Deep groove ball bearing
Basic Parameters
Deep groove ball bearings are a common type of rolling bearings. They consist of an outer ring, an inner ring, a set of steel balls, and a set of retainers. Deep groove ball bearings come in two types: single-row and double-row. The deep groove ball designs also differentiate between sealed and open structures, with open referring to bearings without a sealing structure. Sealed deep groove ball bearings are further categorized into dust-proof sealed and oil-proof sealed types. The dust-proof sealed cover is made of steel stamping and simply prevents dust from entering the bearing raceway. The oil-proof type features a contact seal, effectively preventing the leakage of grease inside the bearing.
Single-row deep groove ball bearing type is designated as 6, while double-row deep groove ball bearing is designated as 4. It features a simple structure and ease of use, making it a widely used bearing type in various production applications.
Working Principle
Deep groove ball bearings primarily bear radial loads and can also simultaneously bear radial and axial loads. When they bear only radial loads, the contact angle is zero. When deep groove ball bearings have a larger radial clearance, they exhibit the performance of a " \t "_blank angular contact bearing, capable of withstanding greater axial loads. The friction coefficient of deep groove ball bearings is very low, and their maximum speed is also very high.
Bearing Characteristics
Deep groove ball bearings are representative rolling bearings with wide applications. They are suitable for high-speed, even ultra-high-speed operation, and are highly durable, requiring minimal maintenance. These bearings have a low friction coefficient, high maximum speed, simple structure, low manufacturing cost, and are easy to achieve high manufacturing precision. The size range and form are diverse, and they are used in precision instruments, low-noise motors, automobiles, motorcycles, and general machinery industries, making them one of the most widely used types of bearings in the mechanical industry. They primarily bear radial loads but can also withstand a certain amount of axial loads.
Selecting a larger radial clearance increases the axial load capacity. When subjected to pure radial force, the contact angle is zero. In the presence of an axial force, the contact angle is greater than zero. Generally, pressed wave-shaped retainers, turned solid retainers, and occasionally nylon retainers are used.
Deep groove ball bearings, once mounted on the shaft, can limit the axial displacement of the shaft or housing in both directions within the bearing's axial clearance range, thus allowing for bidirectional axial positioning. Additionally, these bearings possess a certain degree of self-aligning capability; they can still operate normally when inclined 2′ to 10′ relative to the housing bore, although this may affect the bearing's lifespan. The retainers for deep groove ball bearings are typically stamped steel wave retainers, while larger bearings often use turned metal solid retainers.
Deep groove ball bearings are commonly used rolling bearings. They have a simple structure and are easy to use. Mainly used to bear radial loads, but when the radial clearance of the bearing is increased, they also possess certain performance of angular contact ball bearings, capable of bearing combined radial and axial loads. They can also bear pure axial loads when high rotational speeds are required and thrust ball bearings are not suitable. Compared to other types of bearings with the same specifications as deep groove ball bearings, these have a lower friction coefficient and a higher maximum speed. However, they are not shock-resistant and are not suitable for bearing heavy loads.
Bearing construction
Deep groove ball bearings have a simple structure, making it easier to achieve high manufacturing precision compared to other types. This facilitates series production in large quantities, resulting in lower production costs and widespread use. In addition to the basic type, there are various modified structures, such as deep groove ball bearings with dust covers, deep groove ball bearings with rubber sealing rings, deep groove ball bearings with locking grooves, deep groove ball bearings with ball recesses for high load capacity, and double-row deep groove ball bearings.
Bearing Type
Single-row deep groove ball bearing
2. Single-row deep groove ball bearings with dust cover
3. Single-row deep groove ball bearings with dust cover and sealing ring
4. Single-row deep groove ball bearing with stop slots and rings on the outer ring
5. Deep groove ball bearing with ball seating groove
6. Double Row Deep Groove Ball Bearings
According to the size and dimensions, deep groove ball bearings can be categorized as:
(1) Miniature Bearings - Bearings with nominal outer diameter dimensions of 26mm or less.
(2) Small Bearings - Bearings with nominal outer diameter sizes ranging from 28 to 55mm.
(3) Small and Medium-sized Bearings - Bearings with nominal outer diameter sizes ranging from 60 to 115mm.
(4) Medium to Large Bearings - Bearings with nominal outer diameter sizes ranging from 120 to 190mm
(5) Large Bearings - Bearings with nominal outer diameter sizes ranging from 200 to 430mm.
(6) Extra-large Bearings - Bearings with a nominal outer diameter size of 440mm or more.
Deep groove ball bearings are used in gearboxes, instruments and meters, motors, household appliances, internal combustion engines, vehicles, agricultural machinery, construction equipment, engineering machinery, rollerblades, yo-yos, and more.
Installation Method
Deep Groove Ball Bearing Installation Method 1: Press Fit: When the bearing inner ring and shaft are a tight fit, and the outer ring and bearing housing bore are a loose fit, the bearing can be pressed onto the shaft first using a press machine. Then, insert the shaft along with the bearing into the bearing housing bore. During the pressing, place a soft metal tube (copper or soft steel) made of a soft metal on the " _blank" bearing inner ring face. When the bearing outer ring and housing bore are a tight fit, and the inner ring and shaft are a loose fit, the bearing can be pressed into the housing bore first. At this point, the outer diameter of the assembly tube should be slightly smaller than the bore diameter. If both the bearing ring and the shaft and housing bore are a tight fit, the inner and outer rings must be pressed into the shaft and bore simultaneously. The assembly tube structure should be able to press both the bearing inner and outer ring faces at the same time.
Deep groove ball bearing installation method two: Heat fitting: An installation method that uses heat to expand the bearing or bearing housing, transforming a tight fit into a loose fit. It is a commonly used and labor-saving method. This method is suitable for bearings with larger interference fits. Before heat fitting, the bearing or separable bearing ring should be placed in an oil tank and uniformly heated to 80-100°C, then quickly mounted onto the shaft. To prevent the inner ring face and shaft shoulder from not fitting tightly after cooling, the bearing can be further axially tightened after cooling. When the outer ring of the bearing is tightly fitted with a lightweight metal bearing housing, use the heat fitting method for the bearing housing to avoid damage to the mating surface. When heating the bearing in an oil tank, there should be a grille at a certain distance from the bottom of the tank, or the bearing should be hung with hooks to prevent sediment from entering the bearing or uneven heating. There must be a thermometer in the oil tank to strictly control the oil temperature to not exceed 100°C to prevent tempering effects that may reduce the hardness of the sleeve.
Tolerance
Standard deep groove ball bearings feature a normal grade, all conforming to GB307.1.
Clearance
Standard deep groove ball bearings feature C2, standard (CN), C3, C4, and C5 internal clearances, all conforming to GB4604.
Retaining Rack
Deep groove ball bearings typically use steel stamping retainers or brass solid retainers. For outer diameters less than 400mm, steel stamping retainers are used without a suffix code. For outer diameters greater than 400mm, brass solid retainers are more commonly used without a suffix code.
Three types of bearing processing methods
The processing methods for deep groove ball bearing components are as follows:
1. Multi-process manufacturing: Generally, bearing production requires 20 to 40 processes, with some exceeding 70.
2. Forming Processing: The working surfaces of the bearing parts are rotational forming surfaces, suitable for processing by the forming method.
3. Precision Machining: The vast majority of bearing components require grinding processing, with dimensions and geometric accuracy measured in micrometers (μm).
Deep groove ball bearings, with insufficient bearing load during operation, can cause sliding between the balls and raceways, leading to abrasion. This tendency is especially pronounced in large deep groove ball bearings with heavy balls and retainers. It is anticipated that there may be insufficient load conditions during use. Please contact the relevant personnel promptly when selecting the bearings!
Causes of Rust Formation
In many cases, bearings can suffer from rusting, and there are various reasons for bearing rust. The main factors we commonly encounter in our daily lives are as follows.
1) Due to poor sealing, invasion by moisture, dirt, etc.
2) Bearings have been unused for a long time, exceeding the anti-rust period, and lacking maintenance.
3) The metal surface has a high degree of roughness.
4) Contact with corrosive chemical mediums, insufficient cleaning of bearings, surface contamination, or handling bearings with sweaty hands; failure to promptly package or install bearings after cleaning, prolonged exposure to air, leading to invasion and contamination by air moisture.
5) Environmental temperature and humidity, as well as contact with various environmental media; rust inhibitor failure or non-compliance with quality requirements.
Suffix meaning for deep groove ball
1. CN: Standard radial clearance; commonly used in combination with the following letters to denote a narrower or offset clearance range.
? H: Narrowed gap range, equivalent to the upper half of the original gap range
? L: Narrowed clearance range, equivalent to the lower half of the original clearance range
Offset gap range, equivalent to the upper half of the original gap range and the lower half of the next gap range. The above letters also apply to the following gap groups to form corresponding meanings: C2, C3, C4, and C5, for example, C2
C2: Radial Clearance Less Than Standard Group
2. C3: Radial Clearance Larger Than Standard Group
3. C4: Radial clearance greater than C3
4. C5: Radial Clearance greater than C4
5. DB: Single-row deep groove ball bearings paired in back-to-back arrangement
6. DF: Two single-row deep groove ball bearings paired face-to-face
7. DT: Single-row deep groove ball bearings paired in series
8. E: Reinforced Design
9. GJN: Polyurea grease, NLGI Grade 2, temperature range -30 to +150°C (standard filling quantity)
10. GXN: Polyurea grease, NLGI Grade 2, temperature range -40 to +150°C (standard filling quantity)
11. J: Stampings Steel Retainer
12. LHT23: Lithium-based grease, NLGI Grade 2, temperature range -50 to +140°C (standard filling quantity)
13. LT: Lithium-based grease, NLGI 2 consistency, temperature range -55 to +110°C (standard filling quantity)
14. LT10: Lithium-based grease, NLGI Grade 2, temperature range -50 to +90°C (standard filling capacity)
15. M: Machined brass retainer, ball guide. Different designs and materials are indicated by numbers following the M, such as M2
16. MA: Machined Brass Retainer, Outer Ring Guide
17. MB: Machined brass retaining ring, inner guide
18. MT33: Lithium-based grease, NLGI grade 3, temperature range -30 to +120 degrees Celsius (standard filling quantity)
20. N: Outer ring with stop slot
21. NR: Outer ring with stop groove and stop ring
22. N1: The outer side has grooves (used to accommodate a stopper device to prevent the outer ring from rotating)
23. P5: Dimensional and rotational accuracy meets ISO tolerance grade 5
24. P6: Size and rotational accuracy conform to ISO tolerance grade 6
25. P52：P5+C2
26. P62：P6+C2
27. P63：P6+C3
28. RS1: Contact Sealing Ring of Nitrile Butadiene Rubber (NBR) with Steel Reinforcement on One Side
29. RSH: Contact Sealing Ring of Nitrile Butadiene Rubber (NBR) with Steel Reinforcement on One Side
30. RSL: Low-friction NBR (Nitrile Butadiene Rubber) seals with steel reinforcing on one side
31. RZ: Low-friction NBR (Nitrile Butadiene Rubber) sealing rings with steel reinforcing on one side
32. TH: Fiber Reinforced Phenolic Resin Retainer (Card Type)
33. TN: Injection Molding Nylon Retainer
34. TN9: Injection molded glass fiber reinforced nylon 6,6 retainers
35. VL0241: Outer surface of the outer ring with an aluminum oxide coating, insulation capability up to 1000VDC
36. VL2071: Inner surface with an alumina coating, insulation capability up to 1000VDC
37. WT: Polyurea grease, NLGI 2 consistency, temperature range -40 to +160 degrees Celsius (standard fill quantity)
38. Y: Stamped Copper Retainer
39. Z: Dust cover with stamped steel on one side
40. ZNR: Outer ring with stop slots and stop rings; the other side of the stop slots features a stamped steel dust cover.
41. 2RS1: Contact Sealing Washers with Steel Reinforcement on Both Sides, made of Nitrile Rubber (NBR)
42. 2RSH: Contact seal rings made of nitrile rubber (NBR) with steel reinforcement on both sides
43. 2RSL: NBR low-friction sealing rings with steel reinforced sides
44. 2RZ: Low-friction NBR (Nitrile Butadiene Rubber) seal rings with steel骨架 on both sides
45. 2Z: Dust covers with stamped steel on both sides
46. 2ZNR: Outer ring with stop slots and stop rings, with stamped steel dust covers on both sides
Common suffix for ball hole with packaging:
1. C3: Radial clearance greater than standard group
2. N: Outer ring with stop slot
3. NR: Outer ring with stop slot and stop ring
4. Z: Dust cover with stamped steel on one side
5. ZNR: Outer ring with stop slots and stop rings, the other side of the stop slots featuring a stamped steel dust cover
6. 2Z: Pressed steel dust covers on both sides
7. 2ZNR: Outer ring with stop slots and stop ring, both sides with stamped steel dust covers
The meaning of the suffix for stainless steel:
1. R: Flanged Outer Ring
2. VT378: Non-toxic lubricant (accidentally contacted with food ingredients)
3. 2RS1: Contact seal ring made of NBR (Nitrile Rubber) with steel reinforcing on both sides
4. 2Z: Pressed steel dust covers on both sides
2ZR: Dust caps with stamped steel on both sides and a flanged outer ring
