WO2002024347A1

WO2002024347A1 - Balanced pendulous mechanism

Info

Publication number: WO2002024347A1
Application number: PCT/HU2001/000093
Authority: WO
Inventors: András KERTESZ
Original assignee: Kertesz Andras
Priority date: 2000-09-19
Filing date: 2001-09-19
Publication date: 2002-03-28
Also published as: AU2001287946A1

Abstract

The invention relates to a balanced pendulous mechanism of reciprocating and/or circular movement made for screening machines, flour sieves. Its functional working pendulous mass is compensated by a similar working pendulous mass. The characteristic feature of the invention is the spring foot (2, 23), which serves for functional adverse movement.

Description

BALANCED PENDULOUS MECHANISM

The invention is a balanced pendulous mechanism of reciprocating and/or circular movement made for screening machines, flour sieves. Its functional working pendulous mass is compensated by a similar working pendulous mass.

The pendulous masses are supported from below by a springy foot which fulfils the function of a pendulum and a support as well. There is no need for a high frame or a robust basement.

There are several kinds of pendulous mechanism for screening machines and sieves known according to the literature and the technical practice.

Majority of them are constructed as a suspended pendulum where one element of the cam drive, regularly its shaft, is joined onto the fixed frame of the machine. Such mechanism can be seen in figures No. 14 and 37 of the volume titled Technological Machinery (Technolόgiai gepek) of the Corn Industry Handbook (Gabonaipari kέzikόnyv). We know such a solution as well where the pendulous mass is supported by a springy foot, but the drive is the fixed frame of the machine.

There is such a pendulous mechanism for seed screening machines as for example the one of ZSZM type, where the drive is connected with the two pendulous screen bodies but it is also constructed as a pendulum suspended from a high frame. This solution can be seen in figure No. 35 of the handbook mentioned above.

For the pendulous screening machines known, a rotating balancing ballast mass is used. The disadvantage of this solution is that it ensures only partial balancing and means an additional dynamic load application on the basement.

In mills pendulous flour sieves are generally used; they are suspended from the ceiling by means of a flexible element e.g. a rope. Their working number of cycling is usually higher than their natural number of cycling, therefore their starting and stopping involve the risk of resonance. Such a sieve can be seen on Page 542 of the handbook mentioned. The disadvantages of these known solutions mentioned are the high and expensive supporting structure, the dynamic load application and the risk of resonance.

The aim of the invention is to create such a balanced pendulous mechanism which does not show the mentioned disadvantageous characteristics and is suitable for flour sieves, seed sifters and other machines of similar function.

The invention is based on the recognition that a mass of pendulous motion is the best to be balanced by another pendulous mass moving in the opposite direction. The other recognition is that the high frame can be avoided if, instead of using a suspended pendulum, we use an underhung pendulum and the drive is located between the two pendulous masses. If the springy feet moving oppositely are grouped close to each other, the power impulses will compensate each other in the cushion plate. In the event of the pendulous mechanism with two masses, which constitutes^' the basic idea, we reach the required conditions of movement by the proper selection of the ratio of the masses and the dimensions of the springy foot.

We can accomplish the set aim by the fact that the balanced pendulous mechanism of reciprocating and/or circular movement include a functional pendulous mass, a drive-gear, according to this invention a functional and/or a ballast mass and the pendulous masses have springy feet which serve also as supports. In the following part of the description, also elliptic movement is meant by circular movement.

The drive of the balanced pendulous mechanism practicable in accordance with the invention is joined onto the functional and balancing mass. The individual pendulous masses can be arranged at different or the same height of centre of gravity as compared to the basic level.

According to one shape of construction of the invention, the functional and/or the balancing ballast masses are of the same amount of mass while in another shape of construction the springy feet are of the same length and cross section. Both solutions ensure that the power impulses compensate each other.

Also a thickened design of springy feet can be realised by a known calculation method; in this case the natural number of cycling will be greater than the working number of cycling.

The springy feet are practicable to be manufactured of alloyed spring steel applying heat treatment, including hardening and normalisation.

For several shapes of construction in accordance with the invention, each pendulous mass has more than one springy foot; e.g. for circular mass there are three feet , for rectangular pendulous mass four pieces. For other feasible shapes of construction, the springy feet moving oppositely are grouped close to each other at a minimum distance in order that the power impulses burden the clamping area of the springy feet to the smallest extent possible.

For the further improvement of the construction, the springy foot has a jointing element which is detachable owing to the self-locking coned surface or the wedged plain surface and ensures fastening by fixing at the bottom and/or on the top.

For several shapes of construction practicable according to the invention, the reciprocating motion and/or circular movement are ensured by a cam drive, with a radius rod inserted in the event of reciprocating motion.

For one practicable shape of construction, the pendulous masses are arranged at the same or different heights of the centre of gravity as compared to the basic level. For other practicable shapes of construction in order that no additional load application would occur on the springy feet as a result of the radius rod, the jointed clamping of the cam shaft and the radius rod are located on a horizontal straight line which is perpendicular to the springy feet.

In the event of reciprocating motion, the cross section of the springy foot is expediently smaller in the direction of pendulous movement than in the direction perpendicular to the pendulous movement; while in the event of circular movement, the springy foot has circular cross section.

For the pendulous mechanism accomplished according to the invention, the regular circular movement can be ensured in such a way that the drive is joined onto the pendulous mass in its vertical median, the springy feet are arranged symmetrically about the same axis, and the pendulous mass is created in such away that it has the same stiffness in the different pendulous directions.

It is possible to apply a different construction where elliptic movement takes place; it may be very practicable for certain purposes.

I show the invention through describing an example of construction as follows:

Figure 1- Pendulous mechanism as per the invention, with balancing ballast mass

Figure 2 - Reciprocating masses arranged at different heights, with springy feet of the same length Figure 3 - Functional pendulous mass of circular movement, with springy feet, side-view Figure 4 - Section through A-A indicated in figure 3 Figure 5 - Self-locking clamping of round springy foot, profiled Figure 6 - Top clamping of flat springy foot, viewed Figure 7 - Section through A-A, see Figure 6 Figure 8 - Fixing of springy foot by means of strap and bolt Figure 9 - Springy feet grouped close to each other, viewed Figure 10 - Flat springy foot cross section, profiled

The balanced pendulous mechanism of reciprocating motion constructed according to the invention can be seen in figure 2, where the base frame (3) lays on the basic level (6). The functional pendulous mass (1) and the functional balancing mass are supported by the springy feet of flat cross section (23) which serve also as holders. The balancing ballast mass (5) is added to the functional balancing mass (5) in order that masses (1) and (4) would be of the same size. Driving shaft (7), driving pulley (8) and eccentric (9) are connected to functional mass (1). Radius rod (10) is connected to eccentric (9); its other end is connected with the functional balancing mass (4) through the joint (11). As compared to the basic level (6), the centres of gravity of functional mass (12) and functional balancing mass (13) are located at different heights, in our case symmetrically about the horizontal straight line (17). In the shape of construction shown by the example, the total mass amount of the functional balancing mass (4) and the balancing ballast mass (5) is the same as the size of the functional pendulous mass (1). However, in other shapes of construction the functional balancing mass (4) alone is of the same mass amount as the functional pendulous mass (1).

There are working elements such as sloping flat screening surfaces for sifting seeds located in both pendulous masses /(l) and (4)/. These cannot be seen on the drawings.

Springy feet (23) are of the same length and cross section; they are fixed rigidly by means of the jointing element (14) on the base frame (3) at the bottom and on the mass elements

(1) and (4) on the top. Springy feet (23) are of slender design but also thickened feet are made for certain constructions.

The springy feet are made of alloyed steel and heat treated (hardened and normalised). For other shapes of construction, its material may be e.g. wood, plywood or plastic.

According to the shape of construction shown, the pendulous masses (1) and (4) have four springy feet each. The springy feet moving into the opposite direction are grouped close to each other at the minimum distance (24).

As it can be seen in figures 6, 7, 8, 9, according to the construction as per the example the springy foot of flat cross section (23) is connected with the jointing element (14) by means of strap (25) and bolts (26) which have sufficient stiffness for transmitting the torque. The smaller dimension of the leg cross section (18) is applied in the pendulous direction.

For another construction, instead of a bolted joint, self-locking wedged surfaces ensure detachable and rigid joint, which at the same time is secured against loosening.

In Figures (6) and (7) one portion of the top fixing of flat springy foot (23) can be seen.

Jointing elements (14) are mounted on the side of the pendulous masses as overhung upwards or downwards; thereby springy feet (23) of the same length can be fitted to both pendulous masses on the top (1) and at the bottom (4). Jointing elements (14)are mounted on the pendulous masses (1) and (4) with the distance piece (28) in order to ensure gap

(27).

For this sample shape of construction, there is an eccentric (9) on the drive shaft (7) which connects with the balancing mass (4) through the inserted radius rod (10). The drive shaft (7) is bedded in the side projection (29) of the pendulous mass (1) while the joint clamping of the radius rod (11) is bedded in the side projection (30) of the pendulous mass (4). This construction makes it possible for the drive shaft (7) and the joint clamping of the radius rod (11) to be located on the horizontal straight line (17).

In the event of other practicable solutions as per the invention for ensuring the regular circular movement, the drive shaft (7) connects with the functional pendulous mass (1) in its vertical median (20) on one hand and the eccentric (9) connects with the functional balancing mass (4) in its vertical median (21) on the other hand ; furthermore springy feet (2) are located symmetrically about the vertical medians (20), (21) of pendulous masses and the pendulous masses (1) and (4) are of the same stiffness in the different pendulous directions. For other constructions, the equal stiffness can be ensured for example in the event of a square pendulous mass through connecting four mass elements of the same stiffness (31) with for corner elements of the same stiffness (32).

For shapes of construction applying circular movement it is reasonable to use two round springy feet which can be fixed properly by the jointing element (14) of coned surface (15) onto the pendulous masses (1), (4) and (5) and the base frame (3).

Applying the solutions included in the invention, many other shapes of construction can be prepared in addition to those described in the examples.

We can describe the operation of the double mass balanced pendulous mechanism of reciprocating motion on the basis of Figure 2 as follows:

The electric motor not shown by the drawing can be located for example on the pendulous mass (4) and by weight reduction gear rotates drive shaft (7) which moves pendulous masses (1) and (4) by means of eccentric (9) and radius rod (10) as compared to each other in almost horizontal direction. The amplitude depends on the eccentricity. The number of cycling can be changed by the speed of the drive shaft (7). In the event of two springy feet of sufficient thickness, the band of resonance can be avoided during starting and stopping. The normal operation can be ensured in the event of slender springy feet as well. According to our experiences, even an average electric motor can quickly pass the speed of the resonance band and no irregular or harmful cycles are generated. In comparison with the solutions known, it is characteristic of all shapes of construction that they burden dynamically the basic level (6) only to the minimum extent. For several advantageous shapes of construction, such as e.g. the one shown in Figure 2, it is characteristic that the basic level is not burdened with any dynamic effect during the operation.

We can describe the operation of the double mass balanced pendulous mechanism of circular movement on the basis of Figures 3 and 4 as follows:

It is operated similarly as the mechanism of reciprocating motion, with the difference that the electric motor rotates the drive shaft (7), the eccentric of which connects directly with the pendulous mass. During rotation the two pendulous masses perform circular movement in opposite directions. The load applications on the base frame (3) operate against each other as a result of the two springy feet moving oppositely. For some shapes of construction, like for the one shown in Figures 3 and 4, the opposite power impulses completely compensate each other and no dynamic load operates on the base frame (3).

Both pendulous mechanisms included in the invention performing reciprocating and circular movement have the following excellent advantages:

- no expensive high frame is needed,

- no dynamic effect operates on the basement,

- risk of resonance can be avoided,

- simple and saving construction may be accomplished for screening and sieving machines.

The pendulous mechanisms included in the invention are very simple and they can be driven directly by an electric motor through V-belt transmission. The only maintenance required is the checking of the springy feet fatigue. List of references

1. Functional pendulous mass

2. Round springy foot

3. Base frame

4. Functional balancing mass

5. Balancing ballast mass

6. Basic level

7. Drive shaft

8. Drive pulley

9. Eccentric

10. Radius rod

11. Joint of the radius rod

12. Centre of gravity of functional pendulous mass

13. Centre of gravity of functional balancing pendulous mass

14. Jointing element

15. Self-locking coned surface

16. Self-locking wedged surface

17. Horizontal straight line

18. Dimension of springy foot cross section in the pendulous direction

19. Dimension of springy foot cross section in the direction perpendicular to the rocking

20. Vertical median of the functional pendulous mass

21. Vertical median of the functional balancing pendulous mass

22. Pendulous mass having the same stiffhess in the different directions of rocking

23. Springy foot of flat cross section

24. Minimum distance between the springy feet

25. Strap

26. Bolt

27. Gap

28. Distance piece

29. Side projection of mass (1)

30. Side projection of mass (4)

31. Mass element of the same stiffhess

32. Corner element of the same stiffhess

Claims

1. Balanced pendulous structure with alternating and/or circular movement, the functional pendulous mass of it (1), provided with gear (7,8,9,10), characteriesed in that, parameter the springy foot (2, 23), which serves for functional adverse movement -(4) and / or balance (5) mass and supporting frame.

2. The characteristic of the pendulous structure 1. is the gear (7,8,9,10) connected to the functional (1) and balance (4, 5) mass.

3. The characteristic of the 1. or 2. pendulous structure are, that each centre of gravity (12, 13) are located in different heights related to the basic level (6).

4. The characteristic of each of the 1-3. pendulous structure are, that functional pendulous mass (1) or functional (4) and / or ballast mass (5) are equivalent mass.

5. The characteristic of each of the 1-4 pendulous structure are, that they have equal springy feet (2, 23).

6. The characteristic of each of the 1-5 pendulous structure are, that they have stumpy springy foot 2, 23), which ensures higher own operational number of cycling (n_s) than the operational number of cycling (n_a).

7. The characteristic of each of the 1-6 pendulous structure are, that they have alloyed, heat treated steel springy feet (2, 23).

8. The characteristic of each of the 1-7 pendulous structure are, that the pendulous mass (1, 4, 5) have more, than one springy feet (2, 23).

9. The characteristic of each of the 1-8 pendulous structure are, that the minimal distance of the springy feet (24) moving in contrary directions (2, 23) are assort to each other.

10. The characteristic of each of the 1-9 pendulous structure are, that their springy feet (2, 23) have fixed jointing element (14) at the bottom part and / or the upper part, which ensure the fixing.

11. The characteristic of the 10. pendulous structure is, that the springy feet (2, 23) and the jointing element, which ensures the fixing (14) are jointing together with self-locking coned (15) or self-locking canted plane surface (16) in detachable way.

12. The characteristic of each of the 1-11 pendulous structure are, that they have eccentric gear (7, 8, 9).

13. The characteristic of each of the 1-12 pendulous structure are, that their centre of gravity (1, 13) are at equal height related to the basic level (6).

14. The characteristic of each of the 1-13 pendulous structure with alternating movement, are, that the gear (7, 8, 9) is jointed to one of the pendulous mass (4 or 5) with interposing a radius rod (10).

15. The characteristic of the 14. pendulous structure is, that the shaft of the gear (7) and the jointed fixing (11) of the radius rod (10) are located in a horizontal straight line (17).

16. The characteristic of each of the 1-15 pendulous structure are, that the dimension of the cross section of the springy feet (2, 23) in the pendulous direction (18) is smaller, than the dimension in perpendicular to the pendulous direction (19).

17. The characteristic of each of the 1-12 with regular circle movement pendulous structure are, that the gear (7, 9) is jointed to the pendulous mass (1, 4) in its vertical axis of gravity (20, 21) and it has symmetrical located springy feet (2) related to the vertical axis of gravity (20, 21) and equal rigid mass (22) in the pendulous direction.

18. The characteristic of the 14. pendulous structure is, that it has circular cross section springy feet (2).