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 structure also includes two configurations: 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 that effectively prevents the leakage of grease inside the bearing.
Single-row deep groove ball bearing type is coded as 6, and double-row deep groove ball bearing is coded as 4. It features a simple structure and ease of use, making it a widely used and common type of bearing.
Operating Principle
Deep groove ball bearings mainly bear radial loads and can also bear both radial and axial loads simultaneously. 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, enabling them to bear 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 extremely 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. They come in a variety of sizes and shapes, and 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. 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.
Mounted on the shaft, deep groove ball bearings 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 ability; they can still operate normally when tilted 2′~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 large 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 characteristics of angular contact ball bearings, enabling them to withstand combined radial and axial loads. They can also bear pure axial loads when high-speed rotation is required and thrust ball bearings are not suitable. Compared to other types of bearings with the same specifications as the tapered roller bearings, these have a lower coefficient of friction and a higher maximum speed. However, they are not shock-resistant and are not suitable for bearing heavy loads.
Bearings construction
The deep groove ball bearing has a simple structure, allowing for higher manufacturing precision compared to other types. This facilitates mass production in series, resulting in lower production costs and widespread usage. In addition to the basic type, there are various modified structures, such as deep groove ball bearings with dust covers, those with rubber sealing rings, bearings with stop slots, high-load capacity bearings with ball recesses, 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 seal ring
4. Single-row deep groove ball bearing with stop slots and stop rings on the outer ring
5. Deep groove ball bearing 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 28-55mm.
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 nominal outer diameter sizes of 440mm and above.
Deep groove ball bearings are suitable for gearboxes, instruments and meters, motors, household appliances, internal combustion engines, vehicles, agricultural machinery, construction machinery, engineering equipment, roller skates, yo-yos, and more.
Installation Method
Deep Groove Ball Bearing Installation Method 1: Press Fit: When the inner race of the bearing is a tight fit with the shaft, and the outer race is a loose fit 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 bearing housing bore. During the press fit, place a soft metal tube (copper or soft steel) made of soft metal on the end face of the bearing inner race. When the outer race is a tight fit with the bearing housing bore and the inner race is a loose fit with the shaft, press the bearing into the bearing housing bore first. At this point, the outer diameter of the assembly tube should be slightly smaller than the diameter of the bore. If both the bearing races and the shaft and housing bore are tight fits, 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 end faces of both the inner and outer races of the bearing.
Deep Groove Ball Bearing Installation Method Two: Heat Fit Installation: An installation method that utilizes thermal expansion by heating the bearing or bearing housing to transform a tight fit into a loose fit. 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 separable bearing races into an oil tank and uniformly heat them to 80-100°C. Then, remove them from the oil and quickly fit them onto the shaft. To prevent the inner race face from not fitting tightly against the shaft shoulder after cooling, the bearing can be further axially tightened 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 any scratches on the mating surface. When heating the bearing in an oil tank, there should be a grate 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 lead to sediment 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 the tempering effect that could reduce the hardness of the races.
Tolerance
Standard deep groove ball bearings are of ordinary grade, all conforming to GB307.1.
Clearance space
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. When the outer diameter is less than 400 mm, steel stamping retainers are used without a suffix code. When the outer diameter is greater than 400 mm, 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. Molding Processing: The working surfaces of the bearing parts are rotational molding surfaces, suitable for processing by molding methods.
3. Precision Machining: The majority of bearing parts require grinding processing for their surfaces, with the dimensions and geometric accuracy measured in micrometers (μm).
Deep groove ball bearings, with insufficient bearing load during operation, may cause sliding between the balls and raceways, leading to abrasion. This tendency is especially prevalent in large deep groove ball bearings with heavy ball and " _blank" retainer. It is anticipated that there may be insufficient load conditions in use. Please contact 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 main factors we commonly encounter in our daily lives include:
1) Due to poor sealing, invasion by moisture, dirt, and other contaminants.
2) Bearings have been unused for an extended period, exceeding the anti-rust period, and lack proper maintenance.
3) The metal surface has a high degree of roughness.
4) Exposure to corrosive chemicals, improper cleaning of bearings, surface contamination, or contact with the bearings by sweaty hands; failure to package or install the bearings promptly after cleaning, leading to long-term exposure to air moisture, resulting in contamination.
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 clearance range, equivalent to the lower half of the original clearance range
P: Offset clearance range, consisting of the upper half of the original clearance range and the lower half of the next clearance range. 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 Greater Than Standard Group
3. C4: Radial clearance greater than C3
4. C5: Radial Clearance Larger 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 2 consistency, temperature range -30 to +150 degrees Celsius (standard filling amount)
10. GXN: Polyurea grease, NLGI 2 consistency, temperature range -40 to +150 degrees Celsius (standard fill volume)
11. J: Stamped Steel Retaining Bracket
12. LHT23: Lithium-based grease, NLGI Grade 2, temperature range -50 to +140°C (standard fill quantity)
13. LT: Lithium-based grease, NLGI Grade 2, temperature range -55 to +110 degrees Celsius (standard fill quantity)
14. LT10: Lithium-based grease, NLGI Grade 2, operating temperature range -50 to +90°C (standard fill capacity)
15. M: Machined brass retaining sleeve, 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 race 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 fit 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 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 Sealing Ring of Nitrile Butadiene Rubber (NBR) with Steel Skeleton on One Side
30. RSL: Low-friction NBR (Nitrile Butadiene Rubber) sealing ring with steel reinforcement on one side
31. RZ: Low-friction NBR (Nitrile Butadiene Rubber) seals with a steel reinforcing frame 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 ring with an alumina coating, insulation capability up to 1000VDC
36. VL2071: Inner surface with aluminum oxide coating, insulation capability up to 1000VDC
37. WT: Polyurea grease, NLGI Grade 2, Temperature Range -40 to +160°C (Standard Filling)
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 reinforcing on both sides
43. 2RSL: NBR low-friction sealing rings with steel reinforcement 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, with stamped steel dust caps on both sides
Common suffix for ball gap with packaging:
C3: Radial Clearance Larger Than Standard Series
2. N: Outer ring with stop slot
3. NR: Outer ring with stop slot and stop ring integrated
4. Z: Dust cover with embossed 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: Dust caps with stamped steel sides
7. 2ZNR: Outer ring with stop slots and stop ring, with stamped steel dust caps on both sides
The meaning of suffixes for stainless steel:
1. R: Outer ring with flange
2. VT378: Non-toxic Lubricant (Accidental Contact with Food Ingredients)
3. 2RS1: Contact seals made of NBR (Nitrile rubber) with steel reinforced sides
4. 2Z: Dust covers with stamped steel on both sides
2ZR: Dust covers with pressed steel on both sides and a flanged outer ring
