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 design also includes two structures: sealed and open. Open refers to bearings without a sealing structure. Sealed deep groove ball bearings are further categorized into dust-proof sealed and oil-proof sealed. The dust-proof sealed cover is made of steel plate stamping and simply prevents dust from entering the bearing raceway. The oil-proof type is a contact seal, which effectively prevents the lubricant from spilling out of the bearing.
Single-row deep groove ball bearing type is designated as 6, and double-row deep groove ball bearing as 4. It features a simple structure and ease of use, making it a commonly produced and widely applied type of bearing.
Operating 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 " _blank" angular contact bearings, 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 and even very high-speed operations, 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.
When selecting a larger radial clearance, the axial load capacity increases, and the contact angle is zero when bearing only radial force. When subjected to an axial force, the contact angle is greater than zero. Generally, stamped wave retainers, turned solid retainers, and sometimes nylon frames 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 axial clearance range of the bearing, thereby enabling bidirectional axial positioning. Additionally, these bearings possess certain self-aligning capabilities; they can still function normally when tilted by 2′ to 10′ relative to the housing bore, although this may have an impact on the bearing's lifespan. The retainers for deep groove ball bearings are typically stamped steel sheet wavy retainers, while larger bearings often use turned metal solid retainers.
Tapered roller 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 exhibit certain performance of angular contact ball bearings, capable of bearing combined radial and axial loads. They can also be used to bear pure axial loads when high rotational speeds are involved and thrust ball bearings are not suitable. Compared to other types of bearings with the same specification and size as the tapered roller bearings, these have a lower friction coefficient and 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, which makes it easier to achieve high manufacturing precision compared to other types. This facilitates mass production in series at a lower cost, and they are extremely common in 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 loading notches for high load capacities, and double-row deep groove ball bearings.
Bearings Type
Single-row deep groove ball bearing
2. Single-row deep groove ball bearing 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 bearings with ball retainer 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) Medium and Small 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 suitable for applications such as gearboxes, instruments and meters, motors, household appliances, internal combustion engines, transportation vehicles, agricultural machinery, construction equipment, construction machinery, rollerblades, yo-yos, and more.
Installation Method
Deep groove ball bearing installation method one: Press fit: When the bearing inner race fits tightly with the shaft and the outer race fits loosely with the bearing housing bore, the bearing can be first pressed onto the shaft using a press machine. Then, the shaft with the bearing attached is inserted into the bearing housing bore. During pressing, place a soft metal tube (copper or soft steel) made of soft metal on the " _blank" bearing inner race face. When the bearing outer race fits tightly with the bearing housing bore and the inner race fits loosely with the shaft, the bearing can be pressed into the bearing housing bore first. In this case, the outer diameter of the installation tube should be slightly smaller than the bore diameter. If both the bearing races and the shaft or housing bore are tightly fitted, both the inner and outer races must be pressed into the shaft and bore simultaneously. The structure of the installation tube should be able to simultaneously press the inner and outer race faces of the bearing.
Deep groove ball bearing installation method two: Heat fit: An installation method that utilizes thermal expansion to convert a tight fit into a loose fit by heating the bearing or bearing housing. It is a commonly used and labor-saving method. This method is suitable for installing bearings with large interference fit. Before heat fitting, place the bearing or split-type bearing ring in an oil tank and heat it uniformly to 80-100°C, then quickly install it 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 fitted tightly with a lightweight metal bearing housing, use the heat fitting method for the bearing housing to avoid damaging the mating surfaces. 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, not placed at the bottom of the tank to prevent sediment from entering the bearing or uneven heating. The oil tank must have a thermometer to strictly control the oil temperature to not exceed 100°C to prevent the tempering effect, which may reduce the hardness of the sleeve.
Tolerance
Standard deep groove ball bearings are of ordinary grade and fully comply with GB307.1.
Clearance
Standard deep groove ball bearings come in C2, standard (CN), C3, C4, and C5 internal clearance grades, all conforming to GB4604.
Retainer bar
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: General 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 parts require grinding processing, with both the grinding 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 particularly evident in large deep groove ball bearings with heavy ball and " \t "_blank retainer. 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 may experience rusting, and there are various reasons for this. The most common factors we encounter in daily life include the following.
1) Due to poor sealing, intrusion of moisture, dirt, etc.
2) Bearings left unused for an extended period, exceeding the anti-rust period, and lacking maintenance.
3) The metal surface has a high degree of roughness.
4) Exposure to corrosive chemicals, improper cleaning of bearings, surface contamination, or handling with sweaty hands; failure to package or install the bearings promptly after cleaning, leading to long-term exposure to air and moisture, causing contamination and damage.
5) Environmental temperature and humidity, and contact with various environmental media; rust preventive agent failure or does not meet quality requirements.
Suffix meaning for deep groove ball
1. CN: Standard radial clearance; commonly used in combination with the following letters to indicate a narrower or offset clearance range
H: Narrowed gap range, equivalent to the upper half of the original gap range
Narrowed clearance range, equivalent to the lower half of the original clearance range
Offset gap range, consisting of 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: Two single-row deep groove ball bearings paired back-to-back
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 fill quantity)
10. GXN: Polyurea grease, NLGI Grade 2, temperature range -40 to +150°C (standard filling quantity)
11. J: Stamped Steel Retainer Bracket
12. LHT23: Lithium-based grease, NLGI Grade 2, temperature range -50 to +140°C (standard filling quantity)
13. LT: Lithium-based grease, NLGI Grade 2, temperature range -55 to +110°C (standard fill quantity)
14. LT10: Lithium-based grease, NLGI Grade 2, temperature range -50 to +90 degrees Celsius (standard fill capacity)
15. M: Machined brass retaining sleeve, steel ball guide. Different designs and materials are indicated by numbers following the letter M, such as M2
16. MA: Machined Brass Retaining Ring, Outer Ring Guide
17. MB: Machined Brass Retainer, Inner Ring Guide
18. MT33: Lithium-based Grease, NLGI Grade 3, Temperature Range -30 to +120°C (Standard Filling Quantity)
20. N: Outer ring with stop slot
21. NR: Outer ring with stop slot and stop ring
22. N1: The outer ring side features grooves (for配合with the stop device to prevent the outer ring from rotating)
23. P5: Dimensional and rotational accuracy meets ISO tolerance grade 5
24. P6: Dimensional accuracy and rotational accuracy conform to ISO tolerance grade 6
25. P52：P5+C2
26. P62：P6+C2
27. P63：P6+C3
28. RS1: Contact Seal Ring of Nitrile Butadiene Rubber (NBR) with Steel Reinforcement on One Side
29. RSH: Contact seal made of nitrile butadiene rubber (NBR) with steel reinforcement on one side
30. RSL: Low-friction NBR (Nitrile Butadiene Rubber) sealing ring with steel reinforcing in one side
31. RZ: Low-friction NBR (Nitrile Butadiene Rubber) seals 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 Retainer
35. VL0241: Outer surface of the outer ring coated with alumina, insulation capability up to 1000VDC
36. VL2071: Inner ring outer surface with aluminum oxide coating, insulation capability up to 1000VDC
37. WT: Polyurea grease, NLGI 2 consistency, temperature range -40 to +160°C (standard filling 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 seal circlip with steel reinforcing on both sides, made of nitrile rubber (NBR)
42. 2RSH: Contact seal circlips with steel reinforcement, featuring nitrile rubber (NBR) on both sides
43. 2RSL: NBR low-friction sealing rings with steel reinforcing on both sides
44. 2RZ: Low-friction sealing rings made of nitrile rubber (NBR) with steel reinforcing on both sides
45. 2Z: Dust covers with stamped steel on both sides
46. 2ZNR: Outer ring with stop slot and stop ring, both sides equipped with stamped steel dust covers
Common suffixes for ball socket with gaps:
1. C3: Radial Clearance Larger 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 features a stamped steel dust cover.
6. 2Z: Pressed steel dust caps on both sides
7. 2ZNR: Outer ring with stop slots and stop rings, with stamped steel dust covers on both sides
The meaning of suffixes for stainless steel:
R: Outer ring with flange
2. VT378: Non-toxic lubricant (for accidental contact with food ingredients)
3. 2RS1: Contact Seals of Nitrile Rubber (NBR) with Steel Skeleton on Both Sides
4. 2Z: Pressed steel dust covers on both sides
2ZR: Dust caps with stamping steel on both sides and flanges on the outer ring
