Hydraulic pump and motor device how to choose?
Hydraulic pump and motor device in the hydraulic system in the proportion is very important, a good hydraulic system, a good hydraulic pump, but also a good motor, so, in the configuration of hydraulic pumps and motors, we need to pay extra attention. So, how to choose the hydraulic pump and motor device? AOTS to give you all the explanation.
Hydraulic pump - motor device including hydraulic pumps, electric motors, pump couplings, drive base and piping accessories, also known as the pump group. Figure 16-1 shows a typical pump group structure .
(1) motor power calculation. According to the pressure and flow selected hydraulic pump specifications after driving the hydraulic pump motor power can be calculated according to the following formula P = ppqp / η where P for the motor power, W; pp for the hydraulic pump's great working pressure, Pa; qp for the hydraulic pump's output flow rate, m3 ／ s; η for the hydraulic pump's total efficiency, can be found by the hydraulic pump product samples. At this time, it must be noted that when the pump's operating pressure is lower than its rated pressure, the working flow is less than the rated flow, the total efficiency of the pump will drop a lot. According to the formula (16 singing 7) selected motor power with a certain power reserve, but allows short-term overload 25%. After selecting the motor, motor speed, power has been determined, but the motor type is also related to its installation form.
(2) Installation form of motor. Available motor mounting form there are three main: base with feet, end cover without flange structure; base without feet, end cover with greater than the base of the flange structure; base with feet, end cover with greater than the base of the flange structure. Figure 16-1 shows the structure of the base with a foot, no flange on the end cap, generally used for horizontal placement. If the pump set is placed vertically, it should be used with the structure of the base without feet and the flange on the end cover which is larger than the base. Seat with feet and end caps with flange structure for horizontal placement of the pump group, this time the hydraulic pump through the flange type bracket support on the motor.
(3) Coupling. As the drive shaft of the hydraulic pump can not withstand radial loads and axial loads, but also requires the pump shaft and motor shaft has a high degree of coaxiality, so the general use of flexible coupling connection form. The specification of the coupling is selected according to the maximum value of the transferred torque. If you choose a special shaft end with internal spline connection holes in the motor, you can choose the spline spindle input end of the hydraulic pump, the two are directly inserted into the assembly. This can maintain the concentricity of the two shafts, but also eliminate the coupling, so that the size of the pump group to reduce.
(4) pump base. Small power pumps can be installed in the tank on the cover (top-mounted), the power of a larger need to be installed separately on a special platform (non-top-mounted). Pump set of the base should have sufficient strength and rigidity, to facilitate the installation and maintenance, while in the appropriate parts of the set of oil drain pan to prevent hydraulic fluid contamination of the site. In order to reduce noise and vibration, the pump and the installation platform is better to add elastic material made of vibration pads.
(5) piping accessories. Hydraulic pump suction pipe is generally used hard pipe, pipe as short as possible, as large as possible overflow area to reduce suction resistance. When installing the suction pipe, pay attention to the hydraulic pump has a suction height limit. Installation of non-superpositioned pumps, need to add a gate valve between the oil tank and the pump suction port, in order to facilitate maintenance. Because the oil suction pipe is a hard pipe, so should be set in the suction port rubber compensation pipe (vibration isolation throat), vibration isolation, compensation.
In the configuration of hydraulic pumps and motors, you need to take into account the above factors in order to match yourself to a powerful hydraulic system. In the configuration of the actual situation needs to be based on their own, combined with the workplace, must not go with their own preferences to the system with unsuitable devices, otherwise it will only be counterproductive.
