JP7206083B2 - Vertical axis wind turbine gearbox - Google Patents

Description

The present invention relates to a gearbox for a vertical axis wind turbine used as a wind power generator.

In recent years, the demand for environment-friendly clean energy has been increasing in response to heightened environmental awareness. Wind power generation is one of clean energy representatives. Wind power generation converts wind force into torque and uses that torque to generate electricity, so it has less impact on the environment.
However, intrusion of water into generators and the like is a problem, and companies are devising measures to prevent water intrusion into generators and the like (Patent Document 1).

FIG. 8 is a cross-sectional view showing the arrangement and configuration of gearboxes and the like used in a conventional vertical axis wind turbine. Systematically, the input end of the input shaft 51 of the gearbox 50 is connected to the lower end of the main shaft of the vertical axis wind turbine, and the output end of the output shaft 52 on the lower end side of the gearbox 50 is connected to the generator shaft. method is common. The shaft seals of the input shaft 51 and the output shaft 52 protruding from the housing 53 of the gearbox 50 are each secured with a so-called "spring-loaded" oil seal having a garter spring.

JP-A-8-82322 JP-A-8-322298

A wind power generator is generally installed in a natural environment and is basically powered by irregular wind energy. Therefore, torque that fluctuates relatively greatly acts on components of the wind power generator. Such torque fluctuations affect starting characteristics, resulting in superiority or inferiority in power generation performance. Some large wind power generators are equipped with a power generation control device in order to improve the starting characteristics (Patent Document 2). there were.

By the way, the starting torque is composed of (1) bearing torque of the rotor, (2) frictional resistance of gears of the gearbox, and (3) seal torque of the gearbox. Due to the required sealing performance, a large straining force is applied, and as a result, the component ratio for the starting torque is the largest.
In particular, the oil seal on the high-speed side to which the generator is attached has the greatest effect among the oil seals because the generated torque is amplified when viewed from the input side of the vertical axis wind turbine.
In the speed increaser 50 of the conventional vertical axis wind turbine, not only the oil seal on the input shaft 51 side but also the oil seal on the output shaft 52 on the high speed side adopts a "spring-equipped" oil seal. The seal torque of the entire machine is further increased. As a result, it is difficult to improve the starting characteristics.

SUMMARY OF THE INVENTION An object of the present invention is to provide a speed-up gear for a vertical axis wind turbine that can reduce the cost of a vertical axis wind turbine type wind power generator, improve the starting characteristics, and improve the power generation efficiency.

A gearbox for a vertical axis wind turbine according to the present invention comprises: an input shaft and an output shaft arranged vertically in parallel to each other in a housing; and an upper bearing and a lower bearing for the input shaft and the output shaft which are installed on the upper wall portion and the lower wall portion of the housing and rotatably support the input shaft and the output shaft, respectively. is a gearbox of
each upper end of the input shaft and the output shaft protrudes from the housing, and a bearing lid is attached to the upper surface of the housing, covering individually or together above each upper bearing for the input shaft and the output shaft; The bearing lid is provided with shaft insertion holes through which the input shaft and the output shaft are inserted. An oil seal is provided to contact the outer peripheral surface of the output shaft, and each oil seal is of a springless type without a garter spring that maintains the pressing force of the seal lip against the input shaft and the output shaft, respectively.

With this arrangement, the upper ends of the input and output shafts protrude from the housing, thereby reducing the necessary sealing requirements against oil leakage as compared to the conventional structure in which the lower end of the output shaft protrudes from the housing. Thereby, each oil seal can adopt a springless type without a garter spring that maintains the pressing force of the seal lip against the input shaft and the output shaft, respectively. A springless oil seal is less costly than a springed version with a garter spring.
If it is only necessary to ensure the sealing performance against oil leakage from the gearbox, it is possible to consider eliminating the oil seal itself by arranging the upper ends of the input and output shafts so that they protrude from the housing. A springless oil seal is used because it is necessary to prevent the intrusion of foreign matter such as dust. As a result, the seal torque can be reduced more than the oil seal "with spring", and the power generation efficiency can be improved. In addition, starting characteristics can be improved by reducing seal torque.

The seal lip has a seal base attached to the inner peripheral surface of each shaft insertion hole and the seal lip connected to the seal base, and the seal lip protrudes radially inward from the seal base. It has a lip base end portion and a lip tip portion extending from the inner diameter side tip of the lip base end portion toward the inner side of the housing. and an angle α formed between the outer surface and the input shaft or the output shaft is set larger than an angle β formed between the inner surface and the input shaft or the output shaft. may In this case, when the input shaft and the output shaft rotate, the angle α is larger than the angle β, so in the presence of an oil film in the lip sliding contact surface, the circulating flow is sucked on the β side with a small angle, Since the oil is discharged on the α side (see FIG. 4), the pumping action of the oil seal occurs. By discharging a small amount of air from inside the gearbox by the pumping action of the oil seal, it is possible to prevent water from entering the gearbox through the seal lip.

A cover member may be provided to cover the top of each of the oil seals. In this case, regardless of whether the input shaft and the output shaft are rotating or not rotating, it is possible to reliably prevent water and foreign matter from entering the speed increasing gear from the outside.

The cover member may have a conical portion whose diameter increases downward. In this case, when the input shaft and the output shaft rotate, if water and foreign matter fall from above the gearbox onto the conical portion, they are shaken off radially outward. Therefore, it is possible to more reliably prevent water and foreign matter from entering the gearbox.

A gearbox for a vertical axis wind turbine according to the present invention comprises: an input shaft and an output shaft arranged vertically in parallel to each other in a housing; and an upper bearing and a lower bearing for the input shaft and the output shaft which are installed on the upper wall portion and the lower wall portion of the housing and rotatably support the input shaft and the output shaft, respectively. wherein the upper ends of the input shaft and the output shaft protrude from the housing, and a bearing lid covering individually or together above each upper bearing for the input shaft and the output shaft; The bearing lid is provided with shaft insertion holes through which the input shaft and the output shaft are inserted, and seal lips are attached to the inner peripheral surfaces of the shaft insertion holes of the bearing lid. Each oil seal has a garter spring that maintains the pressing force of the seal lip against the input shaft and the output shaft, respectively. It is a springless type that does not. Therefore, it is possible to reduce the cost of the vertical axis wind turbine type wind power generator, improve the starting characteristics, and improve the power generation efficiency.

1 is a cross-sectional view of a gearbox of a vertical axis wind turbine according to an embodiment of the present invention; FIG. FIG. 2 is a partially enlarged view showing an enlarged portion II of FIG. 1; FIG. 2 is a partially enlarged view showing an enlarged portion III of FIG. 1; (A) is a partially enlarged view showing the vicinity of the oil seal of the gearbox (IV(A) in FIG. 2), and (B) is the vicinity of the oil seal of the gearbox (IV(A) in FIG. 3). (B) part) is a partial enlarged view showing an enlargement. FIG. 5 is a partial enlarged view showing an enlarged vicinity of an oil seal of a gearbox of a vertical axis wind turbine according to another embodiment of the present invention; FIG. 6 is a cross-sectional view of a speed increaser of a vertical axis wind turbine according to still another embodiment of the present invention; It is a figure which shows the positional relationship of the step-up gear of one of embodiment, a windmill, and a generator. FIG. 2 is a cross-sectional view showing the arrangement and configuration of gearboxes and the like used in a conventional vertical axis wind turbine;

[First Embodiment]
An embodiment of the present invention will be described with reference to FIGS. 1 to 4. FIG.
As shown in FIG. 1, in the speed increaser 1 of the vertical axis wind turbine according to the first embodiment, the input shaft 2 and the output shaft 3 are vertically arranged parallel to each other, and the input shaft 2 and the output shaft 3 are arranged vertically. An input side gear 4 and an output side gear 5 provided respectively are engaged with each other. The input side gear 4 and the output side gear 5 are, for example, helical gears.

The input shaft 2 is rotatably supported in the housing 11 by input shaft bearings 6 and 7 located on both sides of the input gear 4 in the axial direction. The output shaft 3 is rotatably supported in the housing 11 by output shaft bearings 8 and 9 located on both sides of the output side gear 5 in the axial direction. A fitting hole 11aa into which the outer ring of the bearing 6 is fitted is formed in the horizontal upper wall portion 11a of the housing 11, and a fitting hole 11aa into which the outer ring of the bearing 7 is fitted into the horizontal lower wall portion 11b of the housing 11. A hole 11ba is formed.

These fitting holes 11aa and 11ba are formed coaxially. However, the lower fitting hole 11ba is formed to have a larger diameter than the upper fitting hole 11aa. A fitting hole 11ab into which the outer ring of the bearing 8 is fitted is formed in the upper wall portion 11a, and a fitting hole 11bb into which the outer ring of the bearing 9 is fitted is formed in the lower wall portion 11b. These fitting holes 11ab and 11bb are formed coaxially. Each bearing 6, 7, 8, 9 is a tapered roller bearing. The pair of input shaft bearings 6 and 7 and the pair of output shaft bearings 8 and 9 are both arranged face to face.
In the following description, bearings 6 and 8 may be called "upper bearings" and bearings 7 and 9 may be called "lower bearings".

The housing 11 includes a horizontal upper wall portion 11a provided with an upper input shaft bearing 6 and an output shaft upper bearing 8, and a lower input shaft bearing 7 and an output shaft lower bearing 9. It has a horizontal lower wall portion 11b and a cylindrical standing wall portion 11c connecting the outer peripheral edges of the upper and lower wall portions 11a and 11b.

The input shaft 2 penetrates the upper wall portion 11a and extends upward, and the main shaft S1 (FIG. 7) of the vertical axis wind turbine 10 is directly or indirectly connected to the input end at the upper end thereof. The output shaft 3 penetrates the upper wall portion 11a and extends upward, and the main shaft S2 (FIG. 7) of the generator 12 is directly or indirectly connected to the output end at the upper end thereof. The lower ends of the input shaft 2 and the output shaft 3 protrude slightly below the lower wall portion 11b.

Bearing lids 13 and 14 are attached to the upper surface of the upper wall portion 11a of the housing 11 to individually cover the tops of the upper bearings 6 and 8 for the input shaft and the output shaft. The input shaft bearing cover 13 covers the upper side of the input shaft upper bearing 6 while being sealed with the input shaft 2 . The output shaft bearing cover 14 covers the upper side of the output shaft upper bearing 8 while being sealed with the output shaft 3 .

An input shaft lower bearing lid 15 and an output shaft lower bearing lid 16 are attached to the lower surface of the lower wall portion 11 b of the housing 11 . The input shaft lower bearing cover 15 covers the lower end of the input shaft 2 and the lower end of the input shaft lower bearing 7 . The output shaft lower bearing lid 16 covers the lower end of the output shaft 3 and the lower end of the output shaft lower bearing 9 . The housing 11 and the input shaft lower bearing lid 15 and the housing 11 and the output shaft lower bearing lid 16 are sealed.

Lubrication and cooling of the input side gear 4, the output side gear 5 and the lower bearings 7 and 9 are provided in the space within the housing 11, the input shaft lower bearing cover 15, and the output shaft lower bearing cover 16. Lubricating oil is enclosed. As the lubricating oil, for example, a synthetic oil containing few impurities and having high fluidity is used. However, it is not limited to synthetic oil. Grease, for example, is sealed in the upper bearings 6 and 8 .

<About the oil seal>
As shown in FIGS. 2 and 4A, the bearing cover 13 is provided with a shaft insertion hole 13a through which the input shaft 2 is inserted. An oil seal 17 is attached to the inner peripheral surface of the shaft insertion hole 13 a of the bearing lid 13 . The tip of the seal lip 17 a of the oil seal 17 contacts the outer peripheral surface of the input shaft 2 . The oil seal 17 is of a so-called springless type that does not have a garter spring that maintains the pressing force of the seal lip 17 a against the input shaft 2 .

As shown in FIGS. 3 and 4B, the bearing lid 14 is provided with a shaft insertion hole 14a through which the output shaft 3 is inserted. An oil seal 18 is also attached to the inner peripheral surface of the shaft insertion hole 14 a of the bearing lid 14 . The tip of the seal lip 18 a of the oil seal 18 contacts the outer peripheral surface of the output shaft 3 . The oil seal 18 is also of a so-called springless type without a garter spring for maintaining the pressing force of the seal lip 18 a against the output shaft 3 .

As shown in FIGS. 4A and 4B, counterbore-shaped annular recesses 28 are formed in the inner peripheral surfaces of the shaft insertion holes 13a and 14a of the bearing covers 13 and 14, respectively. The oil seals 17, (18) have cylindrical seal bases 17b, (18b) fitted to the peripheral surfaces of the annular recesses 28, respectively, and seal lips 17a, (18a) connected to the seal bases 17b, (18b). have The seal lip 17a has a lip base end portion 17aa that protrudes radially inward from one axial end portion of the seal base portion 17b, and a lip tip portion 17ab that extends inside the housing 11 from the inner diameter side tip of the lip base end portion 17aa. have. The seal lip 18a has a lip base end portion 18aa that protrudes radially inward from one axial end portion of the seal base portion 18b, and a lip front end portion 18ab that extends inside the housing 11 from the inner diameter side tip of the lip base end portion 18aa. have. By bringing the other axial ends of the seal bases 17b, 18b into contact with the bottom surface of the annular recess 28, the oil seals 17, 18 are axially positioned.

The lip tip portions 17ab, (18ab) have an outer side surface 19 and an inner side surface 20 which are thinned toward the inner diameter side tip. The outer surface 19 faces the outside of the speed increaser 1 (FIG. 1), and the inner surface 20 faces the inside of the speed increaser 1 (FIG. 1). As shown in FIG. 4A, the angle α formed between the outer surface 19 and the input shaft 2 is set larger than the angle β formed between the inner surface 20 and the input shaft 2 . Further, as shown in FIG. 4B, the angle α formed between the outer surface 19 and the output shaft 3 is set larger than the angle β formed between the inner surface 20 and the output shaft 3 .
A breather 21 for adjusting the internal pressure of the housing 11 is provided on the upper wall portion 11a.

As shown in FIGS. 4A and 4B, grease is enclosed in an annular space surrounded by seal bases 17b, 18b and seal lips 17a, 18a. Grease is also applied in advance to the lip tip portions 17ab, (18ab). The base oil of this grease is preferably the same synthetic oil as the lubricating oil enclosed within the housing 11 (FIG. 1). For example, when Mobil's SHC600 series is used as lubricating oil, Mobil's SHC600 series can be used as grease.

<Effect>
According to the gearbox 1 of the vertical axis wind turbine described above, since the upper ends of the input shaft 2 and the output shaft 3 protrude from the housing 11, the lower end of the output shaft protrudes from the housing. The required seal requirements can be reduced. Thereby, each oil seal 17, 18 can adopt a springless type without a garter spring that maintains the pressing force of the seal lip against the input shaft and the output shaft, respectively.
If it is only necessary to ensure the sealing performance against oil leakage from the gearbox 1, it is possible to consider eliminating the oil seal itself by arranging the upper ends of the input shaft 2 and the output shaft 3 so as to project upward from the housing 11. However, since it is necessary to have a function of preventing the intrusion of foreign matter such as dust from the outside, the oil seals 17 and 18 without springs are used. As a result, the seal torque can be reduced more than the oil seal "with spring", and the power generation efficiency can be improved. In addition, starting characteristics can be improved by reducing seal torque.

The angle α between the outer side surfaces 19 of the seal lips 17a and 18a and the input shaft 2 and the output shaft 3 is larger than the angle β between the inner side surfaces 20 of the seal lips 17a and 18a and the input shaft 2 and the output shaft 3. Therefore, in the presence of an oil film in the lip sliding contact surface, the circulating flow is sucked on the β side with a small angle and discharged on the α side with a large angle (see FIG. 4). When the shaft 3 rotates, the pump action of the oil seals 17 and 18 discharges a small amount of air from inside the gearbox, thereby preventing water from entering the gearbox through the seal lips 17a and 18a. By setting the relationship between the angle .alpha. It can block the ingress of water and prevent deterioration of lubricating oil in the gearbox. In such use, there is a concern that the oil seals 17 and 18 will stick to the input shaft 2 and the output shaft 3 due to the pressure reduction in the gearbox, resulting in an increase in torque. By adjusting the internal pressure of 11, it is possible to prevent excessive pressure reduction in the gearbox. Therefore, it is possible to prevent the oil seals 17 and 18 from being attracted to the input shaft 2 and the output shaft 3, thereby preventing an increase in torque.

<About other embodiments>
In the following description, the same reference numerals are given to the parts corresponding to the items previously described in each embodiment, and duplicate descriptions are omitted. When only a portion of the configuration is described, the other portions of the configuration are the same as those previously described unless otherwise specified. The same configuration has the same effect. It is possible not only to combine the parts specifically described in each embodiment, but also to partially combine the embodiments if there is no particular problem with the combination.

As shown in FIG. 5, a cover member 22 may be provided to cover the oil seals 17 and 18 from above. The cover member 22 is a truncated cone-shaped hood having a disk-shaped upper end portion 23 having an insertion hole 23a through which the input shaft 2 or the output shaft 3 is inserted, and from the outer peripheral edge portion of the upper end portion 23, downwardly It has a large-diameter conical portion 24 and a flange-like collar portion 25 protruding radially outward from the lower end of the conical portion 24 . An insertion hole 23 a of an upper end portion 23 is fitted and fixed to the input shaft 2 and the output shaft 3 .
An annular protrusion 26 protruding upward is provided on the upper portion of the intermediate seal portions 17c, 18c of the oil seals 17, 18. As shown in FIG. The protrusion 16 is provided on each of the oil seals 17 and 18 so that the tip portion of the protrusion 26 is located inside the inner peripheral surface of the lower end of the conical portion 24 of the cover member 22 with a predetermined gap. .

According to the configuration shown in FIG. 5, regardless of whether the input shaft 2 and the output shaft 3 are rotating or not rotating, the cover member 22 can reliably prevent water and foreign matter from entering the gearbox from the outside. It becomes possible. Since the cover member 22 has a conical portion 24 whose diameter increases downward, when the input shaft 2 and the output shaft 3 rotate, if water and foreign matter fall onto the conical portion 24 from above the gearbox, be shaken off. Therefore, it is possible to more reliably prevent water and foreign matter from entering the gearbox. Further, when the annular protrusion 26 is provided in the inner region of the cover member 22, it is possible to further suppress water from entering the gearbox.

In the example of FIG. 5, the cover member 22 is attached to the input shaft 2 and the output shaft 3, but it is not limited to this example. The cover member 22 may be attached to the upper portion of the lid members 13 and 14, the upper wall portion 11a (FIG. 1) of the housing 11 (FIG. 1), or the upper portions of the oil seals 17 and 18.
As shown in FIG. 6 , a bearing lid 27 may be attached to the upper surface of the upper wall portion 11 a of the housing 11 to cover both the upper bearings 6 and 8 from above.

The sliding portion of the seal lip may be subjected to a low-friction surface treatment such as Diamond-Like Carbon (abbreviated as DLC). For the sliding portion of the seal lip, a slippery rubber such as BEAREE ER3201 (BEAREE is a registered trademark) manufactured by NTN may be used. These low-friction surface treatments and slippery rubber may be used in combination.
These configurations further reduce the seal torque.

As mentioned above, although the form for implementing this invention was demonstrated based on embodiment, embodiment disclosed this time is an illustration and is not restrictive at all points. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the meaning and range of equivalents of the scope of the claims.

2 Input shaft 3 Output shaft 4 Input side gear 5 Output side gear 11 Housing 11a Upper side wall 11b Lower side wall 13, 14 Bearing cover 13a, 14a Shaft insertion Holes 17, 18 Oil seal 17a, 18a Seal lip 17aa, 18aa Lip base end 17ab, 18ab Lip tip 17b, 18b Seal base 19 Outer surface 20 Inner surface 22... Cover member, 24... Conical portion

Claims (3)

An input shaft and an output shaft arranged vertically in parallel to each other in a housing, an input side gear and an output side gear provided on the input shaft and the output shaft, respectively, and meshing with each other, an upper wall portion and a lower wall portion of the housing A gearbox for a vertical axis wind turbine comprising an upper bearing and a lower bearing for an input shaft and an output shaft which are installed in and rotatably support the input shaft and the output shaft, respectively,
each upper end of the input shaft and the output shaft protrudes from the housing, and a bearing lid is attached to the upper surface of the housing, covering individually or together above each upper bearing for the input shaft and the output shaft; The bearing lid is provided with shaft insertion holes through which the input shaft and the output shaft are inserted. Each oil seal is provided in contact with the outer peripheral surface of the output shaft, and each oil seal is of a springless type without a garter spring for maintaining the pressing force of the seal lip against the input shaft and the output shaft,
The seal lip has a seal base attached to the inner peripheral surface of each shaft insertion hole and the seal lip connected to the seal base, and the seal lip protrudes radially inward from the seal base. It has a lip base end portion and a lip tip portion extending from the inner diameter side tip of the lip base end portion toward the inner side of the housing. a vertical axis wind turbine having an inner surface, wherein an angle α formed between the outer surface and the input shaft or the output shaft is set larger than an angle β formed between the inner surface and the input shaft or the output shaft. gearbox. 2. The speed increaser for a vertical axis wind turbine according to claim 1 , wherein a covering member is provided to cover the top of each of said oil seals. 3. A speed increaser for a vertical axis wind turbine according to claim 2 , wherein said cover member has a conical portion whose diameter increases downward.

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