Deep groove ball bearing:
Basic Parameters
Tapered roller 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. Tapered roller bearings come in single-row and double-row configurations, and the structure is available in sealed and open styles. Open style refers to bearings without sealing, while sealed types are divided into dust-proof and oil-proof seals. The dust-proof seal cover is made of steel stamping, serving only to prevent dust from entering the bearing raceways. The oil-proof type is a contact oil seal, effectively preventing the leakage of grease within 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 bearing type for general production applications.
Working Principle
Deep groove ball bearings primarily bear radial loads and can also withstand 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 an 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 operations, even at extreme 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-bearing 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, stamped wave-shaped retainers, turned solid retainers, and sometimes nylon frames are used.
Deep groove ball bearings, after mounted on the shaft, can limit the axial displacement of either the shaft or the housing in both directions within the axial clearance range of the bearing, allowing for bidirectional axial positioning. Moreover, these bearings also possess a certain degree of self-aligning capability; they can still function normally when inclined 2′~10′ relative to the housing bore, although this has an impact on the bearing's lifespan. The retainers of 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 exhibit certain characteristics of angular contact ball bearings, allowing them to bear 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 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, which makes it easier to achieve high manufacturing accuracy compared to other types. This facilitates mass production in series and results in lower production costs, making it extremely widespread. 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 stop slots, deep groove ball bearings with ball grooves 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 bearings with dust cover
3. Single-row deep groove ball bearings with dust caps and seals
4. Single-row deep groove ball bearing with stop slots and stop 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-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
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 one: Press fit: When the bearing inner race is a tight fit with the shaft and the outer race is a loose fit with the bearing housing bore, the bearing can be first pressed onto the shaft using a press. Then, the shaft, along with the bearing, is inserted 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 inner race of the blank. When the outer race of the bearing is a tight fit with the bearing housing bore and the inner race is 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 fitting 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, the inner and outer races must be pressed into the shaft and bore simultaneously. The fitting 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: 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 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 mount it onto the shaft. To prevent the inner ring face and the shaft shoulder from not fitting tightly after cooling, additional axial tightening can be applied after the bearing has cooled. 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 damage to the mating surfaces. 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 resting on the bottom, which could lead to sediment entering the bearing or uneven heating. A thermometer must be present 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 rings.
Tolerance
Standard deep groove ball bearings are of ordinary grade, all conforming to GB307.1.
Clearance space
Standard deep groove ball bearings are available in C2, standard (CN), C3, C4, and C5 internal clearance grades, all conforming to GB4604.
Retaining Rack
Deep groove ball bearings commonly 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 bearing parts are rotatable 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 particularly evident in large deep groove ball bearings with heavy ball and retainer weights. 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 experience 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, 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 surface roughness of the metal is quite large.
4) Exposure to corrosive chemicals, inadequate cleaning of bearings, surface contamination, or contact with the bearings by sweaty hands; if not packaged or installed promptly after cleaning, the bearings will be long-term exposed to air, leading to attack and contamination by moisture in the air.
5) Environmental temperature and humidity, as well as contact with various environmental media; failure of rust inhibitors or non-compliance with quality requirements.
Suffix meaning for deep groove ball
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
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 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 2 consistency, temperature range -30 to +150 degrees Celsius (standard fill quantity)
10. GXN: Polyurea grease, NLGI 2 consistency, temperature range -40 to +150°C (standard filling quantity)
11. J: Stamped Steel Retaining Bracket
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 degrees Celsius (standard fill quantity)
14. LT10: Lithium-based Grease, NLGI Grade 2, Temperature Range -50 to +90°C (Standard Filling Level)
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 Circle 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 slots and stop ring
22. N1: The outer ring side has grooves (used to accommodate the locking device to prevent the outer ring from rotating)
23. P5: Dimensional and rotational accuracy conforms to ISO tolerance grade 5
24. P6: Dimensional and rotational accuracy meets 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 ring of nitrile butadiene rubber (NBR) with steel frame 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) 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 66 retainers
35. VL0241: Outer surface of the outer ring coated with alumina, insulation capability up to 1000VDC
36. VL2071: Inner ring outer surface with alumina coating, insulation capability up to 1000VDC
37. WT: Polyurea grease, NLGI 2 consistency, temperature range -40 to +160 degrees Celsius (standard filling quantity)
38. Y: Stampings copper retainer
39. Z: Dust cover with stamped steel on one side
40. ZNR: Outer ring with stop slot and stop ring; the other side of the stop slot features a stamped steel dust cover.
41. 2RS1: Contact Seal Ring with Steel Skeleton on Both Sides, Nitrile Rubber (NBR)
42. 2RSH: Contact seal circlips with steel reinforcing on both sides made of nitrile rubber (NBR)
43. 2RSL: Nitrile rubber (NBR) low-friction seal rings with steel reinforced side walls
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 stop rings, with stamped steel dust covers on both sides
Common suffixes for ball gap with packaging:
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 equipped with a stamped steel dust cover
6. 2Z: Dust caps with stamped steel sides
7. 2ZNR: Outer ring with stop slots and stop ring, both sides equipped with stamped steel dust caps
The meaning of stainless steel suffixes:
R: Flanged Outer Ring
2. VT378: Non-toxic Lubricant (Accidental Contact with Food Ingredients)
3. 2RS1: Contact seals made of nitrile rubber (NBR) with steel reinforcing 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
