Assembly method of negative-clearance three-row roller variable pitch bearing

Abstract

The invention discloses an assembling method of a negative-clearance three-row roller variable pitch bearing. The assembling method comprises the following steps: (1) determining a target heating expansion amount of a first outer ring; (2) a heating belt is wound on the outer circle face of the first outer ring, multiple dial indicator measuring heads make contact with a radial roller path of the first outer ring, and the heating expansion delta d of the first outer ring is measured and calculated in the heating process; (3) the radial rollers and the radial retainers are adhered to the radial raceway of the inner ring through lubricating grease; (4) quickly assembling a first axial roller and a first axial retainer on a first axial raceway of the first outer ring after the heating expansion reaches the standard; (5) hoisting the inner ring provided with the radial roller and the radial retainer into the first outer ring; (6) a second axial roller and a second axial retainer are arranged in a second axial roller path of the second outer ring; (7) mounting an O-shaped sealing ring on the second outer ring by using lubricating grease; and then the second outer ring and the first outer ring are butted and fixed, and a sealing ring at the end part of the bearing is mounted. The method can realize hot assembly of the bearings, and has the characteristics of safety, effectiveness, simplicity and practicability.

Description

Technical Field

[0001] The invention belongs to the technical field of bearing assembly application, and in particular relates to an assembly method of a negative clearance three-row roller pitch bearing. Background Art

[0002] As the power of wind turbines increases, the load on the pitch bearings increases. The pitch bearings of large megawatt wind turbines have changed from the traditional double-row four-point contact ball structure to a three-row roller structure. Figure 1 As shown. The three-row roller pitch bearing of this structure is large in size, usually with an outer ring diameter of more than 3 meters and a weight of more than 1.5 tons. The assembly of this bearing has the following difficulties: ① In order to ensure that the friction torque of the variable pitch bearing meets the requirements, the radial raceway of the three-row roller variable pitch bearing has a negative clearance, and the clearance value is generally less than -0.15mm, and the radial raceway of the inner ring 1 is smaller than the outer diameter of the inner ring. It is difficult to install the radial roller 7 into the middle of the radial raceways of the inner and outer rings according to the conventional assembly machine press-fitting method.

[0003] ② If thermal assembly is adopted, in order to prevent the heating temperature from being too high to damage the performance of the retaining frame and the first O-ring 13 and the second O-ring 14, the bearing heating temperature cannot exceed 100°C. The first outer ring 4 has a small expansion when heated, and the expansion of the first outer ring 4 needs to be measured quickly and assembled, otherwise the first outer ring 4 will lose temperature and cool down, and the expansion will become smaller and cannot be assembled. Usually, a pit-type tempering furnace is used for heating, and personnel need to enter the heating furnace for lifting, which poses a safety hazard. In addition, the heating furnace is not in the assembly area. After heating, the raceway diameter is measured with an inside micrometer. The lifting and measurement time is long, the ring will lose temperature, making the raceway diameter smaller, and it is difficult to successfully complete the bearing assembly.

[0004] ③ The radial cage 6 is a segmented structure. When the radial rollers 7 and the radial cage 6 are assembled, the radial rollers 7 and the radial cage 6 are easy to fall off the radial raceway of the inner ring 1.

[0005] ④ When assembling the first O-ring 13 and the second O-ring 14 on the end face of the second outer ring 9, the O-ring sealing groove on the end face of the second outer ring 9 faces downward, and the two O-rings are easy to fall off from the O-ring sealing groove. When the second outer ring 9 and the first outer ring 4 are put together, the first O-ring 13 and the second O-ring 14 are easy to be sheared, and the sealing effect cannot be achieved. Summary of the invention

[0006] The purpose of the present invention is to provide an assembly method for a negative clearance three-row roller pitch bearing to solve the difficult problems faced by such bearings during the assembly process.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is: an assembly method of a negative clearance three-row roller pitch bearing, wherein the negative clearance three-row roller pitch bearing comprises an inner ring, a first outer ring and a second outer ring, the first outer ring and the second outer ring have two axial ends respectively, and radial raceways are arranged on the inner ring and the first outer ring, and the method comprises the following steps: Step 1: determining a target thermal expansion amount of the first outer ring according to the radial clearance of the bearing; Step 2: Place the large end face of the first outer ring downward on multiple equal-height supports, and wrap the outer circumferential surface of the first outer ring with a heating tape, and place multiple dial indicators near the radial raceway in the first outer ring so that the probes of the dial indicators are in contact with the radial raceway; then heat the first outer ring with the heating tape, and observe the dial indicator needle value at regular intervals, and calculate the heating expansion Δd of the first outer ring according to the change in the dial indicator needle value, where Δd is equal to twice the average value of the change in the dial indicator needle values; Step 3: During the heating process, the radial rollers and the radial cage are adhered to the radial raceway of the inner ring by grease; Step 4: When the heating expansion Δd of the first outer ring reaches the target heating expansion range determined in step 1, the heating is stopped, and the first axial roller and the first axial retainer are quickly assembled on the first axial raceway of the first outer ring; Step 5, stably hoist the inner ring of the radial roller and radial cage installed in step 3 into the first outer ring; Step six, installing the second axial roller and the second axial retainer into the second axial raceway of the second outer ring; Step 7: Apply an appropriate amount of grease to the sealing groove on the small end face of the second outer ring, and then install the O-ring into the corresponding sealing groove; Step 8, lift the second outer ring with the small end facing downward, and hang it steadily on the small end of the first outer ring; Step nine, use screws to connect the first outer ring and the second outer ring together; Step 10: Install the second sealing ring at the ends of the second outer ring and the inner ring, then turn the bearing over, and install the first sealing ring at the ends of the first outer ring and the inner ring to complete the assembly of the bearing.

[0008] In step 2, the dial indicator is installed on a magnetic base, and the magnetic base is adsorbed on a corresponding equal-height support.

[0009] In step 2, the plurality of dial indicators are evenly spaced along the circumferential direction.

[0010] In step 2, after the probe of the dial indicator contacts the radial raceway of the outer ring of the bearing, ensure that the needle indication of the dial indicator is not less than 3 mm, and rotate the bezel of the dial indicator so that the needle of the dial indicator indicates the zero position of the dial. During the monitoring process of the dial indicator, the needle indication is the change in the needle indication.

[0011] In step 2, the measuring range of the dial indicator is not less than 5 mm.

[0012] In step 2, the heating temperature of the heating belt is set to a maximum of 100°C.

[0013] In step 2, when the indication of at least one of the multiple percentage indicators reaches or exceeds half of the target heating expansion, the heating expansion Δd at this time is recorded and calculated. When the indications of the multiple percentage indicators are all lower than half of the target heating expansion, there is no need to record and calculate the indication.

[0014] The grease brand used in steps 3 and 7 is the same as the grease brand required to be added to the bearing.

[0015] In step nine, the screws are tightened in a Pozidriv type manner and tightened three times to the required tightening torque of the screws.

[0016] During the screw tightening process, use a feeler gauge to detect the gap between the fitting surfaces of the first outer ring and the second outer ring.

[0017] The beneficial effects of the present invention are: 1. The present invention adopts a heating belt to heat the first outer ring to facilitate the smooth installation of the inner ring, radial rollers and radial retaining frame. The heating with the heating belt can be carried out at the bearing assembly site. After heating, hot assembly can be carried out immediately and quickly without hoisting the first outer ring. Therefore, it can avoid the situation where the first outer ring cannot be assembled due to instability cooling expansion and reduction caused by long hoisting time.

[0018] 2. After the present invention adopts the heating belt for heating, personnel do not need to enter and exit the heating furnace to hoist the heating outer ring, thereby ensuring the health and safety of the operators.

[0019] 3. The present invention uses multiple dial gauges to monitor the heating expansion of the first outer ring in real time, avoiding the problem of operators being easily scalded by repeatedly entering and exiting the first outer ring for measurement, thereby ensuring safe production. In addition, the use of a dial gauge to monitor the change in expansion in real time makes the measurement process simple, and there is no need to measure the temperature of the first outer ring.

[0020] 4. During the assembly process of the present invention, the radial roller and the radial cage are coated with grease and will not fall out of the radial raceway of the inner ring; the two O-rings on the end face of the first outer ring will not fall out of the sealing groove after being coated with grease, thereby ensuring the smooth progress of the assembly process. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 It is a structural schematic diagram of the negative clearance three-row roller pitch bearing according to the present invention; Figure 2 It is a schematic diagram of heating the first outer ring and measuring the expansion amount during assembly of the negative clearance three-row roller pitch bearing of the present invention; Figure 3 for Figure 2 A top view of Markings in the figure: 1-inner ring, 2-first sealing ring, 3-first axial roller, 4-first outer ring, 5-first axial retaining frame, 6-radial retaining frame, 7-radial roller, 8-screw, 9-second outer ring, 10-second axial roller, 11-second axial retaining frame, 12-second sealing ring, 13-first O-ring, 14-second O-ring, 15-heating belt, 16-equal height support, 17-magnetic base, 18-dial indicator. DETAILED DESCRIPTION

[0023] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but they are not intended to limit the invention in any way.

[0024] The negative clearance three-row roller pitch bearing of the present invention is a conventional bearing in the art. To facilitate the description of its assembly method, the following is combined with Figure 1The structure is briefly described. The bearing comprises an inner ring 1, a first axial roller 3, a first outer ring 4, a first axial retainer 5, a radial retainer 6, a radial roller 7, a second outer ring 9, a second axial roller 10, a second axial retainer 11 and a sealing ring. The first outer ring 4 and the second outer ring 9 have a large end and a small end in the axial direction, respectively, and are assembled outside the inner ring 1 in a manner that the small ends are opposite to each other; a first axial raceway and a second axial raceway are respectively arranged between the inner ring 1 and the first outer ring 4 and between the inner ring 1 and the second outer ring 9, the first axial roller 3 and the first axial retainer 5 are assembled on the first axial raceway, and the second axial roller 10 and the second axial retainer 11 are assembled on the second axial raceway; a radial raceway is arranged between the inner ring 1 and the first outer ring 4, the radial raceway is located between the first axial raceway and the second axial raceway, and the radial roller 7 and the radial retainer 6 are assembled on the radial raceway. The sealing ring comprises a first sealing ring 2, a second sealing ring 12, a first O-type sealing ring 13 and a second O-type sealing ring 14. The first sealing ring 2 is installed on the axial ends of the inner ring 1 and the first outer ring 4, the second sealing ring 12 is installed on the other axial ends of the inner ring 1 and the second outer ring 9, the first O-ring 13 and the second O-ring 14 are arranged between the end faces of the first outer ring 4 and the second outer ring 9, for example, two concentric annular sealing grooves can be arranged on the small end face of the second outer ring 9 to respectively accommodate the first O-ring 13 and the second O-ring 14. The first outer ring 4 and the second outer ring 9 are fixedly connected by screws 8.

[0025] The specifications of the three-row roller pitch bearing described in this embodiment are as follows: the outer diameter of the outer ring is φ3215mm, the inner diameter of the inner ring is φ2690mm, the assembly height is 320mm, the finished product weight is 5220kg, and the radial clearance is -0.20mm; the retaining frame material is POM, the O-ring material is nitrile rubber, and the operating temperature of the retaining frame and the O-ring does not exceed 100°C.

[0026] Based on the above structure, a method for assembling a negative clearance three-row roller pitch bearing according to the present invention is described in detail. The method comprises the following steps: Step 1: Calculate the target heating expansion required for the first outer ring 4. The maximum heating temperature is 100°C. The temperature of the first outer ring 4 before heating is the ambient temperature, which is 20°C. The radial raceway of the first outer ring 4 is φ3032mm, and the heating expansion Δd=10 -6 ×3032×(100-20)=2.5mm, which is larger than the absolute value of the radial clearance -0.20mm and can meet the radial clearance requirement. Therefore, the target thermal expansion of the first outer ring 4 is set to 2mm~2.5mm.

[0027] Step 2, such as Figure 2 , 3As shown, the large end face of the first outer ring 4 is placed downward on three equal-height supports 16, and a heating belt 15 is wrapped around the outer circumferential surface of the first outer ring 4. Three sets of dial indicators 18 are placed on the radial raceway of the first outer ring 4 to monitor the heating expansion of the radial raceway during the heating process in real time; then, the power supply of the heating belt 15 is turned on, the heating temperature is set to a maximum of 100°C, the first outer ring 4 is started to be heated, and the indication of the dial indicator 18 is observed regularly.

[0028] Step 3. During the heating process in step 2, apply an appropriate amount of grease to the radial raceway of the inner ring 1, the radial rollers 7 and the radial retainer 6, and adhere the radial rollers 7 and the radial retainer 6 to the radial raceway of the inner ring 1. The brand of grease applied should be the same as the brand of grease required to be added to the bearing.

[0029] Step 4: When the heating expansion monitored by the dial gauge 18 reaches the target heating expansion, place the first axial roller 3 and the first axial retainer 5 next to the first outer ring 4, and then hoist the inner ring 1 with the radial roller 7 and the radial retainer 6 installed above the first outer ring 4; The power supply of the heating belt 15 is turned off, and the first axial roller 3 and the first axial retaining frame 5 are quickly assembled on the first axial raceway of the first outer ring 4 .

[0030] To prevent the first axial roller 3 and the first axial retainer 5 from taking too long to assemble, which would cause the temperature of the first outer ring 4 to drop and the radial raceway to shrink in size, 4 to 5 people should be assigned to assemble the first axial roller 3 and the first axial retainer 5 at the same time to shorten the assembly time.

[0031] Step 5: Install the inner ring 1 with radial rollers 7 and radial retainer 6 into the first outer ring 4. The descent of the overhead crane should be smooth without sudden drops or stops to prevent the radial rollers 7 and radial retainer 6 from falling off.

[0032] Step six: install the second axial roller 10 and the second axial retainer 11 into the second axial raceway of the second outer ring 9 .

[0033] Step seven, apply a proper amount of grease in the sealing groove of the small end face of the second outer ring 9, and then install the first O-ring 13 and the second O-ring 14 into the corresponding sealing grooves. The brand of grease applied should be the same as the brand of grease required to be added to the bearing.

[0034] Step 8: Use a crane to lift the second outer ring 9 with the small end facing downward, align the connecting screw holes of the second outer ring 9 with the connecting screw holes of the first outer ring 4, and then stably lift it onto the small end face of the first outer ring 4. The crane should be lowered smoothly without sudden drops or stops to prevent the first O-ring 13 and the second O-ring 14 from falling off.

[0035] Step nine, insert the connecting screws 8 into the connecting screw holes of the second outer ring 9, and tighten them with the connecting screw holes of the first outer ring 4.

[0036] The screw 8 is tightened in a Pozidriv type tightening manner and is tightened three times to the required tightening torque of the screw. During the tightening process, a feeler gauge is used to detect the gap between the fitting surfaces of the first outer ring 4 and the second outer ring 9 to ensure that a 0.05 mm feeler gauge does not penetrate.

[0037] Step ten, install the second sealing ring 12 at the ends of the second outer ring 9 and the inner ring 1, then use an overhead crane to turn the bearing over, and install the first sealing ring 2 at the ends of the first outer ring 4 and the inner ring 1 to complete the assembly of the bearing.

[0038] After assembly is completed, mark and assemble the nameplate according to the requirements of the drawing. After the finished product is inspected and qualified, pack the bearing with packaging materials and paste the outer label.

[0039] Furthermore, in step 2, this embodiment uses three dial gauges 18, and the range of the dial gauges 18 is not less than 5 mm, and the three dial gauges 18 are evenly arranged along the circumference. When installing the dial gauge 18, the dial gauge 18 is mounted on the magnetic gauge base 17, and the magnetic gauge base 17 is adsorbed on the equal height support 16, and the position of the dial gauge 18 is adjusted so that the probe of the dial gauge 18 contacts the radial raceway of the first outer ring 4.

[0040] Furthermore, after the probe of the dial indicator 18 contacts the radial raceway of the first outer ring 4, it is ensured that the needle indication of the dial indicator 18 is not less than 3 mm, and the bezel of the dial indicator 18 is rotated so that the needle of the dial indicator 18 indicates the zero position of the dial. In this way, during observation, the indication of the needle of the dial indicator is the change in the needle indication, and no conversion is required, thereby simplifying the observation process.

[0041] The heating expansion Δd of the first outer ring 4 can be calculated according to the change in the needle indication of the dial gauge 18, Δd=2×(A1+A2+A3)÷3, where A1, A2, and A3 are the changes in the needle indications of the three dial gauges 18. According to the previous calculation, the target heating expansion of the first outer ring 4 in this embodiment is 2mm~2.5mm, so the average of the indications of the three dial gauges 18 needs to be greater than or equal to 1mm~1.25mm. During the observation process, when the indication of the dial gauge 18 reaches or exceeds 1~1.25mm, it is necessary to read and record, and calculate the thermal expansion Δd at this time; when the indications of the three dial gauges 18 are all below 1mm, their average cannot be greater than or equal to 1mm~1.25mm, and there is no need to record and calculate at this time.

[0042] In this embodiment, three dial gauges 18 are used for testing, and the arithmetic mean of the measurement results is taken to reduce the detection error. In other embodiments, the number of dial gauges 18 can be more than three, which can further reduce the measurement error and improve the measurement accuracy. When the number of dial gauges 18 is n, Δd=2×(A1+A2+…+An)÷n, n is a natural number greater than or equal to 3, and An is the change in the needle indication of the nth dial gauge, that is, the needle indication.

[0043] The above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit the same. Those skilled in the art should understand that the specific implementation modes of the present invention may be modified or replaced by equivalents with reference to the above embodiments. Any modifications or equivalent replacements that do not depart from the spirit and scope of the present invention are within the scope of protection of the pending claims.

Claims

1. An assembly method for a negative clearance three-row roller pitch bearing, wherein the negative clearance three-row roller pitch bearing comprises an inner ring, a first outer ring and a second outer ring, wherein the first outer ring and the second outer ring have two axial ends which are a large end and a small end respectively, and radial raceways are arranged on the inner ring and the first outer ring, wherein the radial raceways are arranged on the inner ring and the first outer ring, and the method is characterized in that: The method comprises the following steps: Step 1: determining a target thermal expansion amount of the first outer ring according to the radial clearance of the bearing; Step 2: Place the large end face of the first outer ring downward on multiple equal-height supports, and wrap the outer circumferential surface of the first outer ring with a heating tape, and place multiple dial indicators near the radial raceway in the first outer ring so that the probes of the dial indicators are in contact with the radial raceway; then heat the first outer ring with the heating tape, and observe the dial indicator needle value at regular intervals, and calculate the heating expansion Δd of the first outer ring according to the change in the dial indicator needle value, where Δd is equal to twice the average value of the change in the dial indicator needle values; Step 3: During the heating process, the radial rollers and the radial cage are adhered to the radial raceway of the inner ring by grease; Step 4: When the heating expansion Δd of the first outer ring reaches the target heating expansion range determined in step 1, the heating is stopped, and the first axial roller and the first axial retainer are quickly assembled on the first axial raceway of the first outer ring; Step 5, stably hoist the inner ring of the radial roller and radial cage installed in step 3 into the first outer ring; Step six, installing the second axial roller and the second axial retainer into the second axial raceway of the second outer ring; Step 7: Apply an appropriate amount of grease to the sealing groove on the small end face of the second outer ring, and then install the O-ring into the corresponding sealing groove; Step 8, lift the second outer ring with the small end facing downward, and hang it steadily on the small end of the first outer ring; Step nine, use screws to connect the first outer ring and the second outer ring together; Step 10: Install the second sealing ring at the ends of the second outer ring and the inner ring, then turn the bearing over, and install the first sealing ring at the ends of the first outer ring and the inner ring to complete the assembly of the bearing.

2. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1 is characterized in that: In step 2, the dial indicator is installed on a magnetic base, and the magnetic base is adsorbed on a corresponding equal-height support.

3. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1 is characterized in that: In step 2, the plurality of dial indicators are evenly spaced along the circumferential direction.

4. The assembly method of the negative clearance three-row roller pitch bearing according to claim 1 is characterized in that: In step 2, after the probe of the dial indicator contacts the radial raceway of the outer ring of the bearing, ensure that the needle indication of the dial indicator is not less than 3 mm, and rotate the bezel of the dial indicator so that the needle of the dial indicator indicates the zero position of the dial. During the monitoring process of the dial indicator, the needle indication is the change in the needle indication.

5. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, the measuring range of the dial indicator is not less than 5 mm.

6. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, the heating temperature of the heating belt is set to a maximum of 100°C.

7. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step 2, when the indication of at least one of the multiple percentage indicators reaches or exceeds half of the target heating expansion, the heating expansion Δd at this time is recorded and calculated. When the indications of the multiple percentage indicators are all lower than half of the target heating expansion, there is no need to record and calculate the indication.

8. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: The grease brand used in steps 3 and 7 is the same as the grease brand required to be added to the bearing.

9. The method for assembling a negative clearance three-row roller pitch bearing according to claim 1, characterized in that: In step nine, the screws are tightened in a Pozidriv type manner and tightened three times to the required tightening torque of the screws.

10. The method for assembling a negative clearance three-row roller pitch bearing according to claim 9, characterized in that: During the screw tightening process, use a feeler gauge to detect the gap between the fitting surfaces of the first outer ring and the second outer ring.

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