We, Zhenhai Tongda Hydraulic Goods Factory, is a professional factory specialized in producing low-speed big-torsional-moment hydraulic motor. Our products are sold far to national and international countries. And we are located in Zhenhai Harbor District, Ningbo. So the land, water and air communication is very convenient. Our main product is the radial ball tap-style low-speed big-torsional-moment hydraulic motor. Presently, we have already had the variety of 8 series, including fixed displacement, changing displacement, through-hole, transferable, with bearing, with tachometer, with brake, and with valve set, we also have many specifications. Besides, we also produce many kinds of hydraulic valves, all the products listed in this book have already been produced, if customers have other requirements of installation linking dimension and technical parameter, our factory generally can redesign to satisfy the requirements of clients.

　　Product application scope:
　　QJM-type hydraulic motor, matching with all kinds of oil pumps, valves and hydraulic accessories, can make up hydraulic activity. Because it has adopted all kinds of measures on design, it could adapt to the working conditions of all kinds of machines. This type of motor has a series of advantages, such as light weight, small volume, big velocity modulation scope, could change displacement with grades, mechanical brake could automatically open and close, good low-speed stabilization performance, reliable working, shock endurable, high efficiency, long life, and so on. Presently, it has been widely used in the departments of mine construction engineering, lifting transportation, metallurgy heavy-duty, petroleum, coal mine, vessels, machine tool, light industry pouring-plastic, geological exploration, etc. It could directly drive caterpillar walking, applying to the mechanisms of track wheel driving, all kinds of revolution lifting mechanisms, exploration and drilling, band transportation, material agitation, pavement cutting, vessels propulsion, plastics-pouring, etc.

　　Main features of QJM-type hydraulic motor:
　　1, the rolling body of this type of motor using only one steel ball to replace the roll and cross beam of two and upwards used in general inner-curve hydraulic motors, so it has the features of simple structure and reliable working, volume and weight reducing markedly.
　　2, little sport inertia, strong and reliable steel ball, which make this type of motor could work successively under the higher speed of revolution and impact load.
3, little friction, the oil axis balancing the rotor inner force, the ball tap transporting force through the pad made by self-lubrication composite materials, and having the conditions of static pressure balance and good lubrication, adopting the soft plastic piston ring which could automatically compensate wear to seal high-pressure oil, so having higher mechanical and volumetric efficiency, which could stably run under very low speed of revolution, and the starting moment is also bigger.
　　4, because the structure having features, the return-oil back pressure needed by this motor is lower, generally needing 0.3-0.8Mpa, the higher of the speed of revolution, the greater of the back pressure.
　　5, because the oil axle rigidly linking the stator, the pushing-out oil pipe of this type of motor is allowed to use steel pipes to link.
6, this type of motor having two-grades and three-grades of displacement, so it having bigger scope of velocity modulation.
　　7, simple structure, convenient disassembling and fixing, having no special requirement of oil cleanliness, the oil filtration precision could be selected according to the requirements of matching oil pump.
　　8, except for types of transferable and with bearing, the out axle of hydraulic motor is generally only allowed to stand torsional moment, not to stand radial and axial external force.
　　9, the hydraulic motor with “T” type, having a hole in the center, and the drive shaft could pass through hydraulic motor.
　　10, the hydraulic motor with “S” type having the mechanical brake which could automatically open and close, which could realize reliable braking.
　　11, could install tachometer on the back part of the hydraulic motor with “B” type to display the speed of revolution of hydraulic motor.