## 3 Results and Discussion
### Impact of Internal Fitting Diameter on BGD Power Characteristics
As shown in Figure 12, as the inlet diameter of the fitting \(d\) decreases, the incoming air flow is throttled, the compressed air flow rate of the gripping devices is limited, and the lifting force can be reduced to 55% at \(d\) = 2.5 mm (200 kPa, Figure 12). Therefore, depending on the lifting force resulting from the pressure, which is the main technical characteristic of the gripping device, the diameter of the contraction of the compressed air supply fittings will have a critical effect, and for the above gripping parameters, it will have the form seen in Figure 13.  
After analyzing Figure 13, it can be concluded that as the diameter of the hole in the fittings increases, the power characteristics of a BGD will increase at all supply pressures. In particular, for a BGD with the parameters given earlier (\(d\) > 6 mm), the lifting force remains almost unchanged. This is due to the stable parameters of the maximum compressed air flow, which are characterized by the parameters of the nozzle elements and the height of the OM content. Therefore, for diameters, when the constriction of fittings \(d\) > 6 mm, the change in the compressed air flow rate over the entire range of the change in the supplied air  
Figure 12: Influence of fitting constriction diameter on a BGD’s lifting force at different pressures. Figure 13: Influence of supply pressure on BGD lifting force at different diameters of fitting constriction. pressure does not exceed 2%. For a comprehensive study of the influence of consumption and power characteristics, it is proposed to use the so-called C-factor [22]. As defined in [96], the C-factor of a gripper can be computed as the ratio of the force it produces over its weight, multiplied by the stroke. The value obtained is arguably a measure of the efficiency of the gripper, and it can be used for comparison between different products, designs, etc. Therefore, the calculation of the effect of supply pressure on the cost characteristics of a Bernoulli gripping device for lifting one kilogram of payload is as seen in (Figure 14). Figure 14 shows that it is rational to use fittings with an internal diameter of \(d=5\) to 6 mm at a supply pressure of 200 to 300 kPa, and \(d=7\) to 8 mm at a supply pressure of 100 and 400 to 500 kPa. In particular, it should be noted that it is recommended to use several grips for lifting a manipulation object weighing more than 5 kg at lower power pressures. This will make it possible to evenly distribute the load on the object of manipulation and minimize the energy costs for the maintenance of the object. The same statement applies to objects with large overall dimensions. The use of several gripping devices will reduce possible deformations of the object and inertial loads during reorientation of the object. The flow rate of the gripping device also depends on the radius of the conical insert, which forms the length and total area of the circular nozzle member of the gripping device. The impact of fittings tapering on a BGD's flow and power characteristics at different radius of conical insertion of gripping devices \(r_{0}\) has been investigated (Figure 15). The height of the OH's \(h_{c}\) maintenance in such gripping devices is selected according to the maximum lifting force. For the entire range of BGDs with an annular nozzle which lies in the range of 0.2 to 0.3 mm, further studies are carried out with \(h_{c}=0.25\) mm and at an inlet pressure of 300 kPa. Comparing the grippers with different radii of the conical insert and the effect of fitting constriction diameter on BGD (Figure 15), it can be said that the consumption characteristics are clearly correlated with the power characteristics. In particular, it has been found that as the diameter of fitting constriction increases, the lifting force and flow rate increase throughout the study area.