Design
High speed ball bearings, with smaller rolling elements, HS bearings are able to withstand higher rotating speed than the standard design.
43 products in this product line
HS Series
Inner and outer rings
- Standard bearing steel with a content of carbon and chromium was selected and hardened to withstand the intense pressure between the rolling elements and bearing rings.
- Carbonitriding on both inner and outer rings is a basic hardening process for TPI high speed ball bearings. Through this special heat treatment, hardness on the raceway surface is increased; which reduces wear accordingly.
- Ultra-clean steel is available in some of TPI ball bearings manufacturers' product series now, higher wear-resistance is obtained accordingly. Since contact fatigue is often caused by hard non-metallic inclusions, high speed ball bearings nowadays require exceptional levels of cleanliness.
Rolling element
- High precision steel balls ensure TPI's high speed ball bearings have the best precision and stability. This also reflects in bearing performance under high speed rotation.
- A ceramic ball is an additional option when it comes to severe operating conditions. Extreme high speed rotation, heavy-duty applications, and high heat generation while operating are some situations that ceramic balls that can definitely help.
Cage
With the highly engineered arrangement of cages, remarkable characteristics were achieved.
- T1 cage, desinged for the requirement of high RPM and stable temperature rise.
- T2 cage, desinged for low noise level, however, the temperature rise in high RPM is relatively high.
- T3 cage, improvement of T2 cage, it's not only applicable to high RPM operation but also remain low noise level under low RPM.
Seal
The non-contact seal provides general protection for high speed ball bearings. It cannot prevent liquid contamination from getting into the high speed ball bearings. Torque and limiting speeds are the same as the open type.
Grease
For HS series bearings, grease selection must focus on the grease viscosity and penetration. Since the rotating speed of HS series bearing application is normally higher than standard series, bearing lubrication and heat generation shall be carefully considered during grease selection.
Life
Bearing life is usually expressed as the number of hours an individual bearing will operate before material fatigue develops on either the raceways or the rolling element. The usual life rating for industrial applications is called “L10” life. The L10 life is the number of hours which that 90% of bearings will survive; or, conversely, 10% of bearings will have failed in the L10 number of service hours.
Preload / Rigidity
System rigidity, one of the main factors of productivity and accuracy when it comes to machine tools and other precision applications. By preloading the bearings, it becomes extremely rigid and the magnitude of elastic deformation becomes neglectable.
Arrangement
High speed ball bearings in duplex arrangements vary in combinations of two, three, or four, in accordance with the user's required specifications.
Back-to-back duplex (DB) arrangement and face-to-face duplex (DF) arrangement can both sustain radial and axial loads in both directions. The wider distance between the effective load centers of the DB arrangement allows larger moment loads to be handled.
Designation
The designation indicates the form, size, precision, internal structure, etc. of the bearing, and it's shown as below:
| Ball material | 5S1- | Si3N4 (Ceramic ball) |
| Blank | SUJ2 (Steel ball) | |
| Bearing type | 7 | Single-row angular contact ball bearing |
| HS | High speed angular contact ball bearing | |
| BT | High speed angular contact thrust ball bearing | |
| Diameter symbol | 9 | |
| 0 | ||
| 2 | ||
| 3 | ||
| Bore number | 6 - 26 | below number 03 00: 10mm 01: 12mm 02: 15mm 03: 17mm above number 04 bore number x5 mm |
| Contact angle | C | 15° |
| CE1 | 18° | |
| AD | 25° | |
| A | 30° | |
| B | 40° | |
| Blank | 60° | |
| Cage symbol | T1 | Phenolic machined cage |
| T2 | Engineering plastic molded cage | |
| T3 | Engineering plastic molded cage | |
| Bearing arrangement | DB | Back to back arrangement |
| DF | Face to face arrangement | |
| DT | Tandem arrangement | |
| DBT | Tandem and back to back (triple-row) | |
| DTBT | Tandem and back to back (quad-row) | |
| Flush grinding | G | Flush ground type |
| Blank | Without flush ground | |
| Preload | GL | Light preload |
| GN | Normal preload | |
| GM | Medium preload | |
| GH | Heavy preload | |
| GXX | Special preload | |
| Accuracy | P5 | JIS standard class 5 |
| P4 | JIS standard class 4 | |
| P4X | JIS standard class 4, Special bore and outside diameter tolerance | |
| P42 | JIS standard class 4 (dimensional)、 JIS standard class 2 (running accuracy) | |
| P2 | JIS standard class 2 |
Seal
Sealing type
Bearing with seals on both sides to prevent contamination getting in and bearing grease getting out.
Non-contact type (LB)
Preload / Rigidity
Rigidity of Spindle
System rigidity in machine tool applications is extremely important because the magnitude of deflection under load determines machining accuracy. Bearing rigidity is only one factor that influences system rigidity; others include shaft diameter, tool overhang, housing rigidity number, position and type of bearings. For axial rigidity of spindles, bearing rigidity plays an important role of it. Giving preload to a bearing result in the rolling element and raceway surfaces being under constant elastic compressive forces at their contact points. This has the effect of making the bearing extremely rigid so that even when load is applied to the bearing, radial or axial shaft displacement does not occur. If high radial rigidity of bearing is needed, cylindrical roller bearings are normally used. In contrast to angular contact ball bearing, they provide more surface contact and gross sliding and are not suitable for very high-speed applications. For axial loading applications, angular contact ball bearings are normally used. Their larger contact angle type provides higher axial rigidity. The rigidity of this type also depends on number and size of balls. Recently, the ceramic material silicon nitride Si3N4 is used for precision ball bearings. The radial rigidity of this hybrid bearing is approximately 15% higher because of the higher Young's modulus. As mentioned in 4.5, TPI's HS type angular contact ball bearings are optimally designed with their internal configuration to accommodate both low-ball skidding effect and high rigidity by using TH-BBAN.
Bearing Preload
The preload method is divided into fixed position preload and constant pressure preload as shown in Fig. 5.1. The fixed position preload is effective for positioning the two bearings and also for increasing the rigidity. Due to the use of a spring for the constant pressure preload, the preloading amount can be kept constant, even when the distance between the two bearings fluctuates under the influence of operating heat and load.
Fig. 5.1 Preloading methods for bearings
The increased rigidity effect preloading has on bearings is shown in Fig. 5.2. When the offset inner rings of the two paired angular contact ball bearings are pressed together, each inner ring is displaced axially by the amount δao and is thus given a preload, Fao, in the direction. Under this condition, when external axial load Fa is applied, bearing A will have an increased displacement by the amountδao and bearing B's displacement will decrease. At this time the loads applied to bearing A and B are FaA and FaB, respectively.
Under the condition of no preload, bearing A will be displaced by the amount δaoA when axial load Fa is applied. Since the amount of displacement, δa, is less than δaoA, it indicates a higher rigidity for δa. When external axial load Fa keeps increasing until δaA equals to 2δaoA, that is δaB=0. Now, bearing B becomes released from preload while bearing A is loaded with 2.83 times of given preload Fao. This amount of load is called the limiting axial load and it may depend on bearing arrangement and contact angle.
Arrangement
Duplex Arrangement Bearings
As Fig. 1.1 shows, angular contact ball bearings in duplex arrangements vary in combinations of two, three or four, in accordance to user's required specifications. Back-to-back duplex (DB) arrangement and face-to-face duplex (DF) arrangement can both sustain radial and axial loads in both directions. The wider distance between the effective load centers of the DB arrangement allows larger moment loads to be handled. The main spindle in machine tools often uses this arrangement.
Compared with the DB arrangement, the DF arrangement has shorter distance between the effective load centers, therefore the capacity to handle moment loads is small. However, it possesses greater allowable inclination angle than the DB arrangement.
The tandem duplex (DT) arrangement is able to handle both radial load and large axial load, but only in one direction. The four-row duplex (DTBT) arrangement is commonly used for the main spindles of machining centers because it offers high rigidity and accommodates high-speed operation.
Marking of Bearings and Bearing Sets
A “<”shaped marking on the outside surface of the outer rings of matched bearing sets indicates how the bearings should be mounted to obtain the proper preload in the set. The marking also indicates how the bearing set should be mounted in relation to the axial load. The ”<” should point in the direction in which the axial load will act on the inner ring. In applications where there are axial loads in both directions, the ”<” should point toward the greater of the two loads, refer to Fig. 1.2。
For universal combination bearings, the ”<” marking on the outside surface of the outer rings shown in Fig. 1.3, prevent “direction” mistakes, ensure correct matching when they are mounted.
