# US 8,769,815 B2 · Method of lifting nacelle, nacelle lifting mechanism, tower, and wind turbine generator

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- Number: US 8,769,815 B2
- Document ID: US8769815B2
- Status: Granted
- Kind: B2
- Application number: 13/728,156
- Filed: 2012-12-27
- Published: 2014-01-16
- Granted: 2014-07-08
- Earliest claimed: 2012-02-10
- Assignees: Mitsubishi Heavy Industries, Ltd.
- Applicants: Mitsubishi Heavy Industries, Ltd.
- Inventors: Yasuaki Shiraishi; Kunikazu Watanabe
- Web page: https://patentgrep.com/patent/US8769815B2

## CPC

- B23P 6/002: {Repairing turbine components, e.g. moving or stationary blades, rotors, (B23P6/045 takes precedence)}
- F03D 80/50: Maintenance or repair
- B25B 27/023: {using screws}
- F05B 2230/61: using auxiliary equipment for lifting or holding
- F05B 2230/80: Repairing, retrofitting or upgrading methods
- F05B 2240/14: Casings, housings, nacelles, gondels or the like, protecting or supporting assemblies there within
- Y02E 10/72: Wind turbines with rotation axis in wind direction
- Y02P 70/50: Manufacturing or production processes characterised by the final manufactured product
- Y10T 29/49318: Repairing or disassembling
- Y10T 29/49721: with disassembling
- Y10T 29/49822: by applying force
- Y10T 29/53796: Puller or pusher means, contained force multiplying operator
- Y10T 29/53848: having screw operator
- B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q)
- F03D: WIND MOTORS
- B25B: TOOLS OR BENCH DEVICES NOT OTHERWISE PROVIDED FOR, FOR FASTENING, CONNECTING, DISENGAGING, OR HOLDING
- F05B: INDEXING SCHEME RELATING TO WIND, SPRING, WEIGHT, INERTIA OR LIKE MOTORS, TO MACHINES OR ENGINES FOR LIQUIDS COVERED BY SUBCLASSES F03B, F03D AND F03G
- Y02E: REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

A method of lifting a nacelle installed on a tower is provided. The method includes attaching a tapered bushing mechanism to a through-hole provided for a member of the tower; attaching a push-up bolt to the tapered bushing mechanism; and raising the push-up bolt while pushing the push-up bolt against a first member provided for the nacelle. The tapered bushing mechanism includes a tapered bushing inner cylinder and a tapered bushing outer cylinder. The tapered bushing inner cylinder includes a first taper section whose outer diameter becomes larger toward an end of the tapered bushing inner cylinder and a first screw thread formed on an inner surface of the tapered bushing inner cylinder. The tapered bushing outer cylinder includes a second taper section whose inner diameter becomes smaller toward an end of the tapered bushing outer cylinder.

## Claims

### Claim 1

A method of lifting a nacelle installed on a tower, comprising:
attaching a tapered bushing mechanism to a through-hole provided for a member of said tower;
attaching a push-up bolt to said tapered bushing mechanism; and
raising said push-up bolt while pushing said push-up bolt against a first member provided for said nacelle,
wherein said tapered bushing mechanism comprises a tapered bushing inner cylinder and a tapered bushing outer cylinder,
wherein said tapered bushing inner cylinder comprises a first taper section whose outer diameter becomes larger toward an end of said tapered bushing inner cylinder and a first screw thread formed on an inner surface of said tapered bushing inner cylinder,
wherein said tapered bushing outer cylinder comprises a second taper section whose inner diameter becomes smaller toward an end of said tapered bushing outer cylinder,
wherein said attaching said tapered bushing mechanism to said through-hole comprises:
inserting said tapered bushing mechanism in said through-hole such that the end of said tapered bushing inner cylinder is positioned on an up side, the end of said tapered bushing outer cylinder is positioned on a down side, an outer circumferential surface of said first taper section and an inner surface of said second taper section contact, and an outer circumferential surface of said tapered bushing outer cylinder contacts said through-hole; and
pulling down said tapered bushing inner cylinder in a state that said tapered bushing mechanism has been inserted in said through-hole, and
wherein said raising said push-up bolt comprises turning said push-up bolt in a state that said push-up bolt has been engaged with said first screw thread.

### Claim 2 (depends on 1)

The method according to claim 1, wherein said through-hole is formed in a tower top flange attached in an upper end of said tower.

### Claim 3 (depends on 2)

The method according to claim 2, further comprising:
removing a bolt which couples said first member with said tower and which has been engaged with a screw hole provided for said first member through said through-hole; and
inserting a plug in said screw hole,
wherein said raising said push-up bolt comprises pushing said push-up bolt against said plug.

### Claim 4 (depends on 3)

The method according to claim 3, wherein said first member comprises a yaw rotation bearing which rotatably couples said nacelle with said tower.

### Claim 5 (depends on 1)

The method according to claim 1, wherein said pulling down said tapered bushing inner cylinder comprises:
screwing a locknut with a second screw thread provided for the outer circumferential surface of said tapered bushing inner cylinder in the state that said locknut is pushed to said tapered bushing outer cylinder.

### Claim 6 (depends on 5)

The method according to claim 5, wherein said tapered bushing inner cylinder is coupled with said first taper section and comprises a screw section in which said second screw thread is formed,
wherein said screw section has two flat receptor surfaces which are parallel to each other surfaces, and
wherein said receptor surfaces are caught by a tool to support said tapered bushing inner cylinder, when said locknut is engaged with said second screw thread.

### Claim 7 (depends on 1)

The method according to claim 1, wherein a slit is provided for said tapered bushing outer cylinder to extend in a length direction of said tapered bushing outer cylinder.

### Claim 8 (depends on 7)

The method according to claim 7, wherein said tapered bushing outer cylinder further comprises a through-hole which communicates with said slit at an end of said slit and which penetrates between the outer surface and the inner surface of said tapered bushing outer cylinder.

### Claim 9

A nacelle lifting mechanism which is attached to a through-hole provided for a member of a tower, comprising:
a tapered bushing inner cylinder;
a tapered bushing outer cylinder; and
a push-up bolt pushed against a member provided for said nacelle,
wherein said tapered bushing inner cylinder comprises a first taper section whose outer diameter becomes larger toward an end of said tapered bushing inner cylinder and a first screw thread which is engaged with said push-up bolt and formed on inner surface of said tapered bushing inner cylinder,
wherein said tapered bushing outer cylinder comprises a second taper section whose inner diameter becomes smaller toward an end of said tapered bushing outer cylinder, and an outer circumferential surface pushed against said through-hole,
wherein said second taper section comprises an inner surface of a shape which fits with a shape of said outer circumferential surface of said first taper section, and
wherein said push-up bolt moves in a length direction of said tapered bushing inner cylinder, when said push-up bolt is turned in a state that said push-up bolt has been engaged with said first screw thread.

### Claim 10 (depends on 9)

The nacelle lifting mechanism according to claim 9, further comprising:
a locknut which fastens said tapered bushing inner cylinder and said tapered bushing outer cylinder,
wherein said tapered bushing inner cylinder further comprises a screw section coupled with said first taper section, and
wherein a second screw thread is formed on the outer circumferential surface of said screw section so as to be engaged with said locknut.

### Claim 11 (depends on 9)

The nacelle lifting mechanism according to claim 9, wherein said tapered bushing outer cylinder further comprises a slit to extend in a length direction of said tapered bushing outer cylinder.

### Claim 12 (depends on 11)

The nacelle lifting mechanism according to claim 11, wherein said tapered bushing outer cylinder comprises further comprises a penetrating hole which communicates with an end of said slit and which passes between the inner surface and the outer surface of said tapered bushing outer cylinder.

### Claim 13 (depends on 9)

The nacelle lifting mechanism according to claim 9, further comprising:
a locknut pushed against said tapered bushing outer cylinder,
wherein said tapered bushing inner cylinder further comprises a screw section coupled with said first taper section,
wherein a second screw thread is formed on the outer circumferential surface of said screw section to be engaged with said locknut, and
wherein said screw section has two flat receptor surfaces which are parallel to each other.