Spindle Motor Insulating Sheet Reduces Axial Thickness
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Solution Overview
Problem
Conventional spindle motors face challenges in reducing dimension while ensuring electrical insulation between lead wires and the base member, particularly as the motor becomes thinner, risking lead wire damage from contact with the base member, and existing insulation methods increase motor dimension and complexity.
Innovation Solution
The spindle motor design incorporates an insulating sheet portion between the lead wires and the base member, which extends radially outward along the lower surface of the insulating sheet portion and is soldered to the circuit substrate, preventing contact with the base member and using a sealing material to cover the base through-hole, thereby reducing the motor's axial thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an insulation body is interposed between the lead wires and the base member, then electrical insulation is improved, but the dimension of the spindle motor is increased
Solution Approach 1:
The circuit substrate is designed to extend into the base through-hole, merging the insulation function with the existing circuit substrate structure. This eliminates the need for a separate insulation body while maintaining electrical insulation between lead wires and the base member, thereby preventing dimension increase.
Solution Approach 2:
The circuit substrate performs multiple functions: it provides electrical connection between coils and external circuits, and simultaneously serves as an insulation structure by extending into the base through-hole to prevent lead wire contact with the base member. This multi-functionality avoids adding extra insulation components.
2Length of moving object
If the lead wires are made thinner to reduce motor dimension, then the dimension is improved, but the lead wires become more susceptible to damage from contact with the base member
Solution Approach 1:
The circuit substrate acts as an intermediary structure that extends into the base through-hole, creating a protective barrier between the thin lead wires and the base member. This intermediary structure prevents direct contact and potential damage to the thin lead wires while allowing the motor to maintain a reduced thickness.
3Strength
If the base member thickness is increased to ensure rigidity, then the rigidity is improved, but the motor dimension is increased
Solution Approach 1:
The base member thickness is segmented differently in different regions: it is thinner in the region where the circuit substrate extends into the base through-hole (where rigidity is maintained by the circuit substrate), and can be thicker in other regions where structural support is needed. This localized thickness variation maintains overall rigidity while reducing the maximum motor thickness.
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
This design effectively reduces the spindle motor's dimension by preventing lead wire damage and maintaining necessary rigidity and sealing, while ensuring electrical insulation and airtightness, making it suitable for thinner applications such as notebook-type PCs.
Implementation Method 1
torque acting about a center axis is generated by magnetic fluxes generated between the stationary unit and the rotary unit
Implementation Method 2
torque acting about a center axis is generated by magnetic fluxes generated between the stationary unit and the rotary unit
Implementation Method 3
An insulating sheet portion is disposed at the lower surface side of the base member... Lead wires extending from the coils extend toward the lower surface side of the base member through the base through-hole
Implementation Method 4
The lead wires are soldered to land portions of the circuit substrate
Data Source
AI summary
A base member includes a base through-hole which interconnects an upper opening and a lower opening. An insulating sheet portion is disposed at a lower surface side of the base member. The insulating sheet portion covers at least a portion of the lower opening. Lead wires extending from coils extend to the lower surface side of the base member through the base through-hole. The lead wires extend radially outward along a lower surface of the insulating sheet portion while making contact with the insulating sheet portion. The lead wires are soldered to land portions of a circuit substrate. The lower opening is covered with a sealing material. The circuit substrate includes a first region. The insulating sheet portion is defined by a smaller number of layers than the first region.