Butterfly valve, also known as flap valve, is a kind of regulating valve with simple structure. Butterfly valve that can be used for on-off control of low-pressure pipeline medium means that the closing member (disc or butterfly plate) is a disc, which rotates around the valve shaft to achieve opening and closing. of a valve. Butterfly Valve,Butterfly Valve Price,Motorized Butterfly Valve,Butterfly Gate Valve Jiangsu Qiantu Trading Co., Ltd. , https://www.qtpumptrade.com
1 Transmission principle and structural characteristics 1.1 Transmission principle The structure principle of the three-gear linkage double-crank double-ring plate pin-spindle planetary transmission is as shown. When the motor drives the driving gear 6 to rotate clockwise, the driven gears 5 and 8 perform a counterclockwise turning motion due to the meshing of the gears. The crank shafts 4 and 9 fixed to the driven gears 5 and 8 are rotated in the same direction, and the two crank shafts drive two ring plates with pin wheels through two pairs of arm bearings to make the points trajectory round. Translation. At the same time, by the engagement of the pin teeth and the cycloidal teeth, the pin wheel can drive the cycloidal wheel 2 to rotate clockwise around the fixed axis, and the torque after the deceleration and torque increase is transmitted through the output shaft 1.
The gear ratio formula of the three-gear linkage double-ring plate type pendulum planetary transmission is:
I71=71=z5z6
In the zczp-zc type, 7 is the angular velocity of the input shaft and the driving gear 6; 1 is the angular velocity of the cycloidal wheel and the output shaft; z5 is the number of teeth of the driven gear; z6 is the number of teeth of the driving gear; zc is the number of teeth of the cycloidal gear; Zp is the number of teeth of the needle.
1.2 Structural Features The structure diagram of the three-gear linkage double-crank double-ring plate pin-spinning planetary transmission is shown in the figure. It mainly consists of input shaft, three-gear linkage, active crank, connecting rod (ring plate with pin wheel), cycloidal wheel, Output shaft, case and other components.
(1) The input shaft is supported by the two rolling bearings on the reducer side case and the intermediate support plate by two fulcrums, and an involute cylindrical spur gear is mounted on the straight shaft, and the drive gear drives the two crank shafts through the driven gear Rotate around their respective central axes. This structure makes both crankshafts become active cranks, and at the same time transmits power, which can not only be designed as a reduction drive, but also reduces the rotational speed of the crankshaft, thereby reducing vibration and reducing noise, and also overcoming the active crank through the connecting rod in the parallel four-bar mechanism. The motion uncertainty caused by the passive crank over the dead point is solved, and the synchronization problem of the two crankshafts is well solved.
(2) On each eccentric sleeve, two links with a phase difference of 180 are connected to the two active cranks via a slewing bearing, and the two active cranks have the same length and are supported by the same rolling bearing on the reducer housing. The distance between the two active crank fulcrums is the same as the length of the connecting rod, so each connecting rod with two phase differences of 180 on each eccentric sleeve is a connecting rod which only makes translation in the parallel four-bar mechanism. The center of the connecting rod has a pin wheel, which is shaped like a ring plate. Therefore, in the specific structure, the connecting rod is also a ring plate with a pin wheel. In addition, the double-crank double-ring plate pin-spinning planetary transmission uses two parallel four-bar mechanisms with a phase difference of 180 to ensure the static balance of the entire transmission mechanism during motion.
(3) The tooth profile of the cycloidal wheel can be simultaneously meshed with the ideal conjugated multi-tooth of the pin wheel due to the optimized shape of the new tooth shape, and the torque of the double-ring plate type pendulum planetary reducer of the shank is transmitted more. And the transmission is more stable.
(4) The output shaft of the fixed cycloidal wheel is simply supported on the reducer housing by two rolling bearings with two pivot points. Compared with the output shaft of the cantilever structure of a conventional cycloidal pinion planetary reducer using a special output mechanism, it is not only simple in structure but also much more rigid.
2 Force analysis The accurate calculation of the force between the cycloidal wheel and the needle wheel is calculated according to the known conditions of the prototype according to the literature [1] method.
Since the jib bearing is outside the planet gear, the force of the bearing and the bearing of the crankshaft are changed with the position of the active crankshaft to different positions. For this reason, the components of the mechanism need to be separated and solved.
2.1 Analysis of the force of the connecting rod The moving side reaction force of the component i acting on the component j is Rij, which is parallel to the connecting point of the connecting point B and C on the connecting rod, and the vertical direction is the y-axis, and the single ring plate is The dead weight and the weight of the cycloidal wheel are mpg and mcg, respectively, and Fg is the inertial force of a single ring plate. The force analysis of the connecting rods 2 and 2 is as shown in Fig. 4, respectively. The motion reaction forces on the components are given by the component force, and both are set to be positive. The equilibrium equation can be listed as follows. For connecting rod 2, see 3.
The connecting rod 2 is static for one time, so the following deformation coordination conditions are added: because the rigidity of the BC connecting rod is relatively large, it can be regarded as a rigid body without deformation, so the deformation of the two bearings B and C should be equal, and because of the two bearing structure, The same size and the same stiffness, so the two bearings have the same force along the direction of the connecting rod, that is, R12x=R32x for the connecting rod 2, which can be listed as the angle between the active crank and the x-axis in the equation; the LBC is the length of the rack. LBC = LBC.
Similarly, the connecting rod 2 is also static for one time, and the deformation coordination condition is R12x=R32x.
2.2 Crankshaft force analysis Take the crankshaft as a separate body, draw a force analysis diagram as shown in 5. For the active crankshaft 1, the following equations can be listed: r-wheel = 0 vs. active crankshaft 2, which can be listed in the following equation, where e is the crank length (ie the distance from the center of the cycloidal wheel to the center of the needle wheel)
2.3 Output shaft force analysis For the output shaft, force analysis is shown in 7. 6 Force diagram of the output shaft vs. output shaft, the equation can be listed.
3 The force of the bearing The force on the active crank on the B-point slewing bearing F is B=R212x R212y The force on the C-turn arm bearing on the C crank is F=C=R232x R232y
The force F of the B-point slewing bearing on the active crank F is B=R212x R212y The force of the C-point slewing bearing on the active crank F is F=R232x R232y The force on the active crank is supported by the bearing A. R24Ax R24Ay Active crank upper support bearing A is subjected to force F branch A=R24Ax R24Ay Active crank upper support bearing D is subjected to force F branch D=R24Dx R24Dy Active crank upper support bearing D is subjected to force F branch D=R24Dx R24Dy The force F of the support bearing a on the output shaft is a=R2ax R2ay The force on the output shaft b of the support bearing b is b=R2bx R2by
4 Example calculation of known three-gear linkage double crank double-ring plate type pendulum reducer, rated power 11kW, motor speed 1500r/min, pin center circle diameter 218mm, reduction ratio 34, eccentricity 2mm, needle tooth sleeve radius 7mm, needle teeth The pin radius is 5 mm. According to the above-mentioned known conditions, the force between the cycloidal wheel and the pin wheel is calculated according to the above-mentioned known conditions. As shown in the figure, the bearings of the reducer are subjected to the force.
It can be seen that there are 9 teeth at the same time on the cycloidal wheel. The maximum force is 2909.45N. The tangential component force Ft of the total meshing force of the cycloidal wheel is 17751.71N. The component force Fr is 1411.56N, the total meshing force F is 1780774N, and the resultant force angle is 4.55.
(1) The block diagram of computer calculations.
Valves can be used to control the flow of various types of fluids such as air, water, steam, various corrosive media, mud, oil, liquid metal and radioactive media. It mainly plays the role of cutting and throttling on the pipeline. The butterfly valve opening and closing part is a disc-shaped butterfly plate, which rotates around its own axis in the valve body to achieve the purpose of opening and closing or adjustment.
April 13, 2023