flagship coupling line—is an ultra-high-rigidity metal plate spring coupling developed specifically for servo motor applications.They are widely adopted in applications requiring high precision and rigidity, such as dicing saws and CNC lathes used for ultra-precision processing of semiconductor wafers. Miki Pulley
develops couplings for a wide range of applications and conducts ongoing research every day to solve our customers’ challenges in the most optimal way.
Miki Pulley Spring Constant Tester
Unless we install the coupling on your machine, we cannot verify whether the requirements have been met
We needed a highly rigid component (coupling)
Couplings are designed to rotate. Even factors that do not cause problems at low speeds can lead to various phenomena and issues—such as vibration, noise, and heat—when rotating at high speeds.
Consequently, even if we believed there were no issues during the product development phase, new challenges would sometimes arise once the product was installed in our customers’ machinery.
Driven by our pride as a comprehensive manufacturer of drive control equipment with over 80 years of history, we became increasingly determined to conduct tests tailored to our customers’ specifications before shipping products, so that we could deliver them with confidence. To build a spring constant tester capable of verifying rigidity before and after durability testing
, we began designing it in-house. Selecting components with high rigidity was quite a challenge.
Solve your challenges with our proven SFH, SFC, and ETP bushings!
We’ve also succeeded in reducing test setup time!
When developing a new spring constant tester, the time required for test preparation was identified as an area for improvement.
The most time-consuming step was aligning the coupling. To reduce coupling installation time, the coaxiality between the shafts being connected must be highly precise from the outset.
However, measuring this is difficult... To address this, we adopted Miki Pulley’s “ETP Bush (friction-type fastener)” for the fastener connecting the tester and the shaft.
Miki Pulley’s ETP Bush series offers products that meet a coaxiality tolerance of 0.006 to 0.02 mm. By simply tightening a single pressure screw, anyone can achieve the same high-precision connection in about 20 seconds.
Because test preparations are frequent and the spring constant tester and shaft are frequently attached and detached, the ETP Bush truly demonstrates its value in reducing costs.
Furthermore, Miki Pulley’s “SFC and SFH (Metal Plate Spring Couplings)” are proven products that have passed durability tests of 10 million cycles, so we were able to adopt them with confidence. By adopting
these products, we’ve been able to increase the uptime of our torsion testing machines!
Case Studies on the Use of Miki Pulley's SFC and SFH (Metal Plate Spring Couplings) and ETP Bushings (Friction-Type Fasteners)