1) Descriptions of Internal Spur Gear
From the perspective of compact space transmission, an internal
gear is a type of gear whose teeth are distributed along the inner
surface of a ring-shaped component. Typically used in conjunction
with external gears (such as pinions or planetary gears), it
enables power transmission and speed conversion within limited
spatial constraints.
2) Features of Internal Spur Gear
Characterised by an ‘internal meshing’ transmission structure,
where the outer gear is nested within the inner gear, resulting in
a compact overall footprint; Advantages include a reduced centre
distance, significantly diminishing the volume of the equipment's
transmission system. Furthermore, the direction of tooth surface
contact during internal meshing is more optimal, resulting in
superior transmission smoothness compared to externally meshed
gears of the same specification. Operational noise levels are
notably lower (typically 5-10dB quieter than externally meshed
gears).
3) Applications of Internal Spur Gear
Suitable for applications with stringent volume constraints, such
as planetary gear mechanisms in automotive automatic transmissions
(where the inner gear serves as the ring gear), compact reducers
(e.g., robotic joint reducers), power tool drive systems, medical
devices (e.g., wheelchair drive mechanisms), and micro-transmission
modules within precision instruments.
Technical Specifications
| Parameter | Specification |
|---|
| Custom Made | Available |
| Gear Profile Type | Cylindrical Gear |
| Manufacturing Process | Gear Milling & Gear Teeth Hobbing |
| Teeth Grinding | Included |
| Module (M) | 0.5-25 |
| Number of Teeth (Z) | Custom |
| Pressure Angle (α) | Custom |
| Lead Angle | Custom |
| Accuracy Grade | ISO 8-9 Grade |
| Heat Treatment | Nitriding |
| Surface Hardness | 650HV |
Steel Code Grades Comparison
| CHINA/GB | ISO | ГΟСТ | ASTM | JIS | DIN |
|---|
| 45 | C45E4 | 45 | 1045 | S45C | CK45 |
| 40Cr | 41Cr4 | 40X | 5140 | SCr440 | 41Cr4 |
| 20CrMo | 18CrMo4 | 20ХМ | 4118 | SCM22 | 25CrMo4 |
| 42CrMo | 42CrMo4 | 38XM | 4140 | SCM440 | 42CrMo4 |
| 20CrMnTi | | 18XГT | | SMK22 | |
| 20Cr2Ni4 | | 20X2H4A | | | |
| 20CrNiMo | 20CrNiMo2 | 20XHM | 8720 | SNCM220 | 21NiCrMo2 |
| 40CrNiMoA | | 40XH2MA/40XHMA | 4340 | SNCM439 | 40NiCrMo6/36NiCrMo4 |
| 20CrNi2Mo | 20NiCrMo7 | 20XH2MA | 4320 | SNCM420 | |
