Como o nome indica, os rolamentos rígidos de esferas são rolamentos com uma ranhura profunda na qual as esferas rolam e os anéis interior e exterior movem-se um em relação ao outro. Os rolamentos rígidos de esferas foram os primeiros a surgir entre os rolamentos e têm a maior variedade de utilizações. São excelentes para aplicações de alta velocidade e podem suportar tensões radiais e axiais bidireccionais.
Os rolamentos rígidos de esferas são um tipo de rolamento que não pode ser separado. Este tipo de rolamento tem as vantagens de uma estrutura simples, pouca necessidade de manutenção regular durante o funcionamento e um preço baixo. É um rolamento radial muito comum que é adequado para utilização em situações de funcionamento a alta velocidade.
Both the inner and outer rings of single-row deep groove ball bearings have deep groove raceways. The deep groove raceways and the excellent tightness between the raceways and the steel balls make this type of bearings bear radial loads at the same time. It can also bear a certain bidirectional axial load. When the radial clearance of the bearing is appropriately increased, the ability to withstand axial loads can be increased, and sometimes it can be used to replace angular contact ball bearings operating at high speeds.
Princípio de trabalho
Deep groove ball bearings mainly bear radial load, but also can bear radial load and axial load at the same time. When it bears only radial load, the contact angle is zero. When the deep groove ball bearing has a large radial clearance, it has the performance of an angular contact bearing and can withstand a large axial load. The friction coefficient of the deep groove ball bearing is very small and the limit speed is also high.
Types of deep groove ball bearings
The basic type of deep groove ball bearing is composed of an outer ring, an inner ring, a set of steel balls, and a set of cages. There are two types of deep groove ball bearings: single-row and double-row. The structure of a deep groove ball is also divided into two types: sealed and open. seal. The material of the dust-proof sealing cover is stamped steel plate, which simply prevents dust from entering the bearing raceway. The anti-oil type is a contact oil seal, which can effectively prevent the grease in the bearing from spilling out.
For deep groove ball bearings, in addition to the open type, there is also a sealed type filled with grease inside (double-sided dust cover type, code ZZ; double-sided sealed type, code LLB, LLU, LLH), and other design types (with Snap ring type, expansion compensation type, long life type, AC type), etc. The type code of single row deep groove ball bearing is 6, and that of double row deep groove ball bearing is 4. Its structure is simple, easy to use, and it is the most widely produced and widely used type of bearing.
Deep groove ball bearings have a variety of structural types. In addition to general-purpose open bearings, we can also provide customers with closed bearings with dust covers on one side, dust covers on both sides, seals on one side and seals on both sides. Type structure, and contact or non-contact (low friction) seal ring bearings. According to the contact form, the sealing ring is divided into contact type and non-contact type (low friction). Bearings with double-sided sealing rings have been filled with grease before leaving the factory. The amount of grease filled is generally 25% to 35% of the effective space in the bearing. If customers have special requirements, other types of grease can also be filled or the amount can be adjusted. . Bearings with sealing rings on both sides should not be cleaned or heated (oil heating is not allowed) over 80°C during installation, otherwise, the bearings will be easily damaged or the grease will deteriorate and be lost. Bearings with sealing rings can maintain proper working performance in the ambient temperature range of -30°C to +100°C.
Bearings with snap grooves in the outer ring
Deep groove ball bearings with stop grooves on the outer ring can also be provided. The bearings can be positioned with stop rings. When installed, the bearings can be easily fixed in the bearing seat. Therefore, when the installation location is limited, it should be given priority. According to the different characteristics of the bearing application occasions, the above dust cover, sealing ring, stop groove, etc. can also be designed in various combinations and provided to customers.
Low noise bearing
In order to meet customers’ special requirements for bearing low noise (low vibration), deep groove ball bearings with different vibration value groups can be provided to customers.
We can also provide customers with deep groove ball bearings of other structures, such as insulated deep groove ball bearings, ceramic deep groove ball bearings, stainless steel deep groove ball bearings, etc. Products, but due to some reasons are not included in this catalog, if customers need it, please consult with the technical department. GJP can also design and manufacture other types of deep groove ball bearings that meet customers’ individual requirements.
Axial load-carrying capacity
If the deep groove ball bearing needs to bear pure axial load, generally the pure axial load it bears should not exceed 0.5C0. Bearings of small size (bore diameter less than about 12mm) and light series bearings (diameter series 8, 9, 0 and 1) shall not be subjected to axial loads exceeding the equivalent of 0.25C0. Excessive axial load may significantly reduce the life of the bearing.
In order to ensure a good running state of the bearing, the deep groove ball bearing, like other ball bearings and roller bearings, must apply a certain amount of small load, especially for high speed, high acceleration, or under the condition of frequent changes in the load direction Work. Because of these working conditions, the inertial force of the ball and the cage and the friction in the lubricant will have a negative impact on the rolling and rotating accuracy of the bearing, and there may be sliding motion between the ball and the raceway that is harmful to the bearing.
The required minimum load for deep groove ball bearings can be estimated with the following formula:
In the formula:
- V—viscosity of lubricating oil at working temperature, mm2/s
- n—speed, r/min
- dm — average bearing diameter, dm = 0.5(d+D), mm
- Kr — Smaller load constant.
Where bearings are started at low temperatures or where the lubricant viscosity is very high, a larger smaller load may be required. Often, the weight of the bearing support itself, plus the load borne by the bearing, already exceeds the required minimum load. If the minimum load has not yet been reached, the bearing must be subjected to additional radial loads to meet the minimum load requirements. In the application of deep groove ball bearings, the axial preload can generally be applied by adjusting the relative axial positions of the inner and outer rings or using springs.
Dimensions, tolerances, clearances
The external dimensions of standard deep groove ball bearings conform to GB/T307.1 “General Plan for External Dimensions of Rolling Bearings and Radial Bearings”, the tolerances conform to GB/T307.1 “Tolerances of Rolling Bearings and Radial Bearings”, and the clearance conforms to GB/T4604 “Rolling Bearings Radial Clearance” and other regulations.
The dimensional tolerance grade of standard deep groove ball bearings is generally manufactured according to P0 grade (common grade), and the clearance is manufactured according to group 0 (basic group). Provide corresponding products.
Carga dinâmica equivalente
The equivalent dynamic load of deep groove ball bearings is not only related to the ratio of the axial load borne by the bearing to the basic rated static load, but also different radial clearances will also affect the equivalent dynamic load. The radial clearance increases and the shaft load-carrying capacity also increases. For deep groove ball bearings subjected to dynamic loads, the equivalent dynamic load can be calculated as follows:
- P = Fr when Fa/Fr ≤ e
- When Fa / Fr > e P = XFr + YFa
In the formula:
- P—equivalent dynamic load, N
- Fa— axial load, N
- Fr—radial load, N
- X — radial load factor
- Y— axial load factor
- Carga estática equivalente
- For deep groove ball bearings subject to static load, the equivalent dynamic load can be calculated as follows:
- Po = 0.6Fr + 0.5Fa
- When Po < Fr, Po = Fr
Difference between deep groove ball bearing and thrust ball bearing
Although both are ball bearings, the rolling elements are balls, but deep groove ball bearings mainly carry radial loads and thrust ball bearings mainly bear axial loads; they are essentially different in structure;
In addition, thrust ball bearings are widely used in industrial machinery, such as automobiles and machine tool processing industries, while deep groove ball bearings are used in more applications, such as petroleum, aerospace, and food processing.
Difference between deep groove ball bearing and angular contact bearing
There is a contact angle between the ring and the ball of the angular contact ball bearing. The larger the contact angle, the greater the axial load capacity, and the smaller the contact angle, the more conducive to high-speed rotation. It is suitable for high-speed and high-precision rotation occasions;
In addition, the groove position of the outer ring of the deep groove ball bearing is different from that of the angular contact ball bearing, the non-center position and its specific value are considered when designing the angular contact ball bearing and are related to the degree of contact angle.