688 Deep Groove Ball Bearing Ceramic Gyroscope High Quality Roller Skating Skateboard

• Customization: Available
• Type: Roller
• Material: Chrome Steel Gcr15
• Model NO.: 688
• Lubrication: Grease or Oil
• Feature: Long Life / Durable / Low Voice
• Stock Qty: Rich /Great Supplying Ability
• Main Market: Global
• After Service: Within 24 Hours Response
• Delivery Method: Air, Sea, Express
• Precision Rating: P0 P6 P5 P4 P2
• Structure: Spherical/Cylindrical/Deep Groove/Angular Contact
• Cage: Steel Cage.Copper Cage.Nylon Cage
• Transport Package: Industrial or Single Box as Request
• Specification: other
• Trademark: DOKING
• Origin: China
• HS Code: 84821020
• Production Capacity: 2000000/Year
• Package Size: 3.00cm * 3.00cm * 10.00cm
• Package Gross Weight: 0.100kg

Product Description

PRODUCT DETAILS

 

The 688 bearing is a deep groove ball bearing. It plays an important role in numerous mechanical equipment and daily items. Although it is small in size, it possesses powerful performance. 
From the structural composition perspective, the 688 bearing consists of an inner ring, an outer ring, rolling elements, and a cage. The inner ring closely fits with the rotating shaft and rotates synchronously with it; the outer ring is installed on the bearing housing or related mechanical components, serving as a support and positioning function. The rolling elements are high-strength steel balls, evenly distributed between the inner and outer rings' raceways, reducing running resistance through rolling friction instead of sliding friction, ensuring smooth rotation and minimizing energy loss. The cage separates the steel balls to prevent collisions and ensures the smooth operation of the bearing, maintaining good accuracy. 
In terms of working principle, when the shaft drives the inner ring to rotate, the rolling elements roll in the raceways of the inner and outer rings, efficiently transmitting rotational motion and evenly distributing the load they bear. This design enables the 688 bearing to maintain high precision even at high speeds, ensuring that related components operate along the predetermined trajectory. However, when the lubrication conditions are poor or the seal fails, the friction between the rolling elements and the raceways intensifies, generating a large amount of heat, shortening the bearing's service life, and even causing abnormal wear. 
The performance advantages of the 688 bearing are obvious. It has high speed adaptability, thanks to its precise structure and high-quality materials, and can operate stably at high speeds. It has excellent running accuracy, with precisely machined raceways and precisely matched rolling elements, controlling radial and axial runout within a very small range, ensuring the stable and accurate operation of the equipment. Although it is small in size, it can effectively bear a certain load in a limited space, providing convenience for the compact design of equipment. 
The national standard size specification of the 688 bearing is an inner diameter of 8mm, an outer diameter of 16mm, and a thickness of 4mm. If it is a non-standard bearing, the size will be determined according to the actual situation, but it will not differ much from the national standard specification. Due to the high cost, it is rarely used in practice. Its materials are diverse, including carbon steel, bearing steel (GCr15), stainless steel (440 or 304), ceramic balls, plastics, etc.; the cage material includes carbon steel, steel plate stamping, nylon, etc. 
The 688 bearing is widely used in products such as massage belts, electric toys, electronic accessories, instruments and meters, sports equipment, pulleys, etc. In electric toys, the rotor of the assist motor rotates smoothly and at high speed, giving the toys a lively and dynamic feel; in instruments and meters, it ensures the precise operation of the pointer, ensuring accurate data measurement; in sports equipment such as roller skates, it bears the human weight, making the skating smoother. In industrial equipment such as automobiles, machine tools, ships, and railways, the 688 bearing also plays a key role, supporting various rotating components and ensuring the stable operation of the equipment. If the 688 bearing fails, the equipment is prone to abnormal noise, increased vibration, and unstable speed, seriously affecting normal operation. Therefore, regular lubrication and sealing condition checks, as well as timely maintenance and upkeep, are important measures to ensure the long-term stable operation of the equipment.

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CATALOGUE

N0.	Bore	O.D	Width	Chamfer	Load Rating		Maximuum Seed		Weight
	mm	mm	mm	mm	Dynamic Cr	Static Cor	Grease r/min	Oil r/min	Kg/pcs
685	5	11	3	0.15	0.715	0.282	35000	45000	0.0011
686	6	13	3.5	0.15	1.08	0.44	33000	42000	0.0019
687	7	14	3.5	0.15	1.17	0.505	31000	40000	0.0021
688	8	16	4	0.2	1.61	0.715	29000	38000	0.0031
689	9	17	4	0.2	1.72	0.82	28000	36000	0.0032
6800	10	19	5	0.3	1.83	0.925	26000	34000	0.005
6801	12	21	5	0.3	1.92	1.04	22000	30000	0.006
6802	15	24	5	0.3	2.08	1.26	20000	28000	0.007
6803	17	26	5	0.3	2.23	1.46	19000	26000	0.008
6804	20	32	7	0.3	4	2.47	17000	22000	0.019
6805	25	37	7	0.3	4.3	2.95	15000	19000	0.022
6806	30	42	7	0.3	4.7	3.65	13000	17000	0.026
6807	35	47	7	0.3	4.9	4.05	11000	15000	0.029

Bearing NO	(mm)Boundary Dimensions			(Kn)	(Kn)	(r/min) Limit Rotational Speed		(Kg) Weight
	d	D	B	Dynamic Load Rating Cr	Static Load Rating Cor	Grease Lubrication	Oil Lubrication
6000	10	26	8	4.58	1.97	30000	36000	0.019
6001	12	28	8	5.11	2.39	28000	32000	0.021
6002	15	32	9	5.59	2.84	24000	28000	0.03
6003	17	35	10	6.00	3.25	22000	26000	0.04
6004	20	42	12	9.38	5.03	18000	20000	0.068
6005	25	47	12	10.06	5.85	15000	18000	0.079
6006	30	55	13	13.23	8.30	13000	15000	0.113
6007	35	62	14	16.21	10.42	11000	13000	0.149
6008	40	68	15	17.03	11.70	10000	12000	0.185
6009	45	75	16	21.09	14.77	9000	11000	0.231
6010	50	80	16	22.02	16.25	8500	10000	0.25
6011	55	90	18	30.26	21.93	7500	9000	0.362
6012	60	95	18	31.66	24.22	7100	8500	0.385
6013	65	100	18	32.06	24.89	6700	8000	0.408
6014	70	110	20	38.59	30.43	6000	7100	0.537
6015	75	115	20	40.20	33.20	5600	6700	0.603
6016	80	125	22	47.50	39.80	5300	6300	0.821
6017	85	130	22	50.80	42.80	5000	6000	0.848
6018	90	140	24	58.00	49.80	4800	5600	1.103

Designation	Bore diameter	Outside diameter	Width	Basic dynamic load rating	Limiting speed
	[mm]	[mm]	[mm]	[kN]
608	8.0	22.0	7.0	3.45	48000.0
609	9.0	24.0	7.0	3.9	43000.0
623	3.0	10.0	4.0	0.54	80000.0
624	4.0	13.0	5.0	0.936	67000.0
625	5.0	16.0	5.0	1.14	60000.0
626	6.0	19.0	6.0	2.34	50000.0
627	7.0	22.0	7.0	3.45	45000.0
629	9.0	26.0	8.0	4.75	38000.0
634	4.0	16.0	5.0	1.11	60000.0
6020	100.0	150.0	24.0	63.7	5600.0
6021	105.0	160.0	26.0	76.1	5300.0
6022	110.0	170.0	28.0	85.2	5000.0
6024	120.0	180.0	28.0	88.4	4800.0
6026	130.0	200.0	33.0	112.0	4300.0
6028	140.0	210.0	33.0	111.0	4000.0
6030	150.0	225.0	35.0	125.0	3800.0
6032	160.0	240.0	38.0	143.0	3600.0
6200	10.0	30.0	9.0	5.4	36000.0
6201	12.0	32.0	10.0	7.28	32000.0
6202	15.0	35.0	11.0	8.06	28000.0
6203	17.0	40.0	12.0	9.95	24000.0
6204	20.0	47.0	14.0	13.5	20000.0
6205	25.0	52.0	15.0	14.8	18000.0
6206	30.0	62.0	16.0	20.3	15000.0
6207	35.0	72.0	17.0	27.0	13000.0
6208	40.0	80.0	18.0	32.5	11000.0
6209	45.0	85.0	19.0	35.1	11000.0
6210	50.0	90.0	20.0	37.1	10000.0
6211	55.0	100.0	21.0	46.2	9000.0
6212	60.0	110.0	22.0	55.3	8000.0
6213	65.0	120.0	23.0	58.5	7500.0
6214	70.0	125.0	24.0	63.7	7000.0
6215	75.0	130.0	25.0	68.9	6700.0
6216	80.0	140.0	26.0	72.8	6000.0
6217	85.0	150.0	28.0	87.1	5600.0
6218	90.0	160.0	30.0	101.0	5300.0
6219	95.0	170.0	32.0	114.0	5000.0
6220	100.0	180.0	34.0	127.0	4800.0
6221	105.0	190.0	36.0	140.0	4500.0
6222	110.0	200.0	38.0	151.0	4300.0
6224	120.0	215.0	40.0	146.0	4000.0
6226	130.0	230.0	40.0	156.0	3600.0
6228	140.0	250.0	42.0	165.0	3400.0
6230	150.0	270.0	45.0	174.0	3200.0
6232	160.0	290.0	48.0	186.0	3000.0
6234	170.0	310.0	52.0	212.0	2800.0
6238	190.0	340.0	55.0	255.0	2400.0
6300	10.0	35.0	11.0	8.52	32000.0
6301	12.0	37.0	12.0	10.1	28000.0

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