Sealed angular contact thrust ball bearings for ba

2022-10-01
  • Detail

Generally, angular contact thrust ball bearing is used to support the shaft end of ball screw, which is installed in the support unit, and the well is equipped with oil seal. When used in front of machine tools, high precision and rigidity become the key factors to ensure superior machine tool performance. This kind of bearing is equipped with seals at both ends of the bearing (Fig. 1), which can prevent cutting fluid and metal chips from entering the bearing, providing additional value for the application of machine tools. Recently, machine tools are developing in a smaller and more compact direction, requiring the bearing unit of ball screw to be more compact. For this reason, NSK series ball screw support uses sealed angular contact thrust ball bearings

I. features

(I) contact seal

considering the high-speed requirements of machine tool applications, low torque seals with small contact surface are selected from several types of seals currently used. In order to ensure the sealing performance, DDG labyrinth seal (Table 1) is used, which is located between the sealing lip and the inner ring sealing groove. DDG seal has excellent performance in engine accessories and related automotive component bearings. Insert the contact seal into both ends of the bearing to prevent foreign objects from entering the bearing. Another advantage is to prevent grease leakage, which helps to maintain a clean and safe working environment. In order to ensure the installation in the correct direction, the seal is provided with color marks, which has proved to be an effective means to prevent on-site installation errors

(II) WPH grease

for this kind of bearing, NSK adopts WPH grease for many reasons. WPH grease is a kind of efficient grease in automotive water pump bearings. The performance requirements of automotive water pump bearings are much higher than those of machine tool applications. WPH grease is composed of the following components: Pao base oil (superior oxidation stability). Urea based compounds (as thickeners, providing superior water and heat resistance) and other additives to ensure high performance. Other features of WPH grease include:

1. maintain fastness in harsh environment to prevent grease overflow and coolant intrusion, obtain excellent lubrication performance, and prevent bearing peeling

2. High temperature durability can prevent grease degradation and bearing seizure under the condition of high temperature rise

3. it has excellent rust prevention performance even when water or coolant enters the bearing

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(III) interchangeable with TAC

nsk New Sealed angular contact thrust ball bearings for ball screw support have the same overall dimensions (inner diameter, outer diameter and width) and load rating as the current TAC series bearings. It's easy for customers. Zhongwang also made an important breakthrough. This kind of bearing is used to replace the current bearing without any cost reduction changes to the shaft and seat hole. Because this kind of bearing uses a standard universal combination, and the tolerance of internal and external diameters is more strict, and has a continuous honeycomb structure of heat insulation, customers can make any combination with this kind of bearing

II. Performance

see Fig. 2, 3 and 4 for the comparison of starting torque, temperature rise and waterproof performance of sealed angular contact thrust ball bearing for ball screw. See Fig. 5 and 6 for the schematic diagram and photos of the test device. The evaluation results show that the performance of NSK's newly developed sealed angular contact ball bearing for ball screw is better than that of the current oil seal unit

III. application of

sealed angular contact thrust ball bearings provides the best performance for machine tool ball screw support working in harsh environments. In such environments, exposure to cutting oil and metal chips is a potential threat to conventional support

IV. summary

nsk ball screw sealed angular contact thrust ball bearing has standard size and compact size, which can be interchanged, and its excellent support performance can meet the requirements of customers and end users. (end)

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