A yaw satellite reduction motor for wind turbines

Abstract

The present invention discloses a yaw planetary reduction motor applied to a wind turbine. It solves the problem that the existing yaw reducer has a large axial dimension, weak rigidity, and cannot be used in scenarios with strict spatial dimension requirements. The reducer uses the connecting flange of the motor to axially position the planetary gear of the first-stage planetary gear reduction mechanism, the current-stage planetary carrier axially positions the planetary gear bearing, and the upper-stage planetary carrier is axially positioned by the first external tooth of the next-stage sun gear, and a micro-gap is designed with the planetary gear of the next stage. At the same time, the planetary gear and the planetary carrier of the same stage are in direct contact to achieve mutual axial positioning; the planetary carrier of the Nth-stage planetary gear reduction mechanism is fixedly connected to the output gear to achieve power output. Compared with the existing reducer structure, the structure of the present invention not only shortens the overall axial dimension of the planetary gear reducer, but also reduces the characteristics and quantity of parts, thereby reducing manufacturing costs.

Description

Technical Field

[0001] The invention relates to a wind power generation driving device, in particular to a yaw satellite reduction motor applied to a wind power generator. Background Art

[0002] Large and medium-sized wind turbines generally use an electric yaw system to adjust the wind rotor and align it with the wind direction. The yaw system generally includes a wind vane that senses the wind direction, a yaw motor, a yaw reducer, a yaw brake (yaw damper or yaw caliper), a large gear of the rotating body, etc. Its working principle is as follows:

[0003] The wind vane acts as a sensing element and transmits the change of wind direction to the processor of the control loop of the yaw motor using an electrical signal. After comparison, the processor sends a clockwise or counterclockwise yaw command to the yaw motor. In order to reduce the gyroscopic torque during yaw, the motor speed will be slowed down by a coaxially connected reducer, and the yaw torque will be applied to the large gear of the rotating body, driving the wind wheel to yaw towards the wind. When the wind is facing the wind, the wind vane loses the electrical signal, the motor stops working, and the yaw process ends.

[0004] At present, the yaw reducer in the wind turbine mostly adopts the yaw planetary gear reducer. For example, the Chinese patent, publication number: CN102032126A discloses a "yaw movable tooth reducer", which includes a drive motor, a first-stage planetary gear reducer, a second-stage movable tooth reducer and a third-stage movable tooth reducer; the transmission process of the yaw movable tooth reducer is: the input shaft is sleeved on the drive motor shaft, and the torque is transmitted through the motor shaft flat key. The small end of the sun gear is connected to the input shaft with a spline and rotates synchronously. The output shaft is connected to the planetary carrier with a spline. The secondary eccentric wheel is sleeved on the outer circle of the small end of the output shaft, and the torque is transmitted through the secondary output shaft flat key. The third-stage eccentric wheel is sleeved on the outer circle of the small end of the secondary input shaft, and the torque is transmitted through the secondary input shaft flat key. The large gear is connected to the third-stage output shaft through a spline. The power of the driving motor is transmitted to the three-stage output shaft and the large gear through the first-stage planetary gear reducer, the second-stage and the third-stage movable tooth reducer, so as to reduce the speed and increase the torque. However, in actual application, the yaw movable tooth reducer has the following problems:

[0005] 1. Large axial dimensions. As offshore and onshore wind power have entered the stage of large-scale development, considering the installation space limitations and production costs of wind power gearboxes, more and more yaw and pitch reducers tend to be small drive modes, and the miniaturization of reducers is becoming increasingly important. The reducer structure in the yaw reducer has a large axial dimension and cannot meet the current demand for miniaturization of reducers.

[0006] 2. The connection structure used at the large gear for the final power output is unreliable. The output end of the yaw reducer adopts a cylindrical fit, and the coaxiality is lower than that of the conical fit, and low coaxiality will lead to faster gear wear; secondly, the screws of the output structure bear axial force and torsional torque at the same time, which is more prone to wear and failure. Summary of the invention

[0007] In order to solve the problems that the existing yaw reducer has a large axial size, weak rigidity, and cannot be used in scenarios with strict spatial size requirements, the present invention provides a yaw planetary reducer motor for use in a wind turbine.

[0008] The specific technical solution of the present invention is:

[0009] A yaw planetary reduction motor for a wind turbine generator comprises a motor, a reduction mechanism and an output gear; the reduction mechanism comprises an inner gear housing and N-stage planetary gear reduction mechanisms arranged in sequence along the axial direction of the inner gear housing; N≥2; each stage of the planetary gear reduction mechanism comprises a sun gear, a planetary gear, a planet carrier and a planetary shaft;

[0010] The improvements are:

[0011] The sun gear in the first-stage planetary gear reduction mechanism is key-connected to the output shaft of the motor; the front end of the motor is fixedly connected to the inner gear housing through a connecting flange, and a micro-gap is formed between the end face of the connecting flange and the end face of the planetary gear in the first-stage planetary gear reduction mechanism, which is used to axially position the planetary gear in the first-stage planetary gear reduction mechanism;

[0012] The sun gears in the 2nd to Nth stage planetary gear reduction mechanisms are all provided with first external teeth and second external teeth, and the tooth height of the first external teeth is greater than the tooth height of the second external teeth; the first external teeth are meshed with the planetary gear of the current stage, and the second external teeth are key-connected with the planetary carrier of the previous stage; the end face of the planetary carrier of the previous stage contacts the end face of the first external teeth on the sun gear of the current stage, and at the same time forms a micro gap with the end face of the planetary gear of the current stage;

[0013] The planet shaft of each stage of the planetary gear reduction mechanism is interference fit with the planet shaft mounting hole on the planet carrier, and the planetary gear and the planet carrier of the Nth stage of the planetary gear reduction mechanism are in contact with each other to achieve the axial positioning of the planetary gear in the Nth stage of the planetary gear reduction mechanism;

[0014] In the 1st to Nth stage planetary gear reduction mechanism, the outer surface of the planetary shaft located in the planetary wheel bearing mounting hole is provided with S first inner ring outer raceways arranged side by side in the axial direction, S≥2, and a plurality of first steel balls are arranged along the circumferential direction between each first inner ring outer raceway and the hole wall of the planetary wheel bearing mounting hole; the first steel balls installed in each two adjacent first inner ring outer raceways are arranged in a staggered manner in the circumferential direction, thereby forming the planetary wheel bearing of the Nth stage planetary gear reduction mechanism; a circular arc groove protruding inward is provided on the side of the planetary wheel bearing mounting hole close to the planet carrier, which is used to axially position the second steel ball;

[0015] The planet carrier of the Nth-stage planetary gear reduction mechanism and the inner gear housing are rotationally connected via a multi-row contact ball bearing, and the contact ball bearing structure realizes the axial positioning of the planet carrier in the Nth-stage planetary gear reduction mechanism;

[0016] The multi-row contact ball bearing comprises M second inner ring outer raceways arranged along the axial direction on the outer surface of the planet carrier of the N-th stage planetary gear reduction mechanism, and M second outer ring inner raceways corresponding to the M second inner ring outer raceways are arranged on the inner wall of the inner gear housing along the axial direction; M≥2;

[0017] M steel ball installation raceways are formed between the M second inner ring outer raceways and the M second outer ring inner raceways; a plurality of second steel balls are arranged in the circumferential direction in each steel ball installation raceway;

[0018] The planet carrier of the Nth-stage planetary gear reduction mechanism is provided with at least one axial hole, and M ball loading holes are provided at positions corresponding to the axial hole and the outer raceway of the second inner ring, and each ball loading hole is provided with an anti-escape structure to prevent the ball from escaping;

[0019] The planet carrier of the Nth-stage planetary gear reduction mechanism is fixedly connected to the output large gear to achieve power output.

[0020] Furthermore, a stepped through hole is provided at the center of the planetary carrier of the above-mentioned Nth-stage planetary gear reduction mechanism, and the stepped through hole includes a straight hole and a tapered hole, and a baffle is fixedly installed in the straight hole; the output gear includes a gear part and a tapered shaft part; the tapered shaft part of the output gear is inserted into the tapered hole and positioned by a connecting key, and the countersunk screw passes through the baffle and is threadedly connected with the tapered shaft part to realize the fixed connection between the output gear and the planetary carrier of the Nth-stage planetary gear reduction mechanism.

[0021] Furthermore, a limiting hole is also provided on the planet carrier of the above-mentioned Nth-stage planetary gear reduction mechanism, and the limiting hole is connected to the ball loading hole; a limiting device is provided in the limiting hole to prevent the anti-escape structure from moving.

[0022] Furthermore, the above-mentioned limiting hole is a screw hole parallel to the axial hole, and the limiting device is a tightening screw.

[0023] Furthermore, the cross section of the steel ball mounting raceway includes at least one arc that does not coincide with the center of the cross section.

[0024] Furthermore, when the above M is 2,

[0025] The first ball installation raceway consists of four eccentric arcs, each of which occupies 1 / 4 of the cross-section circumference;

[0026] The second ball installation raceway consists of four eccentric arcs, each of which occupies 1 / 4 of the circumference of the cross section;

[0027] The arc of the first steel ball mounting raceway is the same as the arc of the second steel ball mounting raceway, and the second steel ball is in point contact with the four arcs of the first steel ball mounting raceway, as well as the second steel ball and the four arcs of the second steel ball mounting raceway.

[0028] Furthermore, when the above M is 2,

[0029] The first ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the cross-section circumference;

[0030] The second ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the circumference of the cross section;

[0031] The arc of the first steel ball mounting raceway and the arc of the second steel ball mounting raceway are mirror images.

[0032] Furthermore, when the above M is 3,

[0033] The first ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the cross-section circumference;

[0034] The second steel ball installation raceway includes four eccentric arcs, each of which occupies 1 / 4 of the circumference of the cross section. The second steel ball is in point contact with the four arcs of the second steel ball installation raceway.

[0035] The third ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the circumference of the cross section;

[0036] The arc of the first steel ball installation raceway and the arc of the third steel ball installation raceway are mirror images.

[0037] Furthermore, S shallow grooves are arranged on the inner wall of the planetary wheel bearing mounting hole of the above-mentioned Nth stage planetary gear reduction mechanism, and the S shallow grooves correspond one-to-one to the S first inner ring outer raceways; the first inner ring outer raceway is composed of an eccentrically arranged fifth arc and a sixth arc, and the second steel ball is in point contact with the fifth arc and the sixth arc respectively, and contacts with the shallow grooves, thereby forming a three-point contact ball bearing structure.

[0038] Furthermore, the above-mentioned N-stage planetary gear reduction mechanisms share an internal gear housing, and the modules of the planetary gears in each stage of the planetary gear reduction mechanism are the same.

[0039] The present invention has the following beneficial effects:

[0040] 1. The reducer of the present invention adopts the connecting flange of the motor to axially position the planetary gear of the first-stage planetary gear reduction mechanism, the current-stage planetary carrier axially positions the planetary gear bearing, and the upper-stage planetary carrier is axially positioned by the first external tooth of the lower-stage sun gear and is designed with a micro gap between the lower-stage planetary gear. At the same time, the planetary gear and the planetary carrier of the same stage are in direct contact to achieve mutual axial positioning. Compared with the existing reducer structure, the structure of the present invention not only shortens the overall axial size of the planetary gear reducer, but also reduces the characteristics and quantity of parts, thereby reducing the manufacturing cost.

[0041] 2. In the present invention, the tapered shaft portion of the output gear and the tapered hole in the planet carrier are axially tightened and key-connected for positioning by screws, and the concentricity and axial positioning reliability between the planet carrier and the gear are ensured by the tapered surface matching.

[0042] 3. The planet carrier and the inner gear housing of the Nth-stage planetary gear reduction mechanism of the reducer of the present invention are rotationally connected through a multi-row contact ball bearing. This bearing type can not only bear radial loads, but also axial loads. Compared with the structure of the existing reducer, the reducer's bearing capacity for axial and bending loads is greatly improved; at the same time, the multi-row and multi-point contact ball bearing structure adopts a filling structure composed of an axial hole, a ball filling hole and an anti-escape structure, thereby avoiding the problem of splicing gaps that are inevitably generated by adopting an upper and lower splicing structure, thereby improving manufacturing precision, thus effectively ensuring the raceway stiffness and reducing the wear of the balls in the raceway caused by the splicing raceway gaps.

[0043] 4. The planetary wheel bearings in the N-stage planetary gear reduction mechanism of the present invention all adopt a three-point contact ball bearing structure, which has higher manufacturing precision than the cylindrical needle roller bearings used in the existing planetary wheel bearings. At the same time, needle roller bearings generally cannot be assembled with zero clearance or negative clearance due to assembly problems and bending failure problems. The three-point contact ball bearing structure used in the present invention can be preloaded to eliminate bearing clearance, thereby reducing the reverse clearance of the reducer.

[0044] 5. The present invention adopts a common inner gear housing for each stage of the planetary gear reduction mechanism, and the same module design is adopted for each stage of the planetary gear, so that the width dimension of the planetary gear in each stage of the planetary mechanism can be thinned, further reducing the axial dimension of the reducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 It is a schematic diagram of the structure of the yaw planetary reduction motor of the present invention.

[0046] Figure 2 Schematic diagram of a planetary gear bearing without shallow grooves.

[0047] Figure 3 Schematic diagram of a planetary gear bearing with shallow grooves.

[0048] Figure 4 The figure is a schematic diagram of the circumferentially staggered arrangement of the first steel balls in two adjacent rows in the planetary gear bearing.

[0049] Figure 5 It is a structural schematic diagram of the connection between the planet carrier and the inner gear housing of the Nth stage planetary gear reduction mechanism through multi-row contact ball bearings.

[0050] Figure 6 This is a schematic diagram of the end face of the planet carrier of the Nth stage planetary gear reduction mechanism.

[0051] Figure 7 It is a schematic diagram of the first form of the two-row contact ball bearing structure;

[0052] Figure 8 It is a schematic diagram of the second form of the two-row contact ball bearing structure;

[0053] Fig. 9 It is a schematic diagram of the third form of the two-row contact ball bearing structure;

[0054] Fig.10 It is a schematic diagram of a three-row contact ball bearing structure;

[0055] The reference numerals are as follows:

[0056] 1-motor, 11-connecting flange;

[0057] 2-reduction mechanism, 3-output large gear;

[0058] 20-inner gear housing, 201-inner raceway of the second outer ring;

[0059] 30-planetary gear reduction mechanism; 31-sun gear, 311-first outer tooth, 312-second outer tooth, 32-planetary gear, 33-planet carrier, 331-second inner ring outer raceway, 332-axial hole, 333-ball filling hole, 334-anti-escape structure, 335-limiting hole, 336-step through hole, 337-blocking plate, 34-planetary shaft, 341-first inner ring outer raceway, 342-arc-shaped channel, 35-planetary shaft mounting hole, 37-planetary wheel bearing mounting hole, 371-shallow groove;

[0060] 40-First steel ball;

[0061] 50-Steel ball installation raceway;

[0062] 60-second steel ball;

[0063] 70-Countersunk screw. DETAILED DESCRIPTION

[0064] In order to make the above-mentioned purposes, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present invention, but not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary persons in the art without creative work should fall within the scope of protection of the present invention.

[0065] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0066] At the same time, in the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "upper, lower, inner and outer" are based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as limiting the present invention. In addition, the terms "first, second or third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0067] In the present invention, unless otherwise clearly specified and limited, the terms "install, connect, connect" should be understood in a broad sense, for example: it can be a fixed connection, a detachable connection or an integral connection; it can also be a mechanical connection, an electrical connection or a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0068] Since the existing yaw reduction motor has a large axial size and cannot be used in some scenarios with strict space requirements, the present invention provides a yaw planetary reduction motor for a wind turbine, and its basic design idea is:

[0069] The connecting flange of the motor is used to axially position the planetary gear of the first-stage planetary gear reduction mechanism, the current-stage planetary carrier is used to axially position the planetary gear bearing, the upper-stage planetary carrier is axially positioned by the first external tooth of the lower-stage sun gear and a micro-gap is designed with the lower-stage planetary gear. At the same time, the planetary gear and the planetary carrier of the same stage are in direct contact to achieve mutual axial positioning, thereby greatly shortening the axial dimension of the planetary gear reducer.

[0070] The planet carrier and the inner gear housing of the Nth-stage planetary gear reduction mechanism are rotationally connected through a self-made multi-row contact ball bearing. Since the raceway stiffness is greatly increased compared to traditional bearings, the performance of the entire bearing is improved, so that the bearing can carry large loads in multiple directions, and has a long service life and high reliability. At the same time, the multi-row contact ball bearing structure adopts a filling structure composed of an axial hole, a ball filling hole and an anti-escape structure, which avoids the problem of splicing gaps that are inevitably generated by adopting an upper and lower splicing structure, thereby improving manufacturing accuracy, effectively ensuring the raceway stiffness and reducing the wear of the balls in the raceway caused by the splicing raceway gap.

[0071] The output large gear and the tapered hole on the planet carrier of the Nth-stage planetary gear reduction mechanism are axially tightened by screws, and the tightened tapered shaft hole cooperates to ensure the concentricity and axial positioning reliability between the planet carrier and the large gear.

[0072] like Figure 1 As shown, the yaw planetary reduction motor applied to the wind turbine comprises a motor 1, a reduction mechanism 2 and an output gear 3; the reduction mechanism 2 comprises an inner gear housing 20 and N-stage planetary gear reduction mechanisms 30 sequentially arranged along the axial direction of the inner gear housing 20; N≥2; in this embodiment, N is 4, wherein the first-stage planetary gear reduction mechanism is a high-speed input end of the reducer, the second and third-stage planetary gear reduction mechanisms are medium-speed stages, and the fourth-stage planetary gear reduction mechanism is a low-speed output end of the reducer; each stage of the planetary gear reduction mechanism 30 comprises a sun gear 31, a planetary gear 32, a planet carrier 33 and a planetary shaft 34;

[0073] The sun gear 31 in the first-stage planetary gear reduction mechanism is key-connected to the output shaft of the motor 1; the front end of the motor 1 is fixedly connected to the inner gear housing 20 through the connecting flange 11, and the end face of the connecting flange 11 and the end face of the planetary gear 32 in the first-stage planetary gear reduction mechanism are matched with a micro-clearance, which is used to axially position the planetary gear in the first-stage planetary gear reduction mechanism;

[0074] The sun gears 31 in the 2nd to 4th stage planetary gear reduction mechanisms 30 are all provided with first external teeth 311 and second external teeth 312, and the tooth height of the first external teeth 311 is greater than the tooth height of the second external teeth 312; the first external teeth 311 of each stage of the sun gear 30 mesh with the planetary gear 32 of the current stage, and the second external teeth 312 form a key connection with the planetary carrier 33 of the previous stage; the end face of the planetary carrier 33 of the previous stage contacts the end face of the first external teeth 311 on the sun gear 31 of the current stage, and at the same time forms a micro gap with the end face of the planetary gear 32 of the current stage (the position shown by the mark A in the figure is the micro gap), and the value range of the micro gap is: 0.1-0.3mm;

[0075] The planet shaft 34 of each stage of the planetary gear reduction mechanism is interference fit with the planet shaft mounting hole 35 on the planet carrier 33, and the planet wheel 34 and the planet carrier 33 of the fourth stage of the planetary gear reduction mechanism are in contact with each other to achieve the axial positioning of the planet wheel in the fourth stage of the planetary gear reduction mechanism;

[0076] like Figure 2 As shown, in the 1st to 4th stage planetary gear reduction mechanism, the outer surface of the planet shaft 34 located in the planetary wheel bearing mounting hole 37 is provided with S first inner ring outer raceways 341 arranged side by side along the axial direction, S ≥ 2, and a plurality of first steel balls 40 are arranged along the circumferential direction between each first inner ring outer raceway 341 and the hole wall of the planetary wheel bearing mounting hole 37; the first steel balls 40 installed in each two adjacent first inner ring outer raceways 341 are staggered in the circumferential direction, as shown in FIG. Figure 4 As shown, the planetary wheel bearings of the 1st to 4th stage planetary gear reduction mechanism are formed; the side of the planetary wheel bearing mounting hole 37 close to the planet carrier 33 is provided with an inwardly protruding arc-shaped groove 342 for axial positioning of the first steel ball 40; one point to be explained is:

[0077] The reduction motor is used for a wind turbine. Since the force on the low-speed output end is greater, the width of the planetary wheel in the planetary gear reduction mechanism can be increased step by step to meet the force requirements. According to the increase in the width of the planetary wheel, the number of ball rows of the planetary wheel bearings in the 1st to 4th stage planetary gear reduction mechanisms will also be increased step by step.

[0078] In order to make the positioning of the first steel ball more reliable, Figure 3 As shown, in this embodiment, S shallow grooves 371 are also provided on the inner wall of the planetary wheel bearing mounting hole 37 of the 1st to 4th stage planetary gear reduction mechanism, and the S shallow grooves 371 correspond to the S first inner ring outer raceways 341 one by one. The first inner ring outer raceway 341 is composed of two eccentrically arranged arcs, which are respectively recorded as the fifth arc and the sixth arc. The first steel ball 40 is in contact with the two arc points respectively, and is in contact with the shallow grooves 371, thereby forming a three-point contact ball bearing structure.

[0079] like Figure 5 As shown, the planet carrier 33 of the 4th stage planetary gear reduction mechanism is rotationally connected to the inner gear housing 20 via a multi-row contact ball bearing, and the contact ball bearing structure realizes the axial positioning of the planet carrier in the Nth stage planetary gear reduction mechanism;

[0080] The multi-row contact ball bearing includes M second inner ring outer raceways 331 arranged along the axial direction on the outer surface of the planet carrier 33 of the 4th stage planetary gear reduction mechanism, and M second outer ring inner raceways 201 corresponding to the M second inner ring outer raceways 331 are arranged on the inner wall of the inner gear housing 20 along the axial direction; M≥2;

[0081] M steel ball installation raceways 50 are formed between the M second inner ring outer raceways 331 and the M second outer ring inner raceways 201; a plurality of second steel balls 60 are arranged in each steel ball installation raceway 50 along the circumferential direction;

[0082] In order to facilitate installation, at least one axial hole 332 is provided on the planet carrier 33 of the fourth-stage planetary gear reduction mechanism. When one axial hole 332 is provided, all ball filling holes 333 are provided in the axial hole 332. When the number of rows is small, one axial hole 332 may be considered, but when the number of rows is large, an axial hole 332 that is too deep may affect the rigidity of the entire bearing, so it can be evenly distributed; taking the axial holes 332 with the same number as the raceway as an example, each axial hole 332 and the second inner Ball filling holes 333 are provided at corresponding positions of the outer raceway 331. The ball filling holes 333 connect the axial holes 332 with the outer raceway 331 of the second inner ring. During processing, the second steel balls 60 are first fed into the axial holes 332 of each column, and then the second steel balls 60 are loaded into the raceways of that column through the corresponding ball filling holes 333. After the second steel balls 60 in the raceways of all columns are loaded, the ball filling holes 333 are sealed with an anti-escape structure 334 that prevents the balls from escaping, and the installation is completed.

[0083] There are many optional forms of the anti-escape structure 334, and its purpose is to prevent at least the second steel ball 60 from falling out of the ball filling hole 333 during operation, especially under large load conditions, after processing is completed. A better way is that not only will the second steel ball 60 not fall out of the ball filling hole 333 during operation, but also the raceway can be opened to take out the second steel ball 60 when maintenance is needed.

[0084] The ball filling hole 333 should be perpendicular to the steel ball mounting raceway 50, that is, perpendicular to the axial hole 332, which is the best setting. It can also be set obliquely, but when it is set obliquely, firstly, the processing cost will increase, and secondly, there is a risk of reducing the bearing stiffness.

[0085] Based on the above conditions, two specific structures are given for reference.

[0086] 1. An isosceles trapezoidal elastic sleeve is arranged in the ball filling hole 333. The bottom surface of the sleeve with a larger area faces the center of the planetary carrier, and the top surface with a smaller area faces the second outer ring inner raceway 201. The diameter of the larger area is larger than the diameter of the second steel ball 60, and the diameter of the smaller area is smaller than the diameter of the second steel ball 60. However, the difference needs to ensure that the deformation generated during installation can squeeze the second steel ball 60 in, and at the same time, the strength of the second steel ball 60 can ensure that the second steel ball 60 is not squeezed out when the second steel ball 60 is subjected to force at this position during operation.

[0087] When selecting the above structure, it is also possible to consider adding a plug after all the second steel balls 60 are loaded, and directly squeeze the plug into the ball filling hole 333. However, if a plug is added, the surface of the end of the plug extending into the raceway should be coplanar with the raceway wall to avoid squeezing and damaging the second steel balls 60 due to unevenness.

[0088] 2. Set a pin in the ball loading hole 333, and then set a limit hole 335 on the planet carrier 333. The limit hole 335 should at least be connected to the ball loading hole 333. The limit device is installed in the limit hole 335 to position the pin. The best way for the limit hole 335 is that the center axis is parallel to the center axis of the axial hole 332, so that the force is relatively balanced when the limit is tightened. The limit device can choose a structure such as a tightening screw to fix the pin. For a multi-column structure, the limit holes 335 should be staggered. The closer the limit hole 335 is to the center column, the deeper it is. In this case, the axial hole 332 should be equal to the number of raceways. Otherwise, there will be certain problems in opening the limit hole 335.

[0089] like Figure 5 As shown, for a multi-row contact ball bearing, two small plugs ( Figure 5 c), and through a screw ( Figure 5 As shown in (d), the two small plugs are fixedly connected to prevent the anti-escape structure from loosening or even the second steel ball 60 from falling out.

[0090] The multi-row contact ball bearings used here are relatively better solutions, such as Figure 6 As shown, the cross-section of each steel ball mounting raceway 50 includes at least one arc that does not coincide with the center of the cross-section (i.e., an eccentric arc), and the arcs of each steel ball mounting raceway are randomly set, so that the number of load directions is only related to the number of arc segments and the center positions of the arcs. The more center positions and arc segments there are, the stronger the unloading capacity for each direction and the total load.

[0091] Considering that the actual scenario of the reducer of this embodiment is wind power generation, the output torque is relatively large, so the steel ball mounting raceway has at least two rows. The following are three specific reference structures of multi-row contact ball bearings:

[0092] The first structure: Figure 7 As shown, the number of rows of the steel ball mounting raceway 50 is 2, the first row of steel ball mounting raceway includes four arcs that do not coincide with the center of the cross section, and each segment occupies 1 / 4 of the cross section circumference; the second row of steel ball mounting raceway also includes four arcs that do not coincide with the center of the cross section, and each segment occupies 1 / 4 of the cross section circumference; the arcs of the first row of steel ball mounting raceway are the same as those of the second row of steel ball mounting raceway. This is equivalent to the traditional four-point contact ball bearing being repeatedly combined into a double-row four-point contact ball bearing.

[0093] The second structure: the number of rows of 50 steel ball installation raceways is 2, the first row of steel ball installation raceways includes two eccentric arcs, each of which occupies 1 / 2 of the circumference of the cross section; the second row of steel ball installation raceways includes two eccentric arcs, each of which occupies 1 / 2 of the circumference of the cross section; the arcs of the first row of steel ball installation raceways and the arcs of the second row of steel ball installation raceways are mirror images, and the structure presented is a back-to-back mirror image (such as Figure 8 ), or face-to-face mirroring (as Fig. 9 As shown in the figure). Compared with the traditional four-point contact ball bearing, this solution decomposes the traditional two sections of eccentric arcs into two rows of raceways, and the two rows of raceways jointly realize the four-point contact, which increases the load-bearing capacity exponentially. In addition, due to the small errors that may occur during the processing, the actual force direction of each raceway when carrying the load is also doubled due to the increase in the number of raceway rows and the number of balls. Therefore, the overall bearing performance is greatly improved.

[0094] The third structure: Fig.10 As shown, the number of rows of the steel ball installation raceway 50 is 3. The first row of steel ball installation raceways includes a circular arc that does not coincide with the center of the cross section, accounting for 1 / 2 of the cross section circumference; the second row of steel ball installation raceways includes a circular arc that does not coincide with the center of the cross section, accounting for 1 / 4 of the cross section circumference; the third row of steel ball installation raceways includes two eccentric circular arcs, accounting for 1 / 2 of the cross section circumference; the circular arcs of the first row of steel ball installation raceways and the circular arcs of the third row of steel ball installation raceways are mirror images. Compared with the aforementioned 2 rows of steel ball installation raceways, the bearing capacity of the 3 rows of steel ball installation raceways is further enhanced, and the raceway structure of 3 rows and above can choose more circular arc structures, and the specific selection can be considered in combination with the actual working conditions. This combination of mirror image plus center four-point contact can be adapted to most applications, and can bear both axial and radial loads, especially during high-speed rotation, the performance is very excellent.

[0095] When processing and assembling the above-mentioned multi-row contact ball bearings, the following steps can be adopted, but it should be understood that in the above-mentioned three structures, the size of the serial number of each process does not mean the order of execution, and some or all of the steps can be executed in parallel or in sequence. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiment of the present invention.

[0096] Step 1: Processing the inner gear housing 20 and the M second outer ring inner raceways 201 on the inner gear housing;

[0097] Step 2: Process the planet carrier 33 of the 4th stage planetary gear reduction mechanism and M axial holes 332, M ball loading holes 333 and M limiting holes 335 on the planet carrier 33; after the axial holes 332, the ball loading holes 333 and the limiting holes 335 are manufactured, pins are respectively installed in the M ball loading holes 333, and then the limiting devices are installed through the limiting holes 335 to fix the pins. After fixing, the pins are processed so that the ends of the pins away from the second outer ring inner raceway 201 are coplanar with the hole wall of the axial hole 332;

[0098] Step 3: Process the M second inner ring outer raceways 331 on the planet carrier 33. While manufacturing the M second outer ring inner raceways 201, each pin extending into the second inner ring outer raceway 331 through the ball filling hole 333 is processed, so that one end of each pin extending into the second inner ring outer raceway 331 is coplanar with the wall of the second inner ring outer raceway 331; after the manufacturing is completed, the pin and the limit device are removed;

[0099] Step 4: Load the second steel ball 60

[0100] Step 4.1: Load a second steel ball 60 into a raceway through the ball loading hole 333 made in step 3; when performing this step, butter may be applied to the second steel ball 60 and / or the raceway to reduce the difficulty of installation;

[0101] Step 4.2: Rotate the inner gear housing so that the second steel ball 60 loaded in step 4.1 is offset from the ball loading hole 333;

[0102] Step 4.3: Load a second steel ball 60 into the raceway through the ball loading hole 333;

[0103] Step 4.4: Repeat steps 4.2 to 4.3 until all the second steel balls 60 are loaded into the raceway;

[0104] Step 4.5: Repeat steps 4.1 to 4.4 to load other raceways until all are loaded;

[0105] The planet carrier 33 of the 4th stage planetary gear reduction mechanism is fixedly connected to the output large gear 3 to achieve power output. Figure 1As shown, in order to make the concentricity and axial positioning of the output gear 3 and the planetary carrier 33 of the 4th-stage planetary gear reduction mechanism more reliable after the connection between the two, a stepped through hole 336 is provided at the center of the planetary carrier 33 of the 4th-stage planetary gear reduction mechanism, and the stepped through hole 336 includes a straight hole and a tapered hole, and a baffle 337 is fixedly installed in the straight hole 3361; the output gear 3 includes a gear part and a tapered shaft part; the tapered shaft part of the output gear is inserted into the tapered hole and positioned by a connecting key, and the countersunk screw 70 passes through the baffle 337 and is threadedly connected with the tapered shaft part to realize the fixed connection between the output gear 3 and the planetary carrier 33 of the 4th-stage planetary gear reduction mechanism.

[0106] In this embodiment, the four-stage planetary gear reduction mechanism shares an inner gear housing 20, and the modules of the planetary gears 32 in each stage of the planetary gear reduction mechanism are the same, which can make the width dimensions of the planetary gears 32 in each stage of the planetary mechanism (especially the first stage planetary gears and the second stage planetary gears) thinner, thereby further reducing the axial dimensions of the reducer.

Claims

1. A yaw planetary reduction motor for a wind turbine, comprising a motor, a reduction mechanism and an output gear; the reduction mechanism comprises an inner gear housing and N-stage planetary gear reduction mechanisms arranged in sequence along the axial direction of the inner gear housing; N≥2; each stage of the planetary gear reduction mechanism comprises a sun gear, a planetary gear, a planet carrier and a planetary shaft; Features: The sun gear in the first-stage planetary gear reduction mechanism is key-connected to the output shaft of the motor; the front end of the motor is fixedly connected to the inner gear housing through a connecting flange, and a micro-gap is formed between the end face of the connecting flange and the end face of the planetary gear in the first-stage planetary gear reduction mechanism, which is used to axially position the planetary gear in the first-stage planetary gear reduction mechanism; The sun gears in the 2nd to Nth stage planetary gear reduction mechanisms are provided with first external teeth and second external teeth, and the tooth height of the first external teeth is greater than the tooth height of the second external teeth; the first external teeth are meshed with the planetary gears of the current stage, and the second external teeth are key-connected with the planetary carrier of the previous stage; The end face of the previous stage planet carrier contacts the end face of the first external tooth on the current stage sun gear, and at the same time forms a micro gap with the end face of the current stage planet gear; The planet shaft of each stage of the planetary gear reduction mechanism is interference fit with the planet shaft mounting hole on the planet carrier, and the planetary gear and the planet carrier of the Nth stage of the planetary gear reduction mechanism are in contact with each other to achieve the axial positioning of the planetary gear in the Nth stage of the planetary gear reduction mechanism; In the 1st to Nth stage planetary gear reduction mechanism, the outer surface of the planetary shaft located in the planetary wheel bearing mounting hole is provided with S first inner ring outer raceways arranged side by side in the axial direction, S≥2, and a plurality of first steel balls are arranged along the circumferential direction between each first inner ring outer raceway and the hole wall of the planetary wheel bearing mounting hole; the first steel balls installed in each two adjacent first inner ring outer raceways are arranged in a staggered manner in the circumferential direction, thereby forming the planetary wheel bearing of the Nth stage planetary gear reduction mechanism; a circular arc groove protruding inward is provided on the side of the planetary wheel bearing mounting hole close to the planet carrier, which is used to axially position the second steel ball; The planet carrier of the Nth-stage planetary gear reduction mechanism and the inner gear housing are rotationally connected via a multi-row contact ball bearing, and the contact ball bearing structure realizes the axial positioning of the planet carrier in the Nth-stage planetary gear reduction mechanism; The multi-row contact ball bearing comprises M second inner ring outer raceways arranged along the axial direction on the outer surface of the planet carrier of the N-th stage planetary gear reduction mechanism, and M second outer ring inner raceways corresponding to the M second inner ring outer raceways are arranged on the inner wall of the inner gear housing along the axial direction; M≥2; M steel ball installation raceways are formed between the M second inner ring outer raceways and the M second outer ring inner raceways; a plurality of second steel balls are arranged in the circumferential direction in each steel ball installation raceway; The planet carrier of the Nth-stage planetary gear reduction mechanism is provided with at least one axial hole, and M ball loading holes are provided at positions corresponding to the axial hole and the outer raceway of the second inner ring, and each ball loading hole is provided with an anti-escape structure to prevent the ball from escaping; The planet carrier of the Nth-stage planetary gear reduction mechanism is fixedly connected to the output large gear to achieve power output.

2. The yaw planetary reduction motor for wind turbine according to claim 1, characterized in that: A stepped through hole is arranged at the center of the planetary carrier of the Nth-stage planetary gear reduction mechanism, and the stepped through hole includes a straight hole and a tapered hole, and a baffle is fixedly installed in the straight hole; the output gear includes a gear part and a tapered shaft part; the tapered shaft part of the output gear is inserted into the tapered hole and positioned by a connecting key, and a countersunk screw passes through the baffle and is threadedly connected with the tapered shaft part to realize the fixed connection between the output gear and the planetary carrier of the Nth-stage planetary gear reduction mechanism.

3. The yaw planetary reduction motor for wind turbine according to claim 2 is characterized in that: A limiting hole is also provided on the planet carrier of the Nth-stage planetary gear reduction mechanism, and the limiting hole is connected to the ball loading hole; a limiting device for preventing the anti-escape structure from moving is provided in the limiting hole.

4. The yaw planetary reduction motor for a wind turbine according to claim 3 is characterized in that: The limiting hole is a screw hole parallel to the axial hole, and the limiting device is a tightening screw.

5. The yaw planetary reduction motor for a wind turbine according to any one of claims 1 to 4, characterized in that: The cross section of the steel ball mounting raceway includes at least one arc which does not coincide with the center of the cross section.

6. The yaw planetary reduction motor for a wind turbine according to claim 5, characterized in that: When M is 2, The first ball installation raceway consists of four eccentric arcs, each of which occupies 1 / 4 of the cross-section circumference; The second ball installation raceway consists of four eccentric arcs, each of which occupies 1 / 4 of the circumference of the cross section; The arc of the first steel ball mounting raceway is the same as the arc of the second steel ball mounting raceway, and the second steel ball is in point contact with the four arcs of the first steel ball mounting raceway, as well as the second steel ball and the four arcs of the second steel ball mounting raceway.

7. The yaw planetary reduction motor for a wind turbine according to claim 5, characterized in that: When M is 2, The first ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the cross-section circumference; The second ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the circumference of the cross section; The arc of the first steel ball mounting raceway and the arc of the second steel ball mounting raceway are mirror images.

8. The yaw planetary reduction motor for a wind turbine according to claim 5, characterized in that: When M is 3, The first ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the cross-section circumference; The second steel ball installation raceway includes four eccentric arcs, each of which occupies 1 / 4 of the circumference of the cross section. The second steel ball is in point contact with the four arcs of the second steel ball installation raceway. The third ball installation raceway consists of two eccentric arcs, each of which occupies 1 / 2 of the circumference of the cross section; The arc of the first steel ball installation raceway and the arc of the third steel ball installation raceway are mirror images.

9. The yaw planetary reduction motor for a wind turbine according to claim 1, characterized in that: The inner wall of the planet wheel bearing mounting hole of the Nth stage planetary gear reduction mechanism is provided with S shallow grooves, and the S shallow grooves correspond one by one to the S first inner ring outer raceways; the first inner ring outer raceway is composed of a fifth arc and a sixth arc arranged eccentrically, and the second steel ball contacts the fifth arc and the sixth arc respectively, and contacts the shallow grooves, thereby forming a three-point contact ball bearing structure.

10. The yaw planetary reduction motor for a wind turbine according to claim 1, characterized in that: N-stage planetary gear reduction mechanisms share an internal gear housing, and the modules of the planetary gears in each stage of the planetary gear reduction mechanism are the same.

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