### Improve math skills of your kids - Learn step-by-step arithmetic from Math games

Math: Unknown - Step-by-step math calculation game for iOS.

Math: Unknown is much more than a math game. It is a step-by-step math calculation game which will teach users how to calculate in the correct order rather than just asking only the final calculated results.

The app consists of four basic arithmetic operations which are addition, subtraction, multiplication and division. In order to get started, users who are new to arithmetic can learn from animated calculation guides showing step-by-step procedures of solving each type of operation. It is also helpful for experienced users as a quick reference.

Generally, addition and subtraction may be difficult for users who just start learning math especially when questions require carrying or borrowing (also called regrouping). The app helps users to visualize the process of carrying and borrowing in the way it will be done on paper. Once users understand how these operations work, they are ready to learn multiplication and division.

For most students, division is considered as the most difficult arithmetic operation to solve. It is a common area of struggle since it requires prior knowledge of both multiplication and subtraction. To help users understand division, the app uses long division to teach all calculation procedures. Relevant multiplication table will be shown beside the question. Users will have to pick a number from the table which go into the dividend. Multiplication of selected number and divisor is automatically calculated, but the users have to do subtraction and drop down the next digit themselves. Learning whole calculation processes will make them master it in no time.

Math: Unknown is a helpful app for students who seriously want to improve arithmetic calculation skills.

### Ball Detent Torque Limiter: Overload Clutch

A torque limiter is an automatic overload clutch that provides machine protection and reduces repair time during jamming load conditions. This is done to protect expensive machines and prevent physical injuries. A torque limiter may limit the torque by slipping (as in a friction plate slip-clutch), or uncouple the load entirely (as in a shear pin).

Ideally the torque limiter should be placed as close as possible to the source of the jam. This will allow the system inertia and torque to be quickly and effectively disconnected from the jammed section. The system can then be allowed to stop without causing further machine damage. A mechanical torque limiter will provide faster response times and better protection than typical electronic methods at high crash rates.
There are several disconnect types available, but we will focus at the Ball Detent type.

A ball detent type torque limiter transmits force through hardened balls which rest in detents on the shaft and are held in place with springs. An over-torque condition pushes the balls out of their detents, thereby decoupling the shaft. It can have single or multiple detent positions, or a snap acting spring which requires a manual reset. There may be a compression adjustment to adjust the torque limit. Unlike friction style or shear pin type torque limiters, ball detent torque limiter can provide an accurate method of resetting the torque with no operator intervention. A single position clutch will reengage in the exact rotational position each time. This is often necessary for system timing in bottling, packaging, and paper converting type applications.

This is how it works.

1. When the set limit torque is reached, the clutch disengages; the torque drops immediately
2. After the cause of overload has been removed, the clutch re-engages automatically after 360 angular degrees. Other cycle sequences, for example 180 degrees, are also available.
3. The clutch is ready for operation again
The following video clip is from mayr showing how it works to transmit and limit torque. Examples of torque limiter application are provided in the link below with calculation example as a guideline for selecting the right torque limiter model for your mechanical design project.

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### Comments

Rhen Nicey said…
Similarly, as with customary ball-detent torque limiters, spring strain is balanced through the revolution of a nut, just for this situation the components are separately conformed to the sought tangential power, worth, and a torque figuring is made in light of the quantity of components and their separation from the focal point of the rotational pivot. While the prior plans of security component torque limiters included extraordinary Datasheets utilized as a part of a conjunction with estimations taken from the spring stature, progressively makers show the right nut area with a stamped scale.