tennis ball machine Resistance to movement
The tennis originated in France has now become one of the world's most popular ball games, loved by outdoor sports people. But in fact, as a confrontational movement, when you have only one person, perhaps only can only be called, and our idea of this tennis ball machine is to deal with this situation arising. Although it may not be able to get the same as when the fight against the fun, but for the improvement of technology and their own exercise or a great help. Principle: the main use of the planer is the principle of rapid return, because the rapid return phenomenon there is a large instantaneous speed, while the ball in the ball at the same time to obtain a large kinetic energy, in order to achieve the drop. Advantages: the agency can achieve the ball and the ball of the harmonization of the ball, because the use of the planer's back to the principle, so the structure can be slightly smaller. Disadvantages: Because it is a link mechanism, so the speed can not be too large, so the ball's throwing distance will not be very far. Advantages: the body size is relatively small, the organization is relatively smooth. Can achieve the ball and the ball of the harmonization.
Disadvantages: the ball throwing speed calculation is more complex, can only use the empirical formula to rough calculation. Four serve the machine function 1, hair on the ball, under the ball, flat shot. The upper and lower rotations are achieved by the difference in the speed of the upper and lower wheels, and the speed of the upper and lower wheels is the same. 2, the ball in a different direction of the launch, through the rotation mechanism --- gear rack mechanism to achieve 3, the height of the adjustment, by adjusting the length of the rack to achieve adjustable. 2. By adjusting the length of the adjustable bracket on the base, and with the pin to clamp it can play to adjust the overall height of the ball machine purposes. 3. The use of a eccentric wheel above the movement, the ball can be issued regularly, and by changing the eccentric wheel speed can adjust the interval of serve. 4. The use of eccentric wheel movement and gear and rack mechanism to achieve a certain degree of rotation within the engine, in order to achieve automatic change in the angle of the ball. Two eccentric wheels use the same size: eccentric wheel: diameter 20cm, eccentric to the center of the distance 5cm, long rod 20cm, short rod 5cm. 2, gear and rack size gear indexing circle diameter of 20cm, rack length of 7cm 3, slider size 75 × 68 × 68 4, the size of the big wheel and pulley two large round size of 30cm, two large round Between the distance of 65mm below and the right of the two pulleys diameter of 20cm, conical belt pulley diameter 21cm, diameter 19cm 2. parameter determination process and considerations 1, by the diameter of the ball (normal state is about 65.41 - 68.58mm), to determine the tube section of 69 × 69, leaving the appropriate space to facilitate the next ball. 2, to determine the slider width, high 68 × 68. 3, the length of the slider can also be determined by the length of the ball to send the ball, in order to ensure a smooth delivery, accurate, special 75, slightly larger than 68, conducive to sliding into the slider, And with the connecting rod of the connecting rod is not in the middle position, which is to prevent the gear hit the slider! 4, connecting rod length and eccentric wheel size to determine. Slider length of 75, comprehensive consideration, especially considering the actual situation, take the long rod 20cm, short rod 5cm, diameter 20cm, eccentric to the center of the distance of 5cm. 5, in order to make tennis issued when the smooth and powerful, the diameter of the large pulley should be much larger than the tennis diameter, and the spacing is slightly smaller than the tennis diameter. So take the big wheel diameter of 30cm, spacing of 10 65mm.