Abstract:
A method for protecting transmissions against damage during transport, in that at least one transmission component located in the force flow is braced in itself. Thereafter, transporting the transmission to a desired site and then removing the brace to free the drive input and the drive output shafts.

Description:
This application is a National Stage completion of PCT/EP2014/050110 filed Jan. 7, 2014, which claims priority from German patent application serial no. 10 2013 202 044.9 filed Feb. 7, 2013. 
     FIELD OF THE INVENTION 
     The present invention concerns a method for protecting transmissions against damage during transport and a transmission. 
     BACKGROUND OF THE INVENTION 
     Transmissions serve to transform a torque applied to the drive input shaft of the transmission into a torque delivered by the transmission by way of a drive output shaft. Such transmissions are for example used in wind power machines to be able to change the slow rotational movement of the rotor into a fast rotational movement as needed by the generator. 
     Torque transfer transmissions, as part of a device such as a wind power machine, are often manufactured by specialized companies. To be able to fit the transmission into the device such as the wind power machine as a whole, the transmission often has to be transported over long distances from the place where it is manufactured to the location where the device as a whole is assembled. During transport the transmission can be damaged, which incurs high costs. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to enable transmissions to be transported in a better and/or safer manner. 
     This objective is achieved by a method and a transmission as described below. 
     Preferred embodiments emerge from the drawings. 
     In particular, the objective is achieved by a method for protecting transmissions from damage during transport, wherein at least one moving component in the force flow is braced in itself. 
     A transmission is in general understood to be a device that serves to transform torque, rotational direction and/or rotational speed. Such a transmission can be used to transmit the rotational movement of a drive input shaft, appropriately geared, to the drive output shaft. The transmission can be used in a wind power machine wherein the drive input shaft is connected directly or indirectly to the rotor and the drive output shaft is connected directly or indirectly to the generator. Transmissions can also be used in a vehicle wherein the drive input shaft is connected to an electric machine or an internal combustion engine and the drive output shaft passes the torque on to the drive wheels. 
     A transmission is in particular taken to be a planetary gear set, in particular a one- to three-step planetary gear set. These transmissions can also have only one gear ratio. However, in the context of the invention a transmission can also mean a spur gear set, a chain transmission and suchlike, or combinations of the above-mentioned transmissions. 
     A drive input shaft can also be understood to mean the slow shaft and the drive output shaft can mean the fast shaft, i.e. the shaft whose rotational speed is higher relative to the other shafts. 
     A moving transmission component is understood in what follows to mean a component which moves in whole or only in part when the drive input shaft and/or the drive output shaft are moving. A moving transmission component can be a shaft, a gearwheel, a chain, a belt, a bearing or the like. 
     In what follows, a transmission component in the force flow can be understood to mean a component of the transmission upon which a force acts when torque is applied to the drive input shaft. Such a transmission component can be a gearwheel such as a sun gear, a planetary gearwheel, a planetary carrier or a ring gear, a shaft such as a drive input shaft, a drive output shaft, a sun gear shaft, a planetary gearwheel shaft, a planetary carrier shaft and/or a ring gear shaft, or a bearing such as a ball bearing, a conical roller bearing or a slide bearing. 
     In what follows, a transmission component can be said to be braced if a force acts on the transmission component such that the transmission component is prevented from moving. In such a case the transmission component as a whole or only part of the transmission component can be prevented from moving. Furthermore, by means of the force the transmission component or part thereof can be prevented from moving in one direction, in several directions, but preferably in all directions. 
     In particular a component can be considered to be braced if the component or part thereof is pressed against a fixed component or fixed components and in that way prevented from moving. 
     It has been recognized that during transport a transmission can be damaged by an uncontrolled movement of the transmission or a component thereof. In particular, this can also apply to bearings such as roller bearings or slide bearings. It has also been recognized that by virtue of a force introduced into the transmission a transmission component, located for example inside the transmission, can be braced and so prevented from moving. Such a component can be, for example, a bearing such as a slide bearing or a roller bearing, which for example supports a shaft or axle of the transmission. 
     It has also been recognized that when a force is introduced into the transmission, this force at least partially deforms the transmission elastically and the transmission therefore exerts an opposing force. The opposing force can then be used to prevent components of the transmission from moving. 
     Preferably, the drive output shaft is rotated in such manner that at least one moving transmission component located in the force flow is braced in itself. In particular this component in the force flow is braced by rotating the drive output shaft before transport. 
     By applying torque to the drive output shaft, the torque is introduced into the transmission. If now the drive input shaft is prevented from moving in response to the torque on the drive output shaft, the transmission is locked and a transmission component located in the force flow is acted upon by a force. In this way several transmission components or even all the transmission components in the force flow can be acted upon by forces. By virtue of the forces the corresponding transmission components can be prevented from moving, and this prevents the components from being mechanically damaged due to the movement. 
     Preferably, the transmission is in a fast gear ratio, wherein the drive output shaft is easier to rotate than the drive input shaft so that the transmission can be braced more easily. In this way the drive output shaft can be rotated without elaborate technical means of assistance, and this further facilitates the process. 
     The drive input shaft is understood to be the slow shaft, whereas the drive output shaft is the fast shaft, i.e. the shaft whose rotational speed is higher relative to the other shafts. 
     It is also possible to rotate the drive input shaft alone, or both shafts, in order to apply a torque in the transmission. 
     Preferably, in a first step the drive input shaft is locked relative to the housing and in a second step the drive output shaft is rotated. Preferably, the drive output shaft is rotated until the torque required for any further rotation is greater than a defined torque threshold. In this way the drive input shaft can be prevented from moving, for example by fixing the drive input shaft to the transmission housing or to the torque support. This fixing can be carried out without moving the drive input shaft, which is difficult to move. The two steps can also be carried out at the same time, or partly staggered. 
     After the drive output shaft has been rotated, the drive output shaft is secured against further rotation, in particular by locking with a fastening means. 
     The drive output shaft can also be locked relative to the housing by fastening means, and the drive input shaft rotated. In particular, during this a transmission component in the forced flow is braced thereby. Preferably, after being rotated the drive input shaft is secured against further rotation. 
     In particular, the bracing of the transmission can be released by releasing the slow-moving shafts. It has also been recognized that the bracing of the transmission exerts a restoring force on the drive input and the drive output shafts. This restoring force acts in opposition to the direction in which the shaft has been rotated. If now the drive input and/or the drive output shaft is released, the shaft concerned moves under the action of the restoring force. 
     The invention also concerns a transmission comprising a drive input shaft, such that the transmission has at least one fixing means for locking the drive input shaft and/or the drive output shaft. 
     In particular, by virtue of a locked drive input shaft and a locked drive output shaft at least one moving component located in the force flow can be braced in itself. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Below, the invention is explained further with reference to example embodiments with the aid of the drawings, which show: 
         FIG. 1 : A process sequence; 
         FIG. 2 : A transmission, which is secured for transport. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows a flow diagram of the process sequence of an example embodiment of a method for protecting transmissions against damage. The transmission has a drive input shaft and a drive output shaft, wherein the drive input shaft is connected to the drive output shaft in such manner that when the drive input shaft rotates, so too does the drive output shaft. In a first step of the method, the drive output shaft is locked, i.e. prevented from moving relative to the housing of the transmission. This can be done by mechanically connecting the drive output shaft to some other component, but preferably the drive output shaft is connected detachably to the housing. 
     Thus, on the drive output shaft there can be arranged a lever arm that extends radially relative to the drive output shaft. At its end remote from the drive output shaft, the lever arm can be supported against the transmission housing, in particular against the torque support. 
     In a second process step, the drive input shaft is rotated relative to the locked drive output shaft, so that any transmission components in the force flow are themselves braced. The transmission components are therefore prevented from moving. 
     In a third process step, the drive input shaft is locked, in particular connected to the housing in such manner that the movement of the drive input shaft is braked, in particular prevented. It is also not necessary for the drive input shaft to be connected to the housing, but the drive input shaft can even be connected to some other component, even one belonging to a transport device, that prevents movement of the drive input shaft. 
     Instead of locking the drive input shaft and the drive output shaft relative to the transmission housing, the drive input shaft can also be connected to the drive output shaft in a rotationally fixed manner so that the transmission as such is blocked. In this case one or both of the connections to the transmission housing can be omitted. 
     If the drive input shaft and the drive output shaft are blocked, the transmission can be transported, for example in a transporter. 
     At the destination the drive output shaft can now be released, so that it can again move freely relative to the housing. In a sixth step the drive input shaft is released, so that the drive input shaft can rotate relative to the housing. 
       FIG. 2  shows a transmission  1 , in particular a transmission for a wind power machine. This transmission  1  comprises a drive input shaft  2  and a drive output shaft  3 . In this case provision is made for connecting the drive input shaft  2  mechanically to the rotor of a wind power machine and the drive output shaft  3  to a generator. The drive input shaft  2  is connected to the drive output shaft  3  by way of at least one torque transformation element, such as a planetary or a spur gear transmission. On the drive input shaft  2  is arranged a lever  4 , which extends radially away from the drive input shaft  2 . On its drive input shaft side, the lever  4  has a fixing element  5 , which is in contact with the drive input shaft  2  and by means of which the lever  4  can be fixed onto the drive input shaft  2 . The fixing element  5  has a closed shape, for example a ring shape. The fixing element  5  is connected to a lever arm  6 , such that the lever arm  6  extends radially from the fixing element  5 . Around the fixing element  5  is arranged a shrink-disk  7 , so that the fixing element presses onto the drive input shaft held in the fixing element. In a position in which the transmission  1  is blocked so that the transmission can be transported, the end of the lever arm  6  remote from the drive input shaft rests against a torque support  8  of the transmission or is attached thereto. 
     On the drive output shaft  3  a bolt head, for example of hexagonal shape, is fixed at the end. By virtue of the bolt head a power driver, such as a compressed-air driver, can be fitted onto the drive output shaft in order to move the drive output shaft, in particular relative to the fixed drive input shaft, so that the transmission is braced. In such a case the power driver can comprise means for limiting the torque so that the transmission is not damaged by the bracing process. 
     In addition a lever element  9  is arranged on the drive output shaft  3 , the lever element consisting of a fixing element  10  and a lever arm  11 . The fixing element  10  encloses the drive output shaft  3  radially, the fixing element  10  having a closed or nearly closed shape such as a circle or part-circle. Around the fixing element  10  is fitted a shrink-disk  13  to press the fixing element  10  onto the drive output shaft  3 . On the fixing element  10  there is attached a lever arm  11 , which extends radially from the drive output shaft  3 . At the end of the lever arm  11  remote from the drive output shaft  3 , the lever arm  11  rests against or is attached to a projection  14  of the transmission housing.