Both realize energy conversion based on “volume change”. The vane hydraulic pump drives the rotor to rotate through external power, and uses the reciprocating motion of the blades in the rotor slots to make the sealed volume change periodically, converting mechanical energy into hydraulic energy; the vane hydraulic motor relies on the input pressure oil to push the blades and drive the rotor to rotate, realizing the conversion of hydraulic energy to mechanical energy. The essential logic of energy conversion between the two is the same.

In terms of structural composition, their core components are highly similar, including rotors, stators, blades, oil distribution plates and housings. Among them, the internal contour curve design of the stator needs to meet the sliding requirements of the blades, and the sealing cooperation between the blades and the oil distribution plate is basically the same. These common structures ensure the sealing performance and working efficiency of the components. In addition, in the hydraulic system, the pump and the motor play complementary roles: the pump outputs pressure oil as a power source, and the motor consumes pressure oil as an actuator to output rotational mechanical energy, and together build a complete energy transfer system.

• The difference between vane hydraulic pumps and vane hydraulic motors

The energy conversion direction and application scenarios are the most intuitive differences between the two. Pumps use mechanical energy as input and hydraulic energy as output, and are often used in power supply scenarios such as machine tool hydraulic stations and injection molding machines; motors use hydraulic energy as input and mechanical energy as output, and are mostly used in execution links that require rotational motion, such as excavator turntable rotation and printing press roller drive.

In terms of structural design, the two have targeted optimizations. In terms of the oil distribution plate, the pump’s oil suction and oil pressure windows are fixed, and negative pressure oil suction is formed by speed; the motor’s oil distribution plate window is symmetrically designed to meet the needs of forward and reverse rotation, and some are also equipped with pre-tightening oil grooves to ensure that the blades fit the stator when starting. The blades are installed at different angles. To reduce friction, the pump is often tilted forward by 10°-14° and the rotation direction is fixed. To achieve bidirectional rotation, the motor blades are mostly radially installed or symmetrically tilted. There are also differences in the oil leakage method. The leaked oil of the pump can flow back through the internal channel, while the motor requires an independent oil leakage port to prevent excessive pressure at the bearing and seal.

There are also significant differences in working characteristics and performance requirements. With respect to speed, the pump needs a certain speed to achieve the oil suction effect, but speed that is too high is easy to cause cavitation, and a good low speed start torque and wide speed range is expected from the motor. In terms of efficiency and pressure, the rated pressure of the pump can reach 6.3-21MPa, and volumetric efficiency also is as high as 90%-95%, and it represents more of a concern for flow stability, the rated pressure of the motor is slightly lower ( 6.3-16MPa), but the total efficiency is around 80%-90%, and it primarily is aimed at torque pulsation suppression. In terms of flow and torque relationship, the pump output flow is positively correlated with the speed, the motor output torque is proportional to the pressure difference (T=Δp×V/2π), and the speed is related to the input flow.

Although in theory some vane pumps can temporarily act as motors, the lack of dedicated oil drain ports and fixed blade inclination angles will lead to low efficiency and insufficient reliability. Vane hydraulic motors usually need to be specially designed through symmetrical structures, preload mechanisms, etc. to meet actual working conditions.

– Wrong direction of rotation: The motor goes to the wrong rotation and the pump is never able to suck and discharge oil normally. The motor rotation direction should be stopped immediately and corrected.

– Broken or non-rotating pump shaft: Absent is the motor power supply, a coupling, or a key is damaged, or the pump shaft is broken, preventing the rotor from turning. The power supply, coupling and key have to be examined while the damaged pump shaft be repaired or replaced.

– Blockage in suction line: The suction pipeline, suction oil filter, or oil tank filter is blocked because oil cannot go into the pump. The suction line requires inspection and cleaning, and the oil tank filter in case of limited flow needs to be replaced.

– Oil problem: The viscosity of the oil is too high, resulting in large sliding resistance for the blades and making it difficult for them to slide out of the rotor slots; if the viscosity is too low, then leakage increases, thus affecting the flow. Oil with the specified viscosity needs to be used.

– Speed problem: If the speed is too low, the centrifugal force is not enough to throw the blades out normally, affecting the sealing of the discharge chamber.

– Pump cover problem: Poor tightening of the pump cover will cause leakage and affect the flow rate. The pump needs to be reassembled with a torque wrench.

• The pressure of the vane pump cannot rise to the standard level

– Oil pump problem: The oil pump does not oil or the flow rate is insufficient, and the pump cover screws loosen due to long-term vibration of the oil pump, which will cause the pressure to fail to rise. The oil pump failure needs to be eliminated and the screws tightened appropriately.

– Overflow valve failure: The overflow valve adjusts the pressure too low or fails, so that the system pressure cannot be increased. The overflow valve pressure should be re-adjusted or the overflow valve should be repaired.

– System leakage: There is a leak in the system, which will cause the pressure oil to leak back to the oil tank, resulting in the pressure not rising. The system needs to be checked and the leak point needs to be repaired.

– Oil intake problem: A leak in the intake pipe or insufficient oil intake will cause air to be sucked in by the pump thus making pressure establishment more difficult. You need to check every fitting, seal and tighten it all to ensure adequate oil intake.

– Incorrect adjustment of variable pump: Pressure is incorrectly adjusted for the variable pump and needs to be adjusted to the required pressure.

• The noise of the vane pump is higher than the normal range

– Suction problem: Pump will suck air or will endlessly gall-up oil due to smaller suction pipe, blocked oil suction filter, insufficient flow rate at tank side filter, air being sucked by suction pipe, bubbles in the oil tank, oil tank filter being above the oil surface, etc. Appropriate measures must be taken in solving such a problem related to oil suction.

– Pump shaft problem: Air is sucked in the pump shaft oil seal, the coupling makes noise, the pump bearing is damaged, the cam ring is worn, the pump is severely worn, etc., which will also cause noise. It is necessary to check whether the axis is concentric and replace the damaged parts.

– Other problems: The oil tank air filter is blocked or the specification is too small, the rotation speed is too high, the set pressure is too high, the pump cover is not tightened properly, etc., which may also cause noise, and corresponding inspections and adjustments are required.

• The oil temperature in the vane pump is too high

– Pressure and speed: Too high pressure and too fast speed will increase the power loss of the pump and cause the oil temperature to rise. The pressure valve needs to be adjusted to reduce the speed.

– Oil viscosity: If the oil viscosity is too high, it will increase the flow resistance and increase the oil temperature. You should choose an oil with appropriate viscosity.

– Heat dissipation problem: If the oil tank has poor heat dissipation conditions and the oil tank volume is too small, the oil will not dissipate heat well and the oil temperature will increase. You can increase the oil tank volume or add a cooling device.

– Friction problem: If the oil distribution plate and the rotor rub severely, and the blades and the inner surface of the stator are severely worn, a lot of heat will be generated, which will increase the oil temperature. The worn parts need to be repaired or replaced.

• Bombas de engrenagem: soluções básicas econômicas

Os tipos mais simples de bombas hidráulicas Parker são as de engrenamento externo e interno. Bombas de engrenagens externas, como a série PGP, geram sucção de óleo com pressão negativa girando um par de engrenagens de engrenamento e são adequadas para cenários de baixa pressão e alta vazão, como sistemas de irrigação em máquinas agrícolas e circuitos hidráulicos auxiliares em equipamentos de construção. São baratas, possuem forte capacidade antipoluição, são fáceis de manter e são particularmente adequadas para condições operacionais com baixo nível de ruído e requisitos de precisão. Bombas de engrenagens internas (como a série QPM3) utilizam um projeto de dentes cicloides com uma taxa de pulsação de até 3%, adequada para sistemas de lubrificação industrial com altos requisitos de estabilidade de fluxo.

Aplicações típicas de bombas de engrenagens incluem:
Máquinas agrícolas: sistema de elevação hidráulica do trator, transmissão de potência da colheitadeira.
Fabricação industrial: lubrificação de máquinas-ferramentas, circuito auxiliar de óleo de máquinas de moldagem por injeção.
Equipamento móvel: circuito de óleo de controle piloto de pequena escavadeira.

• Bomba de palhetas: escolha eficiente no campo de média pressão

As bombas de palhetas são um tipo de bomba hidráulica Parker altamente técnica e madura, podendo ser classificadas como de simples ação (variável) ou dupla ação (quantitativa). As bombas de palhetas de dupla ação (como as séries T6/T7) são adequadas para aplicações de média pressão (7-21 MPa) e alta precisão, como o circuito de óleo de fixação de moldes de máquinas de moldagem por injeção e o sistema de alimentação de bancadas de máquinas-ferramenta. Elas conseguem isso acionando as palhetas para deslizar no estator através da rotação do rotor para produzir uma saída de fluxo uniforme. Suas vantagens são o baixo ruído (geralmente inferior a 60 decibéis) e a alta eficiência volumétrica (até 95%), mas apresentam altos requisitos de limpeza do óleo e precisam ser usadas com filtros de precisão.

Aplicações típicas de bombas de palhetas incluem:
Indústria de máquinas-ferramenta: sistema servo-hidráulico de centro de usinagem CNC.
Fabricação de automóveis: controle de fixação de linha de produção automatizada.
Engenharia naval: fornecimento de energia para máquinas de convés.

• Bomba de pistão: referência técnica na área de alta pressão

A bomba de pistão é a principal competência da Parker, classificada em duas categorias: bomba de pistão axial e bomba de pistão radial. A bomba de pistão axial (ex.: série PV, série P3) atinge alta pressão (até 420 bar) e grande vazão, ajustando o curso do pistão pelo ângulo da placa oscilante, sendo comumente utilizada no circuito hidráulico principal de máquinas de construção. Suas vantagens são alta eficiência volumétrica (92%-98%) e alta precisão de controle, podendo atingir regulagem de vazão de 0,1% por meio da tecnologia de deslocamento digital. A bomba de pistão radial (como a série Gold Cup) é caracterizada por alto torque de saída e é adequada para sistemas de transmissão fechados, como o controle de passo variável de turbinas eólicas.

Aplicações típicas de bombas de êmbolo incluem:
Máquinas de engenharia: principais sistemas de bombeamento de escavadeiras e carregadeiras.
Aeroespacial: unidades de energia hidráulica de trens de pouso de aeronaves.
Indústria metalúrgica: sistemas de prensagem de laminadores.

As bombas hidráulicas Parker abrangem uma gama completa de cenários, desde baixa pressão até ultra-alta pressão, por meio da matriz de produtos "bombas de engrenagens econômicas + bombas de palhetas eficientes + bombas de êmbolo de alta qualidade". Entre elas, as bombas de êmbolo se tornaram o principal crescimento do negócio de bombas hidráulicas da Parker, com suas vantagens técnicas de alta pressão, alta eficiência e alta confiabilidade.