RU2174622C2 - Pump - Google Patents

Abstract

FIELD: mechanical engineering; liquid handling machinery. SUBSTANCE: pump has housing with suction and discharge holes, cover and working chamber which accommodates driving and driven working members furnished with mechanism to convey motion from driving to driven working members, and suction and discharge zones formed by outer surfaces of working members and outline of working chamber. Novelty is that outline of working chamber is formed by arcs of two intersecting circumferences, driving and driven working members are made in form of disks and mechanism conveying movement from driving working member to driven one is made in form of double-crank antiparallel-link mechanism. Centers of rotation of antiparallel-link mechanism cranks coincide with centers of arcs of working chamber outline. Diameters of working members are equal to length of connecting rod. Length of cranks is not greater than length of connecting rod, sum of length of both cranks and connecting rod is equal to diameter of circumference describing the arcs of outline of working chamber. Suction and discharge zones are variable in size, and suction and discharge holes are made in end face walls of housing and cover in area of intersection of circumferences describing working chamber. EFFECT: increased capacity of pump, reduced labour input in manufacturing, cut down friction losses. 10 dwg

Description

 The invention relates to mechanical engineering and can be used in devices for pumping liquids.

 Known rotary vane (slide) pumps [1], containing a cylindrical housing in which a drum rotates having an axial eccentricity with the housing, and plates installed in the radial slots of the drum, resting during the operation of the pump on the inner surface of the cylindrical housing. The plates slide along the casing during the operation of the pump and separate the variables according to the size of the suction and discharge zones.

The disadvantages of these pumps include the following:
- low productivity;
- friction losses from sliding plates on the inner surface of the housing and their rapid wear.

 Gear pumps are also known ([2] - prototype), containing a housing, a working chamber, the profile of which is outlined by two arcs of circles, the centers of which coincide with the centers of rotation of the working elements, and the distance between the centers is equal to the sum of the radii of these circles. The transmission of motion from the master to the driven is carried out by gearing of the working elements - gears. The suction zone is separated from the discharge zone by lines of contact between the teeth in the gearing and the teeth with the housing. These zones are constant in magnitude both during pump operation and at rest. The contact lines between the teeth and the body (theoretically, in the absence of a gap) are higher kinematic slip pairs. The shape of the suction and discharge openings does not depend on the movement of the working elements, and their "live" sections do not overlap with the working elements. The case is closed by a cover.

The disadvantages of the prototype include:
- the complexity of manufacturing gears;
- losses associated with sliding friction or the gap between the working elements and the profile of the working chamber;
- low productivity.

 The technical result from the use of the present invention relates to an increase in pump productivity with comparable dimensions to the prototype, the use of working elements less labor-intensive in manufacturing, reduction of losses associated with sliding friction or eliminating the radial clearance between the working elements and the profile of the working chamber.

 The specified technical result is achieved by the fact that in the proposed pump V.F. Nefedov, comprising a housing with suction and discharge openings, a cover and a working chamber, in which are located the leading and driven working elements equipped with a mechanism for transmitting movement from the leading to the driven working element, and the suction and discharge zones formed by the outer surfaces of the working elements and the profile of the working chamber, the working chamber is made with a profile defined by the arcs of two intersecting circles, the leading and driven the operating elements are made in the form of disks, the mechanism for transmitting movement from the leading to the driven working element is designed as a two-crank antiparallelogram, while the rotation centers of the antiparallelogram cranks coincide with the centers of the arches of the working chamber profile, the diameters of the working elements are equal to the length of the connecting rod, the length of the crank is not more than half the length of the connecting rod, and the sum of the lengths of both cranks and the connecting rod is equal to the diameter of the circle that defines the arcs of the profile of the working chamber. The suction and discharge zones of the pump are variable in magnitude, and its suction and discharge openings are made on the end walls of the housing and the cover at the intersection of the circles circumscribing the working chamber.

 The invention is illustrated by the following drawings.

 In FIG. 1 shows a general view of the pump; in FIG. 2 - the same with the pump cover removed; in FIG. 3 is a section AA in FIG. 1; in FIG. 4 is a section BB in FIG. 3; the kinematic diagram of a pump with working elements rigidly connected to cranks is shown in FIG. 5; in FIG. 6 is a section BB of FIG. 5. The kinematic diagram of the pump with working elements freely mounted on the axes of the hinge with a connecting rod is shown in FIG. 7; in FIG. 8 is a section GG in FIG. 7; in FIG. 9 shows the successive positions of the working elements and the motion transmission mechanism when the driving crank rotates one revolution φ = 0 to φ = 2π, in FIG. 10 shows a diagram for determining the position and boundaries of the suction and discharge openings.

 The pump of V.F. Nefedov contains a housing 1, the inner surface of which forms a working chamber, outlined by arcs of 2 intersecting circles with centers O1 and O2 (Figs. 7 and 8), coinciding with the rotation axes of the driving 3 and driven 4 crank shafts (cranks) of the mechanism motion transmission from the leading working element to the follower, which is a two-crank antiparallelogram. The mechanism for transmitting movement from the leading working element to the follower is equipped with a connecting rod 5, a leading working element 6, made in the form of a disk freely mounted on the axis of the hinge 7 with a connecting rod 5, as well as a driven working element 8, made in the form of a disk, freely mounted on the hinge axis 9 with a connecting rod 5. The pump contains a suction 10 and a discharge 11 openings made on the end walls of the housing 1 and the cover 12, an inlet 13 connected to the suction hole 10 by channels 14 made in the housing and the cover, the outlet 15 connected to the discharge opening 11 channels 16, also made in the housing and the cover of the pump. To exit the two-crank antiparallelogram from the “dead” positions (extreme positions), a pin 17 is pressed into the connecting rod 5, and a profiled groove 19 is made in the bracket 18.

 Pump V.F. Nefedova works as follows.

The uniform rotation of the leading crank 3 from an external drive (not shown) through the connecting rod 5 is transmitted to the driven crank 4, which rotates unevenly and in the opposite direction relative to the leading crank. The connecting rod 5 makes a complex movement, its midpoint O ₃ moves along an eight-shaped trajectory T (Fig. 10), and the axis of the hinges 7, 9 move in circles with radii equal to the length of the crank, the working elements are disks 6, 8, freely mounted on the axes hinges 7, 9, rolling around each other, simultaneously roll along the arcs 2 of the profile of the working chamber of the pump, making contactless contact of the working elements with the profile of the working chamber, while the friction of movement will be rolling friction, the coefficient of which is much lower than the sliding friction protot pa, which reduces friction losses.

In the initial position of the two-crank antiparallelogram (Fig. 9), characterized by the extreme (left) position, when the angle of rotation of the leading crank φ = 0, the angle of rotation of the driven crank, is also equal to zero γ = 0. (It is customary to consider the angle clockwise - positive, against clockwise - negative). The working element 6 of the leading crank does not have contact points with the profile of the working chamber of the pump, and the working element 8 of the driven crank 4 has a contact point K1. The profile of the working chamber and the radial surface of the working elements form a single region Z filled with a liquid or other working agent, for example, air. When the leading crank 3 is rotated clockwise by an angle φ = φ ₁ until its working element 6 is in contact with the working chamber profile (contact point K2), the driven crank 4 will rotate by an angle γ = γ ₁ counterclockwise. The working element 8 of the driven crank 4 will have a contact point K3 when the length of the crank is less than half the length of the connecting rod
l _k <l _w / 2
or contact point K5 with a crank length equal to half the length of the connecting rod
l _k = l _w / 2,
otherwise there will be no contact point.

 In the following, the pump operation description assumes that the crank length is less than half the length of the connecting rod.

With the position of the working elements at the contact points K ₂ -K _{3, the} single area Z is divided into two: the discharge zone Z ₁ and the suction zone Z ₂ . The fluid located in zone Z ₁ , through the discharge port 11 through channels 16 will flow to the outlet 15. Upon subsequent rotation of the drive crank 3 to the angle φ = φ _{2, the} suction port 10 will open, in the zone Z _{2 the} pressure will decrease and, as a result the liquid from the outside through the inlet 13 through the channels 14 and the suction hole 10 will enter the zone of the working chamber Z ₂ , and from the zone Z ₁ will be pumped through the injection hole 11 through the channels 16 to the outlet 15. In the position of the leading crank φ = φ ₂ , led cree oship takes position γ = γ _2, operating elements will have a contact point with the profile of the working chamber K ₄ -K _5. In this position, the injection hole 11 is closed and until the leading crank rotates through an angle φ = π it will be closed, and the suction hole will be open and through it the liquid will flow from the inlet 15 through channels 16 until the pressure in the cavity Z ₂ is equalized with the inlet pressure or until the suction hole closes when the master crank is rotated through an angle φ = π, while the follower rotates through an angle γ = -π.
In the position of the leading crank φ = π, and the follower γ = -π, the suction 10 and the injection 11 of the hole are completely closed, the areas Z ₁ and Z _{2 will be} combined into a single area Z, the fluid pressure in the working chamber will equalize. With a further rotation of the leading crank to the angle φ = φ ₃ , the follower - to the angle γ = γ _{3, the} injection hole will open, the liquid through the injection hole through the channels will enter the outlet. The suction hole to the contact of the driven working element at the point K ₂ , and the leading at the contact point K ₇ will be blocked.

In the position of the working elements at the contact points K ₂ -K ₇ when the angle of rotation of the leading crank φ = φ ₃ , driven γ = γ _{3, a} single area Z is divided into two zones: Z ₁ and Z ₂ . Before the leading crank rotates through an angle φ = φ ₄ , and the driven crank through an angle γ = γ ₄ , the liquid will enter the outlet through the discharge opening, and through the opening suction hole from the outside into the zone Z ₁ .

In the position φ = 2π; γ = -2π, zones Z ₁ and Z _{2 will be} combined into a single area Z, the suction and discharge openings will be blocked. At the next turn of the leading crank 3 by φ = 2π, the cycle will be repeated.

The boundaries of the suction and discharge openings are determined graphically according to the determination scheme in FIG. 10, where the arcs ab, bc (boundaries of the suction inlet) are obtained as sections of the outer circles of the working elements when the two-crank antiparallelogram is in the extreme positions; arcs ae, cd (boundaries of the suction opening) are obtained as sections of the external circles of the working elements when the working elements have common points of contact with the profile of the working chamber: for the ae arc, the contact points K ₂ - K ₃ , for the cd arc, the contact points K ₂ - K ₇ . The boundary EO ₃ d - is part of the trajectory described by the midpoint of the O ₃ connecting rod with a complete rotation of the drive crank.

 The proposed pump is superior in performance to the prototype, i.e.

Q _p / Q _w > 1,
where Q _p - the performance of the proposed pump,
Q _W - the performance of the gear pump (prototype).

Q _p = S _z • h _p • n _p
Q _W = S _W • H _W • N _W
where S _z is the area of a single region Z in the proposed pump,
S _W - the total area of the gear cavities in the gear pump,
h _pi , h _w - the thickness of the working elements,
n _pi , n _w - the number of revolutions per unit time.

With the same number of revolutions and equal thicknesses of the working elements, the inequality Q _z / Q _w > 1 is equivalent to the inequality S _z / S _w > 1, where S _w = 2πD _i m from the well-known formula for determining the performance of a gear pump (Bashta T.M. Machine-building hydraulics. Reference manual. - M .: Mashgiz, 1963), where D _i is the diameter of the pitch circle of the gear, m is the engagement module.

In conditions of comparable design dimensions of the compared pumps, we assume that:
- the length of the crank is equal to half the length of the connecting rod l _k = l _w / 2;
- the diameter of the working element is equal to the length of the connecting rod d _g = l _w ;
- the outer diameter of the gears is equal to the diameter of the intersecting circles forming the arcs of the profile of the working chamber
D _Hш = l _w + 2l _k ;
- the number of gear teeth is 10.

S_z = 4,525l_ш ²

Таким образом, производительность предлагаемого насоса значительно больше шестеренного при соизмеримых конструктивных размерах.Under such initial conditions

S _z = 4,525l _w ²

Thus, the performance of the proposed pump is much larger than the gear with comparable design dimensions.

 Other options for performing work items are possible. In FIG. Figures 5 and 6 show a variant of the rigid connection of the working elements with the crank (it is possible to rigidly connect the working elements with the connecting rod), while the friction movement between the working elements and the working chamber profile will be sliding friction, but the pump design will be simplified since the crank with the working element rigidly connected to it can be performed as an eccentric, and a connecting rod with a rigidly connected working element - as a connecting rod with developed connecting rod heads. In these cases, the links of the two-crank antiparallelogram will not only perform its characteristic functions, but will also be the working elements of the pump. Based on this, it is possible to make the pump three-chambered, where in the first chamber the working elements are freely mounted on the axis of the hinges, in the second chamber the connecting rod with the developed heads will be the working element, and in the third chamber there are eccentrics. The cameras are connected by channels in series or in parallel with the inlet and outlet openings.

Sources of information
1. Yudin A.P. Hydraulics, hydraulic machines and hydraulic drive. - M.: Higher School, 1965, p. 265, fig. 19.

 2. The same, p. 267, fig. 19-3, 19-4, 19-5 - prototype.

Claims (1)

 A pump comprising a housing with suction and discharge openings, a cover and a working chamber, in which are located the leading and driven working elements equipped with a mechanism for transmitting movement from the leading to the driven working element, and the suction and discharge zones formed by the outer surfaces of the working elements and the profile of the working chamber characterized in that the working chamber is made with a profile defined by arcs of two intersecting circles, the leading and driven working elements are made in the form of disks, the transmission mechanism The drive from the leading working element to the driven one is made as a two-crank antiparallelogram with centers of rotation of the cranks coinciding with the centers of the arches of the working chamber profile, while the diameters of the working elements are equal to the length of the connecting rod, the length of the cranks is no more than half the length of the connecting rod, the sum of the lengths of both cranks and connecting rod is equal to the diameter a circle circumscribing the arcs of the profile of the working chamber; the suction and discharge zones are variable in magnitude, and the suction and discharge openings are made on the end walls of the housing and the cover at the intersection of the circles circumscribing the working chamber.

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