A self-lubricating sintered bearing is a metallic component with high porosity (20-25% in volume), impregnated in a lubricant oil. Such oil-impregnated sintered bearings can be used for a long period of time with no refueling and are thus being broadly employed as bearings for rotating shafts for automobiles, home appliances, acoustic devices, and the like (for example, refer to Japanese Examined Patent Application, Second Publication No. H8-19941). A larger range of Rollers – Durasoft – Shaft Mount – Black Neoprene might be available on the Bearing Shop Online site. The Cu-based sintered bearing 1 of the present embodiment has high strength and can be used for a control motor such as a throttle or a valve system of an internal combustion engine of an automobile. Shaft and bearing surfaces before and after the tests. The team of sintered bearings manufacturers carries out the entire process in our state of art manufacturing unit with dedicated tool room. An oil-impregnated sintered bearing according to a second embodiment will be shown in FIGS. Tacbecon SBF 2309 sintered bearing lubricating oil help to extends equipment high temperature operating capability and minimises sludges and deposit build up for trouble-free operation. When storing and installing sintered bronze bearings, they must not be allowed to come into contact with absorbent materials that could extract the oil from the bearings. Below, the reason for the preferable range of each composition ratio and porosity of Cu base sintered member 10 which constitutes Cu base sintered bearing 1 is explained. In the method for manufacturing a Cu-based sintered bearing according to the present invention, the raw material powder may be Cu—Ni alloy powder, Sn powder, or Cu—P alloy powder. The metal powder used are specifically produced to give flow and compacting characteristics and at the same time ensure best mechanical strength, grade or porosity for oil retention and self lubrication in its finished form. Further, the Cu-based sintered member 10 has a Sn high concentration alloy layer 14 containing Sn at 30 mass% or more inside and on the surface. It is an object of the present invention to avoid local relative sliding between an oil-impregnated sintered bearing and a shaft, and to mitigate stress concentration on the bearing surface of the oil-impregnated sintered bearing. Both shafts showed the friction coefficient of about 0.08 which were comparable to that of noncoated shaft shown in Figure 5 This means that the lubrication condition of the ball-on-plate tests was probably about the same as that of the bearing test of the noncoated shaft and the PTFE-coating showed no particular effect like oil-surface slippage on friction under such lubrication condition. The mold 30 includes a die 31 having a cavity P formed therein, an upper punch 32, a lower punch 33, and a core rod 34 that is configured to penetrate through the cavity P and shape the bearing hole 3 (refer to FIG. In order to determine the frictional sintered bearing characteristics of such oil-starved bearings, sintered bearings in which the oil contents were progressively decreased were prepared and tested. First, a photograph of a random place having the central portion 3BS along the shaft line of the second region 3B in the center is captured at a magnification of 200 times. 9. A relief portion is provided in both end regions of the inner peripheral surface of the electrically conductive sintered bearing so as to allow relative swing displacement between the electrically conductive sintered bearing and the shaft. With this in view the invention consists in a bearing formed by sintering a mixture of metal powders comprising at least 60% by weight of iron powder, and a proportion of a powdered copper-base alloy having a melting point significantly lower than the melting point of copper. The present invention has been made in view of the above problems, and an object of the present invention is to provide a Cu-based sintered bearing that can be used under high surface pressure and has a small dimensional change during sintering and high productivity. In the enlarged diameter portion 6c, an angle (taper angle) θ1 formed by an inclined surface of the enlarged diameter portion and an inner surface of the straight hole portion 6a (or the shaft line of the rotating shaft 2) parallel to the shaft direction of the bearing main body 1 is set to a random angle, for example, approximately 0.1° to 10°. Self-lubricating sintered bearings deliver high performance under load and offer exceptional wear properties. There is also a good range of Magnets – Alnico – Rod – Sintered on the Small Parts and Bearings website. As oil-impregnated sintered bearing for which the amount of Cu used is decreased, Fe—Cu-based sintered metal bearings for which Cu-based flat raw material powder is used are being broadly used (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2006-299347).
Oilite bearings are manufactured in three standard materials. However, the amount of oil in those sliding areas is often insufficient leading to an unsatisfactory friction. Applications that require bearings with a high level of sliding performance, including automotive electrical components such as power window and fan motors, or photocopiers or laser printers, are made of bronze materials. Per square inch is also known, made by sintering a mixture of iron powder with copper powder, the proportion of the latter being up to 25% by weight. The lower friction of the PTFE-coated shaft is attributed to the lower wettability to the impregnated oil than that of the noncoated shaft. Figure 11 shows the calculated capillary force along with ε = 1 (which denotes the contact of the shaft and the bearing), c = 6.5 μm, and the tested bearing dimensions. There is also a good range of Rollers – Solid – Stud Mount – Coloured Urethane on the Small Parts and Bearings website. In the measurement, a sliding test was carried out by rotating the rotating shaft 2 in a state in which a load was applied to a location 2 mm offset from the central portion 3AS along the shaft line of the first region 3A toward the central portion 3BS along the shaft line of the second region 3B in the oil-impregnated sintered bearing 10 shown in FIG. 1. A SINTERED BEARING CONSISTING OF AT LEAST 60% BY WEIGHT OF IRON POWDER, WITH THE REMAINDER SUBSTANTIALLY WHOLLY OF POWDERED COPPER-BASE METAL ALLOY OF MELTING POINT LOWER THAN THE MELTING POINT OF COPPER, FORMED AS A SINTERED POROUS MASS HAVING A POROSITY OF AT LEAST 20%. In both of the enlarged diameter portions 4b and 4c, an angle (taper angle) θ1 formed by an inclined surface of the enlarged diameter portion and an inner surface of the straight hole portion 4a (or the shaft line of the rotating shaft 2) parallel to the shaft direction of the bearing main body 1 is set to a random angle, for example, approximately 0.1° to 10°. Porous bearings are known which are manufactured by mixing, pressing and sintering metal powders. To fulfill our customer needs, we also offer range of product line-up including alloyed core. There is also a good range of Rollers – Solid – Shaft Mount – Coloured Urethane on the Small Parts and Bearings website. Porous iron bearings can take up higher bearing loads but have a lower permissible sliding speed. In order to overcome the disadvantage of the rotating shaft incapable of properly coming into contact with the friction surface inside the bearing in the case of receiving a load in a shear direction as described above, for example, an oil-impregnated sintered bearing including a straight hole portion having a constant diameter and an enlarged diameter portion having a diameter that increases outwards and forming a tapered shape in a bearing hole is known (for example, refer to Japanese Unexamined Patent Application, First Publication No. 2004-308682). After the completion of the radial pressing process, the core rod 13 and the upper and lower punches 14 and 15 are raised integrally, and the sintered bearing material 11 is pulled out of the die 12. As a result, the sintered bearing material 11 is released from the radial pressing force from the die 12, and, as shown in FIG. Avoid putting the bearings in contact with absorbent materials (cardboard, paper, cloth, etc.). Conventionally, bearings made of sintered members of various compositions have been employed in automobile internal combustion engines. The bearing 10 having the above-described configuration is used in a state in which, for example, the bearing main body 1 is impregnated with a lubricant and the rotating shaft 2 is inserted into the bearing hole 3. 1 is a cross-sectional view of the oil-impregnated sintered bearing according to the first embodiment of the present invention along a shaft direction of a rotating shaft. Sintered bronze bearings are characterized by being self-lubricating and maintenance-free. While in the above examples the crowning portions 1c and 2c are formed by the rounded curved surfaces 1d and 2d, it is also possible, as shown, for example, in FIGS. At this time, the vibration generated in the rotating shaft 2 causes the lubricant that lubricates the rotating shaft 2 and the straight hole portion 4a to be pushed out toward the first enlarged diameter portion 4b and the second enlarged diameter portion 4c and loaded into the space between the rotating shaft 2 and the enlarged diameter portion 4b and the space between the rotating shaft 2 and the enlarged diameter portion 4c. The lubricant loaded into the spaces between the rotating shaft 2 and the enlarged diameter portions 4b and 4c is pressurized by the vibration of the rotating shaft 2 so as to be pressed against the enlarged diameter portions 4b and 4c, but the enlarged diameter portions 4b and 4c have been provided to be dense, and thus the lubricant is not pressed into the inside of the bearing main body 1, instead, remains between the rotating shaft 2 and the enlarged diameter portions 4b and 4c, and exerts a repulsive force on the rotating shaft 2. This repulsive force suppresses the vibration of the rotating shaft 2 and prevents the misalignment of the rotating shaft 2 relative to the bearing.
Bowman International offers the widest choice of Oilite bearings anywhere in Europe with standard stock ranges available in metric and imperial. 1. An oil-impregnated sintered bearing comprising: a Fe—Cu-based sintered body being impregnated with a lubricant, a bearing hole being formed in the Fe—Cu-based sintered body and configured to be penetrated by and support a rotating shaft, wherein an inner circumferential surface of the bearing hole includes a first region forming a central portion in a shaft direction, a second region from a first end portion of the first region to a first opening of the bearing hole, and a third region from a second end portion of the first region to a second opening of the bearing hole, in the second region and the third region, a Cu phase formed of Cu powder including Cu-based flat raw material powder is formed, an area ratio of the Cu phase of the second region in a center along the shaft direction is 80% or more and 100% or less of an area ratio of the Cu phase of the third region in a center along the shaft direction the bearing hole includes: a straight hole portion that is formed in the first region and has a constant diameter; and a first enlarged diameter portion and a second enlarged diameter portion that are formed in the second region and the third region, respectively, continue from the straight hole portion, have a diameter that increases outwards, and form a tapered shape, a first straight line, which is extended from an inclined surface of the enlarged diameter portion of the second region in an inclination direction toward the center of the bearing main body, and a second straight line, which extended from an inclined surface of the enlarged diameter portion of the third region located at an opposite corner relative to the inclined surface of the enlarged diameter portion of the second region in an inclination direction toward the center of the bearing main body, are disposed parallel to each other, an interval between the first straight line and the second straight line is larger than a diameter of the rotating shaft, in a case where an axis line of the rotating shaft is inclined in the oil-impregnated sintered bearing, the rotating shaft comes into contact with at least one of the enlarged diameter portions, and the second region is in a lower side and the third region is in an upper side during shaping of the oil-impregnated sintered bearing. The porosity of the bearing 1 can be measured by the open porosity test method (JPMA M 02-1992) for sintered metal materials of the Japan Powder Metallurgy Industry Association. As a result, the shaft 22 is supported by the oil-impregnated sintered bearings 21 in a non-contact manner through the intermediation of the oil films, whereby a smooth sliding state is achieved between the components 21 and 22. Our wide range of speciality lubricants is continuously developing with new impregnating oils and fluids, e.g. high-performance oils covering a temperature range from -65 °C to +230 °C, and special fluids which reduce bearing noise even with frequent changes in direction. 1, the above-mentioned electro-sintered bearing unit (example) was tested by using a test apparatus schematically shown in FIG. 3 is a cross-sectional view showing the oil-impregnated sintered bearing holding the rotating shaft. Oil impregnated flanged sintered bronze bushes. The Cu-based sintered member 10 is suitably used as a bearing that slides a shaft of an Fe-based alloy. However, oil-impregnated sintered bearings shaped as described above have a problem in that, in an inner circumferential surface of a bearing hole, the areas of a Cu phase differ in a region that was an upper side and a region that was a lower side during shaping. 2 is a cross-sectional view showing an oil-impregnated sintered bearing according to a second embodiment of the present invention. First, Cu—Ni alloy powder or Ni—Cu alloy powder, Cu—P alloy powder, Sn powder, and graphite powder having a predetermined average particle diameter in the range of about 10 μm to 100 μm are prepared as starting materials. In such high-load and high-speed applications, conventional Cu-based sintered bearings have insufficient strength and may cause abnormal wear, resulting in insufficient reliability. 4 is a main portion-enlarged view showing a contact state between the oil-impregnated sintered bearing and the rotating shaft. The Cu-based sintered bearing 1 has Ni: 15 mass% to 36 mass%, Sn: 3 mass% to 13 mass%, P: 0.05 mass% to 0.55 mass%, and C: It is preferable that 0.02 mass% or more and 4 mass% or less are included, and the remainder consists of Cu and an unavoidable impurity. For example, the area ratio of the Cu phase does not significantly change across the entire region of the inner circumferential surface of the bearing hole from the first opening to the second opening.
You will find that sintered or self-lubricating bearings are used in many applications including the likes of electric motors for cars, fans and cooking equipment, power tools and a variety of household appliances. In this way, according to the present invention, local sliding between the oil-impregnated sintered bearing and the shaft can be avoided, making it possible to mitigate stress concentration on the bearing surface of the oil-impregnated sintered bearing. In products that have been subjected to the core rod sliding step, a Cu layer of several micrometers to several tens of micrometers is formed on the inner circumferential surface S of the bearing hole 3. Relief portions 5 are provided on both end regions of the electro-sintered bearing 50. These bearings consist of a pressed metal powder whose pores are impregnated with a lubricant. In addition, the area occupied by the Cu phase relative to the area of the inner circumferential surface S in a central portion 6AS of the straight hole portion 6a formed in the first region 6A is set to 50% or more. Regarding the lengths along the shaft line of the first region 6A, the second region 6B, and the third region 6C that are set in the inner circumferential surface S of the above-described bearing hole 6, the lengths of the first region 6A and the third region 6C are almost equal to each other, and the length of the second region 6B is set to be approximately ⅕ of the length of the first region 6A or the third region 6C. In most materials the sintered grain size is proportion to the inverse square root of the fractional porosity, implying that pores are the most effective retardant for grain growth during sintering. According to the present invention, in oil-impregnated sintered bearings for which a Fe—Cu-based sintered metal including Cu-based flat raw material powder is used, it is possible to decrease the uneven distribution of a Cu phase in an inner circumferential surface of a bearing hole. At this time, the core rod 34 is slidden in the cavity P at the same time along the vertical direction, for example, upwards (core rod sliding step). As was described, one of the big problems for the lubricity of oil-impregnated sintered bearings is poor oil supply to the sliding surfaces. It should be noted that between the crowning portions 1c formed by the above sizing and the axial end surfaces (which are chamfered surfaces in this embodiment) of the sintered bearing material 11, there may be generated burrs as a result of the plastic deformation of the inner peripheral surface 11a. Metal surfaces generally show good wettability with oils. 5) by a shoulder portion 51c provided on the shaft 51, and the washer 53 is fixed to the sleeve 56. By this, the stopper is restricted in the other axial direction (to the right in FIG. For testing the solid-lubricity of the PTFE-coated shaft under dry condition, dried” bearing was made by ultrasonic cleaning of oil-impregnated sintered bearing in acetone for more than 10 minutes and tested by the test rig of Figure 3 Both noncoated and PTFE-coated shaft indicated the friction coefficient of 0.2-0.3 which means PTFE-coating had little effect on friction reduction under dry condition. Rings machined from solid rod stock producing true running concentric bearings. In addition, in a region which became the lower side during shaping and in which the area occupied by the Cu phase is small, there has been a problem with durability when the rotating shaft is rotated at a high speed. Because the sintering temperature does not have to reach the melting point of the material, sintering is often chosen as the shaping process for materials with extremely high melting points such as tungsten and molybdenum The study of sintering in metallurgy powder-related processes is known as powder metallurgy An example of sintering can be observed when ice cubes in a glass of water adhere to each other, which is driven by the temperature difference between the water and the ice. An important distinction to make is that self-lubricating bearings are not bearings that come pre-applied with grease or oil lubricant – these bearings are instead referred to as prelubricated bearings. You will find everything about our range of plain bearings in THN’s plain bearing brochure. The permissible sliding velocity for sintered bronze bushings is very high, which makes the bushings suitable for rotating applications. On the other hand, in order to withstand high surface pressures, ferrous and iron-copper sintered members have been used for bearings in applications where high surface pressures due to loads and vibrations act. FU Sintered bronze bearing,its bronze powder is pressed under high pressure and sintered under high temperature,after that,it is oil impregnated for better can be used under condition of medium speed and low load.
In a case where the powder mixture is simply dropped from the upper side of the cavity in the vertical direction in the material loading step, the amount of the Cu powder being attached to the surface of the core rod increases toward the upper side of the cavity. Moreover, when content of C contained in raw material powder exceeds 0.10 mass%, sintering of raw material powders will not progress easily, and the expansion of the dimension by sintering will become large. The shaft 2 made of an Fe-based alloy is likely to be seized depending on the material of the bearing 1 (for example, when an Fe-based alloy is used). 2, the generation of vibration and noise in the rolling bearings is unavoidable (generally, the vibration of rolling bearings causes rolling elements to roll on the raceway surface). 18. The method for producing a Cu-based sintered bearing according to claim 17, wherein a sum of C contained in the raw material powder and C derived from the graphite powder is 0.02 mass% or more and 4 mass% or less. The next figure explains how the SELFOIL® bearings work, detailing the self-lubrication mechanism. In addition, in the production method for an oil-impregnated sintered bearing that is the other aspect of the present invention, the core rod sliding step is a step of collecting the Cu powder in a portion with which the core rod comes into contact in the cavity. Generally, friction of oil-impregnated sintered bearings is larger than fully lubricated bearings, because they are often under boundary lubrication condition. Some exuded oil returns into the pores of the bearing body by capillary force and also leading to insufficient oil on the sliding surface 4 , 6 The porous surface of the bearing means a reduction in the load area, which lowers the loading capacity of the bearing. Next, a production method for the oil-impregnated sintered bearing described in the first embodiment will be described. 6A is a schematic cross-sectional view showing a production method for the oil-impregnated sintered bearing of the present invention. There is also a good range of Rollers – Durasoft – Shaft Mount – Coloured Urethane on the Small Parts and Bearings website. Thus, it is possible to prevent burrs from entering the gap between the oil-impregnated sintered bearing 1 and the shaft 22 to thereby deteriorate the bearing performance. Generally speaking, in an oil-impregnated sintered bearing of this type, the inner diameter of the bearing surface provided in the inner periphery thereof is uniform over its entire axial dimension, and sliding (supporting) is effected between the shaft and the entire bearing surface. In addition, the area occupied by the Cu phase relative to the area of the inner circumferential surface S in a central portion 3AS of the first region 3A is set to 50% or more. The Cu-based sintered bearing according to claim 1, wherein the content of C as the sum is 0.02 mass% or more and 3 mass% or less. In the present embodiment, the ratio of the cells of the copper matrix is computed as an area ratio of the Cu phase in the central portion 3BS along the shaft line of the second region 3B. It is possible to provide a Cu-based sintered bearing having high strength and wear resistance and high dimensional accuracy. In the verification, an oil-impregnated sintered bearing having a taper angle θ1 of 0.1° was regarded as a sample 9, and an oil-impregnated sintered bearing having a taper angle θ1 of 4.0° was regarded as a sample 10. For the respective samples, clearance was adjusted to accordingly accelerate sliding in the enlarged diameter portions. Sintered bearing lubrication requires high performance products, lasting in service for all the life of the equipment without compromising the performance. Standard Oilite bearings are impregnated with a highly refined mineral oil to ISO VG (SAE 30) having a high viscosity index and containing anti-oxidant, anti-rust and defoamant additives. That is, when the powder mixture is loaded into the cavity of the mold through which the core rod has been penetrated, the lower side of the cavity is first buried by the powder mixture in the initial phase of the loading. Please keep the bearings in aluminium foil or in their plastic bags until they are installed. There is also a good range of Housings – Bearing – Pillow Block – Die Cast on the Small Parts and Bearings website. Furthermore, the diameter of the through hole in the sintered body is expanded up to a predetermined depth on both sides by sizing, thereby forming the bearing main body 1 including the straight hole portion 4a and the enlarged diameter portions 4b and 4c. 7B are schematic cross-sectional views showing a production method for the oil-impregnated sintered bearing of the present invention stepwise. 10, it was confirmed that, when the bearing hole of the oil-impregnated sintered bearing is provided with a shape made up of the straight hole portion 4a and the enlarged diameter portions 4b and 4c, it is possible to more significantly decrease the friction coefficient compared with oil-impregnated sintered bearings in which the bearing hole is provided with a straight tube shape as a whole.