Plunger pump principle, single-plunger pump working principle

Piston pump principle First, the radial piston pump features: the plunger arranged in the radial direction of the drive shaft, that is, the plunger centerline perpendicular to the drive shaft centerline 1. Radial piston pump working principle Structure: the stator, rotor, Plunger, oil shaft, etc. ↓ ↓ Eccentric fixed working principle: V close into the formation - the same as the first half of the week, the oil absorption V dense change - the rotor clockwise <second half of the week, the oil displacement V = πd22ez / 4 2) Vn = πd22ezn / 4 q = Vnηpv = πd22eznηpv / 4 Variable Principle: Displacement and Flow Rate of Radial Piston Pump Change the size and direction of the eccentricity to change the size and direction of the output fluid. Valve Diameter radial piston pump works Radial piston pump features: large flow, high pressure, easy to create multi-row plunger form, reliable work, but the radial size, self-absorption ability is poor, with radial flow axis Force imbalance, easy to wear, the gap can not be compensated, it limits the speed and pressure increase. Second, the axial piston pump features: parallel or inclined axis of the plunger axis cylinder 1. Axial piston pump works 1) Swash plate axial piston pump composition: with oil pan, plunger, cylinder Body, tilt plate, etc. Working principle: V close to the formation - the right half of the cylinder with the plunger and the cylinder, V density increases, oil absorption V density change, cylinder reverse <left half weeks, V density decreases, Oil port separated - oil pan on the oil pan and the bottom of the hole through the oil hole 2) inclined axis axial piston pump features: axis of the transmission shaft and the cylinder axis tilt of a γ angle. Composition: Working principle: V densely formed - the same as the right half weeks, the suction V density change - drive shaft reverse <left half weeks, pressure oil pressure port separated - Ibid 2. Axial piston pump displacement and flow 1) Displacement If the plunger number is z, the plunger diameter is d, the diameter of the distribution of the plunger hole is D, the inclination of the swash plate is γ, then the stroke of the plunger is: h = Dtanγ, , The displacement of the pump is: V = Zhπd / 4 = π d2 ZD (tanγ) / 4 2) Flow rate Theoretical flow rate qT = Vn = πd2D (tanγ) z / 4 Actual flow rate q = qTηpv = πd2D (tanγ) zηpv / 4 Conclusions: (1) qT = f (geometric parameter, n, γ) (2) n = c size change, flow rate change γ <direction change, oil change direction principle: ∵ γ = 0 q = 0 size Change, the size of the flow changes γ <direction change, the direction of the oil changes ∴ axial piston pump can be used as a two-way variable displacement pump instantaneous flow: axial displacement of the plunger: s = a'b '= oa'-ob' = Dtanγ / 2 - Dcosωttanγ / 2 = D (1-cosωt) tanγ / 2 The instantaneous moving speed of the plunger: u = ds / dt = Dωtanγsinωt / 2 The instantaneous flow of a single plunger is: q '= πd2u / 4 = πd2Dωtanγsinωt / 8 ∵ The instantaneous flow rate of a single plunger changes according to the law of Xuan arc. The instantaneous flow rate of the whole pump also changes according to the regular law of Xuanxuan. Therefore, the instantaneous flow rate is pulsatile. The pulsation condition is expressed by the pulsation rate δ, generally: z = odd number, z = even, δ often take z = 7 or z = 9 3 axial piston pump structure (1) swash plate axial piston pump 1) non-axial piston pump CY14--1 Axial Piston Pump Body: Pump Self-priming Spring Center <Automatically Compensates For Clearance of Center Cylinder Spring Body Cylinder Opening P ** Excluding Cylinder from Compressor Disc The hydraulic pressure at the bottom of the plunger bore also forces the cylinder against the adapter plate, compensating for the end clearance and increasing the volumetric efficiency. A Slipper and swash plate The spherical head - is in contact with the swashplate for point contact and has high contact stresses and easy to wear. Plunger head structure <Slipper structure - Contact with swashplate for surface contact minimizes wear. B Plunger and Cylinder ② CY14--1 Axial Piston Pump Variable Mechanism Manual * - Rotate the handwheel to control the swash plate and change the angle to change the variable mechanism <Automatic 2) Through-shaft type axial piston pump Non-through-axis structure (Axle): poor state of stress, short life, noise, high cost. Difference <Through shaft structure: The spindle adopts both ends support, the force situation gets better; Install a small auxiliary pump on the outer end of the pump to simplify the oil path. (2) Inclined Axial Piston Pump Features: Drive shaft axis and the cylinder axis tilt a γ angle. Working principle: V densely formed - the same as the right half of the week, the suction V density change - drive shaft reversal <left half weeks, pressure oil pressure port separated - Ibid) plunger pump principle