Deep groove ball bearing:
Basic Parameters
Deep groove ball bearings are a common type of rolling bearing. 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 structure of deep groove balls is available in sealed and open styles. Open style refers to bearings without a sealing structure. Sealed deep groove ball bearings are divided into dust-proof sealed and oil-proof sealed types. The dust-proof seal 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 lubricating grease from leaking out of the bearing.
Single-row deep groove ball bearing type is denoted as 6, and double-row deep groove ball bearing as 4. It features a simple structure and ease of use, making it a widely produced and extensively applied type of bearing.
Operating Principle
Deep groove ball bearings primarily support radial loads and can also bear both radial and axial loads simultaneously. When subjected only to 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 supporting 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 operations, even at high speeds, and are highly durable, requiring minimal maintenance. These bearings have a low friction coefficient, high maximum speed, simple structure, low manufacturing costs, and are easy to achieve high manufacturing precision. The size range and form vary greatly, and they 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 bearing 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. With the presence of an axial force, the contact angle is greater than zero. Generally, stamped wave retainers, turned solid retainers, and sometimes 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, allowing for bidirectional axial positioning. Additionally, these bearings have 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 service life. The retainers for deep groove ball bearings are typically stamped steel wave 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. Primarily designed to withstand radial loads, they also exhibit certain angular contact ball bearing properties when the radial clearance of the bearing is increased, allowing them to bear combined radial and axial loads. They can also be used to bear pure axial loads when high 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.
Bearings construction
Deep groove ball bearings have a simple structure, are easy to achieve high manufacturing precision compared to other types, and are therefore well-suited for mass production in series at a lower cost, making them extremely common. 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 seat groove
6. Double-row deep groove ball bearing
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 Size Bearings - Bearings with nominal outer diameter sizes ranging from 60 to 115mm.
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 nominal outer diameter sizes of 440mm and 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 ring and shaft have a tight fit, and the outer ring and the bearing housing bore have a loose fit, the bearing can be pressed onto the shaft first using a press machine. Then, insert the shaft 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 outer ring of the bearing has a tight fit with the bearing housing bore and the inner ring has a loose fit 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 rings and the shaft and housing bore are tightly fitted, both the inner and outer rings 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 rings of the bearing against their respective faces.
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. This is a commonly used and labor-saving method. It is suitable for installing bearings with a large interference fit. Before heat fitting, place the bearing or the split-type bearing ring into an oil tank and uniformly heat it to 80-100°C. Then, remove it from the oil and quickly fit it onto the shaft. To prevent the inner ring face from not fitting tightly against the shaft shoulder after cooling, retighten the bearing axially after cooling. When the outer race 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 surfaces. When heating the bearing in an oil tank, there should be a grid at a certain distance from the bottom of the tank, or the bearing should be hung with hooks to prevent it from touching the bottom, which could allow impurities to enter 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 the tempering effect, which could reduce the hardness of the sleeve.
Tolerance
Standard deep groove ball bearings are of general grade, all compliant 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.
Retaining Rack
Deep groove ball bearings usually come with a steel stamping retainer or a brass solid retainer. When the outer diameter is less than 400 mm, a steel stamping retainer is used without a suffix code. When the outer diameter is greater than 400 mm, a brass solid retainer is 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 all rotational forming surfaces, suitable for processing by the forming method.
3. Precision Machining: The vast majority of bearing parts require grinding processing, with 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 balls and retainers. It is anticipated that there may be instances of insufficient load 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 numerous reasons for this. The most common factors we encounter in our daily lives include the following.
1) Due to poor sealing, intrusion by moisture, dirt, etc.
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 cleaning of bearings, surface contamination, or contact with the bearings by sweaty hands; failure to package or install the bearings promptly after cleaning, resulting in long-term exposure to air and moisture, leading to contamination and corrosion.
5) Environmental temperature and humidity, as well as contact with various environmental media; rust inhibitor failure or non-compliance with quality requirements.
Deep groove ball suffix meaning
1. CN: Standard radial clearance; typically 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 gap range, equivalent to the lower half of the original gap range
P: Offset clearance range, consisting of the upper part of the original clearance range and the lower part of the next group of clearance ranges. The above letters also apply to the following clearance 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 2 consistency, temperature range -30 to +150°C (standard filling amount)
10. GXN: Polyurea grease, NLGI Grade 2, temperature range -40 to +150°C (standard fill quantity)
11. J: Stamping Steel Retainer Bracket
12. LHT23: Lithium-based grease, NLGI 2 consistency, temperature range -50 to +140 degrees Celsius (standard fill quantity)
13. LT: Lithium-based grease, NLGI Grade 2, temperature range -55 to +110 degrees Celsius (standard filling quantity)
14. LT10: Lithium-based Grease, NLGI Grade 2, Temperature Range -50 to +90°C (Standard Filling Quantity)
15. M: Machined brass retainer, ball guide. Different designs and materials are identified by numbers following the letter M, such as M2
16. MA: Machined Brass Retainer, 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 Fill Quantity)
20. N: Outer ring with stop slot
21. NR: Outer ring with stop slots and stop rings
22. N1: The outer side has grooves (for配合 with the stop device to prevent the outer ring from rotating)
23. P5: Size and rotational accuracy conforms to 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
RS1: Contact Seal Ring made of Nitrile Butadiene Rubber (NBR) with Steel Reinforcement on One Side
29. RSH: Contact Seals made of NBR (Nitrile Butadiene Rubber) 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 Retaining Rack (Card Type)
33. TN: Injection Molding Nylon Retainer
34. TN9: Injection molded glass fiber reinforced nylon 6,6 retaining bracket
35. VL0241: Outer surface of the outer ring coated with aluminum oxide, 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 retaining bracket
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 circlips with steel frame on both sides, made of nitrile rubber (NBR)
42. 2RSH: Contact seal circlips with steel frame and nitrile rubber (NBR) on both sides
43. 2RSL: Nitrile rubber (NBR) low-friction seal rings with steel skeletons on both sides
44. 2RZ: Low-friction NBR (Nitrile Butadiene Rubber) seal rings with steel reinforced side bands
45. 2Z: Pressed steel dust covers on both sides
46. 2ZNR: Outer ring with stop slots and stop rings, both sides equipped with stamped steel dust covers
Common suffix for ball gap with packaging:
1. C3: Radial Clearance Larger Than Standard Group
2. N: Outer ring with stop groove
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 opposite side of the stop slots features a stamped steel dust cover.
6. 2Z: Dust caps with pressed steel on both sides
7. 2ZNR: Outer ring with stop slot and stop ring, with stamped steel dust caps on both sides
The meaning of the suffix for stainless steel:
R: Outer ring with flange
2. VT378: Non-toxic Lubricant (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
5. 2ZR: Dust covers with stamped steel on both sides and a flanged outer ring
