Pin retainer

1. A gear arrangement for a planetary gearbox, said gear arrangement comprising a planet carrier, a planet pin, a planet gear, bearing means located between said planet pin and said planet gear, said bearing means including a bearing ring, and one or more shims located between said retainer and said planet pin;

said planet pin is hollow and is in fluid communication with an inside surface of said bearing ring, said planet pin comprising an inlet at one end;

in which said retainer is secured to said planet carrier by a bolt engaging said inlet;

wherein a fluid forced via said inlet and said hollow planet pin applies a radial force to said bearing ring, reducing said contact friction between said bearing ring and said planet pin and allowing an axial position of said planet pin to be adjusted to provide a correct preloading to said bearing means.

2. The gear arrangement of claim 1 , in which said bearing means is worn through use, an axial position of said planet pin is re-adjusted to provide a correct preloading to said bearing means.

3. The gear arrangement of claim 1 , in which a number and thickness of said one or more spacers is selected to lock said axial position of said bearing means having said correct preload.

4. A gearbox comprising the gear arrangement of claim 1 , said gearbox further comprising:

a front housing having an inspection cover;

a position of said inspection cover configured to be removed to allow access to said retainer;

wherein a fluid forced via said inlet and said hollow planet pin applies a radial force to said bearing ring, reducing said contact friction between said bearing ring and said planet pin and allowing an axial position of said planet pin to be readjusted to provide a correct preloading to said bearing means.

5. The gearbox of claim 4 , in which a number and thickness of said one or more spacers is selected to lock said axial position of said bearing means having said correct preload.

6. A wind turbine comprising the gearbox of claim 4 .

7. A wind turbine comprising the gear arrangement of claim 1 .

8. The gear arrangement of claim 1 , in which said bolt engaging said inlet is hollow, and in which said fluid is forced via said hollow bolt engaging said inlet.

9. A method for adjusting a preload of a bearing arrangement of a gear arrangement for a planetary gearbox, said gear arrangement comprising a planet carrier, a planet pin, a planet gear, bearing means located between said planet pin and said planet gear, said bearing means including a bearing ring, a retainer secured to said planet carrier by one or more bolts, and one or more shims located between said retainer and said planet pin; in which said planet pin is hollow and is in fluid communication with an inside surface of said bearing ring and with an inlet; said method comprising the steps of:

removing said bolts and said one or more shims;

connecting a hydraulic actuator to said inlet;

forcing fluid via a hollow bolt engaging said inlet and said hollow planet pin and applying a radial force to said bearing ring, reducing said contact friction between said bearing ring and said planet pin;

adjusting an axial position of said planet pin to provide a correct preload to said bearing means; and

securing said bolts and said one or more shims.

10. The method of claim 9 , in which said bearing means is worn through use, and wherein said step of adjusting an axial position of said planet pin comprises readjusting an axial position to provide a correct preloading to said bearing means.

11. The method of claim 9 , including the step of: selecting a number and thickness of said one or more spacers to lock said axial position of said bearing means having said correct preload.