Crane

Patent metadata

Field	Value
Publication number	US-10633228-B2
Application number	US-201615249178-A
Country	US
Kind code	B2
Filing date	Aug 26, 2016
Priority date	Feb 26, 2014
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The present invention relates to a crane, in particular to a revolving tower crane, having a boom rotatable about an upright slewing gear axis by a slewing gear drive and having an out-of-operation brake which allows and brakes rotary movements of the boom in the out-of-operation state. In accordance with the invention, the out-of-operation brake is configured as working electrodynamically and comprises an electric motor of the slewing gear drive which can be operated as an electric-motor brake.

First claim

We claim:

1. A revolving tower crane comprising:
a boom rotatably supported about an upright axis of rotation by a slewing gear drive, wherein the boom comprises an out-of-operation brake which permits and brakes rotary movements of the boom in an out-of-operation state of the crane under wind loads,
wherein the out-of-operation brake is configured to operate electrodynamically, and wherein the out-of-operation brake comprises an electric motor of the slewing gear drive which is operable as an electric-motor brake,
wherein the electric motor is configured as an asynchronous motor with which an out-of-operation exciter is connected thereto, and
wherein the out-of-operation exciter comprises a capacitor circuit.

2. The crane of claim 1 , further comprising a brake circuit connected with the electric motor of the slewing gear drive.

3. The crane of claim 2 , wherein the brake circuit comprises at least one series resistance (R v ) which can be activated or connected thereto.

4. The crane of claim 3 , wherein the series resistance (R V ) which can be activated is configured as three-phase or comprises three resistance groups of at least approximately the same size with a single-phase configuration.

5. The crane of claim 3 , wherein the series resistance (R V ) which can be activated comprises a braking resistance which can be activated in normal operation for taking up a reverse power produced in crane operation.

6. The crane of claim 5 , wherein the series resistance (R V ) which can be activated is configured as three-phase or comprises three resistance groups of at least approximately the same size with a single-phase configuration.

7. The crane of claim 2 , wherein the brake circuit comprises a short-circuit switch for short-circuiting a motor winding of the electric motor.

8. The crane of claim 1 , wherein the capacitor circuit comprises excitation capacitors switchable in parallel with the winding of the asynchronous motor and connected to one another in a star or in a triangle.

9. The crane of claim 1 , wherein the out-of-operation brake is configured such that the braking torque is smaller than a predefined torque up to a predefined rotational speed of the boom, said predefined torque being able to be produced by a predefined wind load on the crane and the braking torque only being larger than the predefined torque produced by said wind load on the crane on an exceeding of said rotational speed of the boom.

10. The crane of claim 1 , further comprising a cooling apparatus active in electric-motor braking operation, wherein the cooling apparatus is connected with the electric motor.

11. A revolving tower crane comprising:
a boom rotatably supported about an upright axis of rotation by a slewing gear drive, wherein the boom comprises an out-of-operation brake which permits and brakes rotary movements of the boom in an out-of-operation state of the crane under wind loads,
wherein the out-of-operation brake is configured to operate electrodynamically, and wherein the out-of-operation brake comprises an electric motor of the slewing gear drive which is operable as an electric-motor brake,
wherein the electric motor is configured as an asynchronous motor with which an out-of-operation exciter is connected thereto,
wherein the out-of-operation exciter comprises a capacitor circuit, and
wherein the capacitor circuit comprises excitation capacitors switchable in parallel with the winding of the asynchronous motor and connected to one another in a star or in a triangle.

12. The crane of claim 11 , further comprising a brake circuit connected with the electric motor of the slewing gear drive.

13. The crane of claim 12 , wherein the brake circuit comprises at least one series resistance (R v ) which can be activated or connected thereto.

14. The crane of claim 13 , wherein the series resistance (R V ) which can be activated is configured as three-phase or comprises three resistance groups of at least approximately the same size with a single-phase configuration.

15. The crane of claim 13 , wherein the series resistance (R V ) which can be activated comprises a braking resistance which can be activated in normal operation for taking up a reverse power produced in crane operation.

16. The crane of claim 15 , wherein the series resistance (R V ) which can be activated is configured as three-phase or comprises three resistance groups of at least approximately the same size with a single-phase configuration.

17. The crane of claim 12 , wherein the brake circuit comprises a short-circuit switch for short-circuiting a motor winding of the electric motor.

18. A revolving tower crane comprising:
a boom rotatably supported about an upright axis of rotation by a slewing gear drive, wherein the boom comprises an out-of-operation brake which permits and brakes rotary movements of the boom in an out-of-operation state of the crane under wind loads, wherein the out-of-operation brake is configured to operate electrodynamically, and wherein the out-of-operation brake comprises an electric motor of the slewing gear drive which is operable as an electric-motor brake, and
a cooling apparatus active in electric-motor braking operation, wherein the cooling apparatus is connected with the electric motor.

19. The crane of claim 18 , further comprising a brake circuit connected with the electric motor of the slewing gear drive.

20. The crane of claim 18 , wherein the out-of-operation brake is configured such that the braking torque is smaller than a predefined torque up to a predefined rotational speed of the boom, said predefined torque being able to be produced by a predefined wind load on the crane and the braking torque only being larger than the predefined torque produced by said wind load on the crane on an exceeding of said rotational speed of the boom.

Assignees

• Liebherr Components Biberach Gmbh

Inventors

• Münst Thomas
• Schmid Gerhard
• Wanner Harald

Classifications

• B66C23/84 Primary

  Slewing gear (anti-friction bearings F16C) · CPC title

• B66C23/94 Primary

  for limiting slewing movements · CPC title

• B66C23/88

  Safety gear (for cranes in general B66C15/00; for rope, cable, or chain winding mechanisms B66D1/54) · CPC title

• B66C23/16

  with jibs supported by columns, e.g. towers having their lower end mounted for slewing movements · CPC title