Motor Sizing & Product Selection

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Motor Sizing & Product Selection

Postby om_tech_support_JT » Fri Jan 29, 2016 7:01 pm

Q: I have a conveyor application in which I am looking for a complete motor and controller system with multiple stored speed settings. Due to time and size constraints, I would prefer a compact system which is user friendly, easy to program, control and connect. I see Oriental Motor offers a wide variety of speed control products in various series and sizes. However, there are too many and I am not sure which to select. I also need to determine my motor requirements. Can you please help me select a product for my application? Below are the requirements of my application.

Conveyor Example.jpg
Conveyor Example.jpg (40.31 KiB) Viewed 4603 times


• Low speed 0.5”/sec is object is detected by sensor
• High speed 19.5”/sec if no object is detected by sensor
• Load: 50 lbs
• Pulley Diameter: 3” and weight 0.5lb/piece, 2 pulleys
• Controlled via I/O from PLC
• Alarm output
• AC 110/115VAC input voltage
• IP65 splah-proof rated product
• Stopping accuracy +/- 0.25”

A: On our website, we offer a FREE application motor sizing calculator tool to help customers convert their needs into specifications we can use to select product models. Let’s go through one as an example. Please click the Motor Sizing tab located at the top of our home page which says "Motor Sizing”. We offer 12 available application sizing tools. Select the one closest to your application which in this case is "Belt Conveyor". Website registration is required to use the sizing tool.

Online motor sizing calculator tool - fill in the blanks.jpg
Online motor sizing calculator tool - fill in the blanks.jpg (167.97 KiB) Viewed 4603 times


Next, an application form can be filled out based on your application requirements such as load, mechanism angle, motion profile, safety factor....etc. Once the form is completed (our tech support engineers can assist in completing the form), select “calculate” at the bottom of the page. The calculated results will be generated on the left hand side under the “Sizing Results” section. These are the motor requirements such as speed, torque, and inertia which we use to properly select the most ideal product. To save/print a copy of the sizing results select full report and a detailed sizing result will generate.

Motor sizing for conveyor page and motor sizing results, requirements example.jpg
Motor sizing for conveyor page and motor sizing results, requirements example.jpg (198.57 KiB) Viewed 4603 times


Per the sizing results, your application requirements are as follows:
• Load Inertia: 1818 oz-in2
• Required speed: 3RPM-124 RPM
• Torque Requirement: 56.2 lb-in
• Accuracy of 9.5 degrees

For this example, let’s start with our Brushless Motors as they offer the most flexibility in our early review.

Brushless Products Feature the following:
• Dynamic brake
• Speed control
• Acceleration and Deceleration profile setting
• I/O controlled via PLC
• Quick data setting using control panel (no need for software interface)

With the sizing results, the following is a Step by Step procedure on how to select a brushless speed control motor system for your application. For this example, let us use our general catalog pages to help explain the options with our BMU series. The BMU series catalog can be found on our website. From our homepage, select “Brushless DC Motors”, then select “BMU Series Brushless DC Motor Speed control’, select the “Download Reference” tab, and select “BMU series product catalog”.

1. Determine type of gearhead to use
- Parallel Shaft Type
Brushless round shaft motor speed is 80-4000 rpm (100-3000 rpm for 24VDC types) therefore a gearhead is required to reduce the speed range of 3-124 RPM.

REQUIREMENTS:
• Low speed 3 RPM is object is detected by sensor
• High speed 124 RPM if no object is detected by sensor

Output shaft speed of combination models - BMU series.jpg
Output shaft speed of combination models - BMU series.jpg (60.7 KiB) Viewed 4603 times


The 30:1 gear ratio has a speed range 2.7~133 RPM which is within the application requirement.

2. Compare motor permissible load Inertia to actual load inertia
- Motion Profile
- Acceleration / Deceleration
- Instantaneous Start / Stop

REQUIREMENT:
• Load Inertia: 1818 oz-in2

Permissible load inertia of combination models - BMU series.jpg
Permissible load inertia of combination models - BMU series.jpg (152.89 KiB) Viewed 4603 times


Compare the permissible load inertia for the 30:1 gear ratio selected from all BMU sizes. Consider those that match your application requirements of 1,818 oz-in2 (shown above with the RED STAR symbol). NOTE two load inertia specifications are provided as they differ when using instantaneous stop or instantaneous bi-directional operation is performed.

3. Check required gear ratio
- Compare torque-speed requirement
- Output speed

REQUIREMENT:
• Torque Requirement: 56.2 lb-in

Permissible torque of combination models - BMU series.jpg
Permissible torque of combination models - BMU series.jpg (157.33 KiB) Viewed 4603 times


Compare torque values for all BMU 30:1 gear ratio torque values. Highlight those that match your application requirements of 45lb-in. NOTE after the rated speed of 3000rpm, the torque value decreases.

4. Compare Inertia and torque requirement

REQUIREMENTS:
• Load Inertia: 1818 oz-in2
• Instantaneous stopping is required
• Torque Requirement: 56.2 lb-in

Using steps 2 and 3 to compare sizes which match both the load inertia and the torque requirement for your application. For this example select BMU Part Number for BMU5120 size.

5. Complete the model number using our model number structure below. Select BMU5120AP-30A-3.

BMU series model number code.jpg
BMU series model number code.jpg (94.5 KiB) Viewed 4603 times


From our website homepage use the “Search by Part Number” located on the top right and enter the model number selected. The product spec sheet will be displayed.

BMU5120AP-30A-3 specifications: http://catalog.orientalmotor.com/item/a ... 20ap-30a-3

The above model matches all REQUIREMENTS:
• Low speed 3 RPM if object is detected by sensor
• High speed 124RPM if no object is detected by sensor
• Load Inertia: 1818 oz-in2
• Instantaneous stopping is required
• Torque Requirement: 56.2 lb-in

BMU5120AP-30A-3 product page includes specs, drawings, literature, prices, accessories.jpg
BMU5120AP-30A-3 product page includes specs, drawings, literature, prices, accessories.jpg (134.89 KiB) Viewed 4603 times


Another way to search for a product model with the sizing results is by using our ADVANCED SEARCH. The advanced search is located on the top right corner of our website, select “Specification” then select your product category. Fill in as much information from your sizing report and search results will populate.

Advanced search for motor system selection.jpg
Advanced search for motor system selection.jpg (228.94 KiB) Viewed 4603 times


Our technical support engineers will assist with any sizing questions that may come up. If one of our application sizing forms do not match your application, please contact our technical support engineers for further assistance.

Technical support contact information:
Phone 1-800-468-3982
E-mail techsupport@orientalmotor.com
Chat http://www.orientalmotor.com

LR

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