Non-contact magnetic gears, which utilize magnetic transmission
Transmission parts that utilize magnetic force. Since it is a non-contact transmission, it is suitable for ultra-low dust and quiet applications.
1. What is a non-contact magnetic gear?
Toothless magnet gears. By using magnetic attraction and rebound, rotational motion can be transmitted in a non-contact manner without tooth meshing.
2. The main advantages of non-contact magnetic gears
It rotates in a non-contact way, so it has the following advantages.
It can be used in a clean room with an ultra-low dust generation capacity. Class 1 cleanliness is also available.
Semi-permanent, maintenance-free, no grease required · no need to replace due to wear or damage.
3. Selection steps
Selection of transmission direction (orthogonal or parallel)
Select the product type (see Table 1)
The quantity is calculated based on the size of the workpiece and the distance conveyed
Calculation of load torque (refer to the selection example on the right)
The dimensions are selected according to the required load torque for each
Select the inner diameter size according to the size of the shaft
3.1 Selection examples
Prerequisites:
- Roller diameter: 50mm
- Total weight of rollers: 0.3kg
- Workpiece weight: 5kg
- Shaft size: 12φ
- Weight of the shaft: 0.5kg
- Number of shafts: 7
- Seal friction coefficient: 0.1
- ◦ Data 3: Spatial Magnetic Beam Density (Reference) Transmission Efficiency Corresponding to Different Distances from Non-Contact Magnetic Gears: 0.9
- Safety factor: 3
- Use an induction motor
Preliminary selection:
- Orthogonal
- Select a precision type according to the size of the shaft
- Necessary quantity: 14 pcs
- Calculation of load torque (as shown below)
- Dimensions: D35
- Inner diameter size: d12
Example of torque calculation formula:
F = (workpiece weight (kg) + shaft weight (kg) + roller weight (kg)) × sealing friction coefficient
T = (F(N)×D (roller diameter (m))/2× transmission efficiency) × safety factor
Let's substitute the prerequisites.
F=(5+3.5+0.3)×0.1=0.88kg ⇒ 8.6N
T=(8.6×0.05/2×0.9)×3=0.58(N·m)
0.58/Minimum number of gears to be linked when transferring workpiece is 5 = 0.116 (N·m)
Design considerations:
- When the design is overlapped at the same shaft end, two gears may attract each other and the gear position may shift, so the distance between the gear surfaces (transmission part) should be set to 45 mm or more. In addition, the frontal spacing should be set to 25mm or more. (Photo 1)
- The allowable torque varies with the distance between the gears. (Document 1) The recommended interval is 0.5 mm. Also, to prevent contact, please set a spacing of 0.3mm or more.
- Under the action of magnetic force, the gears attract each other with a force of up to 7kgf ··cm. To prevent contact, fix it with a housing assembly, etc.
Photo 1: Interval when the same shaft end is used on top of each other
Document 1: Rate of change of torque as a function of distance (reference)
Document 2: Temperature-induced rate of change of the magnetic beam (reference)
Document 3: Spatial Magnetic Beam Density Corresponding to Different Distances of Non-Contact Magnetic Gears (Reference)
4 Magnetic wheel product specifications
Resources: https://www.cad2d3d.com/post-2046.html
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