Rotation Brake Method And Device For Working Machine

• US 20070273316A1
• Filed: 03/31/2005
• Published: 11/29/2007
• Est. Priority Date: 04/02/2004
• Status: Active Grant

• Current Assignee: Klaus Schmidt, Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Original Assignee: Klaus Schmidt, Kobelco Construction Machinery Company Limited (Kobe Steel Limited)
• Inventors: Inoue, Koji, Yoshimatsu, Hideaki, Sugano, Naoki, Komiyama, Masayuki
• Granted Patent: US 7,659,677 B2
• Time in Patent Office: Days
• US Class Current: 318/371
• CPC Class Codes: B60L 1/20 Energy regeneration from auxiliary equipment
• CPC Class Codes: B60L 3/0076 relating to braking
• CPC Class Codes: B60L 7/02 Dynamic electric resistor braking B60L7/22 takes precedence
• CPC Class Codes: E02F 9/121 Turntables, i.e. structure rotatable about 360°
• CPC Class Codes: E02F 9/128 Braking systems
• CPC Class Codes: E02F 9/24 Safety devices , e.g. for preventing overload E02F9/226 takes precedence

Abstract

To stop, in an emergency, a revolving superstructure quickly from rotating while preventing damage of a mechanical brake. A revolving superstructure is driven swiveling using a permanent magnetic-type swiveling electric motor; in an emergency, such as a malfunction in a drive or control system for the swiveling electric motor, allowing electric power generated in the electric motor due to inertial rotation to be consumed in an external braking resistor so as to make an electric braking action; and a mechanical brake is activated to stop the rotation and hold the stopped revolving superstructure when a rotation speed of the revolving superstructure becomes equal to or lower than a preset value.

Claims

1. A method for braking a revolving superstructure of a work machine, comprising:

employing a permanent magnet-type electric motor as a swiveling electric motor for drivingly swiveling said revolving superstructure;

in an emergency, allowing electric power generated in said swiveling electric motor due to inertial rotation to be consumed in a braking resistor outside said swiveling electric motor to provide an electric braking action, said electric braking action providing braking and decelerating the revolving superstructure; and

activating a mechanical brake when a rotation speed of the revolving superstructure becomes equal to or lower than a preset value during said decelerating.

2. A system for braking a revolving superstructure of a work machine, comprising:

a swiveling electric motor for drivingly swiveling said revolving superstructure;

a mechanical brake for mechanically braking said swiveling electric motor;

a controller for controlling respective operations of said swiveling electric motor and said mechanical brake; and

a speed detector for detecting a rotation speed of said revolving superstructure,

wherein;

said swiveling electric motor is composed using a permanent magnet-type electric motor designed to make an electric action by allowing electric power generated due to inertial rotation to be consumed in a braking resistor outside said swiveling electric motor; and

said controller is adapted to allow said swiveling electric motor to make the electric braking action in an emergency, and to activate said mechanical brake, based on a speed signal generated from said speed detector, when the rotation speed of the revolving superstructure becomes equal to or lower than a preset value by said electric braking action.

3. The system as defined in claim 2, wherein:

said mechanical brake is composed using a hydraulic negative brake adapted to release a braking force when a hydraulic pressure is introduced therein through a selector valve; and

said controller is adapted to control operation of said selector valve.

4. The system as defined in claim 2, wherein:

said speed detector includes a comparison section for comparing a value of voltage or current resulting from a power generating action of said swiveling electric motor with a preset value; and

said mechanical brake is designed to be activated based on a result of the comparison by said comparison section.

5. The system as defined in claim 2, wherein said speed detector is composed using a speed sensor for detecting a rotation speed of said swiveling electric motor or a speed reduction mechanism of said swiveling electric motor.

6. The system as defined in claim 2, which is designed such that a maximum torque to be obtained by the electric braking action of said swiveling electric motor is set at a value approximately equal to a maximum braking torque of said swiveling electric motor in a normal state.

7. A system for braking a revolving superstructure of a work machine, comprising:

a swiveling electric motor for drivingly swiveling said revolving superstructure;

a mechanical brake for mechanically braking said swiveling electric motor;

control means for controlling respective operations of said swiveling electric motor and said mechanical brake; and

speed detection means for detecting a rotation speed of said revolving superstructure, wherein;

said swiveling electric motor is composed using a permanent magnet-type electric motor designed to make an electric action by allowing electric power generated due to inertial rotation to be consumed in a braking resistor outside said swiveling electric motor; and

said control means is adapted to allow said swiveling electric motor to make the electric braking action in an emergency, and to activate said mechanical brake, based on a speed signal generated from said speed detection means, when the rotation speed of the revolving superstructure becomes equal to or lower than a preset value by said electric braking action.

8. The system as defined in claim 7, wherein:

said mechanical brake is composed using a hydraulic negative brake adapted to release a braking force when a hydraulic pressure is introduced therein through a selector valve; and

said control means is adapted to control operation of said selector valve.

9. The system as defined in claim 7, wherein:

said speed detection means includes a comparison section for comparing a value of voltage or current resulting from a power generating action of said swiveling electric motor with a preset value; and

said mechanical brake is designed to be activated based on a result of the comparison by said comparison section.

10. The system as defined in claim 7, wherein said speed detection means is composed using a speed sensor for detecting a rotation speed of said swiveling electric motor or a speed reduction mechanism of said swiveling electric motor.

11. The system as defined in claim 7, which is designed such that a maximum torque to be obtained by the electric braking action of said swiveling electric motor is set at a value approximately equal to a maximum braking torque of said swiveling electric motor in a normal state.