Thermoplastic Bearing Solutions For Medical
Turcite®, Orkot® and HiMod® Bushings
Key Benefits:
- Used as a rod guide, mainly in reciprocating applications
- Prevents metal-to-metal contact
- Low friction
- No stick-slip
- Do not require external lubrication, reducing contamination
Typical Medical Applications:
Bushings are generally used in low speed, high side-load cylinder applications due to their low friction capabilities. Typical applications are hospital beds, patient lifts and prosthetic joints.
Materials Specific to Medical
The Bushings are typically made of PTFE based Turcite®, Orkot® composite material or HiMod® high modulus plastic including PEEK.
About Bushings
Bushings are used in a variety of medical, pharmaceutical and biotechnology devices and equipment, generally in reciprocating cylinder applications. Bushings can be designed and used as sleeve bushings, flange bushings or as a thrust bearing. The function of the bushing is to allow the rod to move freely with low friction, while preventing metal-to-metal contact. They have a lower load capability than a metal bearing but do not require any external lubrication, keeping contamination to a minimum.
Durobal® Medical Bearing for Rotating Applications
Key Benefits:
- Ideal as a guide mainly in rotating applications
- Prevent metal-to-metal contact
- Low friction
- Self-lubricating for cleaner operating environments
Typical Medical Applications:
Durobal® bearings are generally used in low load, high speed applications such as blood separators, diagnostic equipment, laboratory sample processing equipment, Magnetic Resonance Imaging (MRI) and bioreactor applications in biotech processing equipment.
Materials Specific to Medical
The inner and outer rings are generally made of an acetal-based material with no fillers, as fillers can cause premature failure. The cage can be made with a filler material to enhance rolling element movement and reduce friction. Turcite® A is a typical cage material. The ball bearings can be made of stainless steel, glass or ceramics. All plastic constructions are ideal in applications such as MRI scanners.
About Durobal®
Durobal® bearings are used in a variety of medical, pharmaceutical and biotechnology devices and equipment, generally in rotating applications. They usually consist of seven parts: an outer ring, seal, inner ring, ball bearings, cage, seal and shield.
The inner and outer rings provide support against the mating hardware. The cage maintains ball separation. Seals and/or shields may be added to isolate the bearing from the external environment.
Application Examples
Blood Separators
Customer: Medical Device Manufacturer
Application: Blood separators
Issues:
- Previous bearing too expensive and experienced unacceptable failures
- Exposed to air, mineral oil and autoclave sterilization
Solution
- Durobal® bearing design – PET inner and outer portions, PET compounded cage, 302 stainless steel balls
Significant cost savings were achieved by going to a near net molded part versus the fully machined original. The solution has resulted in reduced service costs and lowered field failures.
This device separates platelets from blood, which can later be used to speed the healing process of wounds or supply hemophiliacs with clotting factor. A bearing is used to provide rotary fluid exchange between the collection tray and the separator unit. The bearing operates at room temperature and rotates at 1,680 rpm without coming into direct contact with the blood.
MRI Scanners
Customer: Major MRI manufacturer
Application: Magnetic Resonance Imaging (MRI) Scanners
Issues:
- Must operate in strong magnetic field
- 360-degree range of motion
Solution
- Custom Durobal® bearing design – two completely non-metallic bearing elements mounted in flanged housing
Included in the design of a major MRI maker’s equipment was a table with a 360-degree range of motion. Because it operates in a very strong magnetic field, the table’s ball bearing had to be completely non-metallic.
Trelleborg Sealing Solutions proposed a custom Durobal®. Unique features of the design included low friction, self-lubrication and zero maintenance. The design allowed the table to move in/out and laterally on the machine’s bearing surface. MRI Scanner.
Extremely smooth movement provided added comfort and extra security to the patient during MRI procedures. As the bearing is composed entirely of thermoplastics and glass, problems with magnetic interference were eliminated.