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 bearing structure is available in two configurations: 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, serving only to prevent dust from entering the bearing raceway. The oil-proof type is a contact seal, effectively preventing 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 commonly produced and widely applied type of bearing.
Operating Principle
Deep groove ball bearings primarily 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, 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, 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. 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, mainly bearing radial loads and also 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, when mounted on an shaft, can limit the axial displacement of the shaft or housing in both directions within the axial clearance range of the bearing, allowing for bidirectional axial positioning. Additionally, these bearings possess a certain degree of self-aligning capability; they can still function 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.
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 also possess 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-speed rotation is required 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 bearings 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 construction
Spherical ball bearings have 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 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.
Bearing Type
1. 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 of the deep groove ball bearings, they can be classified as:
(1) Miniature Bearings - Bearings with an outer diameter size less than 26mm.
(2) Small Bearings - Bearings with nominal outer diameter sizes ranging from 28 to 55mm.
Small and medium-sized bearings - Bearings with nominal outer diameter sizes ranging from 60 to 115mm.
(4) Medium to Large Size Bearings - Bearings with nominal outer diameter sizes ranging from 120 to 190mm
(5) Large Bearings - Bearings with a nominal outer diameter size range of 200-430mm.
(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, rollerblades, 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 initially pressed onto the shaft using a press. Then, the shaft with the bearing attached 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 inner race end face of the bearing. When the outer race 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 housing bore first. In this case, the outer diameter of the assembly tube should be slightly smaller than the diameter of the bore. If both the bearing rings and the shaft as well as the housing bore are tight fits, both the inner and outer races should be pressed into the shaft and the housing 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 ring into an oil tank and heat it uniformly to 80-100°C. Then, remove it from the oil and quickly fit 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 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 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 and allowing 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 and reduce the hardness of the ring.
Tolerance
Standard deep groove ball bearings are of ordinary grade and fully comply with GB307.1.
Slack Clearance
Standard deep groove ball bearings are available in C2, Standard (CN), C3, C4, and C5 internal clearance grades, all compliant with GB4604.
Retaining Rack
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 all rotatable forming surfaces, suitable for processing by the forming method.
3. Precision Machining: Most bearing parts require grinding processing for their surfaces, with 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 retaining cage. 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 numerous reasons for this. The main factors we commonly encounter in our daily lives include:
1) Due to poor sealing, intrusion by moisture, dirt, etc.
2) Bearings have been unused for an extended period, exceeding the anti-rust duration, and lack proper maintenance.
3) The metal surface has a high degree of roughness.
4) Exposure to corrosive chemicals, insufficient cleaning of bearings, surface contamination, or contact with sweat on the bearings; failure to package or install the bearings promptly after cleaning, leading to long-term exposure to air and moisture, resulting in corrosion and contamination.
5) Environmental temperature and humidity, and contact with various environmental media; rust preventative is ineffective or does not meet 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 clearance range, equivalent to the lower half of the original clearance range
P: Offset clearance range, equivalent to the upper half of the original clearance range and the lower half 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: A pair of single-row deep groove ball bearings matched 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: Enhanced Design
9. GJN: Polyurea grease, NLGI Grade 2, operating temperature range -30 to +150°C (standard filling amount)
10. GXN: Polyurea grease, NLGI 2 consistency, temperature range -40 to +150°C (standard filling amount)
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 Grade 2, temperature range -55 to +110 degrees Celsius (standard filling quantity)
14. LT10: Lithium-based grease, NLGI Grade 2, operating temperature range -50 to +90°C (standard filling capacity)
15. M: Machined brass retaining bracket, steel ball guide. Different designs and materials are identified with numbers following the 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 Consistency 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 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 Sealing Ring of Nitrile Butadiene Rubber (NBR) with Steel Reinforcement on One Side
29. RSH: Contact Seals made of NBR (Nitrile Butadiene Rubber) with steel reinforcing on one side
30. RSL: Low-friction Nitrile Butadiene Rubber (NBR) seals with steel reinforcement on one side
31. RZ: Low-friction NBR (Nitrile Butadiene Rubber) sealing rings with a steel frame on one side
32. TH: Fiber Reinforced Phenolic Resin Retaining Racks (Card Type)
33. TN: Injection Molding Nylon Retainer
34. TN9: Injection Molding Glass Fiber Reinforced Nylon 66 Retainer
35. VL0241: Outer surface of the outer ring coated with aluminum oxide, insulation capability up to 1000VDC
36. VL2071: Outer surface of the inner ring with aluminum oxide coating, insulation capacity 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 slot and stop ring; the other side of the stop slot features a stamped steel dust cover.
41. 2RS1: Contact seal rings with steel reinforced nitrile rubber (NBR) on both sides
42. 2RSH: Contact seal ring with steel reinforced NBR (Nitrile Butadiene Rubber) on both sides
43. 2RSL: Nitrile rubber (NBR) low friction seal circlips with steel frame 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 stop rings, with stamped steel dust covers on both sides
Common suffix 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 embossed steel on one side
5. ZNR: Outer ring with stop slots and stop rings, with a stamped steel dust cover on the other side of the stop slots
6. 2Z: Pressed steel dust covers on both sides
7. 2ZNR: Outer ring with stop slots and stop ring, with stamped steel dust caps on both sides
The meaning of stainless steel suffix:
1. R: Outer ring with flange
2. VT378: Non-toxic Lubricant (Accidental Contact with Food Ingredients)
3. 2RS1: Contact seal rings made of nitrile rubber (NBR) with steel skeletons on both sides
4. 2Z: Pressed steel dust covers on both sides
2ZR: Dust caps with stamped steel on both sides and flanged outer ring
