RU2451185C2 - Water displacement pump - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: proposed pump comprises constant-section annular channel arranged in water intake-discharge wall with two pairs of pistons 4 and 5, each being arranged between pistons 4 and 5 of other pair. Said pairs of pistons are rigidly coupled with aligned half shafts articulated with drive shafts via propeller shaft to drive the latter with pistons 4 and 5 in said annular channels intermittently at regular rotation of drive shaft. Angular size of piston does not exceed angular size of intake-discharge opening. Maximum tolerable angular size of piston is defined by claimed formula. Bend angle of propeller shaft gimbal joints are set in compliance with claimed formula.

EFFECT: higher efficiency and reliability.

2 cl, 8 dwg

Description

The invention relates to volume displacement pumps, mainly for filling-draining the ballast tanks of small submarines that do not have a compressor on board and in which air is compressed directly in the ballast tank, filling it with an outboard water pump. For example, a pump for filling-draining ballast tanks in accordance with RU 2423285 and RU 2399544.

Known volume displacement pumps with cyclically uneven rotation of the pistons in the annular channel of constant cross-section, for example, according to UA 75431, RU 2181845, RU 2379552, etc.

Known volumetric pump for water, containing an annular channel of constant cross-section with windows in the wall for water inlet and outlet, and there are two pairs of pistons, each of which is located between the pistons of the other pair, and the pair of pistons are rigidly connected to separate for each pair of coaxial axles connected kinematically with the drive shaft by means of cardan shafts, with the ability to rotate the pistons in the annular channel cyclically non-uniformly with uniform rotation of the drive shaft, for example according to RU 2181845, adopted as a prototype.

The disadvantage of such pumps is that the pump is inoperative if the cavity filled with water between the pistons does not communicate with the windows until the pistons have reached the maximum approximation, since the water is almost not compressible. And if the angular size of the windows is larger than the angular size of the pistons, then four times in one revolution of the drive shaft the suction and pressure windows and the corresponding channels communicate with each other past the pistons. With a significant difference in pressure of water at the inlet and outlet of the pump, this makes the pump also inoperative. Therefore, for the pump to operate, the angular dimensions of the pistons, windows, the location of the windows, the angle of fracture of the universal joints of the cardan shafts for a given supply, pumped for one revolution of the drive shaft, are performed in accordance with the necessary relationships between them. Otherwise, such a water pump is inoperative.

The objective and technical result of the invention is a volumetric pump for water, in which the angular dimensions of the pistons, windows, the location of the windows, the angle of fracture of the axes of the shafts of the universal joints of the cardan shafts for the pump to operate at a given water supply per revolution of the drive shaft are made according to the necessary relationships between them.

SUMMARY OF THE INVENTION

1. A volumetric pump for water, comprising an annular channel of constant cross section with windows in the wall for water inlet and outlet and two pairs of pistons in it, each of which is located between the pistons of the other pair, the pairs of pistons being rigidly connected to the coaxial axles separate for each pair, kinematically connected to the drive shaft by means of cardan shafts, with the ability to rotate the pistons in the annular channel cyclically unevenly with uniform rotation of the drive shaft, and in accordance with the invention the maximum possible angular size βmax piston is determined according to the formula:

βmax = 90 ° -m22.5 °

where m is a given volume of water, expressed in a dimensionless fraction of the total volume of the annular channel, pumped per revolution of the drive shaft, while the angular dimension β of the piston is not greater than the angular size α of the inlet-outlet window, and the angle γ of the axis of the shafts of the universal joints of cardan shafts set accordingly to the formula:

2. The pump according to claim 1 in accordance with the invention is in communication with a suction-pressure channel through a hydraulic lock.

Thanks to this, the volume displacement pump is efficient at pumping water and has a predetermined supply per revolution of the drive shaft.

A volumetric pump for water (hereinafter pump) is installed, for example, as follows.

Figure 1 shows a diagram of a pump.

Figure 2 shows both crosses universal joints of the driveshaft, each of which contains two split halves, a view of the plane of the connector; crosses indicate the bolts connecting them.

Figure 3 schematically shows a hollow in the form of a ring shaft propeller shaft with a pair of coaxial spikes of universal joints inside the ring. The axes of both pairs of spikes lie in a common plane and are mutually perpendicular.

Figure 4 schematically shows the drive shaft connected by splines with two hubs having two coaxial spikes of universal joints from the left and right driveshaft.

Figure 5 schematically shows the connection of a two-way valve with a pump.

Figure 6 schematically shows the pistons of the pump at their extreme rapprochement and the location of the windows in the wall of the pump.

Figure 7 shows the position of the pistons at the greatest difference in their instantaneous angular velocities.

Fig. 8 shows: a dotted line is a graph of the angular deviation of the piston from the drive shaft, a dashed line is a graph of the relative instantaneous angular velocities, a solid line is a graph of the instantaneous angular accelerations of the pistons at the current angle of rotation of the drive shaft, and a straight dotted line is a graph of the angular stationary rotation speed of the drive shaft.

Symbols in figure 1 ... 8 and in the formulas (1) ... (10):

1 - pump housing with inlet-outlet windows (hereinafter referred to as the housing),

2 - annular channel of constant cross-section (hereinafter channel),

3 - hollow half shaft (further half shaft),

4 - an even piston; its angular size is not larger than that of the inlet-outlet window, (hereinafter the piston),

5 - an odd piston; its angular size is not larger than that of the inlet-outlet window, (hereinafter the piston),

6 - with a hollow hub, the cup-fork with holes for a stationary landing of a pair of spikes (hereinafter the cup-fork),

7 - a large cross with a hole along the axis around the point of intersection of the axes of the holes for the spikes (hereinafter cross),

8 - hollow shaft with inner and outer pairs of spikes of universal joints of the driveshaft, and the axis of the pairs of spikes are mutually perpendicular and intersect on the axis of rotation of the shaft 8 (hereinafter the shaft),

9 - a smaller cross with a hole along the axis around the point of intersection of the axes of the holes for the spikes (hereinafter the cross),

10 - slotted hub with a pair of coaxial spikes of the universal joint (hereinafter the hub),

11 - a cardan shaft containing a shaft 8, crosses 7 and 9, the hub 10, the cup-fork 6, (hereinafter cardan),

12 - drive shaft of the machine (hereinafter the shaft),

13 - thrust bearing, for example according to GOST 8995-75, (hereinafter bearing),

14 - pump

15 - bilateral hydraulic lock (hereinafter referred to as the lock),

γ is the angle of fracture (tilt of the axis of the shaft 8 to the axis of the shaft 12, half shaft 3) of the axes of the shafts of the universal joint (hereinafter the angle y),

βmax is the angle of maximum proximity of the pistons 4, 5; the angle between the bisectors of their angular dimensions, the maximum possible angular size of the pistons 4, 5, (hereinafter the angle βmax),

β is the angular size of the piston 4, 5, and β <βmax, (hereinafter the angle β),

α is the angular size of the window, and α≥β, (hereinafter the angle α),

φ is the angle of rotation of the shaft 12 from the initial position taken as zero (hereinafter the angle φ),

ψ is the angle of rotation of the shaft 8 (hereinafter the angle ψ),

φ 'is the angle of rotation of the piston 4, 5 (hereinafter the angle φ'),

Δφ is the angle of advance-lag of the piston 4, 5 from the shaft 12: Δφ = φ'-φ (hereinafter the angle Δφ),

ω is the angular velocity of the shaft 12 during its uniform (stationary) rotation (hereinafter the speed ω),

ω 'is the instantaneous angular velocity of the piston 4, 5 together with its half shaft (hereinafter the speed ω'),

n - exponent equal to 4 (hereinafter exponent n),

t is the current time of stationary rotation of the shaft 12 from the initial position (hereinafter time t),

ε is the instantaneous increment of the relative velocity ω '/ ω at the angle φ of rotation of the shaft 12 (hereinafter the acceleration ε).

Case 1 consists of two symmetrical halves, bolted together along the plane of the connector. Each half of the housing contains its own part of the annular channel 2 with windows in its wall for water inlet and outlet. A left half shaft 3 connected to a pair of pistons 4 and a right half shaft 3 connected to a pair of pistons 5 so that the pistons divide the channel into four chambers are installed in the housing along its axis. The gaps between the pistons 4, 5 and the wall of the channel 2 are blocked by o-rings. The outer end of the half-shaft 3 is made in the form of a gear half-coupling. In the wall of the cup-fork 6 there is a pair of holes in which a pair of pivots of the swivel joint with the spider 7. are fixed coaxially to the axis of the half shaft 7. Other coaxial holes of the spider 7 cover the outer spikes of the shaft 8. The inner spikes of this shaft are covered by a pair of coaxial holes of the spider 9, which another pair of coaxial holes covers the spikes of the hub 10. Cup-fork 6, cross 1, shaft 8 form an external universal joint; the shaft 8, the spider 9, the hub 10 form an internal universal joint, and all together form a left (right) universal joint shaft 11, in which the poles of both universal joints coincide. The hubs 10 are connected by splines to the shaft 12 and are fixed from axial displacement by thrust rings. In this case, the hubs 10 are mounted on the shaft 12 so that the axes of their spikes are located in mutually perpendicular planes and intersect on the axis of rotation of the shaft 12. The shaft 8 rests on its end against the thrust bearing 13 mounted in the housing 1 at an angle y from the axis of the shaft 12. The pump 14 (Fig. 5) is communicated by windows in its wall with suction-pressure channels through the lock 15. The dimensions βmax, β, α, γ of the pump, depending on the given value of m, are determined by the following algorithm.

1. Find a functional relationship between m and βmax.

The volume of the annular channel of 360 ° is taken per unit. Since the cross section of the annular channel is constant, the volume of the annular sector is proportional to its angular size in degrees (hereinafter, the said volume is measured in degrees of the annular channel). Let the pistons 4, 5 with size βmax (theoretically) be in the position of maximum approximation (Fig.6), touch each other and occupy the volume βmax · 4, since there are four such pistons in the annular channel. Therefore, the volume of the channel in which water can be located: 360 ° - 4 · βmax. This volume of water for one revolution of the shaft 12 is pumped four times. Therefore, the volume of water pumped in one revolution of the shaft 12 (excluding the volumetric efficiency) is determined as follows: (360 ° - 4 · βmax) · 4 = m · 360 °. From here:

For example, if m = 0.5, then βmax = 78.75 °; if m = 1.0, then βmax = 67.50 °; if m = 2.0, then βmax = 45 °. In this case, the structural piston size β <βmax is assumed. The size α of the window is slightly larger than the size β or equal to β when performing the edges of the windows with unloading chamfers, that is, α≥β.

2. Find a functional relationship between γ and βmax.

2.1. The circumference of the annular channel (hereinafter OK) (Figs. 6 and 7) is divided into four quarters by two mutually perpendicular axes OXY, respectively §15 of the book by M.Ya. Vygodsky Handbook of elementary mathematics. M .: State publishing house of physical and mathematical literature, 1958, p.348-350, Fig.227, 229 [1]. Let the angle γ lie in a plane perpendicular to the plane of the OXY axes. For the positive direction of rotation of the shaft 12 and the pistons 4 5 take the counterclockwise rotation. For φ = 0 °, the position of the spikes of the hub 10 on the shaft 12 is taken, at which the projections of the axes of the spikes lie on the axis OX. Suppose that the pistons 4 are connected with the shaft 12 so that the bisectors of their angular dimensions and the corresponding axis of the spikes of the hubs 10 to which the pistons 4 are connected lie in the same plane. The same applies to pistons 5, but they lie in a different plane than pistons 4. (Next, the position of the piston is determined by the position of the corresponding bisector). In the position φ '= 0 °, the piston 5 is at the boundary of the beginning of the first quarter of OK (Fig. 7), and the piston 4 is rotated 90 ° in the direction of rotation of the piston 5 and is at an angle of φ' - 90 °, that is, at the boundary of the beginning of the second quarters OK (Fig.6).

2.2. The angle ψ of the shaft 8, as a function of the angle φ of rotation of the shaft 12 from the position φ = 0 °, is determined by the formula 11.4 from the book I. Artobolevsky Theory of mechanisms. M .: Nauka, 1967, p.249 [2], but recorded in the conventions above:

and to determine the angle φ 'of the piston in formula 11.4, instead of φ, substitute the value ψ from formula (2) and after the correct transformations get:

In order to obtain the correct value of the angle φ 'according to formula (3), the sign (±) of the tangent of the quarter of the OK in which the piston 4,5 moves is taken into account.

2.3. The angle Δφ corresponding to the angle φ of rotation of the shaft 12 from the position φ = 0 ° is determined by the formula:

For example, the maximum lead-lag angle of the piston from the shaft 12: Δφmax = ± 11.3 ° at γ = 35.17 °.

2.4. Accept (intuitive assumptions, hypothesis) that:

a) the pistons 4, 5 in the position of ultimate rapprochement (Fig.6) have equal speeds ω ',

b) the acceleration e of the pistons 4, 5 in the position of ultimate rapprochement (Fig.6) are equal in magnitude and opposite in sign,

d) the pistons 4, 5 from the position at φ = 0 ° (Fig. 7) to the position of their maximum rapprochement (Fig. 6) is moved by turning the shaft 12 by an angle of φ = 45 ° and rewrite the formula (3) to calculate φ 'as follows:

Take into account that φ = 45 °, tg 45 ° = 1, φ '= 90 ° -0.5 · βmax, and after substituting into the formula (5) and transformations, we obtain:

βmax, γ is calculated by the formulas (1), (5); if m = 1, then βmax = 67.5 °, γ = 35.17 °; if m = 2, then βmax = 45.0 °, γ = 49.9 °;

3. Check the correctness of the intuitive assumptions in 2.4. For this:

3.1. The speed ω 'is determined as the first derivative of φ' with respect to φ using formula (3):

Substitute φ = 45 ° - calculate the speed ω 'of the piston 5 (Fig.6). Substitute φ = 45 ° + 90 ° - calculate the speed ω 'of the piston 4. These speeds are equal every 90 °, that is, four times in one revolution of the shaft 12, see (Fig. 8).

3.2. The graph of the relative velocity ω '/ ω is performed according to the formula:

Extreme values at γ = 35.17 °; ω'max / ω = 1.5, ω'min / ω = 0.67.

3.2. The acceleration e is determined as the derivative of the velocity ω '/ ω with respect to the angle φ using formula (8):

Substitute φ = 45 ° - calculate the acceleration e of the piston 5 (Fig.6). Substitute φ = 45 ° + 90 ° - calculate the acceleration of the piston 4. These accelerations are equal in magnitude and opposite in sign every 90 °, and ε max = 0.93 [1 / rad].

3.3. Based on calculations by formulas (8). (9) and (10) assume that assumptions a), b), c) of clause 2.4 are correct.

4. The speed ω 'of the piston 4, 5 depending on the speed ω of the shaft 12 and the angle φ = ωt of its rotation from the zero position (from the border at the beginning of the first quarter of OK) is determined by the formula:

The above formulas are used in the design of a volumetric water pump.

Work. Let the shaft 12 rotate with a constant angular velocity ω. Due to the above mutual arrangement of the spikes of universal joints of the universal joint 11, the pistons 4 and 5 rotate cyclically unevenly in opposite phases with two maxima ω'max and two minima ω'min of speeds at each revolution of the shaft 12. This increases the volume of the chambers between the pistons cyclically increase-decrease, and water is pumped through the windows between the inlet and outlet channels. To reverse the water supply, the rotation of the shaft 12 is reversed.

Claims (2)

1. A volumetric pump for water, containing an annular channel of constant cross section in the wall for water inlet and outlet and there are two pairs of pistons, each of which is located between the pistons of the other pair, and the pairs of pistons are rigidly connected to separate for each pair of coaxial axles connected kinematically connected with a drive shaft by means of cardan shafts with the ability to rotate half shafts with pistons in the annular channel cyclically non-uniformly with uniform rotation of the drive shaft, characterized in that the maximum possible angular piston size βmax o limit according to the formula
βmax = 90 ° -m22.5 °
where m is a given volume of water, expressed in a dimensionless fraction of the total volume of the annular channel, pumped per revolution of the drive shaft, while the angular dimension β of the piston is not greater than the angular size α of the inlet-outlet window, and the angle γ of the axis of the shafts of the universal joints of cardan shafts set according to the formula

2. The pump according to claim 1, characterized in that it is in communication with the suction-pressure channels through a hydraulic lock.

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