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 structure also includes two types: sealed and open. Open refers to bearings without a sealing structure. Sealed deep groove ball bearings are further divided into dust-proof sealed and oil-proof sealed types. 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 that effectively prevents the lubricant from leaking out of the bearing.
Single-row deep groove ball bearing type is denoted as 6, while the double-row deep groove ball bearing is denoted as 4. Its structure is simple, easy to use, and it is a type of bearing widely used in 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 "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 a wide range of applications. They are suitable for high-speed operation, even at extremely high speeds, and are highly durable, requiring minimal maintenance. These bearings have a low coefficient of friction, high maximum speed, simple structure, low manufacturing costs, and are easy to achieve high manufacturing precision. They come in a variety of sizes and shapes, and are used in precision instruments, low-noise motors, automobiles, motorcycles, and general machinery industries. They are one of the most widely used types of bearings in the mechanical industry, primarily supporting radial loads but also capable of handling 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, stamping 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 enabling bidirectional axial positioning. Additionally, these bearings possess a certain degree of self-aligning capability; they can still operate normally when inclined 2′~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 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 exhibit certain performance of angular contact ball bearings, allowing them to bear 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 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.
Bearings structure
Spherical ball bearings have a simple structure, making it easier to achieve high manufacturing accuracy 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.
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 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 sizes of 26mm or less.
(2) Small Bearings - Bearings with a nominal outer diameter size range of 28-55mm.
(3) Medium and Small Size 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 above.
Deep groove ball bearings are used in gearboxes, instruments and meters, motors, household appliances, internal combustion engines, vehicles, agricultural machinery, construction equipment, engineering machinery, roller skates, yo-yos, and more.
Installation Method
Deep Groove Ball Bearing Installation Method 1: 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 pressed onto the shaft first using a press. Then, insert the shaft with the bearing into the housing bore. During the press fit, place a soft metal tube (copper or soft steel) made of a soft metal on the " _blank" bearing inner race face. When the outer race fits tightly with the bearing housing bore and the inner race fits loosely with the shaft, press the bearing into the housing bore first; the outer diameter of the assembly tube should be slightly smaller than the bore diameter. If both the bearing races and the shaft and housing bore are tightly fitted, both the inner and outer races must be pressed into the shaft and bore simultaneously. The assembly tube structure should be able to simultaneously press the inner and outer race faces of the bearing.
Deep Groove Ball Bearing Installation Method Two: Heat Fit Installation: An installation method that utilizes thermal expansion to convert a tight fit into a loose fit by heating the bearing or bearing housing. This is a commonly used and labor-saving method. It is suitable for installing bearings with large interference fit. Before heat fitting, place the bearing or separable bearing ring into an oil tank and uniformly heat it to 80-100°C, then remove it from the oil and quickly install it onto the shaft. To prevent the inner ring end face from not fitting tightly with the shaft shoulder 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 scratching the mating surface. When heating the bearing in an oil tank, there should be a grill at a certain distance from the bottom of the tank, or the bearing should be hung with hooks, not placed at the bottom 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 and reduce the hardness of the ring.
Tolerance
Standard deep groove ball bearings have a normal grade, all conforming to GB307.1.
Gap
Standard deep groove ball bearings are available with C2, Standard (CN), C3, C4, and C5 internal clearances, 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: The production of general bearings typically requires 20 to 40 processes, with some exceeding 70.
2. Forming Processing: The working surfaces of the bearing components are all rotating forming surfaces, suitable for processing by the forming method.
3. Precision Machining: The majority of bearing parts require grinding processing, with both the 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 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 can experience rusting, and there are numerous reasons for bearing rust. The main factors we commonly encounter in our daily lives include the following.
1) Due to poor sealing, invasion by moisture, dirt, and other contaminants.
2) Bearings left unused for an extended period, exceeding the anti-rust duration, and lacking proper maintenance.
3) The metal surface has a high roughness.
4) Exposure to corrosive chemicals, inadequate bearing cleaning, surface contamination, or contact with bearings by sweaty hands; if not packaged or installed promptly after cleaning, the bearings are left exposed to air for an extended period, susceptible to moisture and contamination.
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; usually 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
? L: Narrowed gap range, equivalent to the lower half of the original gap 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 Larger Than C3
4. C5: Radial Clearance Larger Than C4
5. DB: Single-row deep groove ball bearings paired in back-to-back configuration
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 degrees Celsius (standard fill quantity)
10. GXN: Polyurea grease, NLGI 2 consistency, temperature range -40 to +150 degrees Celsius (standard filling quantity)
11. J: Stampings 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 filling amount)
14. LT10: Lithium-based grease, NLGI Grade 2, temperature range -50 to +90 degrees Celsius (standard fill capacity)
15. M: Machined brass retaining bracket, steel ball guide. Different designs and materials are indicated by numbers following the M, such as M2
16. MA: Machined Brass Retaining Ring, Outer Circle Guide
17. MB: Machined brass retaining bracket, inner ring guide
18. MT33: Lithium-based grease, NLGI 3 consistency, temperature range -30 to +120 degrees Celsius (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 locking device to prevent the outer ring from rotating)
23. P5: Dimensional and rotational accuracy complies with ISO tolerance grade 5
24. P6: Dimensional and rotational accuracy conforms 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 Seals of Nitrile Butadiene Rubber (NBR) with Steel Reinforcement on One Side
30. RSL: Low-friction NBR (Nitrile Butadiene Rubber) sealing rings 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 coated with aluminum oxide, with insulation capability up to 1000VDC
36. VL2071: Inner surface with an aluminum oxide coating, insulation capacity up to 1000VDC
37. WT: Polyurea grease, NLGI 2 consistency, temperature range -40 to +160°C (standard fill amount)
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 rings with steel reinforced Nitrile Butadiene Rubber (NBR) on both sides
42. 2RSH: Contact seal rings with steel reinforcing on both sides, made of nitrile rubber (NBR)
43. 2RSL: Nitrile rubber (NBR) low friction sealing rings with steel skeletons on both sides
44. 2RZ: Low-friction NBR (Nitrile Butadiene Rubber) sealing rings with steel reinforcing on both sides
45. 2Z: Dust covers with stamped steel on both sides
46. 2ZNR: Outer ring with stop slots and rings, with stamped steel dust covers on both sides
Common suffix for ball socket with gap:
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 slot and stop ring, the other side of the stop slot featuring a stamped steel dust cover
6. 2Z: Dust covers with stamped steel on both sides
7. 2ZNR: Outer ring with stop slots and stop rings, with stamped steel dust covers on both sides
The meaning of the suffix for stainless steel:
1. R: Flanged Outer Ring
2. VT378: Non-toxic lubricant (accidental contact with food ingredients)
3. 2RS1: Contact seal ring made of nitrile rubber (NBR) with steel reinforcing on both sides
4. 2Z: Dust caps with embossed steel on both sides
5. 2ZR: Dust covers with stamped steel on both sides and a flanged outer ring
