术则相对比较成熟。

The operation is relatively mature.

1 泵体内部结构分析

Internal structure analysis of 1 pump body

轴向柱塞泵可分为斜盘式和斜轴式2大类。在变量形式上，斜盘式轴向柱塞泵靠斜盘摆动变量，斜轴式轴向柱塞泵则为摆缸变量。斜盘式轴向柱塞泵有通轴和半轴2种结构，其中通轴型在液压行业使用比较广泛。通轴型斜盘式轴向柱塞泵的结构特征如图所示。

The axial piston pump can be divided into 2 types: inclined disk type and inclined shaft type. In the form of variable, the inclined disk axial piston pump depends on the swing variable of the inclined disk, and the skew axial piston pump is the variable of the pendulum cylinder. The inclined disk axial piston pump has 2 kinds of structure, which are through shaft and half axis, of which the shaft type is widely used in the hydraulic industry. The structure features of the axially inclined axial piston pump are shown in the diagram.

该泵的主轴采用了两端支承，斜盘通过柱塞作用在缸体上的径向力可以由主轴轴承受，因而取消了缸体外缘的大轴承; 该泵无单独的配流盘，而是通过缸体和后泵盖端面直接配油。缸体中孔内的弹簧的作用与非通轴型泵的相同，是将缸体压向右侧配流端面,保证启动时的密封。通轴泵结构的另一特点是在泵的外伸端可以安装一个小型辅助泵(通常为内齿轮泵) ，供闭式系统补油之用，因而可以简化油路系统和管道连接，有利于液压系统的集成化。这是近年来通轴泵发展较快的原因之一。此外，通轴驱动是一种坚固设计，通轴驱动选项便于安装控制装置，附加装置或其他的辅助泵。它能安装同样规格的第二个泵，这就提供了真正的串联泵的结构。

The main shaft of the pump is supported by two ends. The radial force of the swashplate acting on the cylinder body can be sustained by the spindle shaft through the plunger. Therefore, the large bearing on the outer edge of the cylinder body is cancelled. The pump has no separate distributor, but directly matches the oil through the cylinder block and the rear pump cover end. The function of the spring in the hole in the cylinder is the same as that of the non - shaft type pump. It is to press the cylinder body to the right side of the flow face to ensure the sealing of the start. Another feature of the shaft pump structure is that a small auxiliary pump (usually internal gear pump) can be installed at the extended end of the pump, which can be used for the closed system to replenishing oil, so that the connection between the oil system and the pipeline can be simplified, and the integration of the hydraulic system will be beneficial. This is one of the reasons for the rapid development of the shaft pump in recent years. In addition, the through axis drive is a solid design, and the through axis drive option is convenient for installation of control devices, additional devices or other auxiliary pumps. It can install second pumps of the same specification, which provides the real structure of the series pump.

1.1 缸体端面间隙的自动补偿

Automatic compensation for end gap of 1.1 cylinder block

使缸体紧压配流盘端面的作用力，除弹簧的推力外，还有柱塞孔底部台阶面上所受的液压力，此液压力比弹簧力大得多，而且随泵的工作压力增大而增大。由于缸体始终受力而紧贴着配流盘，就使端面间隙得到了自动补偿，提高了泵的容积效率。

The force acting on the end surface of the valve body is tightly pressed. Besides the thrust of the spring, there is also the liquid pressure on the bottom step surface of the plunger hole, which is much larger than the spring force and increases with the increase of the working pressure of the pump. As the cylinder body is always stressed and clinging to the flow plate, the end gap is automatically compensated and the volume efficiency of the pump is improved.

1.2 柱塞头接触方式

Contact mode of 1.2 plunger head

轴向柱塞泵在工作时由于柱塞球头与斜盘平面理论上为一点接触，因而接触应力大，极易磨损。一般轴向柱塞泵都在柱塞头部装一滑履，二者之间为球面接触，而滑履与斜盘之间又以平面接触，从而改善了柱塞工作的受力状况。并且由于各相对运动表面之间通过小孔引入了压力油，实现可靠的润滑，故大大降低了相对运动零件表面的磨损。这样，就有利于泵在高压下工作。

When the axial piston pump is in contact with the plane of the plunger head and the inclined plate, the contact stress is large and it is very easy to wear. In general the axial piston pump plunger head mounted sliding shoe, between the two spherical contact and sliding between the shoe and the inclined plate with surface contact, thereby improving the work force of the piston. Moreover, due to the introduction of pressure oil through the small holes between the relative moving surfaces to achieve reliable lubrication, the wear of the relative moving parts is greatly reduced. In this way, it is good for the pump to work under high pressure.

1.3 滑靴的静压支撑结构

Static pressure support structure of 1.3 slipper

如图所示，滑靴是按静压轴承原理设计的，缸体中的压力油经过柱塞球头中间小孔流入滑靴油室，使滑靴和斜盘间形成液体润滑，改善了柱塞头部和斜盘的接触情况，有利于提高轴向柱塞泵的压力。柱塞由斜盘上的滑靴轴承静压平衡，有效地提供无脉动流量。

As shown, slipper is designed according to the principle of hydrostatic bearing, the oil pressure in the cylinder by the piston ball head into a small hole in the middle of the slipper oil chamber, the liquid lubrication form slipper and swash plate, improve the contact condition of plunger head and the swash plate, improve the pressure of axial piston pump. The plunger is balanced by the static pressure of the slipper bearing on the inclined plate to provide no pulsating flow effectively.

1.4 壳体内的泄油压力

Oil relief pressure in 1.4 shells

壳体内的泄油压力取决于轴封所能允许的最高压力。德国REXROTH 公司生产的斜轴式轴向柱塞泵和马达的壳体泄油压力一般为012 M Pa，也有高达1 MPa的(如A2F定量泵系列)，国产轴向柱塞泵和马达的壳体泄油压力应严格遵照产品使用说明书的规定，过高的壳体泄油压力将导致轴封的早期损坏。

The oil discharge pressure in the shell is determined by the maximum allowable pressure in the shaft seal. The German company REXROTH axial plunger pump and motor oil pressure is 012 M Pa, there are up to 1 MPa (such as A2F, a series of quantitative pump) of domestic axial piston pump and motor oil pressure shall be in strict accordance with product instructions, a high relief the oil pressure will lead to the early damage of seal.

1.5 柱塞数

1.5 plunger number

图表 3 柱塞泵内部 如图所示，设柱塞直径为d，柱塞数为Z，柱塞中心分布圆直径为D，斜盘倾角为C，则 柱塞泵的排量和流量分别为

Chart 3, as shown in the plunger pump, the diameter of the plunger is D, the number of plungers is Z, the central diameter of the plunger is D, the obliquity of the swashplate is C, and the displacement and discharge of the plunger pump are respectively.

式中: n为泵的转速; GpV为泵的容积效率。轴向柱塞泵的输出流量是脉动的。 理论分析和实验研究表明,当柱塞个数多且为奇数时流量脉动较小。从结构和工艺考虑，柱塞个数多采用7或9。

In the type: n is the speed of the pump; GpV is the volume efficiency of the pump. The output flow of the axial piston pump is pulsating. Theoretical analysis and experimental study show that the flow pulsation is smaller when the plunger is more than a number of odd numbers and is odd. In terms of structure and technology, the number of plungers is more than 7 or 9.

2 轴向柱塞泵失效分析

Failure analysis of 2 axial piston pump

基于轴向柱塞泵的结构分析，其失效的外在因素主要有:

Based on the structural analysis of axial piston pump, the main external factors of its failure are as follows:

(1) 泵安装位置不好导致轴承润滑不足。例如:没有压力的循环会引起泄漏油反向，液压油将从壳体通过阀板的泄漏孔流到液压缸，在这种条件下工作的泵将使轴承无法润滑，造成损坏。因此，泄漏必须安装成允许液压油能从油箱中吸出，为了实现此目的:1 泄漏管必须低于油箱液面; 2 在泄漏管中不允许有单向阀; 3 如有单向阀，壳体必须用外部流量冲洗。

(1) the poor installation of the pump leads to the lack of lubrication of the bearing. For example, a cycle without pressure will cause the reverse of the leakage oil. The hydraulic oil will flow from the shell to the hydraulic cylinder through the leakage port of the valve plate. Under this condition, the pump will cause the bearing to be unable to lubricate and cause damage. Therefore, leakage must be installed to allow hydraulic oil to be sucked out of the tank. In order to achieve this goal: 1, the leakage pipe must be lower than the tank level; 2, no one-way valve is allowed in the leakage pipe; 3, if there is a check valve, the shell must be washed by external flow.

(2) 油液清洁度不符合要求。正确的油液状态对于延长液压元件和系统的寿命来说至关重要。但轴向柱塞泵实际运行中，常因以下原因导致液压油清洁度不符合要求: 1 在日常检修施工，比如更换密封件、换软管或配管，检修施工人员不注意清洁，导致杂物混入系统; 2 泵长时间工作后，斜盘与滑靴摩擦及缸体与柱塞摩擦产生细小铜粉进入系统，导致油液污染; 3 在更换新油缸时，油缸试压的油与系统用油不同，结果2种油相混进入系统，导致油液变质。

(2) the cleanliness of the oil is not in conformity with the requirements. The correct oil state is essential to prolonging the life of the hydraulic components and the system. But the axial piston pump in actual operation, often due to the following causes of cleanliness of hydraulic oil does not meet the requirements: 1 in the daily maintenance of construction, such as the replacement of seals, hose or piping for maintenance, construction personnel do not pay attention to clean debris mixed system; 2 pump after long time working, the swash plate and the cylinder friction and sliding boots with the piston friction to produce fine copper powder into the system, resulting in oil pollution; 3 in the replacement of the new oil cylinder, oil cylinder and oil pressure test system, results of 2 kinds of oil mixed into the system, resulting in deterioration of oil.

(3) 油温过高及油温过低，循环冷却能力不足,系统散热不良。液压泵的最低工作温度一般根据油液黏度随温度降低而加大来确定。当油液黏稠到进口条件不再保证液压泵完全充满时将发生气蚀。抗燃液压油的密度大于石油基液压油，有时低温黏度也更大。许多抗燃液压油含水，如果压力低或温度高则水会蒸发。因此，使用这些油液时，泵进口条件更加敏感。常用

(3) too high oil temperature and low oil temperature, insufficient circulating cooling capacity and bad cooling system. The lowest working temperature of the hydraulic pump according to the general oil viscosity increases with decreasing temperature and increasing the determination. Cavitation will occur when the oil is viscous until the inlet conditions are no longer guaranteed to be full of the hydraulic pump. The density of the anti combustion hydraulic oil is greater than that of the oil based hydraulic oil, and sometimes the viscosity of the low temperature is greater. Many anti combustion hydraulic oils are hydrated, and water vaporizes if the pressure is low or the temperature is high. Therefore, when the oil is used, the inlet conditions of the pump are more sensitive. Common