Ò»¡¢Summary

YP series (pressure type) hydraulic dynamometers have been widely used abroad in the 1960s and 1970s. In 1985, through license trade, China introduced the technology of Zoller Company, West Germany, to develop and produce this type of advanced dynamometer. At present, the process technology has been used in the production of a whole series of products in China. Internationally, there are Fraud in England and Cairn Company in the United States. In addition, two domestic companies have produced this series of products in small batches through imitation. Our company digests and absorbs foreign technology, carries out new optimization design and production, and can provide a full range of products.

¶þ¡¢Technical specifications

1£®Main features
¡ôSmall size, easy installation£»
¡ôSimple structure, easy operation and maintenance£»
¡ôHigh braking moment£»
¡ôHigh accuracy of measurement£»
¡ôWork stably and reliably£»
¡ôAchieving High Precision Instantaneous Speed Measurement with Magnetoelectric Velocity Sensor£»
¡ôFast Load Control of Electronically Controlled Butterfly Valve£»
¡ôFast response, suitable for dynamic test

2£®Measuring performance indicators

3.Technical parameter

Table units£ºmm

4£® Characteristic curve

The application scope of hydraulic dynamometer can b e seen from its characteristic curve as shown in Fig. 1 (a), (b), ?, (d), €, (f), (g), (h). Characteristic curve shows the power range that dynamometer can absorb at different rotational speeds.
The OA curve represents the maximum power line that the dynamometer can absorb with the change of rotational speed under a certain inlet pressure.
When AB line keeps the dynamometer's maximum torque, the maximum power line that dynamometer can absorb will change with the speed.
When the AC line (YP20) and BC line are not more than the maximum permissible discharge temperature of dynamometer, the maximum power limit line that dynamometer can absorb.
CD line is the maximum speed limit line of dynamometer.
OD curve is the braking power line (air friction resistance) of Dynamometer when it is not filled with water.
The area surrounded by the curve graph OABCDO indicates the power range that the hydraulic dynamometer can absorb. This is also the basis for choosing dynamometer in power machine performance test. In general, all the characteristics of the power machine can be tested on this type of hydraulic dynamometer within the range of curve and figure.
©~When choosing dynamometer, users must pay attention to whether the test point of the dynamometer is within the range of the characteristic curve of the dynamometer and avoid the edge of the curve as far as possible.
©~The minimum absorptive power line (full open position of butterfly valve) is slightly higher than OD line under the optimal control of water filling, and should not be too close to OD line when selecting type.

Èý¡¢Structure of dynamometer

YP type hydraulic dynamometer is mainly composed of body parts, force measuring mechanism parts, intake and drainage parts, correction parts, electric drainage valve parts, automatic regulating device parts and lubricating parts. See Figures II (a), (b).
1£®Body parts
The body parts are the main parts of dynamometer to absorb the effective torque of power machine by using water. See Figures III (a), (b).
The mechanical energy output from the power machine is converted into heat energy here, which is absorbed by the water entering the shell and discharged. A very small part of the mechanical energy is dissipated to the air by the wall of the dynamometer shell.
The simple structure consists of a swinging housing mounted on a rolling bearing and a rotor mounted on a spindle. The dynamometer rotor is installed in the middle of the main shaft, and the left and right side shell and the left and right bearing shell are symmetrically installed on both sides of the rotor. The working cavity is formed by the rotor pit and the left and right side shell pit. The bimetallic bushing connected with the shell of the left and right bearing not only acts as the bushing, but also acts as the sealing water. YP880, Y1200, YP1900, YP2500, YP3300 and YP5900 dynamometers are sealed by clearance to prevent water from entering the bearing, thus ensuring the service life of the bearing.
There are drainage holes on the shell and water intake holes on the left and right bearing shell to ensure the entry of low-temperature water and the discharge of high-temperature water. There is an overflow pipe in both the left and right bearing housing, and the water thrown out by the water throwing ring is discharged after the overflow pipe enters the base.
The spindle is equipped with coupling at both ends of the cone, and the speed measuring gear is installed on one side. Through the speed measuring sensor, the spindle speed can be displayed in the digital display table.

Figure two£¨b£©Y880-S¡¢Y1900-S¡¢Y3300-SOutline schematic diagram of hydraulic dynamometer

1¡¢Body parts2¡¢Dynamometer unit 3¡¢Lubrication parts 4¡¢Intake and drainage components5¡¢correcting member6¡¢Automatic adjusting device components

Figure three£¨a£©YP1900Structural sketch of airframe components

1¡¢base  2¡¢Left and Right Bearing Seats  3¡¢Spindle components  4¡¢Coupling  5¡¢Bearing plate  6. Skeleton oil seal 7, axle sleeve 8.9, bimetal axle sleeve & nbsp; 10, left and right bearing shell & nbsp; 11, left and right side shell & nbsp; 12, screw & nbsp; 13, rotor 14, shell & nbsp; 15, water seal ring & nbsp; 16, speed measuring gear & nbsp; 17, speed sensor & nbsp; 18, overflow pipe & nbsp; 19, cock

Figure three£¨b£©YP1900Structural sketch of airframe components

1¡¢base 2. Bearing seat 3, coupling 4, spindle component 5, bearing shell 6, shell 7, side shell 8, rotor 9, speed sensor 10, speed measuring gear

It is mainly composed of brake arm, tension pressure sensor and movable bolt. The braking moment produced by the body parts is balanced with the reaction moment of the brake arm pull-up pressure sensor, and the braking force is displayed by an electronic digital display instrument. In order to protect the sensor, nylon ring or rubber ring is installed at one end of the movable plate bolt to play a buffer role. At the same time, in order to prevent the sensor from being damaged by vibration in transportation, a supporting and fixing protection device is provided. The bolt of the fixed sensor must be loosened in use, and the movable plate should be pulled to one side. If there is no movable plate, the bolt can be screwed off.

Figure four£¨a£©YP20¡¢YP60¡¢YP120¡¢YP250¡¢YP380¡¢YP520¡¢YP660

Drawing of Force Measuring Mechanism Components

1. Brake arm 2, tension and pressure sensor 3, movable bolt 4, support 5, protective cover 6, movable plate 7, bolt 4

Figure four£¨b£©YP1900Schematic diagram of dynamometer mechanism

1. Brake arm 2, fixed bolt 3, movable bolt 4, tension pressure sensor

The intake parts of YP880, YP1200, YP1900, YP2500, YP3300 and YP5900 dynamometers are composed of intake valve parts and intake pipes. The drainage components are composed of a drainage butterfly valve, a drainage elbow and a drainage actuator.

Figure five£¨a£©Drawing of Intake and Drainage Components

1. Overflow pipe 2, permeable pipe 3, intake parts (5, elbow 6, pipeline 7, bracket) 4, drainage parts (8, bracket 9, pipeline 10, elbow)

Figure five£¨b£©Y880-S¡¢Y1900-S¡¢Y3300-Sdrawing of Intake and Drainage Components

1. Spillway 2, Intake Component 3, Drainage Actuator 4, Drainage Butterfly Valve 5, Drainage Bend

Fig. 6. Schematic diagram of correction components
1. Correction arm 2, lifting parts 3, lifting rod 4, tray 5, weights

YP60¡¢YP120¡¢YP250¡¢YP380¡¢YP520¡¢YP660 Hydraulic dynamometers use this form to control the drainage butterfly valve

Figure sevenDiagram of DPF Electric Drainage Valve Components

1. Potentiometer 2, Torque Motor 3, Planetary Pair 4, Shell 5, Butterfly Valve

Fig. 8. Component sketch of automatic regulating device
1. Drainage Actuator 2.3, Gear Pair (Synchronized Tooth Belt) 4, Angle Iron 5, Drainage Butterfly Valve 6, Support Plate

It is mainly composed of drainage actuator, drainage butterfly valve, supporting plate, gear pair, etc.

YP880, YP1200, YP1900, YP2500, YP3300, YP5900 hydraulic dynamometers all use this form to control the drainage butterfly valve.

YP880, YP1200, YP1900 dynamometers are equipped with YZ60A drainage actuator produced by our factory, YP2500, YP3300, YP5900 dynamometers are equipped with YZ20 drainage actuator.

L---Calculated arm length is 0.9549(m)

The circulating water supply system is mainly composed of heat sink, water pump, stabilized water tank, intake and drainage connection pipeline, water pressure meter, valve and so on. The volume of the pool should consider heat dissipation and measure the maximum power consumption, and there is a certain amount of surplus to compensate for water dissipation in the process of circulation. It is suggested that the volume of the pool should be increased as much as possible when conditions permit. The volume of water tank should be considered when the maximum water consumption is constant water supply (see the table of technical parameters for water consumption). When the water supply of the pump is larger than the maximum power consumption of the dynamometer, the volume of the stabilized tank can be recommended to be about 2-5 M3. The smaller the water consumption is, the larger the water consumption is. The volume of the tank is generally about five times that of the tank. If conditions permit, try to be as large as possible.

The diameters of intake and drainage pipes should meet the requirements of the diameters of intake and drainage of dynamometers.

A gate valve and a water pressure gauge shall be connected in series in the intake pipeline. The gate valve is used to regulate the intake pressure. For a fixed engine type, it usually stops moving after one adjustment. Therefore, the gate valve can be installed in any convenient position, while the ball valve on the dynamometer intake pipe is used for opening and closing water supply.

Drainage pipes are generally larger than intake pipes. Drainage pipes can be circulated through clay pipes to the pool. If the user's water source is rich, it can also be discharged into the sewer. Two problems should be paid attention to in drainage pipeline: one is that the drainage can not be connected with the overflow pipe to prevent the overflow pipe from backfilling with excessive drainage pressure; the other is that if the drainage pipeline is not smooth, it will cause excessive backpressure, which will affect the normal test of dynamometer. Therefore, the pipeline arrangement should be as short as possible and with fewer elbows.

The circulating water will be used as dynamometer water after descaling, which will reduce the formation of scale in dynamometer. If there is no water treatment equipment, tap water or clean river water is allowed, but no sediment and other impurities are allowed to mix in. It is not suitable to use sea water. Depending on whether the PH value of water in different areas is high or not, it is necessary to install scale remover.

Figure nine Schematic diagram of water supply system

Fig. 10 Foundation Map for Installation of Hydraulic Dynamometer

The dimensions, intake and drainage diameters and locations of the installation foundation are shown in the table.

List of Foundation Dimensions for Installation of YP Hydraulic Dynamometer and Location of Overflow and Drainage Port of Dynamometer Base

List of Intake and Drainage Diameters and Locations of YP Hydraulic Dynamometer

The table is not marked in millimetres.