At present, the system used in series by multiple cycloidal motors (see Figure 1) is applied to sweepers, trenchless drills and airport luggage carts. The output shaft of the hydraulic motor often leaks oil during use, so it is useless to replace the dynamic seal of the output shaft. In series application, the problem of casing oil leakage pressure is ignored. The oil leakage pressure of the housing refers to the maximum pressure that the motor shaft seal can bear after the hydraulic motor is fully lubricated inside; If the hydraulic motor is applied special-purpose Cycloidal hydraulic motor with brake Improper. After the machine has been working continuously for a period of time, due to various factors, the oil in the housing will not be released, resulting in higher and higher pressure in the housing of the hydraulic motor, which first leads to the failure of the shaft seal. The casing leakage pressure mentioned here is not the bursting pressure of the casing, but the pressure that the motor output shaft dynamic seal can bear. In the motor samples of some manufacturers, only the back pressure is mentioned. Actually, back pressure refers to electricity Cycloidal hydraulic motor with brake manufactor The return oil pressure of the engine, not the oil discharge pressure of the casing. During operation, the requirements for the oil discharge pressure of the cycloidal motor housing are as follows. Eaton is the world's first cycloid motor manufacturer. In China's domestic cycloidal motor manufacturing industry, Jining Jinjia Hydraulic Co., Ltd. uses Eaton technology to produce cycloidal motors. Its output shaft dynamic seal has better bearing capacity, that is, the unique internal oil circuit design of the company's products enables internal oil drainage not only to lubricate parts, but also to discharge excess oil while maintaining a certain housing oil drainage pressure.

When the working load changes from low speed to high speed in a wide range, the hydraulic motor is also required to be able to drive and regulate speed in the corresponding wide range, which requires the motor to have good low-speed stability and high speed performance. The speed regulation range K of the hydraulic motor is usually expressed by the ratio of the allowable maximum speed to the minimum speed. special-purpose Cycloidal hydraulic motor with brake It is the highest operating speed of hydraulic motor, but it is limited by many factors, mainly including: 1. Service life. After the speed increases, each pair is worn Lishui manufactor The service life is shortened. 2、 Mechanical efficiency limits. At high speed, the hydraulic motor needs to input large flow, accordingly, the hydraulic loss of each circulating component increases, reducing the mechanical efficiency.

1. The hydraulic system is characterized by high energy density. For motors with the same power, hydraulic motors are much smaller and lighter than motors. And it is easy to apply to mobile devices. 2. The hydraulic motor has convenient speed regulation, which can be adjusted infinitely from 0 to the maximum speed according to the adjustment of the hydraulic valve. The motor itself does not need special design and has low cost. This is much cheaper than motor+reducer, or variable frequency motor and servo motor. 3. The hydraulic motor is totally enclosed and can be safely used in dusty, wet (even underwater) and flammable environments, which is much more reliable than explosion-proof (flameproof) motors. 4. The hydraulic system has strong anti overload capacity, and it is protected by the overflow valve, allowing long (relatively) frequent overloads. It is easy to recover under overload conditions, without damaging the equipment or restarting the equipment. These unparalleled advantages of motors have made hydraulic motors and hydraulic technology rapidly spread and popularized around the world in the past 20 years. People increasingly feel the importance of hydraulic motors in practice.

The hydraulic motor has two circuits: the hydraulic motor series circuit and the hydraulic motor braking circuit. These two circuits can be classified into the next category. One of the series circuits of hydraulic motors: three hydraulic motors are connected in series with each other, and a reversing valve is used to control the start stop and steering. The flow through the three motors is basically the same. When the displacement is the same, the speed of each motor is basically the same. The oil supply pressure of the hydraulic pump Lishui manufactor High, small pump flow, generally used for light load and high speed. Serial circuit II of hydraulic motor: each reversing valve in this circuit controls one motor, each motor can work independently or simultaneously, and the rotation direction of each motor is also special-purpose Cycloidal hydraulic motor with brake optional. The oil supply pressure of the hydraulic pump is the sum of the working pressure difference of each motor, which is applicable to the condition of high speed and small torque.