RU2349813C1 - Two-shaft connecting rod gear - Google Patents

Abstract

FIELD: mechanics.

SUBSTANCE: two-shaft connecting rod gear consists of two sync-running crankshafts arranged in parallel and coupled by gears with gear ratio equal to 1, at least one rocker, one or several rods at least one floating lever and an operating member. The rocker ends are pivoted to the identical rod journals of two aforesaid crankshafts with the help of a pair of con rods. Note that the central swivel couples the rocker with the floating lever hinged to the housing. The rod can move in the guide. Note here that one end of the said rod is coupled with the central pin of the rocker, while its other end is linked up with the piston or some other part. Additionally a device to vary the mounting angle of the said shafts with respect to each other can be arranged in the gear between the shafts.

EFFECT: higher reliability, positive torque, piston stroke adjustment in operation.

4 cl, 16 dwg, 1 tbl

Description

The invention relates to mechanical engineering and can be used in internal combustion engines, pumps, compressors and mechanisms for transferring the reciprocating movement of a part to the rotational movement of the crankshafts and from the rotational movement of the crankshafts to the reciprocating motion of any part, with the possibility of setting and changes during operation of the characteristics parameters of this reciprocating motion.

The use of a two-shaft crank mechanism (hereinafter referred to as DCSHM) in the drive of the working piston of an internal combustion engine (hereinafter referred to as ICE) allows to provide the maximum torque of the mechanism at the very beginning of the expansion of the working charge, when its pressure is close to the maximum, which in turn gives the ability to increase the specific power and efficiency of the internal combustion engine, to increase its efficiency.

The presence in it of a device for changing the angle of installation of the crankshafts of the mechanism relative to each other allows you to change the working stroke of one or more working pistons during engine operation, which in turn will allow you to change the working volume of the combustion chamber, thereby changing the compression ratio and providing the ability to configure the engine for various modes work, and also, if necessary, its work on various types of fuel (gas, gasoline, diesel fuel, etc.).

A close analogue of the claimed device is the technical solution described in the patent of the Russian Federation No. 2275519 dated 12/07/2004. The disadvantage of this is that through the beam on the rod in this device there are large transverse forces that are perceived by the guide in which the rod itself moves and, accordingly , in the node rod-guide there are large friction losses and the node has low reliability. The inability to change the piston stroke during operation is also a disadvantage of this mechanism.

In the proposed DKShM, all the forces perpendicular to the rod acting through the connecting rods on the beam are absorbed by the pendulum pivotally attached at one end to the beam and at its other end pivotally to the engine or mechanism body. The use of the pendulum will make it possible to use a rod of smaller overall dimensions, avoid large friction losses, increase the reliability of the mechanism, and the reaction of the pendulum creates an additional positive torque on the shafts of the mechanism.

Installation of a device for changing the crank angle between each other will allow changing the magnitude of the piston stroke during operation.

Declared DKShM consists of two synchronously rotating crankshafts (cranks) 1 and 2 located parallel or coaxially and connected to each other by gears 3 and 4 with a gear ratio equal to one, rocker arm 9, connected to the connecting rod journals of the same two crankshafts by said rods 7 and 8, the rod 10, one end connected to the beam, and the other end connected to the part or piston 12 located in the cylinder 13, the pendulum 11, one end connected to the beam, and the other end connected to the housing Ma or the motor housing 14, all compounds in double-shaft crank-rocker-crank mechanism pivotally carried.

The claimed two-shaft crank mechanism is illustrated by drawings.

Figure 1 shows the kinematic diagram of the DKShM, where 1 and 2 are parallel crankshafts, 3 and 4 are gears, 5 and 6 are the hinges of the rods, 7 and 8 are the rods of the corresponding shafts, 9 is the rocker arm, 10 is the rod, 11 is the pendulum 12 - a working body or piston, 13 - a cylinder or a guide of a working body, 14 - a case of a mechanism or engine, 15 - a device for changing the angle of installation of cranks relative to each other;

Figure 2 is a bottom view of the kinematic diagram of the DCSM.

Figure 3 is a bottom view of the kinematic scheme DKShM, where two rods 10 are used, between which the rods 7 and 8 are moved.

Figure 4 is a kinematic diagram of the inventive DCM in the internal combustion engine, when moving the piston in the expansion cycle, where the connecting rods 7 and 8 are located crosswise to each other, and the rocker 9 and the piston 12 lie on opposite sides of the plane in which the axles of the crankshafts 1 and 2 lie , rod 10 crosses this plane.

Figure 5 - kinematic diagram of the internal combustion engine with the claimed DKShM when moving the piston in a compression cycle, where the connecting rods 7 and 8 are located crosswise to each other, and the rocker 9 and the piston 12 lie on opposite sides of the plane in which the axles of the crankshafts 1 and 2 lie, rod 10 crosses this plane.

6 is a variant of the kinematic scheme of the crankshaft, in which the rocker 9 and the working body 12 are on the same side of the plane in which the axles of the crankshafts lie, and the connecting rods 7 and 8 intersect each other.

7 is a variant of the kinematic scheme of the crankshaft in which the connecting rods 7 and 8 do not intersect each other, and the working body or piston are located on opposite sides of the plane in which the axles of the crankshafts lie, and the rod 10 intersects this plane.

On Fig - a variant of the kinematic scheme of the crankshaft in which the connecting rods 7 and 8 do not intersect each other, and the working body or piston are located on one side of the plane in which the crankshaft axes lie.

Figure 9 shows a variant of the kinematic scheme of the crankshaft in which the single-bearing crankshafts 1 and 2 are aligned with each other and are connected by bevel gears 3 and 4 through an intermediate gear 16, and the beam and piston or working body lie on opposite sides of the axis, through which are the axles of crankshafts 1 and 2, where 5 and 6 are the hinges of the connecting rods, 7 and 8 are the connecting rods of the corresponding shafts, 9 is the rocker, 10 is the rod, 11 is the pendulum, 12 is the working body or piston, 13 is the cylinder or guide of the working body , 14 - housing of the mechanism or engine, 15 - device for changing the angle SETTING cranks with respect to each other.

In Fig.10 - the same as in Fig.9, a side view A.

In Fig.11 - the same as in Fig.9, view B from below.

On Fig shows a variant of the kinematic scheme DKShM, in which the single-bearing crankshafts 1 and 2 are aligned with each other, where 5 and 6 are the hinges of the rods, 7 and 8 are the rods of the corresponding shafts, 9 is the beam, 10 is the rod, 11 is the pendulum, 12 - working body or piston, 13 - cylinder or guide of the working body, 14 - body of the mechanism or engine, 15 - device for changing the angle of the cranks relative to each other, and the rocker 9 and the piston 12 or working body are located on one side of the axis, through which are the axis of the crankshafts 1 and 2.

In Fig.13 is a simplified kinematic diagram of a single-piston ICE made on the basis of the declared DKShM with the locations of the piston, which shows the distance from the top dead center to the piston every 30 degrees of crankshaft rotation.

On Fig - a simplified kinematic diagram of a traditional single-shaft single-piston engine, which shows the angles that the traditional crankshaft rotates at the positions of the piston, repeating the position of the piston CSN made on the basis of the declared DKShM every 30 degrees of crankshaft rotation.

On Fig - a simplified kinematic diagram of a single-piston ICE, made on the basis of the declared DKShM with the location of the piston, which shows the position of the connecting rods and rocker when crankshaft is turned 30 degrees from the top dead center of the piston and shows the tangential forces Tex acting on the shafts of the experimental ICE every 30 degrees of crankshaft rotation with Rrab = 1.

On Fig - graphs of changes in torque for one working cycle of expansion of the working gas of a traditional single-cylinder internal combustion engine - curve A and the inventive single-cylinder internal combustion engine - curve B

Declared DKShM has several options.

Variant of the DKShM used in the design of the internal combustion engine. The proposed mechanism consists of two parallel located crankshafts (cranks) 1 and 2 with gears 3 and 4 mounted on them. Crankshafts 1 and 2 have the ability to synchronously rotate in any direction and are connected via hinges 5 and 6 with rods 7 and 8. Cranks 7 and 8 are in different planes and pivotally connected to the body of the beam 9. The beam 9 is pivotally connected to the rods 7 and 8 and the rod 10. The beam 9 has a shape and size that allows you to pivotally connect its body to the corresponding shaft by at least one Atun, and one or more operating members are pivotally connected with the rocker arm via at least one rod, wherein the connecting rods 7 and 8 are movable in their own plane, while the hinge connections are made in the required place in the parameters of the rocker casing. One or more of the rod 10 is pivotally connected at its one end to the working body, and its other end, as indicated above, is pivotally connected to the body of the beam. The rod 10 has a shape that allows rods 7 and 8 to move freely, can be, as one of the options, made in the form of a fork or two rods are used. As a working body, in this embodiment, a piston 12 is used, which is movably mounted in the cylinder 13. The rocker arm is also pivotally attached to one end of the pendulum 11, which, in turn, is pivotally attached to the housing of the mechanism 14 with its other end. the forces acting on the beam will be perceived by the pendulum and will not exert a bending effect on the rod.

If the proposed mechanism is used in an internal combustion engine, then it works as follows.

During the combustion of the fuel-air mixture, the expanding gases act with a force P on the piston 12, which causes it to move inside the cylinder 13 (see figure 3). The piston 12 pushes the rod 10, which, through the rocker arm 9 and the connecting rods 7 and 8, drives the crankshafts (cranks) 1 and 2 into rotation. When the piston 12 reaches the bottom dead center (hereinafter referred to as the BDC), the inertia from the crankshafts 1 and 2 acts through the connecting rods 7 and 8, which moves the piston 12 through the rod to the TDC, and the combustion products are released and pushed out, after whereupon the piston 12 returns to the BDC and supply a new portion of the fuel-air mixture (see figure 4). Next, the rocker 9 through the connecting rods 7 and 8 is affected by the inertia force from the rotating crankshafts 1 and 2, which through the rod moves the piston 12 to the TDC position, thereby compressing the fuel-air mixture (see Fig. 5). Next, the cycle repeats. The characteristic of the torque on crankshafts 1, 2 and the speed of movement of the piston 12 in the forward and reverse direction, with the radius of the cranks unchanged, can be different and depend on the installation angle α of one crank relative to another. Also, the characteristics of the torque on crankshafts 1, 2 and the speed of movement of the piston 12 can be set by the geometric dimensions of the connecting rods 7 and 8, the rocker arm 9, the interaxal distance of the shafts 1 and 2, as well as by changing their proportions. Changes in the characteristics of the torque on crankshafts 1, 2 and the speed characteristics of the reciprocating motion of the piston 12 in both forward and reverse directions without changing the radii of the crankshafts 1 and 2 and their given angular velocity can be made by changing the length of the connecting rods 7 and 8. The greater the length of the connecting rods 7 and 8 with the other geometric parameters of the mechanism unchanged, the smaller the ratio of the angle of rotation of crankshafts 1 and 2 when the piston moves from BDC to TDC to the rotation angle when moving from TDC to BDC and, accordingly, the same the ratio of speed will change when the piston 12 moves from BDC to BDC to piston speed 12 from BDC to BDC. The same regularities obey the ratio of the maximum torques on the shafts in these ranges. The greater the length of the connecting rods, the smaller the ratio of these values and, conversely, the smaller the length of the connecting rods, the greater the ratio of speeds and maximum torques and the minimum length of the connecting rods is limited by the structural ratios of the remaining geometric parameters of the mechanism, ensuring its operability, unimpeded rotation of the shafts 1 and 2 and excluding jamming mechanism.

The necessary parameters of the mechanism can be calculated using the following formulas

The torque of the mechanism is determined by the formula: Mkr = M1 + M2, where:

M1 - crankshaft torque 1;

M2 - crankshaft torque 2.

The torque of the shaft 1 is determined by the formula: M1 = T1 × R1, where:

T1 - tangential force of the crankshaft 1;

R1 - radius of the crankshaft (crank) 1.

The torque of the shaft 2 is determined by the formula: M2 = T2 × R2, where:

T2 - tangential force of the crankshaft 2;

R2 - crankshaft radius 2.

The tangential force acting on the shaft 1 is determined by the formula:

T1 = P × Sinγ1 / Cosβ1, where:

P is the pressure of the gases on the piston.

The tangential force acting on the shaft 2 is determined by the formula:

T2 = P × Sinγ2 / Cosβ2, where:

P is the pressure of the gases on the piston.

Work with rotational motion is found by the formula:

where: MKR is the torque on the ICE shafts, acting over an angle from 0 to φ2 is the angle by which the shafts rotate when the working gas expands and the piston travels from TDC to BDC.

Work in one cycle of expansion of the working charge is equal to the sum of the torques acting during the rotation of the shafts, during which the expansion of the working gases occurred. It follows: the area under the curves will be equal to the perfect work of the actual cycle.

Consider, for example, the kinematic diagram of a 107cc single-cylinder four-stroke ICE mounted on a REGGI mini-scooter. Fig.14. The cylinder-piston group (hereinafter referred to as CPG) and the crank mechanism (hereinafter referred to as KShM) which have the following geometric dimensions: crank radius Kst = 25 mm, piston stroke = 50 mm, respectively, connecting rod length L = 80 mm, cylinder and piston diameters D = 52 mm. For comparison, we will design and consider a two-shaft crank-beam-rocker-connecting rod mechanism (hereinafter referred to as DKShM) with a similar piston stroke. The following values are obtained: crankshaft radii K1 = K2 = 22 mm, center distance = 96 mm, piston stroke = 52 mm, rod length = 200 mm, angle between shafts = 60 degrees. Fig.13. Applying the above geometric parameters DKShM and KShM, using the data of one CPG in the calculations, as well as the above formulas and using the same data on the pressure on the piston, it is possible to calculate the operation of one duty cycle for both engines.

As an example, consider the position of a piston on an experimental internal combustion engine when its crankshafts rotate 30 degrees from the position of the piston when it occupies the TDC and the piston moves 5 mm. At the same distance we move the piston on a standard REGGI ICE. Since both engines consider the same position of the pistons, the same over-piston volume, the pressure in them will be the same, then to simplify the calculation, we can take the calculated working pressure as the standard unit Prab = 1 and using the above formulas, we find the tangential force T for the experimental ICE:

on crankshaft 1 - T1 = P × Sinγ1 / Cosβ1;

on crankshaft 2 - T2 = PxSinγ2 / Cosβ2,

for each piston position T1 through T5. Further, multiplying these values by the real values of the decreasing pressure Prab, we obtain the effective values of the tangential force T for each position of the piston and crankshafts. The results are listed in table 1. We multiply these values by the radii of the cranks used, and we obtain the actual torques on the shafts of the crankshaft.

M1 = T1R1; M2 = T2R2

Next, we find the total torque Mkr.ex on the shafts of the experimental engine. The torque of the experimental internal combustion engine is the sum of the torques on its shafts

Microex = M1 + M2

The results are listed in table 1.

We make the same calculations for the standard traditional REGGI ICE, we find Tst - the tangential force on the crankshaft:

Tst = Pst × Sinγ / Cosβ,

multiplying by the radius of the shaft of the standard ICE Kst = 25 mm, we find the torque on the shaft of the standard ICE Mkr.st,

Micr.st = Tst * Rst

The results are listed in table 1.

Comparing the obtained values, we see: the torque in this position of the piston on the shafts of the experimental ICE is 1.5 times greater than the torque on the shaft of the standard ICE. Considering the torques for different positions of the piston, we obtain the values that are reflected in the table and graphs under the letters A and B of Fig. 16.

The curve indicated by the letter A is the torque value on the crankshaft of the standard REGGI engine, and the area under the curve is the work performed by the standard ICE in one working expansion cycle. The curve indicated by the letter B is the sum of the torque on the crankshafts of the inventive experimental engine, and the area under the curve is the work performed by the experimental internal combustion engine in one working expansion cycle. The area of the figure under the curve indicated by the letter B is 17% larger than the area of the figure under the curve indicated by the letter A, which shows that in one working cycle the experimental ICE performed the same amount of work as the standard ICE. But due to the complexity of the design, due to the replacement of a single-shaft KShM by DKShM, the mechanical efficiency of the claimed ICE has become lower, therefore, part of the increase in the efficiency of the experimental ICE will be spent on overcoming the increased mechanical losses.

Based on the claimed DKShM, an experimental internal combustion engine was built on the basis of 107 cm cubic four-stroke internal combustion engine installed on a REGGI mini-scooter, and comparative tests were conducted on fuel consumption. An electric generator was installed on a standard engine of the indicated brand and cubic capacity, and with this installation one liter of water was brought to a boil in an electric kettle and fuel consumption was measured. Further, the cylinder-piston group from this REGGI engine, with a standard gas distribution mechanism, with the same power and ignition system, was installed on the DKShM, with the same piston stroke, and the same experiment was performed. Measurements of fuel consumption showed that, compared with a standard internal combustion engine, an experimental internal combustion engine for the same work performed consumes less fuel by 7%, and 10% of 17% spent on overcoming friction in a more complex mechanism and confirmed the theoretical calculation of increasing the internal combustion engine efficiency and its profitability.

In the example shown, it can be verified that setting the maximum of the own torque characteristic closer to the start of the shaft rotation from the TDC of the piston due to the installation of one crank relative to the other with an angle α, allows more efficient use of the energy of the expanding charge, increase the torque on its shafts, power, efficiency and the economy of ICE.

This mechanism has the ability to change various parameters, such as: increasing the torque without increasing the radius of the cranks, increasing and shifting to the beginning of the rotation angle (when the piston is in the TDC) the maximum value of the intrinsic asymmetric mechanical characteristic of the transmission of torque of the mechanism when the piston moves from TDC to BDC , a change in the stroke of the piston without changing the radius of the cranks, a decrease in the set values of the acceleration of the piston when changing the direction of movement in the BDC and TDC, respectively, is reduced e inertial loads on the details of the mechanism.

The above parameters can be changed depending on the task, varying the shift of the angle α between the cranks and varying the geometric dimensions of the rocker arm, connecting rods, axle spacing of the shafts and changing their proportions, which are limited by the specified weight and size indicators of the mechanism and the strength of the materials used.

DKShM can also be performed in the following variants.

A possible variant of the kinematic scheme of the bcc, in which the rocker 9 and the working body 12 are located on one side of the plane in which the axis of the knees of the shafts lie (see Fig.6).

A variant of the kinetic scheme of the crankshaft is possible, in which the connecting rods 7 and 8 do not cross each other, and the working body or piston is located on opposite sides of the plane in which the crankshaft axes lie, and the rod 10 intersects this plane (see Fig. 7).

A variant of the kinematic scheme of the crankshaft is possible, in which the connecting rods 7 and 8 do not cross each other, and the working body or piston is located on one side of the plane in which the crankshaft axes lie (see Fig. 8).

A variant of the DKShM kinematic scheme is possible, in which the single-bearing crankshafts 1 and 2 are coaxial with each other and connected by bevel gears 3 and 4 through an intermediate gear 16, providing counter-rotation of the shafts, and the rocker and piston or working body lie on opposite sides of the axis, through which the axles of the crankshafts 1 and 2 pass (see Fig. 9).

A variant of the DKShM kinematic scheme is possible, in which the single-bearing crankshafts 1 and 2 are aligned with each other and connected by bevel gears 3 and 4 through an intermediate gear 16, providing counter-rotation of the shafts, and the beam 9 and piston 12 or working body are located on one side of the axis through which the axles of the crankshafts 1 and 2 pass (see FIG. 12).

The coaxial arrangement of the shafts allows to reduce the length of the connecting rods and, accordingly, to reduce the weight and size characteristics of the internal combustion engine with the same technical characteristics. The magnitude of the piston stroke in a DKShM with parallel shafts depends on the radius of the cranks and their center distance, and the coaxial arrangement of the shafts allows the piston stroke to be made dependent only on the magnitude of the radius of the cranks and the angle between the shafts. Moreover, to increase the torque by increasing the radius of the cranks of the coaxial shafts, we slightly increase the piston stroke and its linear speed.

All versions of the DKShM can be performed in such a way that the piston 12 is connected to the beam 9 with two rods 10 (for example, in FIG. 3). This design allows you to arrange the connecting rods 7 and 8 at a minimum distance to each other and to minimize the forces that will have a bending effect on the connecting rods.

A device for changing the angle of the shafts relative to each other allows you to change the angle of the shafts relative to their symmetrical installation relative to each other, thereby changing the piston stroke. With a symmetrical installation of the shafts relative to each other, when the angle is equal to zero, the piston stroke will be maximum for this design, the larger the installation angle between the shafts, the smaller the piston stroke. When setting the angle between the shafts equal to 180 degrees, the piston stroke can be zero (the piston will stand still).

The device can be placed on one of the gears connecting the crankshafts to each other. In Fig. 1, the device is indicated by the number 15. The device operates as follows: during the installation of the shafts, as well as during the operation of the mechanism, the device rotates the desired angle of the gear 4 relative to the crank 2, respectively, the position of the shafts 1 and 2 will change by the same angle relative to each other.

Table 1 Shaft rotation 0 ° 30 ° 60 ° 90 ° 120 ° 150 ° 180 ° Crank position 0 one 2 3 four 5 6 Action one 0.5 0.2 0.125 0.09 0.08 - V one 1/2 1/5 1/8 1/11 1/12 - γ ₁ 23 ° 33 ' 53 ° 26 ' 89 ° 38 ' 129 ° 41 ' 169 ° 13 ' 206 ° 1 ' - γ ₂ 14 ° 7 ' 9 ° 50 ' 38 ° 56 ' 71 ° 91 ' 105 ° 3 ' 142 ° 7 ' - β ₁ 66 ° 27 ' 66 ° 36 ' 60 ° 22 ' 50 ° 19 ' 40 ° 47 ' 33 ° 59 ' - β ₂ 50 ° 19 ' 51 ° 4 ' 48 ° 51 ' 44 ° 30 ' 37 ° 53 44 ° 7 ' - T1 + T2 with Rrab = 1 0 24 thirty 26 16 0 - T1 + T2 at action 0 12 6 3.25 1.44 0 - CDM ex (T1 + T2) × Re 0 264 132 71.5 31.68 0 - α 0 31 ° 39 ' 60 ° 67 ° 47 ' 90 ° 106 ° 12 ' 120 ° 152 ° 25 ' 180 ° β 0 9 ° 26 ' 16 ° 45 ' 17 ° 28 ' 8 ° 19 ' 0 Tst with Rrab = 1 0 fourteen 21 eighteen four 0 Tst at Action 0 7 4.2 2.25 0.36 0 Mkr st (Tst × Rst) 0 175 120 105 74 56 40 9 0

Claims (4)

1. Crank-rocker-connecting rod mechanism made of at least two crankshafts connected by gears with a gear ratio equal to one unit of at least one rocker arm, one or more rods, at least one pendulum, at least at least one working body installed in the housing (or frame), where at least one connecting rod for each shaft is pivotally attached to the rocker arm with its one ends, and the connecting rods are pivotally attached to the connecting rod necks of these crankshafts with their other ends, the rocker arm also pivotally attached at its one end a pendulum with its other end pivotally attached to the housing of the mechanism, the rocker arm is also at its one end is hinged to at least one rod, its other end attached to the at least one working member. 2. Crank-rocker-connecting rod mechanism according to claim 1, characterized in that the hinges of the rocker arm lie in different planes. 3. Crank-rocker-connecting rod mechanism according to claim 1, characterized in that the hinges of the rocker arm lie in the same plane. 4. The crank-beam-connecting rod mechanism according to claim 1, characterized in that in the drive between the crankshafts there is a device for changing the angle of the shafts relative to each other.

Images