Listen to NSK bearings rolling determine whether normal operation

1. NSK bearings raceway ring raceway is due to the rotating roller in the raceway roll and inspire a smooth and continuous noise, only when the sound pressure level or tone great concern. Actually raceway sparked by the sound of sound energy is limited, such as in normal circumstances, quality of bearing raceway is 25 ~ 27 db. This noise to bear radial load of single row deep groove ball bearing is the most typical, it has the following characteristics: a. Randomness of noise and vibration; b。 The vibration frequency above 1 KHZ; c。 No matter how the speed of change, the main frequency noise almost unchanged while the sound pressure level increase with the increase of rotational speed; d。 When the radial clearance increases, the sound pressure level increased dramatically; e. Bearing stiffness increases, the lower the total sound pressure level, even if the speed increases, the total sound pressure level increases; f。 Lubricant viscosity is higher, the lower the sound pressure level, but for grease lubrication, the viscosity, the shape of soap fiber size can influence the noise value. Raceway acoustic source lies in the inherent vibration caused by ring after exposure to the load. Because of the ring and rolling body elastic contact nonlinear vibration system. When lubrication or the machining accuracy is not high will stimulate the related to the elastic characteristics of natural vibration and passed to the was noise in the air. As is known to all, even if is to use the NSK bearings contemporary the most advanced manufacturing technology and processing parts, there will always be the working surface of varying degrees of tiny geometric error, thus make the raceway and rolling body produces slight fluctuations inherent vibration excitation vibration system. Although it is inevitable, but can take work surface precision machining parts, choose correct bearing and precise use bearing noise vibration reduction. 2. Fall the rumbling noise usually, mostly appear in low speed and large bearing to bear radial load. When under radial load bearing, NSK bearing the load and the load area, if the bearing has a certain radial clearance, the load of roller and inner raceway is not contact, but because of the action of centrifugal force may be in contact with the outer ring, therefore, under the low speed, when the centrifugal force is less than the rolling body weight, scrolling experience fall with inner raceway or bearing cage collision and to stimulate the natural vibration and noise, and has the following characteristics: a. Grease lubrication easy generation, oil lubrication is not easy to produce. When using inferior grease is easier to produce. b。 Often occur in winter. c。 For only when radial load and the radial clearance is bigger, also easy to produce. d。 Also can produce in a certain range and the different size of bearing its speed range is also different. e. Could be continuous sound may be interrupted. f。 The forced vibration often stimulate the outer ring of the second order and third order bending vibration mode, which produces the noise. By using the load method can effectively reduce the noise, reduce work bearing radial clearance after installed, choose good lubricant can improved, some foreign enterprises to adopt light rolling body, such as ceramic roller or hollow roller and other technical measures to prevent the generation of this kind of noise. 3. Sharp singing it is sliding friction between the metal to produce sharp scream, even as the bearing temperature rise is not high, is little effect on bearing life and grease life, also does not affect the rotation, but not sweet sound disturbing, especially bear radial load large short cylindrical roller bearing is the noise, its characteristic is: a. Bearing radial clearance when easy to produce. b。 Usually appear in the grease lubrication and oil lubrication are relatively rare. c。 And decreases as the bearing size, and often appears in a certain speed range. d。 Often appear in winter. e. It is no rules, and unpredictable, and fat mass and performance, installation and operation conditions. This can be used to reduce noise bearing radial clearance and shallow outer ring raceway structure is used to prevent. 4. Maintains a sound in the process of bearing rotating cage free vibration and its collision with roller or ring will send out the noise. It can occur in all kinds of bearing, but the sound pressure level is not high and low frequency. Its features are: a. Punching cage and plastic cage can be produced. b。 Whether it is a thin oil or grease will appear. c。 Most likely to occur when the outer under bending moment. d。 It's easy to have a large radial clearance. Because of cage pocket hole clearance and cage with ring gap inevitably exists in the bearing products, thus eliminate cage is very difficult, but can be by reducing assembly error, optimizing the reasonable gap and keep the momentum to improve. Using the hearing to identify irregular operation is a very common method. For example, with the aid of electronic stethoscope check feel a certain parts of the abnormal noise is often experienced methods used by the operator. If imported bearing in good state to swing low whimpering sound. If a sharp hissing sound, make sound, and other irregular often said bearing in adverse to swing. High-pitched squeaky noise may be caused by improper lubrication. Improper NSK bearing clearance can cause metal sound. Bearing outer ring orbit of concave dent causes vibration of the orbit, and cause smooth and crisp voice. If because of the installation caused by hitting scar also can produce noise, the noise will be as the bearing rotating speed of high and low. If there are intermittent noise, rolling parts may be damaged. This voice is happens when the damaged surface is rolled out, NSK bearing inner if pollutants often causes hissing sound. Serious with bearing damage can produce irregular and big noise.