Patent Application
20110185832
This is a U.S. national stage of International Application No. PCT/EP2009/059796, filed on 29 Jul. 2009. This patent application claims the priority of German Patent Application No. 10 2008 044 900.8, filed 29 Aug. 2008, the entire content of which application is incorporated herein by reference.
1. Field of the Invention
The present invention is directed to a transmission or gearboxes and, more particularly, to a wind power installation gearbox and auxiliary drive for a wind power installation gearbox.
2. Description of the Related Art
For maintenance or inspection of a wind power installation, it is often necessary to rotate a wind power installation drive train which has a gearbox and generator. In the case of relatively large wind power installations, rotation of the drive train by human muscle power is normally no longer possible particularly because of high inertia moments resulting from large rotor diameters. In prior solutions, an auxiliary drive which is connected to the wind power installation gearbox via an additional input gearbox is used for this purpose. This is disadvantageous for space, weight and cost reasons. In particular, a design change to a pod of a wind power installation because of an increased space requirement resulting from a gearbox equipped with an auxiliary drive and input gearbox is extremely complex and expensive.
It is therefore an object of the present invention to provide a maintenance-friendly and inspection-friendly industrial gearbox which allows a space-saving, minimized-weight design, and can be produced at low cost.
This and other objects and advantages are achieved in accordance with the invention by a wind power installation gearbox and by an auxiliary drive for a wind power installation gearbox having at least one gearbox stage which comprises at least one first gearwheel and one second gearwheel. In addition, a third gearwheel is provided, which is axially connected to the first gearwheel or the second gearwheel and is centered thereon. At least the first, the second and the third gearwheels are surrounded by a gearbox housing. An auxiliary drive is flange-connected to the gearbox housing and its torque can be transmitted to the third gearwheel by a fourth gearwheel which can be moved axially along a drive shaft, which is driven by a motor, and which fourth gearwheel can thus be rotated by the drive shaft. When the auxiliary drive is connected, the third gearwheel engages with the fourth gearwheel. A wind power installation gearbox can be provided which costs less and is more compact because of the lack, in accordance with the invention, of an input gearbox and a reduction in the resultant number of individual parts.
The fourth gearwheel is preferably moved along the drive shaft of the auxiliary drive by a lever mechanism. Furthermore, the lever mechanism may comprise an adjusting lever, which is secured against inadvertent operation by a positioning bolt which can be latched in, thus reducing the risk of control errors. The positioning bolt advantageously has a spring mechanism to return the positioning bolt to an axial rest position.
In accordance with a further embodiment of the present invention, the adjusting lever can be moved by a return spring to a rest position in which torque transmission between the auxiliary drive and the first or second gearwheel of the epicyclic stage is interrupted. In this way, the first gearwheel is automatically returned to an initial position after use of the auxiliary drive, in which initial position it no longer engages with the second gearwheel. In combination with the positioning bolt, which comprises the above spring mechanism, automatically returning the adjusting lever offers an advantage, with regard to safety at work with appropriate dimensioning, that two operators are required for starting the motor of the auxiliary drive. In this case, a first operator operates the adjusting lever, and a second operator operates a switch, which is physically remote from this, for starting the motor.
An electromagnetic limit switch is preferably provided for detection of connection of the auxiliary drive by operation of the adjusting lever, which limit switch can be switched by the adjusting lever and is connected to a wind power installation control unit. As a result, it is possible to avoid damage caused by the wind power installation being started up when the third and fourth gearwheels for the auxiliary drive are still engaged with one another.
The electromechanical limit switch is advantageously connected to the adjusting lever by a guide disk, which has a radial cutout for operation of the electromechanical limit switch. Here, the guide disk can be rotated by operation of the adjusting lever. If the guide disk is designed appropriately, the electromechanical limit switch and the adjusting lever in combination with the positioning bolt, which comprises the above spring mechanism, are separated. Consequently, damage to or manipulation of the positioning bolt normally does not necessarily lead to measures for protection of the auxiliary drive against being started up inadvertently being rendered ineffective, provided that the limit switch is still serviceable as a redundant safety apparatus. By way of example, the limit switch can be configured to produce a switch-off signal for the wind power installation control unit.
In accordance with a further embodiment of the present invention, a movement of the adjusting lever can be transmitted by a shaft to a guide lever which is rigidly coupled to the adjusting lever. In addition, a gripper, which clasps the fourth gearwheel, is arranged at a free end of the guide lever. Here, the fourth gearwheel can be moved axially along the drive shaft of the auxiliary drive by the gripper. As a result, it becomes possible to provide a mechanically reliable movement mechanism for the fourth gearwheel.
Preferably, the first and the second gearwheels have helical tooth systems, and the third and the fourth gearwheels have straight tooth systems. Furthermore, the fourth gearwheel may have chamfers or rounded areas on one or both flanks, thus allowing the fourth gearwheel to be moved axially, and to be easily engaged with the third gearwheel.
In accordance with a preferred embodiment of the present invention, the motor has a motor shaft which runs at right angles to the drive shaft and is coupled to it. In addition, the gearbox stage is an epicyclic or spur-gear gearbox stage. This results in a particularly space-saving arrangement of the auxiliary drive, which does not disadvantageously increase the axial extent of the wind power installation gearbox. Furthermore, the third gearwheel is preferably arranged in a space-saving manner axially between the first gearwheel or the second gearwheel and a gearbox bearing on the generator side, which is surrounded by the gearbox housing.
The auxiliary drive, in accordance with an embodiment of the invention, for a wind power installation gearbox, which has at least one first gearwheel and one second gearwheel, can be flange-connected to a gearbox housing which surrounds the first and the second gearwheel, and a third gearwheel which is axially connected to the first gearwheel or the second gearwheel and is centered thereon.
In addition, the auxiliary drive has a fourth gearwheel, which can be moved axially along a drive shaft that is driven by a motor of the auxiliary drive, which fourth gearwheel can rotate with the drive shaft and engages with the third gearwheel when the auxiliary drive is in a connected state.
Other objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It is to be understood, however, that the drawings are designed solely for purposes of illustration and not as a definition of the limits of the invention. It should be further understood that the drawings are not necessarily drawn to scale and that, unless otherwise indicated, they are merely intended to conceptually illustrate the structures and procedures described herein.
The invention will be explained in more detail in the following text using one exemplary embodiment and with reference to the drawing, in which:
The wind power installation gearbox 1 illustrated in
The use of the present invention is not restricted to coupling an auxiliary drive to a spur-gear gearbox. For example, the third gearwheel 6 can also be coupled to a sun wheel of an epicyclic gearbox.
The first gearwheel 5 and the second gearwheel of the spur-gear gearbox stage 3 preferably have helical tooth systems, while the third gearwheel 6 and the fourth gearwheel 8 have straight tooth systems, in order to allow the two gearwheels to engage more easily during axial movement of the fourth gearwheel 8. For this reason, the fourth gearwheel 8 also has chamfers or rounded areas on one or both flanks. Since only relatively small torques are transmitted by the third gearwheel 6 and the fourth gearwheel 8, in comparison to the first gearwheel 5 and the second gearwheel, there is no need for a relatively complex helical tooth system for the third gearwheel 6 and the fourth gearwheel 8. Furthermore, there is no need to compensate for any axially acting force components with a straight tooth system.
Furthermore, the motor of the auxiliary drive 4 has a motor shaft which extends at right angles to the drive shaft 10 and is coupled to it. This allows the auxiliary drive 4 to be arranged in a space-saving manner transversely with respect to the gearbox axis, as a result of which the auxiliary drive 4 results at most in an insignificant, non-critical increase in the axial extent of the wind power installation gearbox 1.
As can be seen in the detail in
The adjusting lever 11 can be moved by a return spring 13 to a rest position in which torque transmission between the auxiliary drive 4 and the spur-gear gearbox stage 3 is interrupted. Movement of the adjusting lever 11 is transmitted by a shaft 14 to a guide lever 15, which is rigidly coupled to the adjusting lever 11. A gripper 16, which clasps the fourth gearwheel 8, is attached to a free end of the guide lever 15. The gripper 16 is used to move the fourth gearwheel 8 axially along the drive shaft 10 of the auxiliary drive 4. Auxiliary drive rotation is transmitted to the fourth gearwheel 8 by a radial interlock between the drive shaft 10 and the fourth gearwheel 8.
Furthermore, an electromagnetic limit switch 17, which is illustrated in
The electromechanical limit switch 17 is connected to the adjusting lever 11 by a guide disk 18 which, on its circumference, has a radial cutout for operation of the electromechanical limit switch 17. The guide disk 18 can be rotated by operation of the adjusting lever 11. A switching element, which interacts with the cutout, on the electromechanical limit switch 17 can be deflected by the radial cutout, thus opening and closing the electromechanical limit switch 17.
The use of the present invention is not restricted to the described exemplary embodiment.
Thus, while there are shown, described and pointed out fundamental novel features of the invention as applied to preferred embodiments thereof, it will be understood that various omissions and substitutions and changes in the form and details of the illustrated apparatus, and in its operation, may be made by those skilled in the art without departing from the spirit of the invention. Moreover, it should be recognized that structures shown and/or described in connection with any disclosed form or embodiment of the invention may be incorporated in any other disclosed or described or suggested form or embodiment as a general matter of design choice.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2008 044 900.8 | Aug 2008 | DE | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/EP2009/059796 | 7/29/2009 | WO | 00 | 4/8/2011 |
