1. FIELD OF THE INVENTION

This invention is related to the field of vibration of mechanical rotary system caused by unbalanced masses.

2. THE TECHNICAL PROBLEM

To reduce vibration of rotating machines many type of balancing machines have been invented. All of them are working in a way where vibration are sensed by sensor and sensed vibration data are processed in computer to determined unbalanced mass in that rotary system. When position and amount of mass is determined it is up to operator of that machine to put proper mass on proper place to balance system. It is costly and timely process. But there is machines that running with different mass each time so balancing of that machines in that way is impossible, like washing machines for example.

3. BACKGROUND ART

To solve this problem it should be some kind of auto balancing mechanism that is able to determined amount and position of unbalanced mass and according to that be able to put proper amount of balancing mass on proper position so that equilibrium of masses can be achieved. Aldo, there are many auto balancing mechanisms that have been invented, in my understanding all of this mechanisms working in the way where balancing masses in form of balls or cylinders are put in fluid and rotating together with unbalanced rotary system. Problem of this working principal is that balls or cylinders are pressed to the walls by strong influence of centrifugal forces so the friction between balls and walls increasing by square function of rotary speed of the unbalanced system. This friction preventing balls to rich proper position because inertial force of the balls can not overcome friction. To overcome friction auto balancing mechanism should minimize negative effect of centrifugal force and friction in one way and maximize effect of inertial forces of balancing masses in other way. Inertial auto balancing mechanism doing just that, friction produced by centrifugal forces are minimized and it is contained inside roller bearings on one side while in the other side, effect of inertial forces a increased dramatically by adding arm to this force and creating inertial moment which easily can overcame friction in the bearing and also friction of viscosity of the fluid. 4. SUMMARY OF THE INVENTION

Inertial auto balancing mechanism is doing that, friction produced by centrifugal forces are minimized and it is contained inside roller bearings on one side while in the other side, effect of inertial forces a increased dramatically by adding arm to this force and creating inertial moment which easily can overcame friction in the bearing and also friction of viscosity of the fluid. This auto balancing mechanism can be used on every kind of rotating machines and can be designed for any rotational speed or any amount of unbalanced mass.

Also, all known auto balancing mechanisms don't taking in account dynamical nature of vibration so they are incapable to truly balance one unbalanced rotary system. In many real life application it is not possible to put balancing mass in same plane of unbalancing mass, or unbalancing mass changing position in axial direction like for example in washing machine, it will be impossible to put any kind of auto balancing mechanism in plane of unbalanced mass because mechanism will fill valuable space inside washing machine drum and disrupt washing process. Also, mass of washing cloth can change position axially in any direction. So auto balancing mechanism should be able to perform dynamical balancing (out of plane balance) even if it is not physically positioned in plane of unbalanced mass.

5. BRIEF DESCRIPTION OF FIGURES

Figure 1 : Inertial auto balancing mechanism attached to unbalanced rotary system.

1- Unbalanced rotational system

2- Unbalanced mass

3- Housing of inertial auto balancing mechanism

4- Fluid

5- Balancing mass 1

6- Balancing mass 2

7- Bearing 1

8- Bearing 2

9- Shaft

Figure 2: Forces, moments and kinematics in inertial auto balancing mechanism attached to the unbalanced rotary system.

Fucg - Centrifugal force of unbalanced mass (2) Fbcg - Centrifugal force of balancing mass (5) and (6) IfI - Inertial force of balancing mass (5) If2 - Inertial force of balancing mass (6) ImI - Inertial moment of balancing mass (5) Im2 -Inertial moment of balancing mass (6) Figure 3: Tridimensional view of mechanism, engaged, with balancing masses shifted in opposite direction of unbalanced mass by inertial forces.

Figure 4: Position of two balancing masses in rotary system where unbalanced mass is not present.

Figure 5. Position of tree balancing masses in rotary system where unbalanced mass is not present.

Figure 6. Three-dimensional sketch of inertial auto balancing mechanism in case where unbalancing mass of rotational system is not in same plane with balancing masses of mechanism (dynamic balancing) while both housing of mechanism are positioned on side relative to plane of unbalanced mass.

Figure 7. Three-dimensional sketch of inertial auto balancing mechanism in case where unbalancing mass of rotational system is not in same plane with balancing masses of mechanism (dynamic balancing) while one housing of mechanism is on one side relative to plane of unbalanced mass and second housing is on other side relative to plane of unbalanced mass.

Figure 8. Three-dimensional sketch of inertial auto balancing mechanism with one housing in case where unbalancing mass is not in same plane with balancing masses of mechanism (dynamic unbalance).

6. DETAILED DESCRIPTION OF THE INVENTION

Inertial auto balancing mechanism in self-contained manner balancing one unbalanced rotational (1) system of any rotational speed or any unbalanced mass (2) even if unbalanced masses (2) changing position or value during rotation in way that center of mass is align with rotational center of rotational system in every time, automatically, by mechanism itself.

Auto balancing mechanism (Figure 1) consists of: housing (3), two or more balancing masses (5) and (6), shaft (9) and fluid (4) of proper viscosity. Balancing masses (5) and (6) are on same distance from the center of rotation on a same plane normal to the axis of rotation and connected via bearings (7) and (8) to the shaft (9) of balancing mechanism, Shaft (9) of balancing mechanism is aligned with rotational center of the unbalanced system (1) that has to be balanced. There are no torque or rotation that are transmitted to the balancing masses (5) and (6) via shaft that they are connected. Rotation of balancing masses (5) and (6) are caused with viscosity forces of the fluid (4) contained inside housing (3). Fluid acting like coupling between balancing masses (5) and (6) and shaft (9) and also like dumper for motion of balancing masses. Auto balancing mechanism in full automatic and self-contained manner by inertial forces moving balancing mass (5) and (6) to proper distance from rotational center of rotating system and shifting center of mass of unbalanced rotating system (1) toward the rotational center of that system (Figure 2) thereby making mechanical balance of that system and preventing vibration caused with unbalanced masses. Its balancing masses (5) and (6) are shifted to each other by inertial moment (ImI and Im2) which is product of inertial force (IfI and If2) and distance of that mass from the center of rotation. Amount of inertial moment (ImI and Im2) is proportional to the weight of unbalanced mass (2) ,so when unbalanced mass (2) is bigger inertial moment (ImI and Im2) of balancing masses (5) and (6) is higher and accordingly moving balancing mass toward each other , angel between them become smaller, they combined center of weight is shifted out of center of rotation in direction opposite of unbalanced mass (2) thereby creating balance between unbalanced (2) and balanced masses (5) and (6) , When balance is established inertial forces (IfI and If2) and inertial moment (ImI and Im2) of balancing masses disappear, so they stop to move toward each other and keeping that position by help of centrifugal forces of each balancing mass. If unbalancing mass (2) change position or value balancing masses (5) and (6) of this mechanism will move to other position where state of the balance is established and inertial moment (ImI and Im2) of balancing masses (5) and (6) become zero . If there is no unbalanced masses (2) in that rotational system balancing masses (5) and (6) will be 180 deg, toward each other, if are two of them (Figure 3), or 120 deg. if are three of them (Figure 4), they combined center of masse will be aligned with center of rotation.

In other words balancing masses (5) and (6) trying to find position of zero moment of inertia and that position is in point where state of the balance between unbalancing (2) and balancing mass (5) and (6) is established . Small oscillatory motion which can occur between balancing masses (5) and (6) during the motion are prevented with dampening effect of viscosity of the fluid (4). Engagement of mechanism is obtained by viscosity of the fluid.

Mechanism that consist of one housing is capable to provide equilibrium of masses if unbalanced and balanced masses are in same plane, while mechanism with two functionally connected housing placed on shaft of rotation are capable to balance rotary system where unbalanced mass is not in same plane, even if unbalanced mass moving axially in any direction. In case with dynamic balancing, mechanism with one housing can not establish state of balance , because one another parameter will emerge in form of moment Meg created by couple of centrifugal forces of unbalanced and balanced masses (Figure 8) which will cause vibration .

Inertial auto balancing mechanism consisted of one housing and positioned in plane of unbalanced mass provide static balancing (in plane balance) Figure 1, while mechanism consisted of two housing positioned in different plane than plane of unbalanced mass provide dynamic balancing (out of plane balancing) Figure 6 and 7.

Inertial auto balancing mechanism for dynamic balancing consist of two functionally interconnected housing placed in two parallel planes different than plane of unbalanced mass. To successfully balance such system auto balancing mechanism should not just sense amount and position of unbalanced mass bat also it should sense axial position of unbalanced mass and according to all that parameters it should place balancing masses in both housing proportional and simultaneously.

Figure 7 showing position of balancing masses in case of dynamic balancing where both housings are placed on one side relative to plane of unbalanced mass. Here, balancing masses of one housing are shifted in opposite direction of balancing masses of other housing in way that balancing masses of housing more distant from plane of unbalanced mass are shifted in direction of position of unbalanced mass while balancing masses of housing close to plane of unbalanced mass are shifted in opposite direction of position of unbalanced mass.

In fact balancing masses in more distant housing increasing value of unbalancing mass but in same time unbalanced mass is moved axially toward plane of other housing more close to plane of unbalanced mass, where balancing masses of this housing moving in opposite direction of position of unbalanced mass and making balance of all system. In this way unbalancing and balancing masses are aligned in same plane agene.

While mechanism is not in motion, balancing masses are attached to shaft in way that they support each other against gravity moment and closing angel relative to each other so they can easily engage in low rotational speed. Otherwise for engagement, mechanism will need high rotational speed and vibration will occur in low rotational speed.

Inertial auto balancing mechanism is designed in way that attachment of balancing masses to shaft providing free motion of balancing masses in same plane normal to axis of rotation. Otherwise, they centrifugal forces will produce moment around axis normal to axis of rotation and this moment will cause vibration even if there is no unbalanced mass in system.

Dr DIANA PROTIO-TKALCtC

Zastupnik za zaέtltu lnd^^ Sarajevo