Lubricating and cooling structure for double-row tapered roller bearing of wind power gear box

Abstract

The utility model provides a double-row tapered roller bearing lubricating and cooling structure of a wind power gear box, which relates to the technical field of bearing lubricating and cooling and comprises a high-speed shaft, a box body, a left tapered roller bearing, a bearing spacer ring, a right tapered roller bearing and an end cover, a first oil channel and a second oil channel are arranged on the box body, a first groove is arranged on the bearing spacer ring, and a second groove is arranged on the end cover. A first oil spraying hole and a second oil spraying hole are formed in the first groove, the first oil spraying hole is obliquely formed towards the right side of the left side tapered roller bearing, and the second oil spraying hole is obliquely formed towards the left side of the right side tapered roller bearing; and a second groove and a third oil spraying hole are formed in the end cover, and the third oil spraying hole is obliquely formed towards the right side of the right tapered roller bearing. On the premise of not increasing the amount of lubricating oil, the lubricating efficiency can be improved, the cooling effect is enhanced, and the bearing can continuously operate for a long time under the working conditions of high rotating speed and high power.

Description

Technical Field

[0001] This utility model relates to the field of bearing lubrication and cooling technology, and in particular to a lubrication and cooling structure for a double-row tapered roller bearing in a wind turbine gearbox. Background Technology

[0002] A wind turbine gearbox is a specialized mechanical device used in wind power generation. Its main function is to transmit the power generated by the wind turbine under wind power to the generator, enabling it to achieve the corresponding rotational speed and thus generate electricity. Wind turbine gearboxes contain bearings in multiple locations for the rotation and support of the shaft and its components, with the high-speed output shaft experiencing the most demanding conditions. The high-speed output shaft bearings in wind turbine gearboxes operate at high speeds and are subjected to complex forces, generating significant heat during operation. To ensure operating temperatures, lubricating oil is commonly used to cool the bearings. In recent years, with the continuous improvement of wind turbine generator sets, the high-speed, high-power, and longer continuous operation conditions have placed higher demands on the cooling capacity of the high-speed output shaft bearings. Under these conditions, power losses caused by load and friction result in intense bearing heating. The existing double-row tapered roller bearings with their built-in ring lubrication and cooling structures are no longer sufficient to meet the bearing cooling requirements. Gearboxes often have to shut down due to excessively high bearing temperatures, affecting power generation.

[0003] Currently, double-row tapered roller bearings typically use a spacer between the two bearings for lubrication and cooling. The spacer has a groove for storing lubricating oil, and this groove has a number of small holes arranged in a row. Once the groove is full, the lubricating oil flows through the holes to lubricate the two double-row tapered roller bearings. Because the two bearings experience different forces and generate different amounts of heat, each bearing requires a different amount of lubricating oil. However, the existing lubrication and cooling structures lack a spray angle for the small holes, and the current structures cannot control the direction and flow rate of the lubricating oil. The lubricating oil forms a pool and distributes freely, with the majority flowing into the bearing experiencing less stress. This results in insufficient cooling oil for the bearing experiencing greater stress, leading to high bearing temperatures.

[0004] Existing lubrication and cooling structures are prone to causing high operating temperatures in high-speed bearings, exceeding usage requirements. Therefore, a new type of lubrication and cooling structure is urgently needed for high-speed bearings. Utility Model Content

[0005] To address the aforementioned technical problems, a lubrication and cooling structure for a double-row tapered roller bearing in a wind turbine gearbox is provided. The technical means employed in this invention are as follows:

[0006] A lubrication and cooling structure for a double-row tapered roller bearing in a wind turbine gearbox includes: a high-speed shaft, a housing, a left tapered roller bearing, a bearing spacer, a right tapered roller bearing, and an end cover. The left and right tapered roller bearings are both installed between the high-speed shaft and the housing. The inner rings of the left and right tapered roller bearings are fixedly connected to the high-speed shaft, and the outer rings are fixedly connected to the housing.

[0007] The bearing spacer is installed between the outer ring of the left tapered roller bearing and the outer ring of the right tapered roller bearing, and the bearing spacer is fixedly connected to the housing; the end cover is fixedly connected to the right side of the housing, and the left end face of the end cover extending into the housing fits against the right end face of the outer ring of the right tapered roller bearing.

[0008] The housing has a first oil passage and a second oil passage. The bearing spacer has a first groove communicating with the first oil passage. The first groove has a first oil injection hole and a second oil injection hole. One end of the first oil injection hole and the second oil injection hole are both communicating with the first groove, and the other end of the first oil injection hole and the second oil injection hole are both communicating with the space between the left tapered roller bearing and the right tapered roller bearing. The first oil injection hole is inclined toward the right side of the left tapered roller bearing, and the second oil injection hole is inclined toward the left side of the right tapered roller bearing.

[0009] The end cap is provided with a second groove and a third oil injection hole. The second groove is connected to the second oil passage. One end of the third oil injection hole is connected to the second groove. The other end of the third oil injection hole is connected to the space between the right tapered roller bearing and the end cap. The third oil injection hole is inclined toward the right side of the right tapered roller bearing.

[0010] The first fuel injection hole is provided in one location with a diameter of Φ5mm; the second fuel injection hole is provided in four locations with a diameter of Φ4mm; the four second fuel injection holes are evenly distributed within a 120° range in the upper half; the third fuel injection hole is provided in three locations with a diameter of Φ4mm.

[0011] The first oil injection hole has the same inclination angle as the ball contact angle of the left tapered roller bearing and is directed toward the ball cage of the left tapered roller bearing; the second oil injection hole has the same inclination angle as the ball contact angle of the right tapered roller bearing and is directed toward the ball cage of the right tapered roller bearing.

[0012] The third injection hole has the same inclination angle as the second injection hole, but faces the opposite direction.

[0013] Furthermore, the diameter of the first and second oil injection holes is determined by the heat generated by the bearing.

[0014] Furthermore, a fourth oil injection hole is provided in the second groove, and the third oil injection hole is connected to the second groove through the fourth oil injection hole.

[0015] Furthermore, the bearing spacer is fixedly connected to the housing by a locating pin.

[0016] Furthermore, a positioning groove is provided on the bearing spacer ring, and the positioning pin is engaged in the positioning groove.

[0017] Furthermore, a round nut is provided on the right side of the tapered roller bearing, away from the left tapered roller bearing. The round nut is connected to the high-speed shaft and is used to position the left and right tapered roller bearings.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. The lubrication and cooling structure for double-row tapered roller bearings in wind turbine gearboxes provided by this utility model designs lubrication spray points with different orifice diameters and numbers according to the oil volume required by the bearing, ensuring the rationality of flow distribution. In contrast, existing lubrication and cooling structures do not differentiate between oil volume differences and set the same number of lubrication spray points.

[0020] 2. The lubrication and cooling structure for double-row tapered roller bearings in wind turbine gearboxes provided by this utility model designs the spray angle of the oil injection holes according to the bearing's own structure, forcing the flow of lubricating oil so that the lubricating oil is evenly sprayed onto the heat-generating bearings. In contrast, existing lubrication and cooling structures have no spray angle in the lubrication holes, and the lubricating oil forms an oil pool and is freely distributed. The lubricating oil flows to the bearings that are easiest to enter rather than the bearings that generate the most heat. Usually, the bearings that are easiest to enter are the bearings with the least stress and the least amount of oil required.

[0021] 3. The lubrication and cooling structure for the double-row tapered roller bearing in the wind turbine gearbox provided by this utility model provides double-sided cooling and lubrication for the right-side tapered roller bearing, ensuring the bearing cooling effect. In contrast, existing lubrication and cooling structures only provide single-sided cooling and lubrication.

[0022] 4. The lubrication and cooling structure for the double-row tapered roller bearings in wind turbine gearboxes provided by this utility model eliminates lubricant waste. All lubricant enters the heated bearing as needed, ensuring that the bearing temperature meets the requirements for normal gearbox operation without increasing the oil volume. In contrast, existing lubrication and cooling structures result in a large volume of ineffective cooling oil and significant oil waste.

[0023] 5. Under the same gearbox and the same oil volume, the operating temperature of the double-row tapered roller bearing lubrication and cooling structure for wind power gearbox provided by this utility model is 68℃, while the operating temperature of the bearing in the current structure is 78.5℃.

[0024] 6. The lubrication and cooling structure for the double-row tapered roller bearing in a wind turbine gearbox provided by this utility model has high lubrication efficiency, achieving the effect of cooling the bearing with a very small amount of oil, thus reducing the risk of oil leakage at the output end. Existing lubrication and cooling structures require a large amount of oil, resulting in a high risk of oil leakage. In addition, since the total lubricating oil flow rate of the gearbox is fixed, a large amount of oil at this point will lead to insufficient oil at other lubrication points, increasing the risk of damage to other parts.

[0025] Based on the above reasons, this utility model can be widely promoted in the fields of bearing lubrication and cooling. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the lubrication and cooling structure of the double-row tapered roller bearing in a wind turbine gearbox, as described in a specific embodiment of this utility model.

[0028] Figure 2 This is a left view of the bearing spacer in a specific embodiment of this utility model.

[0029] Figure 3 This is a right view of the bearing spacer in a specific embodiment of this utility model.

[0030] Figure 4 This is a schematic diagram of the end cap structure in a specific embodiment of this utility model.

[0031] Figure 5 This is a cross-sectional view of the end cap in a specific embodiment of the present utility model.

[0032] Figure 6 This is a schematic diagram of an existing lubrication and cooling structure.

[0033] In the diagram: 1. High-speed shaft; 2. Housing; 3. Left tapered roller bearing; 4. Locating pin; 5. Bearing spacer; 51. First groove; 52. First oil injection hole; 53. Second oil injection hole; 54. Locating groove; 6. Right tapered roller bearing; 7. Round nut; 8. End cap; 81. Second groove; 82. Third oil injection hole; 83. Fourth oil injection hole. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0035] This invention provides a lubrication and cooling structure for a double-row tapered roller bearing in a wind turbine gearbox. Applied to the gearbox, it is used for bearing lubrication and cooling. This invention improves lubrication efficiency and enhances cooling effect without increasing the amount of lubricating oil, enabling the bearing to operate continuously for extended periods under high-speed, high-power conditions.

[0036] like Figure 1As shown, this utility model discloses a lubrication and cooling structure for a double-row tapered roller bearing in a wind turbine gearbox, comprising a high-speed shaft 1, a housing 2, a left tapered roller bearing 3, a locating pin 4, a bearing spacer 5, a right tapered roller bearing 6, a round nut 7, and an end cover 8. The left tapered roller bearing 3 and the right tapered roller bearing 6 are mounted from left to right on the high-speed shaft 1 and the housing 2, respectively, and are positioned by the round nut 7. The inner rings of both the left and right tapered roller bearings 3 and 6 are fixedly connected to the high-speed shaft 1, and their outer rings are fixedly connected to the housing 2. The right end face of the inner ring of the left tapered roller bearing 3 is in contact with the left end face of the inner ring of the right tapered roller bearing 6. The round nut 7 is located on the right side of the right tapered roller bearing 6, away from the left tapered roller bearing 3, and is connected to the high-speed shaft 1. The bearing spacer 5 is installed between the outer ring of the left tapered roller bearing 3 and the outer ring of the right tapered roller bearing 6, and the bearing spacer 5 is fixedly connected to the housing 2. The end cover 8 is fixedly connected to the right side of the housing 2, and the left end face of the end cover 8 extending into the housing 2 is in contact with the right end face of the outer ring of the right tapered roller bearing 6. The housing 2 has a first oil passage and a second oil passage in the radial direction. The bearing spacer 5 has a first groove 51 that communicates with the first oil passage. The first groove 51 has a first oil injection hole 52 and a second oil injection hole 53. One end of the first oil injection hole 52 and the second oil injection hole 53 are connected to the first groove 51, and the other end is connected to the space between the left tapered roller bearing 3 and the right tapered roller bearing 6. The first oil injection hole 52 is inclined toward the left tapered roller bearing 3, and the second oil injection hole 53 is inclined toward the right tapered roller bearing 6. The end cover 8 has a second groove 81 and a third oil injection hole 82. The second groove 81 is connected to the second oil passage. One end of the third oil injection hole 82 is connected to the second groove 81, and the other end of the third oil injection hole 82 is connected to the space between the right tapered roller bearing 6 and the end cover 8. The third oil injection hole 82 is inclined toward the right side of the right tapered roller bearing 6.

[0037] When the wind turbine gearbox is running, the cooled lubricating oil flows into the bearing spacer 5 and the end cover 8 through the first and second oil passages of the housing 2, respectively. The bearing spacer 5 and the end cover 8 are respectively provided with a first groove 51 and a second groove 81. The oil injection holes are respectively opened in the first groove 51 of the bearing spacer 5 and the second groove 81 of the end cover 8. This ensures that even if the oil passages of the housing 2 are not aligned with the oil injection holes (first oil injection hole 52, second oil injection hole 53) of the bearing spacer 5 and the third oil injection hole 82 of the end cover 8, the lubricating oil can still enter the bearing spacer 5 and the end cover 8 (first entering the grooves of the bearing spacer 5 and the end cover 8, and then flowing from the grooves into the corresponding oil injection holes in the grooves). The diameters of the first oil injection hole 52 and the second oil injection hole 53 on the bearing spacer 5 are determined by the heat generated by the bearing. The inclination angles of the first oil injection hole 52 and the second oil injection hole 53 are determined by the bearing ball contact angle and the position of the ball cage, which allows the lubricating oil to enter the bearing smoothly for lubrication and cooling. The inclination angle of the first oil injection hole 52 is the same as the ball contact angle of the left tapered roller bearing 3 and faces the ball cage of the left tapered roller bearing 3. The inclination angle of the second oil injection hole 53 is the same as the ball contact angle of the right tapered roller bearing 6 and faces the ball cage of the right tapered roller bearing 6.

[0038] The left tapered roller bearing 3 experiences less force and generates less heat. Taking a certain model as an example, the heat generated by the left tapered roller bearing 3 is P = 7.7kW. Therefore, the required amount of lubricating oil for the left tapered roller bearing 3 is Q = 60P / ΔT / ρ / C. p =13 L / min, where ΔT is the temperature difference of the oil entering and exiting the bearing, ρ is the density of the lubricating oil, and C p This refers to the specific heat of the lubricating oil. The flow rate and pressure difference through the orifice are calculated using the formula Q = d. 2 C q ΔP 1 / 2 C qLet d be the flow coefficient and ΔP be the pressure difference before and after the oil injection hole. The diameter of the first oil injection hole 52 is d = φ5mm. Therefore, one Φ5mm first oil injection hole 52 is provided on the bearing spacer 5. It is important to note that the diameter of the first oil injection hole 52 cannot be too small. When the equipment is first started, the oil temperature is low, and if the diameter of the first oil injection hole 52 is too small, the lubricating oil cannot pass through. The diameter of the first oil injection hole 52 also cannot be too large. First, the diameter cannot be greater than the width of the bearing spacer 5. Second, multiple oil injection holes should be designed to ensure smooth passage of lubricating oil, resulting in uniform oil spraying and good lubrication and cooling effects. Therefore, one first oil injection hole 52 is provided, with a diameter of Φ5mm. The right-side tapered roller bearing 6 experiences high force and generates a large amount of heat, requiring a large amount of lubricating oil. The existing single-sided lubrication and cooling effect is not ideal; therefore, this lubrication and cooling structure is designed for double-sided cooling. In this model, the heat generated by the right-side tapered roller bearing 6 is P = 30.8 kW. According to the above lubricating oil quantity formula Q = 60P / ΔT / ρ / C p The required lubricating oil volume Q for the right tapered roller bearing 6 is calculated to be 52 L / min. Based on the calculated heat generation of the right tapered roller bearing 6, four second oil injection holes 53 are provided on the bearing spacer 5. The diameter of each second oil injection hole 53 is Φ4mm, and the oil injection position avoids the cage. The inclination angle of the second oil injection hole 53 is the same as the ball contact angle of the right tapered roller bearing 6. The third oil injection hole 82 on the other side is designed on the end cover 8. The number, diameter, position, and angle of the third oil injection hole 82 are set in the same way as above. There are three third oil injection holes 82, and three fourth oil injection holes 83 (vertical oil injection holes in the same radial direction as the high-speed shaft 1) are opened in the second groove 81. Each third oil injection hole 82 is connected to the second groove 81 through the fourth oil injection hole 83. The inclination angle of the third oil injection hole 82 is the same as that of the second oil injection hole 53, but the orientation is opposite. If the right-side tapered roller bearing 6 has only one corresponding oil injection hole, the diameter of that hole would be approximately 11 mm. However, since the right-side tapered roller bearing 6 generates a large amount of heat, uniform lubrication during rotation provides better cooling than single-point lubrication. Therefore, four second oil injection holes 53 are designed on the bearing spacer 5, and three third oil injection holes 82 are designed on the end cover 8. The flow rate of a single oil injection hole is approximately 7.43 L / min. According to Q=d 2 C q ΔP 1 / 2 The diameter of a single oil injection hole is Φ4 mm. Since the lower ends of both the left tapered roller bearing 3 and the right tapered roller bearing 6 are immersed in the oil bath, oil spray lubrication does not need to consider the lower half of the bearing immersed in the oil bath; only the upper half of the bearing not immersed in the oil needs to be considered. Because the right tapered roller bearing 6 generates a large amount of heat, simultaneous multi-point lubrication on both sides is more effective than single-point lubrication. As the bearing rolls, multiple oil injection holes spray oil from different positions, which can evenly carry the oil into the moving bearing, resulting in uniform lubrication and cooling and a good temperature reduction effect.

[0039] The four second oil injection holes 53 on the bearing spacer 5 are evenly distributed within a 120° range in the upper half (see...). Figure 2 and Figure 3 The lubricating oil can be directly sprayed onto the upper half of the balls in the right tapered roller bearing 6, and can also flow into each ball by gravity, improving the lubrication and cooling effect of the bearing. Since the lower half of the balls in the right tapered roller bearing 6 is immersed in lubricating oil, the lower half of the balls do not need to be lubricated by spraying oil, while the upper half of the balls do. Similarly, the lower half of the balls in the left tapered roller bearing 3 is also immersed in lubricating oil and does not need to be lubricated by spraying oil. The lubricating oil is directly sprayed onto the upper half of the balls in the left tapered roller bearing 3 through the first oil spray hole 52. In order to ensure that the oil spray point is always in the upper half, a positioning groove 54 is opened on the bearing spacer 5. A positioning pin 4 is connected in the positioning groove 54. The positioning pin 4 fixes the bearing spacer 5 to the housing 2, which prevents the bearing spacer 5 from rotating and ensures the accuracy of the spray angle.

[0040] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

Claims

1. A wind turbine gearbox double row tapered roller bearing lubrication cooling structure, characterized in that, include: The high-speed shaft (1), housing (2), left tapered roller bearing (3), bearing spacer (5), right tapered roller bearing (6) and end cover (8) are provided. The left tapered roller bearing (3) and the right tapered roller bearing (6) are both installed between the high-speed shaft (1) and the housing (2). The inner rings of the left tapered roller bearing (3) and the right tapered roller bearing (6) are fixedly connected to the high-speed shaft (1), and the outer rings are fixedly connected to the housing (2). The bearing spacer (5) is installed between the outer ring of the left tapered roller bearing (3) and the outer ring of the right tapered roller bearing (6), and the bearing spacer (5) is fixedly connected to the housing (2); the end cap (8) is fixedly connected to the right side of the housing (2), and the left end face of the end cap (8) extending into the housing (2) is in contact with the right end face of the outer ring of the right tapered roller bearing (6); The housing (2) is provided with a first oil passage and a second oil passage. The bearing spacer (5) is provided with a first groove (51) that communicates with the first oil passage. The first groove (51) is provided with a first oil injection hole (52) and a second oil injection hole (53). One end of the first oil injection hole (52) and the second oil injection hole (53) are both connected to the first groove (51), and the other end is connected to the space between the left tapered roller bearing (3) and the right tapered roller bearing (6). The first oil injection hole (52) is inclined toward the right side of the left tapered roller bearing (3), and the second oil injection hole (53) is inclined toward the left side of the right tapered roller bearing (6). The end cap (8) is provided with a second groove (81) and a third oil injection hole (82). The second groove (81) is connected to the second oil passage. One end of the third oil injection hole (82) is connected to the second groove (81). The other end of the third oil injection hole (82) is connected to the space between the right tapered roller bearing (6) and the end cap (8). The third oil injection hole (82) is inclined toward the right side of the right tapered roller bearing (6). The first oil injection hole (52) is provided in one place with a diameter of Φ5mm; the second oil injection hole (53) is provided in four places with a diameter of Φ4mm; the four second oil injection holes (53) are evenly distributed in the upper half within a 120° range; the third oil injection hole (82) is provided in three places with a diameter of Φ4mm; The first oil injection hole (52) has the same inclination angle as the ball contact angle of the left tapered roller bearing (3) and is directed toward the ball cage of the left tapered roller bearing (3); the second oil injection hole (53) has the same inclination angle as the ball contact angle of the right tapered roller bearing (6) and is directed toward the ball cage of the right tapered roller bearing (6). The third oil injection hole (82) has the same inclination angle as the second oil injection hole (53), but faces the opposite direction.

2. The wind turbine gearbox double row tapered roller bearing lubrication cooling structure according to claim 1, characterized in that, The diameter of the first oil injection hole (52) and the second oil injection hole (53) is determined by the heat generated by the bearing.

3. The wind turbine gearbox double row tapered roller bearing lubrication cooling structure according to claim 1, characterized in that, The fourth oil injection hole (83) is arranged in the second groove (81), and the third oil injection hole (82) communicates with the second groove (81) through the fourth oil injection hole (83).

4. The wind turbine gearbox double row tapered roller bearing lubrication cooling structure according to claim 1, characterized in that, The bearing spacer ring (5) is fixedly connected with the box body (2) through the positioning pin (4).

5. The wind turbine gearbox double row tapered roller bearing lubrication cooling structure according to claim 4, characterized in that, The bearing spacer ring (5) is provided with a positioning groove (54), and the positioning pin (4) is connected in the positioning groove (54).

6. The wind turbine gearbox double row tapered roller bearing lubrication cooling structure according to claim 1, characterized in that, The right conical roller bearing (6) is provided with a circular nut (7) on the right side away from the left conical roller bearing (3), the circular nut (7) is connected on the high-speed shaft (1), and is used for positioning the left conical roller bearing (3) and the right conical roller bearing (6).

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