Vertical Roller Mill Drive Arrangement with Segmented Motors
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Solution Overview
Problem
Existing drive arrangements for vertical roller mills require high-design and manufacturing effort, are costly, and suffer from reduced operability due to reliance on a single high-power electric motor, which can lead to system failure if the motor fails.
Innovation Solution
Implementing a drive arrangement with multiple standard-design, high-speed electric motors that provide partial drive power, allowing for improved operability and reduced costs through the use of spur gears and planetary gears, eliminating the need for a clutch and enabling continued operation with motor failure, and incorporating frequency converters for load distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a single high-power electric motor is used to provide 100 percent of the nominal drive power, then the drive arrangement can meet the power requirements, but the design and manufacturing costs increase and operability deteriorates due to system failure risk
Solution Approach 1:
The single high-power motor is segmented into multiple electric motors (at least two), each providing partial drive power (e.g., 50 percent or less of nominal drive power). This segmentation improves reliability because if one motor fails, the vertical roller mill can continue operating with reduced power, and it reduces design complexity by allowing use of standard motor designs rather than custom high-power motors
2Power
If a single high-power electric motor is used, then the power requirement is met, but design and manufacturing effort and costs increase due to special design requirements
Solution Approach 1:
The drive power is divided among multiple motors, allowing each motor to be designed using standard configurations rather than requiring custom high-power motor designs with special cooling systems and medium speeds, thereby reducing design and manufacturing effort
Solution Approach 2:
The invention changes the speed parameter of the electric motors to high speed, which increases power density and allows use of standard motor designs. This parameter change enables motors to be more compact and easier to manufacture while still meeting the overall power requirements when multiple motors are used
3Reliability
If multiple electric motors are used to provide partial drive power, then operability and ease of manufacture improve, but the device complexity increases due to additional motors and gear configurations
Solution Approach 1:
Multiple electric motors are merged with a common gear device (planetary gears or spur gears) that distributes power from all motors to the pressure plate. This merging approach manages the complexity by integrating multiple motors into a unified transmission system rather than requiring separate drive mechanisms for each motor
Solution Approach 2:
The gear device acts as an intermediary between the multiple electric motors and the pressure plate, coordinating the power from multiple motors and distributing it appropriately. This intermediary component manages the complexity by providing a standardized interface that handles the coordination of multiple motors
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution reduces design and manufacturing effort, lowers costs, and enhances operability by allowing the vertical roller mill to function with reduced power if one motor fails, while providing even load distribution and speed control through multiple motors and gear configurations.
Implementation Method 1
electromotive drive means (50) having a number, of at least two electric motors (52, 54) with respective rotors (53, 55)
Implementation Method 2
The electric motors are preferably water-cooled electric motors
Implementation Method 3
The electric motors are preferably water-cooled electric motors
Implementation Method 4
each connected via spur gear (70) in a rotary drive connection to the gear device (30)
Implementation Method 5
the gear device, which preferably has one or more planetary gears
Data Source
Figure 1
Figure 2
AI summary
The invention relates to a drive arrangement (1) for a vertical roller mill, having: a housing (10), a pressure plate (20) which is supported on the housing in a rotatable manner about a vertical pressure plate rotation axis (R1), a transmission device (30) which is arranged, beneath the pressure plate, in the housing, is supported on the latter and is in rotary driving connection with the pressure plate, and drive means (50) which are driven by an electric motor, are integrated, beneath the transmission device, into the housing and have at least one rotor (53, 55) having a rotor rotation axis (R2, R3) which extends parallel to and radially offset with respect to the pressure plate rotation axis, wherein the at least one rotor is in rotary driving connection with the transmission device via a spur gear transmission (70). The invention provides a drive arrangement which, with improved operating capacity, requires less structural and production complexity. This is achieved in that the drive means have a number of at least two electric motors each having rotors, the rotor rotation axis of which extends in each case parallel to and radially offset with respect to the pressure plate rotation axis and which are each in rotary driving connection with the transmission device via the spur gear transmission.