RU203414U1 - PLANETARY CRANKSHAFT MECHANISM WITH INTERNAL GEAR WHEELS - Google Patents

Abstract

The utility model relates to mechanical engineering. Such a mechanism can be used in reciprocating internal combustion engines, pumps and compressors. The well-known widespread crank mechanism of a classical internal combustion engine due to the absence of a torque shoulder when the piston is at top dead center, which gradually increases along the piston movement in the expansion cycle and reaches a maximum value within 80 ° of crankshaft rotation after top dead center, is unable to effectively convert the high pressure of the gases of the working fluid on the piston into the rotational motion of the crankshaft, and also has a drawback in the presence of the lateral force of the piston on the cylinder walls, which causes additional mechanical losses and wear .Planetary crank mechanism with internal gears FIG. 1 consists of a4 crown gear (Crown), a2 satellite gear (Satellite) with a tooth ratio of 3: 1. The crown is fixedly connected to the engine casing coaxially with the center A2 of the engine shaft. The satellite is in engagement with the crown, rotates around it on the axis A11 of the arm A2A11. The other axle A2 of the drive is the motor shaft. The connecting rod A6A7 is hinged to the satellite at point A6 and to the piston at point A7, which moves along the axis of the cylinder along the line a6.Kinematic calculations of the torques on the engine shaft when the piston is subjected to the same force show that the proposed mechanism creates a significantly higher value (maximum - 3.997 y e.) than other designs of the mechanisms under consideration (maximum - 2.6 cu). The piston speed increases by 33.3% from top to bottom dead center, which occurs after 120 ° of the carrier revolution, versus 180 ° for a classic engine. The connecting rod of the proposed design deviates at an angle of no more than 2 ° in both directions from the cylinder axis line, against the order of 17 ° of the classical internal combustion engine. The proposed model of the planetary crank mechanism with gears solves the technical problem of increasing the efficiency of converting the reciprocating piston motion under the influence of gas pressure during the rotational motion of the crankshaft by increasing the torque on the crank mechanism shaft, reducing the time of piston movement from top to bottom dead center in the expansion cycle, which reduces the time spent in the cylinder of the working fluid with a high temperature and reduces engine heat losses, the lateral force of the piston on the cylinder walls is reduced, which leads to a decrease in mechanical losses, an increase in the efficiency and service life of the internal combustion engine. The application of the proposed design does not imply the need to make changes to other elements, units, systems of an internal combustion engine. The proposed model is implemented using universal equipment and elements widely used in industry (gears, shafts, axles, bearings), can be used to create an internal combustion engine, pump or compressor with increased efficiency.

Description

Technical field to which the utility model belongs

The planetary crank mechanism with internal gears belongs to mechanical engineering. Such a mechanism can be used in reciprocating internal combustion engines, pumps and compressors.

State of the art

The well-known widespread crank mechanism of an internal combustion engine due to the absence of a torque arm when the piston is at top dead center (TDC), which gradually increases along the direction of the piston movement in the expansion cycle and reaches a maximum value within 80 ° of crankshaft rotation after the upper dead center, is unable to effectively convert the high pressure of the gases of the working fluid on the piston into the rotational motion of the crankshaft, as well as having a drawback in the presence of the lateral force of the piston on the cylinder walls, which causes additional mechanical losses and wear.

The proposed model of the planetary crank mechanism with internal gears has the positive properties of the known models:

planetary crank mechanism with elliptical gears (patent No. RU 197176 U1), which differs in that the angle of the carrier and the connecting rod, at which the maximum torque occurs, is close to the angle at which the maximum pressure is created in the cylinder, which increases efficiency converting the force of pressure on the piston into work on the engine shaft, which has disadvantages in the presence of the lateral force of the piston on the cylinder walls, which causes additional mechanical losses and wear, as well as in the complexity of the development and manufacture of small elliptical gears with sufficient strength;

internal combustion engine S. Balandin, in which the transformation of the reciprocating movement of the pistons into the rotational movement of the shaft is carried out by a rodless power mechanism (S. S. Balandin. Rodless piston internal combustion engines. M., Mashinostroenie, 1968), which differs in that when its use completely eliminates the pressure of the piston on the cylinder walls and significantly reduces the loads and friction in the kinematic pairs of the mechanism per unit of developed power, which has a drawback in the absence of a torque arm when the piston is at top dead center, which gradually increases in the direction of piston movement in the expansion cycle and reaches its maximum value at 90 ° angle of rotation of the engine shaft after the top dead center of the piston position.

The use of a useful model of sieves is the technical problem of increasing the efficiency of converting the reciprocating movement of the piston under the influence of gas pressure into the rotational movement of the crankshaft by increasing the torque on the shaft of the crank mechanism, reducing the time of movement of the piston from top to bottom dead center in the expansion cycle, which reduces the time spent in the cylinder of the working fluid with a high temperature and reduces the heat loss of the engine, decreases the lateral force of the piston on the cylinder walls, which leads to a decrease in mechanical losses, an increase in the efficiency and service life of the internal combustion engine.

Disclosure of the essence of a utility model

The planetary crank mechanism with internal gears of FIG. 1 (shown schematically) consists of a crown gear a ₄ (Crown), a satellite gear a ₂ (Satellite) with a tooth ratio of 3: 1. The crown is fixedly connected to the motor housing coaxially with the center A ₂ of the motor shaft. The satellite is in engagement with the Crown, rotates around it on the axis A _{11 of the} carrier A ₂ A ₁₁ . The other axle A _{2 of the} carrier is the motor shaft. The connecting rod A ₆ A _{7 is} pivotally connected to the satellite at point A ₆ and to the piston at point A ₇ , which moves along the axis of the cylinder along the line a ₆ .

Kinematic calculations of the torque u, the speed of the piston and the angle of deflection of the connecting rod, depending on the position of the piston, starting from the top dead center for the designs of the crank mechanisms of the classical internal combustion engine (Classic), the engine designed by S.S. Balandin (S. ) and the internal gear mechanism (Internal gear) presented in this proposal. To compare the calculations, the dimensions of the structures of the crank mechanisms were used, which ensure the same piston stroke, equal angular speeds of rotation of the engine shaft. The amount of torque on the engine shaft was determined from the condition that the same (unit) force acts on the piston along the cylinder axis downward.

The results of calculating the torques on the motor shaft are shown in the tables: Fig. 2 - for internal engagement, FIG. 3 - for S. Balandin, fig. 4 - for Classic designs of crank mechanisms. Similar calculations were carried out for the position of the piston, as well as the angle of deflection of the connecting rod from the line of the center of the cylinder, depending on the angle of rotation of the shaft (carrier).

From the graphs in FIG. 5 of the torques on the engine shaft when the same force is applied to the piston, it can be seen that the internal gearing creates a significantly greater value (maximum 3.997 cu in Fig. 2) than other designs of the mechanisms under consideration (maximum 2.6 cu in Fig. 3) throughout the expansion cycle, which means an increase in the torque and power of such a piston internal combustion engine, all other things being equal.

It can be seen from the graphs that the internal engagement crank mechanism provides a high speed of movement of the piston of FIG. 6 and, accordingly, a 33.3% smaller (120 ° versus 180 °) angle of rotation of the engine shaft, at which the piston moves from top dead center to bottom dead center of FIG. 7 in the expansion cycle. This means that the time spent in the cylinder of the working medium with a high temperature is reduced, which, in turn, reduces the heat loss of the engine - increases the efficiency of the piston internal combustion engine.

Comparative analysis of the graphs of the angle of deflection of the connecting rod from the line of the center of the cylinder in FIG. 8 shows that the proposed design of the internal gearing has a connecting rod deflection angle of not more than 2 ° in both directions, when the Classic crank mechanism has a deflection of the order of 17 °. A significant decrease in the angle of deflection of the connecting rod in the design of the internal gearing leads to a decrease in the lateral pressure of the piston on the cylinder walls, which reduces mechanical losses for friction and wear - the efficiency and service life of the piston internal combustion engine increase.

The calculations were carried out without taking into account additional mechanical losses associated with the introduction of additional elements and movable joints.

The application of the proposed design does not imply the need to make changes to other elements, units, systems of the internal combustion engine.

The proposed model is implemented using universal equipment and elements widely used in industry (gears, shafts, axles, bearings) can be used to create an internal combustion engine, pump or compressor with increased efficiency.

Claims (1)

Planetary crank mechanism with internal gears, converting the reciprocating piston motion into rotary shaft movement, made in the form of a planetary gear train, consisting of two internal gears with a ratio of the number of teeth of 3: 1, containing a fixed crown wheel and a satellite attached to the carrier and connected to the connecting rod, which is connected to the piston.

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