YD13006155
Product Description
Transmission system
Transmission
Description of transmission
The YD13 type powershift transmission (with the maximum input power of 130 KW) consists of a hydraulic torque converter and a rear-mounted fixed shaft transmission with multi-disc friction clutch. Our company provides Loader LG938L equipped with YD13 transmission (4 forward gears and 3 reverse gears), road roller RS8220 equipped with YD133 transmission (3 forward gears and 3 reverse gears, without torque converter) and road roller RP9300 with YL13 transmission (2 forward gears and 2 reverse gears).
Fig.2-1 | 1. Transmission control valve 2. Oil filter 3. Torque converter oil temperature measuring port 4. Oil outlet of torque converter to oil cooler 5. Oil suction pipe 6. Transmission body 7. Nmeplate |
8. Eye screw 9. Auxiliary PTO 10. Main PTO 11. KVK1 clutch shaft 12. KRK2 clutch shaft 13. K3K4 clutch shaft 14. Parking brake | Fig.2-2 |
Fig.2-3 | 1. Hydraulic torque converter 2. Transmission pump 3. PTO gear 4. Clutch (triad) 5. Output shaft 6. Parking brake |
Basic parameters of torque converter and transmission assembly
Items | YD13 | YD133 | YL13 | ||
Torque converter | Type | ZFW305 | N/A | ZFW320 | |
Transmission | Torque ratio | 2.3 | N/A | 2.52 | |
| Working | 80~100°C, a | N/A | 80~100°C, a | ||
| temperature | maximum of 120°C | maximum of 120°C | |||
Type | Fixed-shaft powershift | Fixed-shaft powershift | Fixed-shaft powershift | ||
| Transmission range | 4 forward gears and 3 reverse gears | 3 forward gears and 3 reverse gears | 2 forward gears and 2 reverse gears | ||
| Driveratio | Forward I | 3.91 | 8.936 | 3.7 | |
Forward II | 2.304 | 4.543 | 1.603 | ||
Forward III | 0.964 | 1.90 | N/A | ||
Forward IV | 0.617 | N/A | N/A | ||
Reverse I | 3.91 | 8.936 | 3.7 | ||
Reverse II | 2.304 | 4.543 | 1.603 | ||
| Reverse III | 0.964 | 1.90 | N/A | ||
Type of transmission pump | Built-in gear pump | Built-in gear pump | Built-in gear pump | ||
| Pressure (bar) | 13~17 | 13~17 | 13~17 | ||
Gearshift principle of transmission
1. Transmission structure principle
Actuator in YD13 transmission is composed of 6 clutches (i.e. K1, K2, K3, K4, KV (forward gear clutch) and KR (reverse gear clutch)), and different gearshifts can be achieved through the intercombinations among them, and each gearshift requires two clutches working simultaneously; YD13, YD133 and YL13 transmission working principles are respectively shown in Fig.2-4, Fig.2-5 and Fig.2-6.
| Fig.2-4 (YD13) | Fig.2-5 YD133 | Fig.2-6 (YL13) |
2. Principle of transmission hydraulic oil system – take YD13 for example
The gear pump to supply oil for the torque converter and control valve is installed inside the transmission and driven directly by the engine via PTO shaft, with flow of Q=35 L/1000 r/min. The oil pump absorbs oil through the oil suction filter (primary filter) in the oil circuit, pumping the pressurized oil into the spin-on oil filter (fine filter). The oil filteration precision is 0.025 mm, and the filteration area is 5,100 cm2.
The oil flowing from the filter with the working pressure restricted by the pressure control valve (main pressure regulating valve) passes through the pressure control valve to the control valve. The pressure control valve regulates the boost pressure of the clutch cylinder at the moment of gear shifting, i.e. the oil pressure will drop instantaneously when gearshifting, but after gearshifting (after clutch engagement), it will return to 13~17 bar (the pressure restricted by the pressure control valve). This can reduce the impact of gearshifting and improve gearshifting efficiency; the oil passed through the control valve flows directly to the clutch. The shifter valve is positioned by steel ball, spring and groove.
The oil inlet line of the torque converter is equipped with a by-pass valve (opening pressure of 8 bar) to prevent the element damages due to high internal pressure of the torque converter.
According to the hydraulic transmission working principle, the oil is the medium for energy transfer inside the torque converter. To avoid oil cavitation, the torque converter cavity should always be full with oil, which is guaranteed by the torque converter pressure control valve (back pressure valve) installed on the torque converter oil outlet line (opening pressure of 2.5 bar). The oil spilled from the torque converter flows directly into the oil cooler.
The oil flowing from the oil cooler enters the transmission lubricating oil circuit, providing all lubricating points with sufficient lubricating cooling oil. An additional pressure cut-off valve can be installed to the transmission upon operational requirements.
The pressure cut-off valve can be easily controlled through a secondary brake pedal regulating the air pressure or oil pressure. The hydraulically controlled pressure should be no less than 40 bar. The pneumatically controlled pressure should be no less than 2.5 bar.The pressure cut-off valve functions to cut off the oil pressure of the clutch oil line, and the clutch can be disengaged when the gearshift valve stops working. So the engine output power can be supplied to the external pump completely. If the pressure cut-off valve is used, there’s no need to put the gearshift valve at the neutral position.