Method for installing variable-speed bull gear inner cone bearing in double-speed main speed reducer

Abstract

The invention belongs to the technical field of bearing installation, and discloses an installation method of a variable-speed bull gear inner cone bearing in a double-speed main speed reducer. The method comprises the steps of 1, determining the model and boundary dimension of a cone bearing; 2, detecting the inner diameter, the outer diameter and the height difference of the inner ring and the outer ring of the cone bearing; 3, detecting an inner hole of a variable-speed large gear and the outer diameter of a variable-speed shaft; 4, calculating the variation of the bearing width caused by the radial fit interference magnitude of the inner ring and the outer ring of the single cone bearing; step 5, determining the width S of a paired cone bearing spacer sleeve in the variable-speed bull gear; and 6, judging whether the current installation is in a constant-temperature environment or not, if the current installation is in the constant-temperature environment, directly installing the spacer sleeve, otherwise, calculating a temperature compensation value and a width variation, adjusting the width of the spacer sleeve, and then installing and pre-tightening. According to the method, uniform load distribution of the cone bearings on the two sides can be guaranteed when the main speed reducer works, and the service life of the bearings is prolonged; the end face run-out value of a main reducer change gear is reduced, and the service life of a gear pair is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of bearing installation, in particular to a method for installing an inner taper bearing of a variable-speed large gear in a dual-speed main reducer. BACKGROUND

[0002] Large co-rotating or counter-rotating twin-screw mixing and extruding pelletizing unit (200,000 tons / year and above) is one of the important equipment in the domestic and foreign petrochemical industry. The PP or PE powder produced in the upstream polymerization is produced into pellets by the extruding pelletizing unit, which is used as a master batch.

[0003] The large mixing and extruding pelletizing unit is equipped with a main motor and a main reducer. The power of the main motor is usually as high as tens of thousands of kilowatts, and the AC motor is usually selected for economic reasons. The main reducer generally adopts a mechanical gear shifting structure with high and low speed gear shifting mechanism to meet the needs of producing different output and melt index materials.

[0004] The installation method of the inner taper bearing of the variable-speed large gear in the dual-speed main reducer is critical, otherwise the following problems may occur:

[0005] 1) Uneven load distribution between the inner taper bearings of the main reducer during production, reducing the service life of the bearings;

[0006] 2) Large gear end face runout value of the main reducer, abnormal vibration and abnormal noise, and shortening the service life of the variable-speed gear pair. SUMMARY

[0007] Based on the shortcomings of the prior art, the present application proposes a method for installing an inner taper bearing of a variable-speed large gear in a dual-speed main reducer, mainly applied to the inner taper bearing of a variable-speed large gear in a co-rotating twin-screw main reducer and a counter-rotating twin-screw main reducer with high and low speed gears designed in a large extruding pelletizing unit in the petrochemical industry, and also applicable to a main reducer with high and low speed gears designed in other industries.

[0008] The technical solution of the present application is as follows: a method for installing an inner taper bearing of a variable-speed large gear in a dual-speed main reducer, considering the temperature influence during actual assembly, determining the width S of the distance sleeve of the inner taper bearing matched with the variable-speed large gear; the specific steps are as follows:

[0009] Step 1. Determine the type and outer dimension of the taper bearing;

[0010] Step 2. Detect the inner diameter, outer diameter, and height difference between the inner and outer rings of the taper bearing;

[0011] Step 3. Detect the inner hole of the variable-speed large gear and the outer diameter of the variable-speed shaft;

[0012] Step 4. Calculate the change amount of the bearing width caused by the radial interference amount of the inner and outer rings of the single taper bearing;

[0013] Step 5. Determine the width S of the constant distance sleeve of the mating tapered bearing in the variable gear;

[0014] ;

[0015] Wherein, is the bearing width change amount caused by the interference fit between the outer ring of tapered bearing A and the inner hole of variable gear; is the bearing width change amount caused by the interference fit between the outer ring of tapered bearing B and the inner hole of variable gear; is the bearing width change amount caused by the interference fit between the inner ring of tapered bearing A and the variable shaft; is the bearing width change amount caused by the interference fit between the inner ring of tapered bearing B and the variable shaft; A3 is the height difference between the inner and outer ring end faces of the small end of the tapered bearing A; B3 is the height difference between the inner and outer ring end faces of the small end of the tapered bearing B; C is the measured value of the axial width of the gear hole step; is the set axial pre-tightening value;

[0016] Step 6. Determine whether the current installation is in a constant temperature environment. If it is in a constant temperature environment, directly install the constant distance sleeve. Otherwise, calculate the temperature compensation value, width change amount , adjust the width of the constant distance sleeve, and then install and pre-tighten.

[0017] The step 2 is specifically:

[0018] Step 2.1) Place in a three-coordinate detection workroom for 48 hours, and the room temperature of the three-coordinate detection workroom is kept at 20±1℃, at this time the influence of temperature difference on the installation width of the constant distance sleeve is not considered;

[0019] When installing, the influence of different temperatures of the bearing outer ring, bearing inner ring and rolling body on the installation width of the constant distance sleeve is considered; record the room temperature and the temperature T of the bearing when measuring; the bearings are installed back to back, and the bearing width change amount is: ;

[0020] T: the room temperature when measuring;

[0021] Step 2.2) Label the bearings in sequence;

[0022] Step 2.3) Detect the actual size of the bearing, accurate to 3 decimal places;

[0023] Step 2.4) Detect the height difference between the back of the bearing outer ring and the front of the bearing inner ring.

[0024] The step 3 is specifically: two variable gears are provided; the inside diameter micrometer and the outside diameter micrometer are placed in the gear grinding machine workroom for 48 hours;

[0025] Step 3.1) Put the gear and shaft into the constant temperature gear lapping machine for 48 hours; the temperature of the lapping machine is kept at 20±1℃, and the temperature difference is not considered at this time;

[0026] When installing, record the temperature T of the room and the bearing at the time of measurement, and the change in the width of the gear and shaft: ;

[0027] T: the temperature of the room at the time of measurement;

[0028] Step 3.2) Measure the actual size of the two inner holes D1-D2 of the gear with an inside micrometer, measure at least 3 times for each inner hole, evenly divided in angle, and the maximum and minimum numerical difference is less than 0.015mm, take the arithmetic mean;

[0029] Step 3.3) Measure the boss width H of the gear inner hole, measure at least 4 times, evenly divided in angle, and the maximum and minimum numerical difference is less than 0.015mm, take the arithmetic mean;

[0030] Step 3.4) Measure the actual size of the shaft at 4 positions with an outside micrometer, measure at least 2 times for each position, and the maximum and minimum numerical difference is less than 0.015mm;

[0031] Step 3.5) Step 3.6) Record the room temperature, the temperature of the gear and the shaft.

[0032] The step 4 is specifically:

[0033] The bearing width change caused by the interference fit of the outer ring gear inner hole of the tapered bearing:

[0034] Similarly;

[0035] A1: the interference amount of the radial fit of the outer ring of tapered bearing A and the gear inner hole;

[0036] Y1: the interference amount calculation coefficient of the outer ring of tapered bearing A;

[0037] The bearing width change caused by the interference fit of the inner ring of the tapered bearing and the shaft:

[0038] Similarly;

[0039] A2: the interference amount of the radial fit of the inner ring of bearing A and the shaft;

[0040] Y2: the interference amount calculation coefficient of the inner ring of bearing A.

[0041] ; d is the nominal inner diameter of the bearing; D is the nominal outer diameter of the bearing.

[0042] ; d is the nominal inner diameter of the bearing; D is the nominal outer diameter of the bearing.

[0043] The present application has the advantages that the method of the present application can ensure uniform load distribution of the two side taper bearings during operation of the main reducer, thereby improving the service life of the bearings; and the end face runout value of the variable speed gear of the main reducer is reduced, thereby improving the service life of the gear pair. BRIEF DESCRIPTION OF DRAWINGS

[0044] Figure 1 It is a flow chart of the installation method of the inner taper bearing of the variable speed gear in a two-speed main reducer.

[0045] Figure 2 It is a schematic diagram of the main reducer designed for high and low speed gear shifting.

[0046] Figure 3 It is a schematic diagram of the bearing profile.

[0047] Figure 4 It is a schematic diagram of the height difference detection of the inner and outer rings of the bearing.

[0048] Figure 5 It is a schematic diagram of the gear. (a) is a high speed gear, and (b) is a low speed gear.

[0049] Figure 6 It is a schematic diagram of the variable speed shaft.

[0050] Figure 7 It is the meaning of each mark of the paired taper bearings.

[0051] Figure 8 It is a layout diagram of the same direction double screw main reducer for two-speed gear shifting.

[0052] Figure 9 It is a structure diagram of the high and low speed variable speed gear taper bearings.

[0053] In the figure: 1. variable speed shaft; 2. high speed gear; 3. low speed gear; 4. taper bearing a; 5. taper bearing b; 6. taper bearing c; 7. taper bearing d; 8. spacer sleeve a; 9. spacer sleeve b. DETAILED DESCRIPTION

[0054] 1. Determine the type and profile size of the taper bearing.

[0055] According to the technical parameters of the main reducer, the type and profile size of the high and low speed gear variable speed gear inner taper bearing are calculated and determined. The high and low speed variable speed gear taper bearings include a variable speed shaft 1, a high speed gear 2, a low speed gear 3, a taper bearing a 4, a taper bearing b 5, a taper bearing c 6, a taper bearing d 7, a spacer sleeve a 8, and a spacer sleeve b 9.

[0056] Bearing model LM665949 / LM665910, for example, 4 bearings for each speed reducer.

[0057] Bearing inner ring width B = 82.550 mm; bearing outer ring width C = 63.500 mm;

[0058] Bearing inner diameter d = 385.762 mm; bearing outer diameter W = 514.350 mm;

[0059] 2. Detect the inner diameter d, outer diameter D, and the height difference between the inner and outer rings of the tapered bearing.

[0060] 2.1), the bearing should be placed in a constant temperature three-coordinate detection laboratory for 48 hours (the laboratory temperature is maintained at 20±1℃). At this time, the effect of temperature difference on the installation width of the spacer sleeve is not considered.

[0061] Otherwise, the effect of different temperatures of the bearing outer ring, bearing inner ring, and rolling body on the installation width of the spacer sleeve should be considered. Record the room temperature and the temperature T of the bearing at the time of measurement; the bearing is installed back to back, and the bearing width change amount is: .

[0062] T: room temperature at the time of measurement;

[0063] 2.2), 4 bearings are sequentially labeled.

[0064] 2.3), detect the actual size of the bearing, accurate to 3 decimal places.

[0065] Inner diameter d = 385.762 mm, outer diameter W = 514.350 mm, inner ring width B = 82.550 mm, outer ring width C = 63.500 mm.

[0066] 2.4) Detect the height difference between the back of the bearing outer ring and the front of the bearing inner ring, and the detection method is shown in the attached Figure 3 .

[0067] The method for measuring the height difference is as follows, which should be more familiar to the operation and will not be repeated here, only the measurement load is noted, 300N is recommended when the outer diameter is less than 240mm, and 500N is recommended when the outer diameter is greater than 240mm. Also refer to the relevant bearing sample, and take 5 / 1000~1 / 100 of the rated dynamic load as the measurement load. Before measurement, the bearing inner and outer rings are concentric, at least 4 points are detected, and the maximum and minimum numerical difference is less than 0.015 mm. The detection result takes the arithmetic mean value t of each point. When the outer ring is higher than the inner ring, t is positive; when the outer ring is lower than the inner ring, t is negative.

[0068] 3. Detect the inner hole of the variable speed gear and the outer diameter of the variable speed shaft (2 gears and 1 shaft)

[0069] 3.1) 2 variable gear, 1 variable shaft, 1 variable gear inside the fixed sleeve.

[0070] Put the variable gear and variable shaft in the constant temperature gear grinding machine working chamber for 48 hours (according to the temperature of spring and autumn, summer and winter, the room temperature of the working chamber is maintained at 20±1℃). At this time, the influence of temperature difference on the installation width of the fixed sleeve is not considered.

[0071] The inner hole of the gear is marked respectively, see Figure 4 From left to right, D1-D4.

[0072] Otherwise, record the room temperature and the temperature T of the bearing when measuring, the change of the width of the variable gear and the variable shaft:

[0073] T: the room temperature when measuring.

[0074] 3.2) Measure the actual size of 514.350mm of the inner hole D1-D4 of the two gears with the inner diameter micrometer, measure at least 3 times for each inner hole, angle is divided, the maximum and minimum numerical difference is less than 0.015mm, take the arithmetic mean.

[0075] 3.3) Measure the actual size of the boss width H=197.45mm of the gear inner hole, measure at least 4 times, angle is divided, the maximum and minimum numerical difference is less than 0.015mm, take the arithmetic mean.

[0076] 3.4) Measure the actual size of the variable shaft at 4 positions, measure at least 2 times for each position, the maximum and minimum numerical difference is less than 0.015mm, see Figure 6 .

[0077] 3.5) The inner and outer diameter micrometer used is placed in the gear grinding machine working chamber for at least 24 hours.

[0078] 3.6) Record the room temperature, gear, variable shaft temperature.

[0079] 4. Calculate the change amount of the bearing width caused by the radial interference amount of the inner and outer rings of the single tapered bearing;

[0080] The inner and outer rings of the tapered bearing are interference fit with the inner hole of the gear and the variable shaft. When the inner and outer rings swell due to interference, the change size in the width direction is related to the thickness of the tapered bearing. The actual thickness of the inner and outer rings of each set of bearings is slightly different. Here is a formula that meets the basic requirements. In general, it can be calculated according to this.

[0081] The change amount of the bearing width caused by the interference fit of the outer ring of the tapered bearing with the inner hole of the gear:

[0082] ​(shafting A outer ring interference amount calculation coefficient) Similarly;

[0083] A1: the bearing A outer ring and gear hole radial interference amount;

[0084] Y1: bearing A outer ring interference amount calculation coefficient, bearing factory provides;

[0085] Three-dimensional drawing can be drawn, integral calculus solution; empirical formula:

[0086] The inner ring of the tapered bearing and the variable speed shaft interference fit causes the bearing width change amount:

[0087] (shafting A inner ring interference amount calculation coefficient) Similarly;

[0088] A2: the bearing A inner ring and variable speed shaft radial interference amount; mm

[0089] Y2: bearing A inner ring interference amount calculation coefficient, bearing factory provides;

[0090] Three-dimensional drawing can be drawn, integral calculus solution; empirical formula:

[0091] When calculating the radial interference amount of the inner and outer rings of the tapered bearing, the influence of surface roughness should be considered. The surface roughness plane will be partially flattened under tight fit, and the actual interference amount is smaller than the measured value. For example, the interference amount is 100 μm, the surface roughness conversion value of the shaft is 3 μm, and the bearing surface is 2 μm, then the actual interference amount is 100-2(3+2)=90 μm, (because the diameter direction is considered, so multiply by 2). Figure 6 Therefore, the flattened value needs to be subtracted.

[0092] For example:

[0093] The measured interference amount is 100 μm, the surface roughness conversion value of the shaft is 3 μm, and the bearing surface is 2 μm, then the actual interference amount is 100-2(3+2)=90 μm, (because the diameter direction is considered, so multiply by 2).

[0094] For different machining surface roughness conversion values, it is recommended to refer to the following range (the bearing fitting surface can use 2 μm):

[0095]

[0096] 5. Determine the variable speed gear inner matching tapered bearing spacer width S;

[0097] The width S value calculation formula of the variable speed gear spacer is as follows: (the formula does not consider the influence of temperature difference)

[0098] S

[0099] Take TIMKEN brand two ends of the same type of tapered pair LM377449 / 410 as an example, as shown in the attached Figure 7 Provide accurate data: ;

[0100] Tapered bearing A outer ring and gear bore interference fit caused by the change in the amount of bearing width;

[0101] Tapered bearing B outer ring and gear bore interference fit caused by the change in the amount of bearing width;

[0102] Tapered bearing A inner ring and shaft interference fit caused by the change in the amount of bearing width:

[0103] Tapered bearing B inner ring and shaft interference fit caused by the change in the amount of bearing width:

[0104] A1: bearing A outer ring and gear bore radial interference amount;

[0105] B1: bearing B outer ring and gear bore radial interference amount;

[0106] A2: bearing A inner ring and shaft radial interference amount;

[0107] B2: bearing B inner ring and shaft radial interference amount;

[0108] A3: bearing A roller small end inner and outer ring end face height difference;

[0109] B3: bearing B roller small end inner and outer ring end face height difference;

[0110] C: gear hole step axial width measurement value;

[0111] S: inner ring width value of the spacer sleeve;

[0112] The set axial pre-tightening value, normal in 0.05-0.10mm.

[0113] 6. The main influencing factors during installation;

[0114] 6.1 The influence of temperature.

[0115] Constant temperature assembly in the studio.

[0116] All parts are placed in the constant temperature room for 24 hours, the room temperature is kept at 20±1℃, at this time, the influence of temperature difference on the installation width S of the spacer sleeve is not considered. Otherwise, record the room temperature and the temperature T of the bearing when measuring, and the width change: ;

[0117] T: room temperature at the time of measurement.

[0118] 6.2 Analysis of the relationship between the pre-tightening of the shift bearing and stress:

[0119] The setting of the axial pre-tightening value needs to take the following factors into account: excessive pre-tightening can easily cause a sharp increase in stress, and insufficient pre-tightening can lead to a fit clearance, and at the same time, a compensation allowance needs to be reserved for temperature changes. It is usually recommended to set this value in the range of 0.05 mm to 0.10 mm.

Claims

1. A method of installing a variable speed bull gear inner cone bearing in a two speed main reduction gear, characterized by, Determine the width S of the distance sleeve of the mating tapered bearing in the variable speed gear considering the temperature influence in actual assembly; the specific steps are as follows: Step 1. Determine the type and size of the tapered bearing; Step 2. Detect the inner diameter, outer diameter, height difference between the inner and outer rings of the tapered bearing; Step 3. Detect the inner hole of the variable speed gear and the outer diameter of the variable speed shaft; Step 4. Calculate the change amount of the bearing width caused by the radial interference amount of the inner and outer rings of the single tapered bearing; Step 5. Determine the width S of the distance sleeve of the mating tapered bearing in the variable speed gear; ； Wherein, is the bearing width change amount caused by the interference fit between the outer ring of tapered bearing A and the inner hole of the variable speed gear; is the bearing width change amount caused by the interference fit between the outer ring of tapered bearing B and the inner hole of the variable speed gear; is the bearing width change amount caused by the interference fit between the inner ring of tapered bearing A and the variable speed shaft; is the bearing width change amount caused by the interference fit between the inner ring of tapered bearing B and the variable speed shaft; A3 is the height difference between the inner and outer ring end faces of the small end of the roller of tapered bearing A; B3 is the height difference between the inner and outer ring end faces of the small end of the roller of tapered bearing B; C is the measured value of the axial width of the variable speed gear hole step; is the set axial pre-tightening value; Step 6. Determine if the current installation is in a constant temperature environment, in a constant temperature environment, directly install the spacer sleeve, otherwise, calculate the temperature compensation value, width change , adjust the width of the spacer sleeve, and then install and pre-tighten.

2. The method of installing a double reduction final drive variable speed bull gear inner cone bearing of claim 1, wherein, The step 2 is specifically: Step 2.1) Place in the constant temperature three coordinate detection working chamber for 48 hours, the chamber temperature of the three coordinate detection working chamber is kept at 20±1℃, at this time, the influence of temperature difference on the installation width of the distance sleeve is not considered; When installing, the influence of different temperatures of the bearing outer ring, bearing inner ring and rolling body on the installation width of the spacer sleeve is considered; the room temperature and the temperature T of the bearing are recorded when measuring; the bearings are installed back to back, and the bearing width variation is: ; T: room temperature at the time of measurement; Step 2.2) Label the bearings in turn; Step 2.3) Detect the actual size of the bearing, accurate to 3 digits after the decimal point; Step 2.4) Detect the height difference between the back of the bearing outer ring and the front of the inner ring.

3. The method of installing a double reduction final drive variable speed bull gear inner cone bearing of claim 1, wherein, The step 3 is specifically: the variable speed gear is provided with two; the inner diameter micrometer and the outer diameter micrometer are placed in the grinding machine working chamber for 48 hours; Step 3.1) Place the variable speed gear and the variable speed shaft in the constant temperature grinding machine working chamber for 48 hours; the chamber temperature of the grinding machine working chamber is kept at 20±1℃, at this time, the influence of temperature difference on the installation width of the distance sleeve is not considered; At the time of installation, the temperature of the room and the bearing T at the time of measurement, the change in the width of the transmission gear and the transmission shaft are recorded: ; T: room temperature at the time of measurement; Step 3.2) Measure the actual size of the two inner holes D1-D2 of the variable speed gear by the inner diameter micrometer, at least 3 times for each inner hole, angle is divided, the maximum and minimum numerical difference is less than 0.015mm, take the arithmetic mean value; Step 3.3) Measure the boss width H of the inner hole of the variable speed gear, at least 4 times, angle is divided, the maximum and minimum numerical difference is less than 0.015mm, take the arithmetic mean value; Step 3.4) Measure the actual size of the four positions of the variable speed shaft by the outer diameter micrometer, at least 2 times for each position, the maximum and minimum numerical difference is less than 0.015mm; Step 3.5) Step 3.6) Record the room temperature, the temperature of the variable speed gear and the variable speed shaft.

4. The method of installing a double speed main reduction gear range change large pinion inner cone bearing of claim 1, wherein, The step 4 is specifically: The change amount of the bearing width caused by the interference fit of the outer ring of the tapered bearing in the gear inner hole: By analogy; A1: the radial interference amount of the outer ring of the tapered bearing A and the gear inner hole; Y1: the interference amount calculation coefficient of the outer ring of the tapered bearing A; The change amount of the bearing width caused by the interference fit of the inner ring of the tapered bearing and the variable speed shaft: By analogy; A2: the radial interference amount of the inner ring of the bearing A and the variable speed shaft; Y2: the interference amount calculation coefficient of the inner ring of the bearing A.

5. The method of installing a double reduction final drive range change pinion inner cone bearing of claim 4, wherein, ; d is the nominal inside diameter of the bearing; D is the nominal outside diameter of the bearing.

6. The method of installing a double ratio main reduction gear range changing large pinion inner taper bearing of claim 4, wherein, ; d is the nominal inside diameter of the bearing; D is the nominal outside diameter of the bearing.

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