Three-screw pump shaft sleeve and the cause of the diameter of axle gap, holding in death of a cause analysis according to the performance of the sliding bearing, the general three screw pump bushing hole and shaft is clearance fit, the diameter of axle parts graph and the bushing aperture size deviation, are generally according to the average temperature of 20 ℃ ensure reasonable clearance between shaft and bushing hole change and uncertain. Many factors affect the sliding bearing overheating fault in bearing structure design is reasonable, the materials to choose the right circumstances, the size of the sliding bearing overheating mainly bearing radial clearance improper assembly and improper use. Sliding bearing radial clearance of bearing overheating fault, the influence of radial clearance of sliding bearing Δ is the difference between the axis neck diameter and the diameter of bearing hole, sliding bearing should have certain radial clearance, its action is as follows: is the realization of shaft and bearing activity join at least conditions; Is the assurance of running accuracy control shaft; Is the important condition of formation fluid lubrication. Sliding bearing radial clearance, therefore, very important, too big or too small are extremely harmful. Gap is too small, it is difficult to form oil film, friction heat is not easy to be taken away, the bearing temperature, serious when holding shaft; Clearance is too large, the oil film also difficult to form, can reduce the running accuracy of machine can produce violent vibration and noise, and even lead to the tile burning failure. Second, the determination of sliding bearing radial clearance of the screw pump technology performance: the shaft rotational speed n = 2950 r/min, shaft neck diameter d = 30 mm; Motor for synchronous motor, oil residue, bearing materials for tin copper. Sliding bearing radial clearance of the theoretical value of sliding bearing radial clearance Δ = k. d. Type: K - — — High precision bearing coefficient, the 'mechanical design manual' Chad K = 0. 0008. ｄ— — — The diameter of the shaft neck, d = 30 mm. Substitution: Δ = 0. 02 mm by 'mechanical design manual' Chad, maximum clearance Δ Max = 0. 10ｍｍ。 To measure the original collar, data and location:, to measure the diameter of axle by corresponding position size data: trunnion gezer. 99 mm29。 94mm29. 90 mm diameter of axle outwardly. 92mm29. 90mm29. 90 mm collar 1:30. 01 mm29。 97 mm29。 92 mm collar '. 94mm29. 92mm29. 915 mm slide bearing radial clearance: the real value of maximum clearance active rod: 0. 3 mm follower lever: 0. 02mm。 The bearing in the process of actual use, due to the gap is too small, friction heat is not easy to be taken away, and lubricating oil as medium residue, impurity is more, easy entry clearance, bearing overheating, serious 'axis', when they appear tile burning phenomenon. Three, prevention and improvement measures in order to prevent bearing overheating fault, if the large radial clearance, Δ = 0. 03ｍｍ。 When the bearing vice although it can work normally, but greatly shorten its service life, therefore when determining bearing radial clearance, should guarantee the bearing on the premise of normal work leave less as far as possible. After the bearing assembly, first of all should be in accordance with the running-in test run specifications in terms of the good and the test run, then gradually loading speed, the shaft and bearing with surface bulge smooth, and then put into normal operation. Otherwise, even if the gap is not small, but try not to get up to speed after because assembly operation, and put into normal operation, which can lead to bearing overheating or even burning. To this, the sliding bearing radial clearance should be controlled in 0. 10毫米~ 0。 15ｍｍ。 Sliding bearing radial clearance of bearing overheating and life influence is very big, so for the radial clearance, must be strictly controlled in a reasonable range. In determining the bearing radial clearance, should fully consider factors that affect the radial clearance, besides considering shaft diameter, rotational speed, load and the precision of the machine, also should consider the following: a. Bearing materials. Bearing material is different, different expansion coefficient, clearance is different also. b。 The roughness of the shaft and bearing surfaces. c。 Journal and bearing geometry and mutual position error ( Namely, roundness, cylindricity, alignment, etc. ) 。 d。 The bearing temperature. f。 A sudden change in the starting conditions. Four, conclusion different medium and different rotational speed of screw pump shaft sleeve clearance requirements are not the same. Through the calculation and analysis, it is concluded that the collar the best clearance data. Equipment works all normal transformation over the past year, our analysis is verified is feasible.