Understanding SYK and TMT Ball Screw Solutions: Frequently Asked Questions #
1. Difference Between SYK and TMT Brands #
SYK-branded products feature bearings manufactured in Japan or Taiwan, ensuring high quality and reliability. In contrast, TMT-branded products use bearings made in China.
2. Specifications and Brands of Built-in Bearings for Support Units #
- Grades C3, C5, and C7 correspond to ball screw accuracy levels.
- SYK (Unmarked Grade): Suitable for C3~C7 ball screws. Fixed-side units use Taiwanese-made P5 matched pair angular contact ball bearings with zero axial play and medium pre-load.
- SYK C3: Uses Japanese-made P5 matched pair angular contact ball bearings with zero axial play and medium pre-load.
- SYK C5: Features Japanese-made matched pair angular contact ball bearings with zero axial play. For sizes 06~08, EZO P5 class bearings with light pre-load are used; for sizes 10~40, NSK or IJK P0 class bearings with medium pre-load are used.
- TMT C7: Employs Chinese-made P0 paired angular contact ball bearings with axial play within 0.02 mm.
- Supported-side Bearings: SYK C3 uses Japanese-made deep groove ball bearings; TMT C7 uses Chinese-made deep groove ball bearings.
3. Suitable Ball Screw Accuracy Grades for Support Units #
- SYK C3: Compatible with ball screw accuracy grades C0~C7.
- SYK C5: For grades C5~C7.
- SYK (Unmarked): For grades C0~C7.
- TMT: For grade C7.
4. Maximum Temperature Resistance #
Support units can withstand temperatures up to 120℃.
5. Bearing Replacement in Support Units #
A repair kit is available for direct replacement of damaged bearings. However, it is recommended to replace the entire set to maintain proper tolerances among related parts.
6. Bearing Arrangement in Fixed-side Support Units #
- The standard arrangement is DF (Face to Face).
- Some fixed-side units can be customized with DB (Back to Back) arrangement.
- Heavy load types offer DF, DB, DFD, or DFF arrangements.
7. Installation of Fixed-side Support Units with Precision Ground Ball Screws #
For ground ball screws, the shaft end is relatively short, requiring only one collar next to the lock nut. Rolled ball screws require collars on both shaft ends.
8. RoHS Compliance #
All products comply with RoHS requirements. Additional information is available on the website.
9. Suitable Ball Screw Types for MGD/MC Nut Brackets #
- MGD Series: Designed for European standard DIN 69051 nuts, compatible with Rexroth Bosch nut brackets.
- MC Series: Matches the THK MC nut bracket standard.
10. Pre-load and Axial Play in Fixed-side Support Units #
All SYK fixed-side support units are pre-loaded with zero axial play. The level of pre-load (light or medium) depends on the unit size.
11. Installation Methods for Ball Screw Support Units #
- Fixed-Supported: Common for automation and industrial equipment.
- Fixed-Fixed: Used in high-precision automation equipment and machine tools.
- Fixed-Free: Suitable for short ball screw equipment.
12. Causes of Lock Nut Loosening During Operation #
Lock nuts are inspected with standard thread gauges. Loosening is typically due to insufficient locking force or a screw shaft end with a pitch circle diameter that is too small, resulting in inadequate tooth thickness or broken teeth.
13. Selecting or Purchasing Motor Bracket Specifications #
Use the Purchase Guide on the SYK website:
- Select unknown brand
- Choose the motor flange (PCD)
- Select the ball screw outer diameter (O.D.)
- Choose the support-side
14. Absence of Position Holes in Motor Brackets #
Position holes are omitted due to the use of calibration assembly, which ensures high accuracy.
15. Motor Bracket Collation #
A correction surface is provided on the side. Use a dial gauge to calibrate and ensure parallelism with the linear guide.
16. Choosing Axial Limit Load for Support Units #
Consider external factors such as load capacity and speed. It is recommended to apply a 40% reduction to the axial limit value listed in the catalogue for safety.
17. Repairing Integrated Motor Brackets with Damaged Bearings #
A repair kit is available for direct replacement of damaged bearings.
Contact Information
SYK Taiwan Headquarters
Sonyung Industry Co., Ltd.
No. 9, Lugong N. 5th Rd., Lugang Township, Changhua County 50544, Taiwan
TEL: 886-4-7812698
FAX: 886-4-7812458
E-MAIL: syk090@syk.tw
SKYPE: syk090@syk.tw
SYK China Branch
Shanghai Sonyung Trading Co., Ltd.
No. 588, Beisong Road, Minhang District, Shanghai, China
TEL: +86-21-64760638
FAX: +86-21-64760992
E-MAIL: sean@syk.tw
SKYPE: sean@syk.tw