Flanged Linear Bushings
Product name | Flanged Linear Bushings - Center Flange |
Part number | LHMRWMF20 |
Features | A load can be placed near the center of the linear bushing to evenly distribute the load and space. |
* Orange colored cells in the table below indicate the part numbers used in this example.
Selection criteria
Select a center flanged type so that the plate moving up and down is positioned at the center of the bearing.
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Available sizes
■Flanged Linear Bushings - Center Flange
Type | Outer Cylinder | Ball | Retainer | Operating Ambient Temperature | Accessory |
Material | Hardness | Surface Treatment | Material | Material |
Round Flange Square Flange Compact Flange | 52100 Bearing Steel | 58HRC- | - | 52100 Bearing Steel | Plastic (Duracon M90 Equivalent) | -20-80℃ | Seal: Material Nitrile Rubber (-20 to 120°C) |
Stainless(SUS) | -20-100℃ |
Electroless Nickel Plating | 440C Stainless Steel | Plastic (Duracon M90 Equivalent) | -20-80℃ |
Stainless Steel (SUS) | -20-100℃ |
440C Stainless Steel | 56HRC- | - | Plastic (Duracon M90 Equivalent) | -20-80℃ |
Stainless Steel (SUS) | -20-100℃ |
■Sizes and Dimensions
I.D. (mm) | Length (mm) |
6 | 35 |
8 | 45 |
10 | 55 |
12 | 57 |
13 | 61 |
16 | 70 |
20 | 80 |
25 | 112 |
30 | 123 |
35 | 135 |
40 | 151 |
50 | 192 |
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Selection steps
■Linear Bushing Selection Steps
- Determine conditions of use
- (Loads, Motion pattern, Life hours)
↓
- Temporarily select the specifications of linear bushings
- (Shaft dia. and length are temporarily selected according to the conditions of use.)
↓
- Basic safety check
-
- ●Basic Static Load Rating
- ●Basic Dynamic Load Rating
- ●Allowable Static Moment
- Operating Life
↓
- Considerations Based on Required Performance
- ●Life Variations Due to Temperature Changes
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Accuracy Info
■Accuracy Info. of Flanged Linear Bushings
(mm)
I.D. | I.D. Tolerance | Overall Length Tolerance |
6 | 0 -0.010 | ±0.3 |
8 |
10 |
12 |
13 |
16 |
20 | 0 -0.012 |
25 |
30 |
35 | 0 -0.015 |
40 |
50 |
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Performance info.
■Speeds / Loads (Load Info.) of Flanged Linear Bushings
I.D. (mm) | Basic Load Rating |
Basic Dynamic Load Rating (N) | Basic Static Load Rating (N) |
6 | 324 | 529 |
8 | 431 | 784 |
10 | 588 | 1100 |
12 | 657 | 1200 |
13 | 813 | 1570 |
16 | 1230 | 2350 |
20 | 1400 | 2740 |
25 | 1560 | 3140 |
30 | 2490 | 5490 |
35 | 2650 | 6270 |
40 | 3430 | 8040 |
50 | 6080 | 15900 |
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Technical calculations
■Life of Flanged Linear Bushings
When the linear system is loaded in linear reciprocating motion, scaly damages called flaking appear due to material fatigue as the repeated stress is applied on the rolling elements and the rolling contact surfaces constantly. Total travel distance until the first flaking occurs is called the life of linear system.
Rated life can be calculated with the basic dynamic load rating and the actual load applied on the linear bushings, as shown below.
- L: Rated Life (km)
- fH: Hardness Factor (See Fig.1)
- fT: Temperature Factor (See Fig.2)
- fC: Contact Factor (See Table-3)
- fW: Load Factor (See Table-4)
- C: Basic Dynamic Load Rating (N)
- P: Applied Load (N)
Hardness Factor (fH)
For liner system applications, sufficient hardness is required for ball contact shafts. Inappropriate hardness causes less allowable load, resulting in shorter life.
Fig. 1. Hardness Factor
Temperature Factor (fT)
When the temperature of linear system exceeds 100°C, the hardness of the system and shafts will be reduced and the allowable loads will also be reduced compared to being used at room temperature, resulting in a shorter life.
Fig. 2. Temperature Factor
Contact Factor (fC)
More than two linear systems are used for one shaft in general. In this case, the load applied to each linear system varies depending on machining precision and is not uniformly distributed. As a result, allowable load per linear system changes depending on the number of linear systems used on one shaft.
Table-3. Contact Factor
Number of Bearings Installed on One Shaft | Contact Factor fC |
1 | 1 |
2 | 0.81 |
3 | 0.72 |
4 | 0.66 |
5 | 0.61 |
Load Factor (fW)
To calculate load applied to the linear system, in addition to object weight, it requires inertia force attributed to motion velocity or moment loads. Further, it is necessary to accurately determine the temporal change of each. However, it is difficult to calculation the load accurately due to potential vibrations and shocks caused by other element than repeated start-stop motions during reciprocating motion. Therefore, use the table below in order to simplify the life calculations.
Conditions of Use | fw |
No shocks / vibrations, low speed: 15m/min. or less | 1.0~1.5 |
No significant shocks / vibrations, medium speed: 60m/min. or less | 1.5~2.0 |
With shocks / vibrations, high speed: 60m/min. or more | 2.0~3.5 |
Life in hours can be obtained by calculating the travel distance per hour. When the stroke length and the number of strokes are constant, it can be calculated using the formula below.
- Lh: Life (Hr.)
- L: Rated Life (km)
- Ls: Stroke length (m)
- n1: Number of Cycles per Minute (cpm)
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