TA type three-stage planet carrier and machining process thereof

Abstract

The invention discloses a TA type three-stage planet carrier and a machining technology thereof, and relates to the technical field of three-stage planet carrier machining, the TA type three-stage planet carrier comprises a planet carrier body, a first plate and a second plate are connected through a plurality of sets of supporting columns distributed at equal intervals, and by arranging thermocouples on the surface of the three-stage planet carrier and at inner hole steps, the actual temperature is monitored in real time; the heat preservation time is calculated according to the thickness of the three-stage planet carrier, the heat preservation time is increased by 1-1.5 hours every time the thickness is increased by 15 mm, the temperature in the furnace is controlled to fluctuate within + / -3 DEG C, nitrogen with the purity larger than or equal to 99.99% is introduced into the furnace, oxidation is prevented, and the heat preservation time is increased by 1-1.5 hours every time the thickness is increased by 15 mm; and after the heat preservation time is finished, the temperature in the furnace is controlled to be reduced to 100 DEG C or below, and the product is taken out, and the cooling rate is smaller than or equal to 20 DEG C / h, so that the stress relief rate of stepped grooves formed in the three-stage planet carrier can reach 95% or above, normal use of the planet carrier can be guaranteed for a long time, and cracks of the stepped grooves are avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of the processing of three-stage planet carriers, and particularly relates to a three-stage planet carrier of TA model and its processing technology. Background Art

[0002] The planet carrier is one of the main components of the planetary gear transmission device. The planet wheel shaft or bearing is installed on the planet carrier. In the wind power generation system, the planet carrier mainly plays the role of connecting the blade and the generator and transmitting torque.

[0003] When most of the existing three-stage planet carriers are in use, the stepped circular groove holes opened thereon for installing bearings are prone to deformation under the action of friction and stress during long-term use, reducing the performance and service life of the planet carrier, causing many inconveniences to the stable use of the planet carrier, and at the same time posing a huge potential safety hazard. Summary of the Invention

[0004] The purpose of the present invention is to provide a three-stage planet carrier of TA model and its processing technology, which solves the technical problem that the stepped circular groove holes for installing bearings on the planet carrier in the prior art are prone to cracks.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A three-stage planet carrier of TA model,

[0007] including a planet carrier body, wherein the planet carrier body further includes a first plate and a second plate which are symmetrically arranged, and the first plate and the second plate are connected by a plurality of groups of equally spaced support columns;

[0008] A main shaft sleeve seat is arranged on the rear end face of the first plate. A first main shaft groove is penetrated through the central area of the first plate and the second plate. A second main shaft groove matching the first main shaft groove is penetrated through the central area of the second plate. A plurality of groups of equally spaced side shaft grooves one are penetrated through the front end face of the first plate around the first main shaft groove. A plurality of groups of side shaft grooves two matching the side shaft grooves one are penetrated through the front end face of the second plate around the second main shaft groove.

[0009] Preferably, the materials of the planet carrier body and the main shaft sleeve seat are QT700 alloy steel.

[0010] Preferably, the cross-section of the support column is triangular, and the second main shaft groove, the side shaft groove one and the side shaft groove two are all stepped grooves.

[0011] Preferably, a limiting protrusion is arranged on the inner wall of the first main shaft groove along the extension direction of the main shaft sleeve seat.

[0012] Preferably, a limiting groove is opened on the inner wall of the side shaft groove two.

[0013] A processing technology for the three - stage planet carrier of TA model, characterized by including the following steps:

[0014] Step 1: First, perform sandblasting on the three - stage planet carrier casting to remove the surface oxide scale, then ultrasonically clean the oil stains on the surface, and then dry it.

[0015] Step 2: Use an ultrasonic flaw detector to check whether there are cracks or hidden damages in the three - stage planet carrier to be processed. Fix the undamaged three - stage planet carrier on the horizontal machining center BTD - 150H.R22 numerically controlled planer - type boring and milling machine through a soft - jaw fixture;

[0016] Step 3: Input the dimensional parameters of the main - shaft groove two (5), side - shaft groove one (6) and side - shaft groove two (7) to be opened into the horizontal machining center BTD - 150H.R22 numerically controlled planer - type boring and milling machine. First, perform rough machining of the stepped groove. Use a indexable face - milling cutter to open holes on the end faces of the first plate (101) and the second plate (102), and reserve a machining allowance of 10 - 30 mm for the subsequent stepped part;

[0017] Step 4: Perform semi - finishing machining. Use an indexable ball - nose milling cutter and feed six to eight times to reduce the deformation caused by cutting force, and machine the approximate contour of the stepped groove in the main - shaft groove two (5), side - shaft groove one (6) and side - shaft groove two (7), and reserve a machining allowance of 3 - 5 mm for finishing;

[0018] Step 5: Perform finishing machining. Use a sharp cemented carbide tool (rake angle γ = 8 - 12°, edge radius ≤ 0.02 mm) for milling, and control the milling speed at 150 - 180 mm / min to machine the final stepped - groove shape in (5), (6) and (7).

[0019] Step 6: After finishing machining, perform natural aging for 4 hours to release stress, then apply high - frequency vibration (frequency 100 - 200 Hz, amplitude 0.1 - 0.3 mm) to the three - stage planet carrier for 20 - 30 minutes to eliminate most of the residual stress, and then perform annealing at 200 - 300 °C for 2 - 6 hours to further eliminate stress;

[0020] Step 7: Clean the processed three - stage planet carrier, and then coat diamond coatings on the main - shaft groove two (5), side - shaft groove one (6) and side - shaft groove two (7), mainly coating at the step roots and transition areas.

[0021] Preferably, the specific processing process of Step 1 is: the ultrasonic cleaning frequency is 28 - 40 kHz, the cleaning time is 10 - 20 minutes, the cleaning temperature is 60 - 80 °C, use acetone or absolute ethanol as the cleaning agent, put it into a vacuum drying oven for drying after cleaning, the drying temperature is 70 - 85 °C, and the drying time is 1 - 3 hours.

[0022] Preferably, the specific processing procedure of Step 4 is as follows: When milling the stepped groove with an indexable ball-end milling cutter, the depth of each cut ≤ 0.5 mm, the feed rate ≤ 0.1 mm / r, and the roundness error is controlled ≤ 0.02 mm.

[0023] Preferably, the specific processing procedure of Step 5 is as follows: When milling the stepped groove, the cemented carbide tool adopts a compound strategy of variable pitch helical milling combined with trochoidal milling. In the initial stage, a large pitch is used to quickly remove the surplus material, and when approaching the forming stage, it is switched to a small pitch for precision finishing to reduce the fluctuation of the radial cutting force. Cycloidal cycles are periodically inserted into the helical path to disperse the cutting heat and reduce the single-sided contact time of the tool. Based on the real-time feedback of the cutting force sensor, the feed speed is dynamically adjusted to maintain a constant chip thickness h = 0.1 mm, and a spiral involute tool withdrawal is adopted, thereby ensuring the integrity of the cutting arc and the surface quality.

[0024] Preferably, the specific processing procedure of Step 6 is as follows: Use a heat-resistant steel bracket to suspend the three-stage planet carrier in a box-type resistance furnace, ensure that the distance between the bottom wall of the three-stage planet carrier and the furnace bottom ≥ 300 mm to avoid direct contact with the furnace bottom, ensure smooth circulation of hot air, arrange thermocouples on the surface and inner hole steps of the three-stage planet carrier to monitor the actual temperature in real time, slowly heat up to the target temperature at a rate ≤ 50 °C / h to avoid thermal shock, anneal for 2 - 6 hours, and the holding time is calculated according to the thickness of the three-stage planet carrier. For every 15 mm increase in thickness, the holding time increases by 1 - 1.5 hours. Control the temperature fluctuation in the furnace within ±3 °C, introduce nitrogen with a purity ≥ 99.99% into the furnace to prevent oxidation. After the holding time ends, control the temperature in the furnace to drop below 100 °C and then take it out, and the cooling rate ≤ 20 °C / h.

[0025] Advantages of the present invention:

[0026] 1. In the present invention, by arranging thermocouples on the surface and inner hole steps of the three-stage planet carrier to monitor the actual temperature in real time, slowly heat up to the target temperature at a rate ≤ 50 °C / h to avoid thermal shock, anneal for 2 - 6 hours, and the holding time is calculated according to the thickness of the three-stage planet carrier. For every 15 mm increase in thickness, the holding time increases by 1 - 1.5 hours. Control the temperature fluctuation in the furnace within ±3 °C, introduce nitrogen with a purity ≥ 99.99% into the furnace to prevent oxidation. After the holding time ends, control the temperature in the furnace to drop below 100 °C and then take it out, and the cooling rate ≤ 20 °C / h. Thus, the stress elimination rate at the stepped groove opened on the three-stage planet carrier can reach more than 95%, which can ensure the normal use of the planet carrier for a long time and avoid deformation of the stepped groove.

[0027] 2. In the present invention, by coating the diamond coating in the stepped groove, the friction between the inner wall of the stepped groove and the fitting during subsequent assembly can be effectively reduced, and further protection is formed for the stepped groove. Description of the Drawings

[0028] The present invention will be further described below in conjunction with the accompanying drawings.

[0029] Figure 1 It is a three-dimensional schematic diagram of the whole device of the present invention;

[0030] Figure 2 It is a three-dimensional schematic diagram of the main shaft groove in the present invention;

[0031] Figure 3 It is a three-dimensional schematic diagram of the limiting protrusion in the present invention.

[0032] In the figure: 1. planet carrier body; 101. plate No. 1; 102. plate No. 2; 103. support column; 2. main shaft sleeve; 3. main shaft groove 1; 4. limiting protrusion; 5. main shaft groove 2; 6. side shaft groove 1; 7. side shaft groove 2; 8. limiting groove. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] See also Figures 1-3 As shown, the present invention is a TA type three-stage planetary carrier.

[0035] The planet carrier body 1 includes a first plate 101 and a second plate 102 which are symmetrically arranged. The first plate 101 and the second plate 102 are connected by a plurality of groups of support columns 103 which are equidistantly distributed. A main shaft sleeve 2 is arranged on the rear end surface of the first plate 101. A main shaft groove 1 3 is formed through the central area of ​​the first plate 101 and the second plate 102. A main shaft groove 2 5 which matches the main shaft groove 1 3 is formed through the central area of ​​the second plate 102. The front end surface of plate No. 101 is surrounded by the main shaft groove 1 3 and penetrates through a plurality of groups of equidistantly distributed side shaft grooves 1 6. The front end surface of plate No. 2 102 is surrounded by the main shaft groove 2 5 and penetrates through a plurality of groups of side shaft grooves 2 7 matching the side shaft groove 1 6. The gear set is placed between plate No. 101 and plate No. 2 102. The main shaft groove 1 3 and the main shaft groove 2 5 are used to install the main shaft and the main shaft bearings. The side shaft groove 1 6 and the side shaft groove 2 7 are used to install the axles and bearings on the side gears.

[0036] In this embodiment, specifically, the material of the planet carrier body 1 and the main shaft sleeve seat 2 is QT700 alloy steel.

[0037] In this embodiment, specifically, the cross-section of the support column 103 is triangular, and the main shaft groove II 5, the side shaft groove I 6, and the side shaft groove II 7 are all stepped grooves.

[0038] In this embodiment, specifically, a limiting protrusion 4 is arranged along the extension direction of the main shaft sleeve seat 2 on the inner wall of the main shaft groove I 3.

[0039] In this embodiment, specifically, a limiting groove 8 is formed on the inner wall of the side shaft groove II 7.

[0040] A processing technology for a three-stage planetary carrier of a TA model is characterized by comprising the following steps:

[0041] Step 1: First, perform sandblasting on the three-stage planetary carrier casting to remove the surface oxide scale, then ultrasonically clean the oil stains on the surface, and then dry it.

[0042] Step 2: Check whether the to-be-processed three-stage planetary carrier has cracks or hidden damages through an ultrasonic flaw detector, and fix the undamaged three-stage planetary carrier on a horizontal machining center BTD-150H.R22 numerically controlled planer boring and milling machine through a soft jaw fixture;

[0043] Step 3: Input the dimension parameters of the main shaft groove II 5, the side shaft groove I 6, and the side shaft groove II 7 that need to be opened into the horizontal machining center BTD-150H.R22 numerically controlled planer boring and milling machine. First, perform rough machining of the stepped groove, open holes on the end faces of the first plate 101 and the second plate 102 through an indexable face milling cutter, and reserve a machining allowance of 10 - 30 mm for the subsequent stepped part;

[0044] Step 4: Perform semi-finishing machining. Through an indexable ball-nose milling cutter, feed six to eight times to reduce the cutting force deformation, and machine the approximate contour of the stepped groove in the main shaft groove II 5, the side shaft groove I 6, and the side shaft groove II 7, and reserve a machining allowance of 3 - 5 mm for finishing;

[0045] Step 5: Perform finishing machining. Use a sharp cemented carbide tool with a rake angle γ = 8 - 12° and an edge radius of bluntness ≤ 0.02 mm for milling. Control the milling speed at 150 - 180 mm / min to machine the final stepped groove shapes in 5, 6, and 7.

[0046] Step 6: After finishing machining, perform natural aging for 4 hours to release stress, then apply a high-frequency vibration with a frequency of 100 - 200 Hz and an amplitude of 0.1 - 0.3 mm to the three-stage planetary carrier for 20 - 30 minutes to eliminate most of the residual stress, and then perform annealing at 200 - 300 °C for 2 - 6 hours to further eliminate stress;

[0047] Step 7: Clean the processed three-stage planetary carrier, and then coat diamond coatings on the main shaft groove II 5, the side shaft groove I 6, and the side shaft groove II 7, mainly coating the root and transition area of the steps.

[0048] In this embodiment, specifically, the specific processing procedure of Step 1 is as follows: The ultrasonic cleaning frequency is 28 - 40 kHz, the cleaning time is 10 - 20 minutes, the cleaning temperature is 60 - 80 °C. Acetone or absolute ethanol is used as the cleaning agent. Both acetone and absolute ethanol are commonly used cleaning solvents, with strong decontamination ability and volatility, and can effectively remove the oil stains and organic impurities on the surface of the workpiece. Then, it is rinsed with clean water or deionized water to remove the residual cleaning agent on the surface of the workpiece. After the cleaning is completed, it is placed in a vacuum drying oven for drying. The drying temperature is 70 - 85 °C, and the drying time is 1 - 3 hours. It should be noted that the three-stage planetary gear carrier casting has been preheated at this time to eliminate the stress in the three-stage planetary gear carrier casting.

[0049] In this embodiment, specifically, the specific processing procedure of Step 4 is as follows: When milling the stepped groove with an indexable ball-nose milling cutter, the cutting depth per cut ≤ 0.5 mm, the feed rate ≤ 0.1 mm / r, and the roundness error is controlled ≤ 0.02 mm.

[0050] In this embodiment, specifically, the specific processing procedure of Step 5 is as follows: When milling the stepped groove, the cemented carbide tool adopts a compound strategy of variable pitch helix plus cycloidal milling. In the initial stage, a large pitch is used to quickly remove the surplus material. When approaching the forming stage, it is switched to a small pitch for finishing, reducing the radial cutting force fluctuation. Cycloidal cycles are periodically inserted in the spiral path to disperse the cutting heat and reduce the single-sided contact time of the tool. Based on the real-time feedback of the cutting force sensor, the feed speed is dynamically adjusted to maintain a constant chip thickness h = 0.1 mm. Helical involute tool withdrawal is adopted, which can ensure the integrity of the cutting arc and the surface quality.

[0051] In this embodiment, specifically, the specific processing procedure of Step 6 is as follows: The three-stage planetary gear carrier is suspended in a box-type resistance furnace using a heat-resistant steel bracket, ensuring that the distance between the bottom wall of the three-stage planetary gear carrier and the furnace bottom ≥ 300 mm to avoid direct contact with the furnace bottom and ensure smooth circulation of hot air. Thermocouples are arranged on the surface and the inner hole step of the three-stage planetary gear carrier to monitor the actual temperature in real time. It is slowly heated to the target temperature at a rate ≤ 50 °C / h to avoid thermal shock, and annealed for 2 - 6 hours. The holding time is calculated according to the thickness of the three-stage planetary gear carrier. For every 15 mm increase in thickness, the holding time increases by 1 - 1.5 hours. The temperature fluctuation in the furnace is controlled within ± 3 °C. Nitrogen with a purity ≥ 99.99% is introduced into the furnace, and the nitrogen covers the surface of the workpiece to form an isolation layer to prevent oxidation and decarburization, thereby reducing the surface stress concentration caused by oxidation. After the holding time ends, the temperature in the furnace is controlled to drop below 100 °C and then taken out, and the cooling rate ≤ 20 °C / h.

[0052] The above has described in detail an embodiment of the present invention, but the above content is only a preferred embodiment of the present invention and cannot be considered as defining the scope of implementation of the present invention. All equivalent changes and improvements made in accordance with the scope of the application of the present invention shall still fall within the scope covered by the patent of the present invention.

Claims

1. A three - stage planet carrier of TA model, characterized in that: It includes a planet carrier body (1), and the planet carrier body (1) further includes a first plate (101) and a second plate (102) which are symmetrically arranged. The first plate (101) and the second plate (102) are connected by several groups of equally - spaced support columns (103); A main shaft sleeve seat (2) is arranged on the rear end face of the first plate (101). A main shaft groove one (3) is penetrated through the central area of the first plate (101) and the second plate (102). A main shaft groove two (5) which is matched with the main shaft groove one (3) is penetrated through the central area of the second plate (102). Several groups of equally - spaced side shaft grooves one (6) are penetrated through the front end face of the first plate (101) around the main shaft groove one (3). Several groups of side shaft grooves two (7) which are matched with the side shaft grooves one (6) are penetrated through the front end face of the second plate (102) around the main shaft groove two (5).

2. A three-stage planet carrier of TA model according to claim 1, characterized in that, The material of the planet carrier body (1) and the main shaft sleeve seat (2) is QT700 alloy steel.

3. A three-stage planet carrier of TA model according to claim 2, characterized in that, The cross - section of the support column (103) is triangular, and the main shaft groove two (5), the side shaft groove one (6) and the side shaft groove two (7) are all stepped grooves.

4. A three-stage planet carrier of TA model according to claim 1, characterized in that, A limiting protrusion (4) is arranged on the inner wall of the main shaft groove one (3) along the extension direction of the main shaft sleeve seat (2).

5. A three-stage planet carrier of TA model according to claim 1, characterized in that, A limiting groove (8) is opened on the inner wall of the side shaft groove two (7).

6. The processing technology of a three-stage planet carrier of TA model according to any one of claims 1, characterized in that, It includes the following steps: Step 1: First, perform sand - blasting treatment on the three - stage planet carrier casting to remove the surface oxide scale, then ultrasonically clean the oil stains on the surface, and then dry it. Step 2: Use an ultrasonic flaw detector to check whether there are cracks or hidden damages in the to - be - machined three - stage planet carrier. Fix the intact three - stage planet carrier on the horizontal machining center BTD - 150H.R22 CNC planer - type boring and milling machine through soft - jaw fixtures; Step 3: Input the dimensional parameters of the main shaft groove two (5), the side shaft groove one (6) and the side shaft groove two (7) to be opened into the horizontal machining center BTD - 150H.R22 CNC planer - type boring and milling machine. First, perform rough machining of the stepped groove. Use a face - milling cutter with indexable inserts to open holes on the end faces of the first plate (101) and the second plate (102), and reserve a machining allowance of 10 - 30 mm for the subsequent stepped part; Step 4: Perform semi - finishing machining. Use an indexable ball - nose milling cutter to feed six to eight times to reduce the deformation caused by cutting force, and machine out the approximate contour of the stepped grooves in the main shaft groove two (5), the side shaft groove one (6) and the side shaft groove two (7), and reserve a machining allowance of 3 - 5 mm for finishing machining; Step 5: Perform finishing machining. Use a sharp cemented carbide tool (rake angle γ = 8 - 12°, edge radius ≤ 0.02 mm) for milling. Control the milling speed at 150 - 180 mm / min to machine out the final stepped groove shapes in 5, 6 and 7. Step 6: After finish machining, conduct natural aging for 4 hours to release stress, then apply high-frequency vibration (frequency 100 - 200 Hz, amplitude 0.1 - 0.3 mm) to the three-stage planet carrier for 20 - 30 minutes to eliminate most of the residual stress, and then conduct annealing at 200 - 300 °C for 2 - 6 hours to further eliminate stress; Step 7: Clean the machined three-stage planet carrier, and then coat diamond coatings on the main shaft groove II (5), side shaft groove I (6) and side shaft groove II (7), mainly coating at the root of the step and the transition zone.

7. The processing technology of a three-stage planet carrier of TA model according to claim 6, characterized in that, The specific treatment process of the said Step 1 is as follows: the ultrasonic cleaning frequency is 28 - 40 kHz, the cleaning time is 10 - 20 minutes, the cleaning temperature is 60 - 80 °C, acetone or absolute ethanol is used as the cleaning agent, after cleaning, put it into a vacuum drying oven for drying, the drying temperature is 70 - 85 °C, and the drying time is 1 - 3 hours.

8. The processing technology of a three-stage planet carrier of TA model according to any one of claims 6, characterized in that, The specific treatment process of the said Step 4 is as follows: when milling the stepped groove with an indexable ball-nose end mill, the depth of each cut ≤ 0.5 mm, the feed rate ≤ 0.1 mm / r, and the roundness error is controlled ≤ 0.02 mm.

9. The processing technology of a three-stage planet carrier of TA model according to claim 6, characterized in that, The specific treatment process of the said Step 5 is as follows: when milling the stepped groove, the cemented carbide tool adopts a composite strategy of variable pitch spiral plus trochoidal milling. In the initial stage, a large pitch is adopted to quickly remove the surplus, and when approaching the forming, it is switched to a small pitch for finishing to reduce the radial cutting force fluctuation. Cyclic trochoidal cycles are inserted periodically in the spiral path to disperse the cutting heat and reduce the single-side contact time of the tool. Based on the real-time feedback of the cutting force sensor, the feed speed is dynamically adjusted to maintain a constant chip thickness h = 0.1 mm, and a spiral involute tool withdrawal is adopted, thereby ensuring the integrity of the cutting arc and the surface quality.

10. The processing technology of a three-stage planet carrier of TA model according to claim 6, characterized in that, The specific treatment process of the said Step 6 is as follows: Use a heat-resistant steel bracket to suspend the three-stage planet carrier in a box-type resistance furnace, ensure that the distance between the bottom wall of the three-stage planet carrier and the furnace bottom is ≥ 300 mm to avoid direct contact with the furnace bottom, ensure the smooth circulation of hot air, arrange thermocouples on the surface and the inner hole step of the three-stage planet carrier to monitor the actual temperature in real time, slowly heat up to the target temperature at a rate of ≤ 50 °C / h to avoid thermal shock, conduct annealing for 2 - 6 hours, and the holding time is calculated according to the thickness of the three-stage planet carrier. For every 15 mm increase in thickness, the holding time increases by 1 - 1.5 hours. Control the temperature fluctuation in the furnace within ± 3 °C, introduce nitrogen with a purity ≥ 99.99% into the furnace to prevent oxidation. After the holding time ends, control the temperature in the furnace to drop below 100 °C and take it out, and the cooling rate ≤ 20 °C / h.

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