Compact Encoder Cable Outlet Structure for Sealing and EMI Shielding
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Solution Overview
Problem
Conventional cable glands fail to accommodate the stricter sealing and electromagnetic shielding requirements of signal cables in motor encoders, especially when installation space is limited and a minimum bending radius is necessary.
Innovation Solution
The proposed outlet structure for encoders includes an encoder case, a metal ring, a fixing member, a first O-shaped ring, and a second O-shaped ring, which together provide a compact design with enhanced bending space and IP67-class sealing, while also ensuring effective electromagnetic shielding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If conventional cable glands are used, then cable outlet is achieved, but the structure is too large and bending space is insufficient
Solution Approach 1:
The patent implements nesting by placing the metal ring inside the encoder case's cable through hole, and positioning the fixing member within the metal ring structure. The O-shaped rings are nested on the fixing member and cable. This nested arrangement allows the outlet structure to be compact and integrated within the encoder case, eliminating the need for external protruding cable glands while providing sufficient cable bending space.
2Reliability
If conventional cable glands are used, then cable outlet is achieved, but sealing performance is insufficient
Solution Approach 1:
The patent employs O-shaped rings (flexible sealing elements) at two critical locations: the first O-shaped ring seals between the fixing member and encoder case, while the second O-shaped ring seals between the fixing member and cable. These flexible sealing elements deform to conform to the mating surfaces, achieving IP67-class sealing performance without requiring complex multi-component sealing structures.
Solution Approach 2:
The outlet structure combines multiple materials with complementary properties: the metal ring provides electromagnetic shielding and structural support, the fixing member (likely polymer) provides isolation and mounting functionality, and the O-shaped rings (elastomeric material) provide sealing. This composite material approach achieves high reliability sealing and shielding while maintaining relatively simple structure.
3Object-affected harmful factors
If conventional cable glands are used, then cable outlet is achieved, but electromagnetic shielding is insufficient
Solution Approach 1:
The metal ring serves as an intermediary element between the cable shielding layer and the encoder case grounding system. It is deformable to clasp the cable's shielding layer, establishing an continuous electromagnetic shielding path from the cable through the outlet structure to the encoder case, thereby blocking external electromagnetic interference without requiring complex shielding mechanisms.
4Volume of moving object
If the outlet structure is made compact, then installation space is reduced, but cable bending space may be compromised
Solution Approach 1:
The patent repositions the cable bending space requirement from the external direction (where conventional cable glands protrude) to the internal dimension within the encoder case. By integrating the outlet structure within the case and providing internal space for cable routing, the design achieves compact external dimensions while maintaining adequate cable bending radius inside the encoder housing.
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 achieves a more compact and efficient cable outlet structure that meets stringent sealing and shielding requirements, providing a greater bending space and maintaining an IP67-class sealing effect, thus addressing the limitations of conventional cable glands.
Implementation Method 1
The metal ring is deformable under an external force to clasp the shielding layer
Implementation Method 2
the second O-shaped ring is also capable of applying an elastic force to the metal ring such that the metal ring remains abutting against the encoder case
Implementation Method 3
The first O-shaped ring is capable of sealing a slit between the fixing member and the encoder case
Implementation Method 4
the second O-shaped ring is capable of sealing a slit between the fixing member and the cable
Data Source
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AI summary
An outlet structure for an encoder includes: an encoder case (10), a metal ring (20), a fixing member (30), a first O-shaped ring (40), and a second O-shaped ring (50). A first cable through hole (12) is disposed in the encoder case (10). The metal ring (20) is disposed in the first cable through hole (12) and is capable of clasping a shielding layer (72) of a cable (70). A second cable through hole (32) is disposed in the fixing member (30), and the fixing member (30) is insertable with interference into the first cable through hole (12) from an outer side of the encoder case (10). The first O-shaped ring (40) is sleeved onto the fixing member (30) to seal a slit between the fixing member (30) and the encoder case (10). The second O-shaped ring (50) is disposed in the second cable through hole (32) and is capable of sealing a slit between the fixing member (30) and the cable (70), and the second O-shaped ring (50) is also capable of applying an elastic force to the metal ring (20) such that the metal ring (20) remains abutting against the encoder case (10). The outlet structure is compact, and provides a greater bending space for cable (70) outlet of the encoder.