CN115013285A - Compressor with slide way structure piston and slide way curve design method - Google Patents

Compressor with slide way structure piston and slide way curve design method Download PDF

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CN115013285A
CN115013285A CN202210833555.9A CN202210833555A CN115013285A CN 115013285 A CN115013285 A CN 115013285A CN 202210833555 A CN202210833555 A CN 202210833555A CN 115013285 A CN115013285 A CN 115013285A
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piston
curve
slide way
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acceleration
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CN115013285B (en
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何志龙
马凯
王潇
丘宏烨
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Xian Jiaotong University
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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/0005—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00 adaptations of pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
    • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
    • F04B39/00—Component parts, details, or accessories, of pumps or pumping systems specially adapted for elastic fluids, not otherwise provided for in, or of interest apart from, groups F04B25/00 - F04B37/00
    • F04B39/12—Casings; Cylinders; Cylinder heads; Fluid connections
    • F04B39/122—Cylinder block
    • G—PHYSICS
    • G06—COMPUTING; CALCULATING OR COUNTING
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Abstract

A compressor with a piston of a slide way structure and a slide way curve design method are provided, the compressor with the piston of the slide way structure comprises a first-stage piston and a second-stage piston which are fixedly connected, the rotary reciprocating motion of the first-stage piston drives the rotary reciprocating motion of the second-stage piston, a slide way structure is processed on the cylindrical surface of the first-stage piston, a connecting rod passes through a central hole of the first-stage piston, when the connecting rod rotates for one circle, the piston realizes the reciprocating motion for two times, the slide way curve is symmetrical about a plane axis, when the slide way curve is at the top dead center of the piston, the speed change of the piston is slowed down, so that the piston force is reduced when the slide way curve passes through the top dead center; when the piston rotates at the connecting rod, the cylinder is provided with a positioning column matched with the slide way structure, so that the reciprocating motion of the piston is realized. The design method of the slide curve comprises the following steps of determining the most value range of reciprocating inertia force according to gas force and characteristic angles; and adjusting any one or both of the acceleration curve and the piston group mass to enable the force applied to the two-stage pistons to be uniform. The invention can increase the service life of the piston assembly.

Description

Compressor with slide way structure piston and slide way curve design method
Technical Field
The invention belongs to the field of compressors, and particularly relates to a compressor with a piston of a slide way structure and a slide way curve design method.
Background
The compressor for air suspension is a reciprocating air compressor, and generally adopts a crank-link mechanism to realize single-stage or two-stage compression. When the motor shaft moves, the crank connecting rod mechanism converts the rotation motion of the motor shaft into the reciprocating motion of the piston. Besides reciprocating inertia force, the crank link mechanism has rotating inertia force, a balance block is usually required to be added during balance, however, the structure of the air suspension compressor is compact in several places, the balance space is small, and secondary reciprocating inertia force and secondary rotating inertia force exist, so that balance is difficult. For the two-stage reciprocating air suspension compressor, the space position for mounting on the vehicle body is limited, so that the two-stage reciprocating air suspension compressor is often integrated and has a more compact structure. Besides the piston compressor, the linear compressor can also be used as a power source for air suspension, and the reciprocating motion of the piston is controlled by the opening and closing of the electromagnet. However, the difficulty of controlling the linear motor by electromagnetically controlling the piston is that the efficiency of the compressor depends on the opening and closing of the electromagnet. In the linear motor, a motor shaft (piston rod) reciprocates with the reciprocation of a piston. Besides the linear compressor, a slide way structure can be adopted to realize the reciprocating motion of the piston.
Usually, a slide way structure is arranged on the cylindrical surface of the piston, a structure matched with the slide way structure is arranged on the cylinder, and when the piston rotates, the matched structure on the cylinder enables the piston to move along the slide way curve on the cylindrical surface of the piston. The piston moves along an axial curve and reciprocates from a bottom dead center to a top dead center of the piston. The good slide curve can make the reciprocating inertia force that the piston received balance the gas power, makes the piston operate steadily, can not block. The two-stage crank connecting rod mechanism commonly used for the air suspension compressor has rotation inertia force, and due to the compact structure, the rotation inertia force of the swinging piston cannot be balanced, and a large clearance volume exists. The linear piston is adopted for reciprocating motion, no rotating inertia force exists, and reciprocating inertia force can be balanced with the mass of the piston group through a slideway curve on the surface of the piston. Therefore, the piston slide way is good in design, the gas force borne by the piston can be reduced, and the clearance volume of the piston is reduced, so that the service life of the compressor is prolonged, the power consumption of the motor is reduced, and the endurance of the electric automobile is increased.
Disclosure of Invention
The present invention is directed to solve the above problems in the prior art, and an object of the present invention is to provide a compressor with a piston having a slideway structure and a slideway curve design method, so that when the piston rotates, the piston can smoothly reciprocate along the slideway curve of the cylindrical surface of the piston, and the acceleration curve or the mass of the piston can be changed according to the gas force applied to the piston, so that the maximum resultant force applied to two stages of pistons is within a certain range, and the service life of the piston assembly is prolonged.
In order to achieve the purpose, the invention has the following technical scheme:
a compressor with a piston of a slide way structure comprises a primary piston and a secondary piston which are fixedly connected, wherein the rotary reciprocating motion of the primary piston drives the rotary reciprocating motion of the secondary piston, a slide way structure is processed on the cylindrical surface of the primary piston, a connecting rod passes through a central hole of the primary piston, when the connecting rod rotates for one circle, the piston realizes twice reciprocating motion, a slide way curve is axially symmetrical about a plane, when the slide way curve is at the top dead center of the piston, the speed change of the piston is slowed down, and the piston force is reduced when the piston passes through the top dead center; when the piston rotates at the connecting rod, the cylinder is provided with a positioning column matched with the slide way structure, so that the reciprocating motion of the piston is realized.
As a preferred solution, the curve expression of the chute structure is as follows:
Figure BDA0003749272960000021
in the formula, S is the piston stroke, and R is the first-stage piston radius;
the parameter A, D in the equation is a constant and is related to the piston stroke, and the following relationship is satisfied: a + D ═ S;
wherein B is a constant and is related to the period of the piston slip curve, and B is equal to period/2, and C is a phase angle and a constant; the displacement, velocity and acceleration of the piston are related only to z of the ramp curve, where:
speed of the piston: v ═ z ═ f' (S, R, θ);
acceleration of the piston: a ═ z ═ f ″ (S, R, θ);
wherein z is the piston axial displacement, z 'is the piston axial velocity, z "is the piston axial acceleration, f' () is the first derivative, and f" () is the second derivative.
The invention also provides a design method of the slideway curve in the compressor with the slideway structure piston, which comprises the following steps:
calculating the piston displacement and the corresponding connecting rod rotation angle after the piston expansion process is finished;
calculating the piston displacement and the corresponding connecting rod corner after the piston compression process is finished;
calculating the gas force applied to the piston;
determining the most value range of the reciprocating inertia force according to the gas force and the characteristic angle;
and adjusting any one or both of the acceleration curve and the piston group mass to enable the force applied to the two-stage pistons to be uniform.
Preferably, the piston displacement x at the end of the piston expansion process is calculated e And corresponding link angle theta e The expression of (a) is as follows:
Figure BDA0003749272960000031
x e ＝z(θ e )
calculating the piston displacement x of the end of the piston compression process c And corresponding link angle theta c The expression of (a) is as follows:
Figure BDA0003749272960000032
x c ＝z(θ c )
wherein, pi/2 is more than theta c ＜π，θ i Is the angle of rotation of the connecting rod, theta i ∈(0,π)；
In the formula, p s Is the intake pressure, δ s For intake pressure loss, p d Is the discharge pressure, δ d For loss of exhaust pressure, V 0 To a clearance volume, V h Is the stroke volume, A p Is the piston area, m is the expansion process index, and n is the compression process index;
the following characteristic angles of the motion process of the primary piston and the secondary piston are determined by the formula:
θ e,1 the rotation angle of the connecting rod when the expansion process of the primary piston is finished;
θ c,1 the rotation angle of the connecting rod when the first-stage piston compression process is finished;
θ e,2 the rotation angle of the connecting rod when the expansion process of the primary piston is finished;
θ c,2 the angle of the connecting rod at the end of the primary piston compression process.
Preferably, said step of calculating the gas force to which the piston is subjected is according to the rotation angle θ i In the 0-2 pi change process, the following expressions are correspondingly calculated respectively:
and (3) an expansion process:
Figure BDA0003749272960000041
and (3) a gas suction process: p is a radical of i ＝p s (1-δ s ) θ e ＜θ i ≤π
And (3) a compression process:
Figure BDA0003749272960000042
and (3) an exhaust process: p is a radical of i ＝p d (1+δ d ) θ c ＜θ i ≤2π
For any rotation angle theta i Gas force F acting on the piston g,i The calculation expression is as follows:
F g,i ＝A p,c p i,c -A p,a p i,a -A a p a
in the formula, A p,c Is a first-order cylinder area, p i,c Is a first-order in-cylinder pressure, A p,a Is the area of the secondary cylinder, p i,a Is a secondary in-cylinder pressure, A a p a Is the link area.
Preferably, when the maximum range of the reciprocating inertia force is determined according to the gas force and the characteristic angle, the resultant gas force is Fg in the first half period 1 The latter half period is Fg 2 When the gas force is balanced, the balance range of the total force received by the piston is determined according to the values of tension and compression of the piston according to the following formula:
Figure BDA0003749272960000043
in the formula, Fg 1 The resultant force of the gases in the previous half cycle,
Figure BDA0003749272960000044
is Fg 2 About
Figure BDA0003749272960000045
The function of the symmetry is such that,
Figure BDA0003749272960000046
the resultant force of the gas to which the piston assembly is subjected for the second half cycle
Figure BDA0003749272960000047
Value after symmetry, Fg 2 The resultant force of the gas to which the piston assembly is subjected is the second half cycle.
As a preferable mode, the step of adjusting either or both of the acceleration curve and the piston group mass to make the force applied to the two-stage pistons uniform adjusts the acceleration curve according to the following formula:
Figure BDA0003749272960000048
in the formula, F g,0 For the newly balanced resultant force, p s,c Is a first suction pressure, p d,a Is the secondary exhaust pressure, δ s,c For first order suction pressure loss, δ d,a For two-stage exhaust pressure loss, m s Is the piston group mass, a 0 The acceleration of the piston group is set, and the starting acceleration and the ending acceleration are as large as possible;
at theta e,1 At that time, the acceleration is reduced to 0, at which time a e,1 ＝0；
At theta c,1 Due to symmetry, θ c,1,duichen ＝θ c,1 -90 °; at this time, the process of the present invention,
Figure BDA0003749272960000051
in the formula, theta e,1 At a first expansion end angle, θ c,1 At a first compression end angle, θ c,1,duichen Is theta c,1 Angle of symmetry of (D), F g,c1duicheng Is the limit value of the force applied to the piston, a c1duicheng Is at theta c,1,duichen The acceleration of the piston group.
Preferably, the step of adjusting either or both of the acceleration curve and the piston group mass to equalize the forces experienced by the two-stage pistons adjusts the piston group mass according to the following equation:
Figure BDA0003749272960000052
in the formula,. DELTA.m s2 To balance the mass, m, required to be added to the rear secondary piston s Is the piston group mass, a 0 Is the piston set acceleration.
Compared with the prior art, the invention has the following beneficial effects:
the resultant force applied to the air suspension compressor piston mainly consists of a gas force and a reciprocating inertia force. The reciprocating inertia force of the compressor of the invention is related to the curve of the piston slideway. When the diameter and the stroke of the piston are given and the clearance volume coefficient is given, the maximum value of the gas force to which the two-stage piston is subjected is determined. The trend of pressure change in the first-stage and second-stage cylinders is only related to the curve of the slideway and the rotation angle of the slideway. The reciprocating friction force received by the piston is along the direction of the motor and the connecting rod, and the reciprocating friction force accounts for 60-70% of the whole friction power of the compressor. The reciprocating friction force has small value change along with the curve of the piston surface slideway, and the value is about 10N, and the influence on the resultant force received by the piston is small. On the premise of ensuring that the resultant force on the piston is as uniform as possible, the maximum value needs to be as small as possible. The uniform stress of the piston is realized by changing the partial points of the mass of the secondary piston and the curve of the slide way. According to the invention, when the piston rotates, the piston can smoothly reciprocate along the slide way curve of the cylindrical surface of the piston, when the connecting rod rotates for one circle, the piston realizes two times of reciprocating motion, and the slide way curve is axially symmetrical about a plane. And the most value range of the reciprocating inertia force is determined according to the gas force and the characteristic angle, and the acceleration curve and/or the mass of the piston group are/is adjusted, so that the force applied to the two-stage pistons is uniform, and the service life of the piston assembly is prolonged.
Drawings
FIG. 1 is a schematic diagram of the curves of different piston ramps of the compressor having pistons of the ramp configuration of the present invention;
FIG. 2 is a schematic diagram of displacement, velocity and acceleration curves for a compressor piston having a piston with a slideway structure according to the present invention;
FIG. 3 is a graph of the gas force experienced by a compressor piston having a piston with a slideway structure according to the present invention;
FIG. 4 is a graph of the calculation of the difference in gas force for a compressor having a piston with a slideway structure according to the present invention: (a) fg 1 And
Figure BDA0003749272960000061
the result is; (b) Δ Fg results;
FIG. 5 is a graph of a curve fit of the reciprocating inertial force of a compressor having a piston with a slideway structure according to the present invention;
fig. 6 is a diagram of piston driven by different piston materials for the compressor with the piston having the slideway structure according to the invention: (a) the first-stage piston and the second-stage piston are made of aluminum alloy; (b) the first-stage piston is made of aluminum alloy, and the second-stage piston is made of copper material added into the aluminum alloy;
fig. 7 is a perspective view of a slide structure of a primary piston of a compressor with a slide structure piston according to the present invention.
Detailed Description
The present invention will be described in further detail with reference to the accompanying drawings.
The invention provides a compressor with a slide way structure piston, which comprises a primary piston and a secondary piston which are fixedly connected, wherein the rotary reciprocating motion of the primary piston drives the rotary reciprocating motion of the secondary piston, a slide way structure is processed on the cylindrical surface of the primary piston, a connecting rod passes through a central hole of the primary piston, when the connecting rod rotates for one circle, the piston realizes twice reciprocating motion, a slide way curve is axially symmetrical about a plane, when the slide way curve is at the top dead center of the piston, the speed change of the piston change is slowed down, so that the piston force is reduced when the piston passes through the top dead center; when the piston rotates at the connecting rod, the positioning column matched with the slide way structure is arranged on the cylinder, and the reciprocating motion of the piston is realized.
The slide way structure of the piston is only arranged on the cylindrical surface of the first-stage piston, and the curve expression of the slide way structure is as follows:
Figure BDA0003749272960000062
in the formula, S is the piston stroke, and R is the first-stage piston radius;
the parameter A, D in the equation is a constant and is related to the piston stroke, and the following relationship is satisfied: a + D ═ S;
wherein B is a constant and is related to the period of the piston slip curve, and B is equal to period/2, and C is a phase angle and a constant; the displacement, velocity and acceleration of the piston are related only to z of the ramp curve, where:
speed of the piston: v-z '-f' (S, R, θ);
acceleration of the piston: a ═ z ═ f ″ (S, R, θ);
wherein z is the piston axial displacement, z 'is the piston axial velocity, z "is the piston axial acceleration, f' () is the first derivative, and f" () is the second derivative.
The following embodiments are provided to provide a method for designing a slideway curve in a compressor with a piston having a slideway structure, including:
1) determining the working conditions of normal work of the two-stage compressor, including pressure, speed, air quantity and the like;
p s1 ＝1bar,p d2 ＝10bar,n＝3000rpm
2) calculating to obtain the diameter D of the primary piston 1 Second stage piston diameter D 2 And a stroke S;
D 1 ＝50mm,D 2 ＝24mm,S＝10mm
3) giving clearance volumes of a first-stage cylinder and a second-stage cylinder;
V 01 ＝1.7671e -6 m 3 ,V 02 ＝2.8274e -7 m 3
4) giving a form of a piston slide curve;
the slide structure of piston only locates one-level piston face of cylinder, and one-level piston links firmly with the second grade piston, and the rotary reciprocating motion of one-level piston drives the rotary reciprocating motion of second grade piston. The motion law of the primary piston is the same as that of the secondary piston, and only the phase angle is different by a half period. The piston stroke is S, the radius of the primary piston is R, then:
the mathematical expression of the first-stage piston slideway curve is
Figure BDA0003749272960000071
A, B, C, D in the above equation relates to the piston stroke, the period of the piston slip curve.
The displacement, velocity and acceleration of the piston are only related to the ramp curve.
One ramp curve equation given in this example is:
Figure BDA0003749272960000081
the speed of the piston is:
Figure BDA0003749272960000082
the acceleration of the piston is:
Figure BDA0003749272960000083
this form of piston displacement, velocity and acceleration is shown in figure 2.
5) Calculating the piston displacement x at the end of the piston expansion process e The corresponding connecting rod angle is theta e . And piston displacement x at the end of the piston compression process c Corresponding to a link angle of theta c ；
Piston displacement x at the end of the piston expansion process e Corresponding to a link angle of theta e Calculated as follows:
Figure BDA0003749272960000084
piston displacement x at the end of the piston compression process c Corresponding to a link angle of theta c ，π＜θ c < 2 π, calculated as:
Figure BDA0003749272960000085
and determining characteristic angles of the motion process of the primary piston and the secondary piston, wherein the reciprocating inertia force is symmetrical about a half-period axis.
θ e,1 Angle of rotation of the connecting rod at the end of the expansion process of the primary piston, theta e,1 ＝27°；
θ c,1 Angle of rotation of the connecting rod at the end of the compression process of the primary piston, theta c,1 ＝145°；
θ e,2 Angle of rotation of the connecting rod at the end of the expansion process of the primary piston, theta e,2 ＝112°；
θ c,2 Angle of rotation of the connecting rod at the end of the compression process of the primary piston, theta c,2 ＝49°；
6) Calculating the gas force to which the piston is subjected:
and (3) an expansion process:
Figure BDA0003749272960000086
and (3) a gas suction process: p is a radical of i ＝p s (1-δ s ) θ e ＜θ i ≤π
And (3) a compression process:
Figure BDA0003749272960000091
and (3) an exhaust process: p is a radical of i ＝p d (1+δ d ) θ c ＜θ i ≤2π
Any angle of rotation theta i Gas force F acting on the piston g,i
F g,i ＝A p,c p i,c -A p,a p i,a -A a p a
The gas forces experienced by the piston are shown in figure 3.
7) And determining the maximum range of the reciprocating inertia force according to the gas force and the characteristic angle. In balancing gas forces, the resultant gas force is Fg in the first half period 1 The latter half period is Fg 2 . In order to make the most stressed values of the pistons the same, namely the values of tension and compression are basically the same, the balance range of the total stress of the pistons is determined as follows:
Figure BDA0003749272960000092
in the formula, Fg 1 The resultant force of the gases in the previous half cycle,
Figure BDA0003749272960000093
is Fg 2 About
Figure BDA0003749272960000094
The function of the symmetry is such that,
Figure BDA0003749272960000095
the resultant force of the gas to which the piston assembly is subjected for the second half cycle
Figure BDA0003749272960000096
Value after symmetry, Fg 2 The resultant force of the gas to which the piston assembly is subjected is the second half cycle.
The gas force difference calculation chart is shown in (a) and (b) of fig. 4.
8) Adjusting acceleration curves and/or piston group masses
The acceleration of the piston slip curve should satisfy the following condition: the acceleration of the start and the end is as large as possible;
at this time, the process of the present invention,
Figure BDA0003749272960000097
at theta e,1 The time acceleration is reduced to 0, at which time a e,1 ＝0。
At theta c,1 Due to symmetry, θ c,1,duichen ＝θ c,1 -90 deg., at which time,
Figure BDA0003749272960000098
after fitting calculation according to the formula, a better reciprocating inertia force curve is obtained, and the reciprocating inertia force curve is shown in fig. 5.
The fitted reciprocating inertia force curve is as follows:
Figure BDA0003749272960000099
among the resultant forces experienced by the two-stage piston, the reciprocating inertial force is used to balance the gas forces at the two ends of the piston. Can be changed by changing the activityThe plug mass changes the uniformity of the resultant force. When the curve of the piston slideway is fixed and unchanged, the force applied to the piston can be uniform by setting reasonable mass distribution. The piston slide structure is arranged on the cylindrical surface of the primary piston, and a double lug, a supporting pin and other fixing devices for connecting the primary piston and the secondary piston are arranged in the primary piston. The central hole of the primary piston is passed by a connecting rod, and a sealing element for ensuring the reciprocating and rotating motion of the connecting rod is arranged in the piston. The two-stage piston only extends out of the connected double-lug structure, and the inside of the two-stage piston can be solid, or the material of the two-stage piston is changed, and aluminum alloy is changed into copper. The mass of the primary piston group is m s1 Mass of the secondary piston group is m s2 The mass of the secondary piston group after balancing should be increased by:
Figure BDA0003749272960000101
the force variation of the pistons with different piston materials is shown in (a) and (b) of fig. 6. The first-stage piston is made of aluminum alloy, and the second-stage piston is made of copper material added into the aluminum alloy. The most significant change in the force applied to the piston is as follows:
F 1,max ＝349.9917N；F 1,min ＝-432.7253N
F 2,max ＝360.9318N；F 2,min ＝-364.2041N
finally, the slide way three-dimensional structure of the primary piston cylindrical surface is obtained as shown in fig. 7.
The invention provides a design method of a piston slide way of an air suspension compressor, so that when a piston rotates, the piston can smoothly reciprocate along a slide way curve of a cylindrical surface of the piston. And the acceleration curve or the mass can be changed according to the gas force borne by the piston, so that the maximum value of the resultant force borne by the two-stage piston is in a certain range, and the service life of the piston assembly is prolonged.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same; although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present application, and they should be construed as being included in the present application.

Claims (8)

1. A compressor with slide structure piston, its characterized in that: the piston reciprocating mechanism comprises a primary piston and a secondary piston which are fixedly connected with each other, wherein the rotary reciprocating motion of the primary piston drives the rotary reciprocating motion of the secondary piston, a slide way structure is processed on the cylindrical surface of the primary piston, a connecting rod passes through a central hole of the primary piston, when the connecting rod rotates for one circle, the piston realizes two reciprocating motions, a slide way curve is axially symmetrical about a plane, when the slide way curve is at the top dead center of the piston, the change of the speed of the piston is slowed down, and the force of the piston is reduced when the slide way curve passes through the top dead center; when the piston rotates at the connecting rod, the positioning column matched with the slide way structure is arranged on the cylinder, and the reciprocating motion of the piston is realized.
2. The compressor with a piston having a slide structure according to claim 1, wherein the curve of the slide structure is expressed as follows:
Figure FDA0003749272950000011
in the formula, S is the piston stroke, and R is the first-stage piston radius;
the parameter A, D in the equation is a constant and is related to the piston stroke, and the following relationship is satisfied: a + D ═ S;
wherein B is a constant and is related to the period of the piston slip curve, and B is equal to period/2, and C is a phase angle and a constant; the displacement, velocity and acceleration of the piston are related only to z of the ramp curve, where:
speed of the piston: v ═ z ═ f' (S, R, θ);
acceleration of the piston: a ═ z ═ f ″ (S, R, θ);
wherein z is the piston axial displacement, z 'is the piston axial velocity, z "is the piston axial acceleration, f' () is the first derivative, and f" () is the second derivative.
3. A method for designing a curve of a slide in a compressor having a piston of a slide structure according to claim 1, wherein:
calculating the piston displacement and the corresponding connecting rod rotation angle after the piston expansion process is finished;
calculating the piston displacement and the corresponding connecting rod corner after the piston compression process is finished;
calculating the gas force applied to the piston;
determining the most value range of the reciprocating inertia force according to the gas force and the characteristic angle;
and adjusting any one or both of the acceleration curve and the piston group mass to enable the force applied to the two-stage pistons to be uniform.
4. A method for designing a slide curve according to claim 3, wherein the piston displacement x at the end of the piston expansion process is calculated e And corresponding link angle theta e The expression of (a) is as follows:
Figure FDA0003749272950000021
x e ＝z(θ e )
calculating the piston displacement x of the end of the piston compression process c And corresponding link angle theta c The expression of (c) is as follows:
Figure FDA0003749272950000022
x c ＝z(θ c )
wherein, pi/2 is more than theta c ＜π，θ i Is the angle of rotation of the connecting rod, theta i ∈(0,π)；
In the formula, p s Is the intake pressure, δ s For intake pressure loss, p d Is the discharge pressure, δ d For loss of exhaust pressure, V 0 To a clearance volume, V h Is the stroke volume, A p Is the piston area, m is the expansion process index, and n is the compression process index;
the following characteristic angles of the motion process of the primary piston and the secondary piston are determined by the formula:
θ e,1 the rotation angle of the connecting rod when the expansion process of the primary piston is finished;
θ c,1 the rotation angle of the connecting rod when the first-stage piston compression process is finished;
θ e,2 the rotation angle of the connecting rod when the expansion process of the primary piston is finished;
θ c,2 the angle of the connecting rod at the end of the primary piston compression process.
5. The method for designing a curve for a slide according to claim 4, wherein said step of calculating the gas force experienced by the piston is performed according to a rotation angle θ i In the 0-2 pi change process, the following expressions are correspondingly calculated respectively:
and (3) an expansion process:
Figure FDA0003749272950000023
0≤θ i ≤θ e
and (3) a gas suction process: p is a radical of formula i ＝p s (1-δ s )θ e ＜θ i ≤π
And (3) a compression process:
Figure FDA0003749272950000031
π≤θ i ≤θ c
and (3) an exhaust process: p is a radical of i ＝p d (1+δ d )θ c ＜θ i ≤2π
For any rotation angle theta i Gas force F acting on the piston g,i The calculation expression is as follows:
F g,i ＝A p,c p i,c -A p,a p i,a -A a p a
in the formula, A p,c Is a first cylinder area, p i,c Is a first-order in-cylinder pressure, A p,a Is the area of the secondary cylinder, p i,a Is a secondary in-cylinder pressure, A a p a Is the link area.
6. The method for designing the curve of the slide way according to claim 5, wherein when the maximum value range of the reciprocating inertia force is determined according to the gas force and the characteristic angle, the resultant gas force is Fg in the former half period 1 The latter half period is Fg 2 When the gas force is balanced, the balance range of the resultant force of the piston is determined according to the values of tension and compression of the piston according to the following formula:
Figure FDA0003749272950000032
in the formula, Fg 1 The resultant force of the gases in the previous half cycle,
Figure FDA0003749272950000033
is Fg 2 About
Figure FDA0003749272950000034
The function of the symmetry is such that,
Figure FDA0003749272950000035
the resultant force of the gas to which the piston assembly is subjected for the second half cycle
Figure FDA0003749272950000036
Value after symmetry, Fg 2 The resultant force of the gas to which the piston assembly is subjected is the second half cycle.
7. The method of claim 6, wherein the step of adjusting the acceleration profile and/or the mass of the piston assembly to equalize the forces experienced by the two-stage pistons is performed by adjusting the acceleration profile according to the following equation:
Figure FDA0003749272950000037
in the formula, F g,0 For the newly balanced resultant force, p s,c Is a first suction pressure, p d,a Is the secondary exhaust pressure, δ s,c For first order suction pressure loss, δ d,a For two-stage exhaust pressure loss, m s Is the piston group mass, a 0 The acceleration of the piston group is set, and the starting acceleration and the ending acceleration are as large as possible;
at theta e,1 At that time, the acceleration is reduced to 0, at which time a e,1 ＝0；
At theta c,1 Due to symmetry, θ c,1,duichen ＝θ c,1 -90 °; at this time, the process of the present invention,
Figure FDA0003749272950000038
in the formula, theta e,1 At a first expansion end angle, θ c,1 At a first compression end angle, θ c,1,duichen Is theta c,1 Angle of symmetry of (D), F g,c1duicheng Is the limit value of the force applied to the piston, a c1duicheng Is at theta c,1,duichen The acceleration of the piston group.
8. The method of claim 6, wherein the step of adjusting either or both of the acceleration profile and the piston set mass to equalize the forces experienced by the two-stage pistons adjusts the piston set mass according to the following equation:
Figure FDA0003749272950000041
in the formula,. DELTA.m s2 To balance the mass, m, required to be added to the rear secondary piston s Is the piston group mass, a 0 For acceleration of piston groups。
CN202210833555.9A 2022-07-15 2022-07-15 Compressor with slide way structure piston and slide way curve design method Active CN115013285B (en)

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Publication number Priority date Publication date Assignee Title
CN101644246A (en) * 2009-08-24 2010-02-10 浙江鸿友压缩机制造有限公司 Spin-orbit-type reciprocating piston compressor
JP2010286709A (en) * 2009-06-12 2010-12-24 Ricoh Co Ltd Piston, air pump, air discharge device and image forming device
CN107110021A (en) * 2016-06-01 2017-08-29 上海长辛实业有限公司 A kind of novel air pressing transmission device
WO2019042829A1 (en) * 2017-08-31 2019-03-07 Knorr-Bremse Systeme für Schienenfahrzeuge GmbH Low-vibration multistage piston compressor, particularly for rail vehicles
CN214273878U (en) * 2020-06-19 2021-09-24 郭富娟 Linear orbital ring for linear piston compressor

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2010286709A (en) * 2009-06-12 2010-12-24 Ricoh Co Ltd Piston, air pump, air discharge device and image forming device
CN101644246A (en) * 2009-08-24 2010-02-10 浙江鸿友压缩机制造有限公司 Spin-orbit-type reciprocating piston compressor
CN107110021A (en) * 2016-06-01 2017-08-29 上海长辛实业有限公司 A kind of novel air pressing transmission device
WO2019042829A1 (en) * 2017-08-31 2019-03-07 Knorr-Bremse Systeme für Schienenfahrzeuge GmbH Low-vibration multistage piston compressor, particularly for rail vehicles
CN214273878U (en) * 2020-06-19 2021-09-24 郭富娟 Linear orbital ring for linear piston compressor

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