Academia.eduAcademia.edu

Figure from:Enhanced Power Transmission System

See full PDFdownloadDownload figure
Figure 9. Passenger vehicle automatic transmission performance [14]. transmission. It can be seen from the plot that the present system is operating between two limits that represent the vehicle performance at minimum and maximum engine speeds. Additionally, these operating limits cover a larger area than the automatic transmission that operates at fixed gear ratio lines in the performance map. This area is the confined between the upper operating line of the upper limit and the lower operating line of the lower limit. This is conversely to the operation of the automatic transmission that offers a single operating line for every gear ratio over the engine speed limits. Moreover, no transmission gap is observed in the present system since it acts as continuously variable transmission.

Figure 9 Passenger vehicle automatic transmission performance [14]. transmission. It can be seen from the plot that the present system is operating between two limits that represent the vehicle performance at minimum and maximum engine speeds. Additionally, these operating limits cover a larger area than the automatic transmission that operates at fixed gear ratio lines in the performance map. This area is the confined between the upper operating line of the upper limit and the lower operating line of the lower limit. This is conversely to the operation of the automatic transmission that offers a single operating line for every gear ratio over the engine speed limits. Moreover, no transmission gap is observed in the present system since it acts as continuously variable transmission.

Related Figures (11)

The system layout presented in this paper is composed of a blend of two configurations t ntroduce two modes of power splitting operation; one at low speed and the other at hig speed. Figure 1 demonstrated the first configuration that is composed of conventional torqu onverter, planetary gear set which are reaction planetary set and output planetary set. Thi -onfiguration is configured in such a way that it is composed of two simple planetary set [he torque converter is the power splitter that its two power paths are controlled via the van -oupling then power is recombined with the two planetary sets. The reaction set (casin ylanetary set) has its ring gear fixed and its sun gear is attached to the converter casin hrough vane coupling and its planetary carrier is the output (input to the second planetar sear set). The output planetary set (turbine planetary set) has its sun gear is mechanical sngaged to the turbine output shaft through the vane coupling. The ring gear (input ring gea: of the output planetary set is attached to the output carrier from the first planetary gear se [he output shaft is connected to the second planet carrier of planetary gear set. The red line epresent the power flow paths and directions. The second configuration consists mainly of torque converter, planetary gear sets, and the vane coupling is shown in Fig. 2. The torque converter is the splitter unit. The reaction planetary set (casing planetary set) has its arm fixed and its sun gear is attached to the converter casing through the vane coupling, and its ring gear is the output (input to the output planetary gear set). The output planetary (turbine planetary set) set has its sun gear is mechanically engaged to the turbine output shaft through vane coupling. Its planet carrier is connected to the second ring gear of the planetary gear set.
The system layout presented in this paper is composed of a blend of two configurations t ntroduce two modes of power splitting operation; one at low speed and the other at hig speed. Figure 1 demonstrated the first configuration that is composed of conventional torqu onverter, planetary gear set which are reaction planetary set and output planetary set. Thi -onfiguration is configured in such a way that it is composed of two simple planetary set [he torque converter is the power splitter that its two power paths are controlled via the van -oupling then power is recombined with the two planetary sets. The reaction set (casin ylanetary set) has its ring gear fixed and its sun gear is attached to the converter casin hrough vane coupling and its planetary carrier is the output (input to the second planetar sear set). The output planetary set (turbine planetary set) has its sun gear is mechanical sngaged to the turbine output shaft through the vane coupling. The ring gear (input ring gea: of the output planetary set is attached to the output carrier from the first planetary gear se [he output shaft is connected to the second planet carrier of planetary gear set. The red line epresent the power flow paths and directions. The second configuration consists mainly of torque converter, planetary gear sets, and the vane coupling is shown in Fig. 2. The torque converter is the splitter unit. The reaction planetary set (casing planetary set) has its arm fixed and its sun gear is attached to the converter casing through the vane coupling, and its ring gear is the output (input to the output planetary gear set). The output planetary (turbine planetary set) set has its sun gear is mechanically engaged to the turbine output shaft through vane coupling. Its planet carrier is connected to the second ring gear of the planetary gear set.
configuration and finally the second configuration. Another solution for the reduction gets clutch and vane coupling attached to it, is that the vane coupling of the first and second configurations should be operated in the unlocking mode. One of the three clutches is locked to operate the system in one of the three modes. When the three clutches are disengaged, the transmission is in the netural condition.
configuration and finally the second configuration. Another solution for the reduction gets clutch and vane coupling attached to it, is that the vane coupling of the first and second configurations should be operated in the unlocking mode. One of the three clutches is locked to operate the system in one of the three modes. When the three clutches are disengaged, the transmission is in the netural condition.
the power paths. This coupling, Fig. 4, has typical components of axiymmetric vane pump that is composed mainly of rotor, vanes, casing. The only distinct feature is that the casing is connected to another shaft. During torque transmission, preventing oil from discharge from the oil ports results in no relative rotation between the rotor and the casing. In this case, the coupling operates in the locking mode leading the released case to spin with the rotor together according to the transmitted torque. For less torque transmission demand, the build-up pressure inside the coupling is reduced. This causes the casing to spin slower than the rotor and some oil is discharged from this coupling because of the relative motion between the rotor and casing. Thereafter, when the required transmitted torque is established, no relative motion appears between the rotor and the casing. If there is no build-up pressure, the vane coupling is idled or fully unlocked. Changing the build-up pressure is accomplished by electronically controlled hydraulic system attached to the vane couplings. This alters their torque capacities and results in transmitting a particular torque according to the build-up pressure.
the power paths. This coupling, Fig. 4, has typical components of axiymmetric vane pump that is composed mainly of rotor, vanes, casing. The only distinct feature is that the casing is connected to another shaft. During torque transmission, preventing oil from discharge from the oil ports results in no relative rotation between the rotor and the casing. In this case, the coupling operates in the locking mode leading the released case to spin with the rotor together according to the transmitted torque. For less torque transmission demand, the build-up pressure inside the coupling is reduced. This causes the casing to spin slower than the rotor and some oil is discharged from this coupling because of the relative motion between the rotor and casing. Thereafter, when the required transmitted torque is established, no relative motion appears between the rotor and the casing. If there is no build-up pressure, the vane coupling is idled or fully unlocked. Changing the build-up pressure is accomplished by electronically controlled hydraulic system attached to the vane couplings. This alters their torque capacities and results in transmitting a particular torque according to the build-up pressure.
Table 1. Torque converter dimensions used in [2]. All the simulated results performed at engine rpm equals 1600. Simulations deal with present model validity, present system performance, assessment and merits. For model validity, the present of the model is compared with the previous experimental results of conventional torque converter [2, 4]. The dimensions and specifications of such torque converter are in the tables | and 2.
Table 1. Torque converter dimensions used in [2]. All the simulated results performed at engine rpm equals 1600. Simulations deal with present model validity, present system performance, assessment and merits. For model validity, the present of the model is compared with the previous experimental results of conventional torque converter [2, 4]. The dimensions and specifications of such torque converter are in the tables | and 2.
Table 2. Geometry parameters of hydraulic torque converter [4]. It is notable that the blade angles in table | are measured from the horizontal direction while in table 2 are measured from the vertical direction. After model validity, performance assessment and merits will be demonstrated. Comparison is performed between the present power transmission system and automatic transmission [14]. In this case, assessment is achieved on the basis that the torque converter of [2] is installed in the present power transmission system. Consequently, the gear ratios of the present system have to be assigned. For the first and second configurations, planetary gear data are stated in table 3. In the two configurations, the number of teeth for the corresponding gears is the same. Additionally, the second configuration output is connected to a reduction gear with a gear ratio of 1.428:1. Kinetics and model can therefore be used to assess the present power transmission system.
Table 2. Geometry parameters of hydraulic torque converter [4]. It is notable that the blade angles in table | are measured from the horizontal direction while in table 2 are measured from the vertical direction. After model validity, performance assessment and merits will be demonstrated. Comparison is performed between the present power transmission system and automatic transmission [14]. In this case, assessment is achieved on the basis that the torque converter of [2] is installed in the present power transmission system. Consequently, the gear ratios of the present system have to be assigned. For the first and second configurations, planetary gear data are stated in table 3. In the two configurations, the number of teeth for the corresponding gears is the same. Additionally, the second configuration output is connected to a reduction gear with a gear ratio of 1.428:1. Kinetics and model can therefore be used to assess the present power transmission system.
RESULTS AND DISCUSSION Table 3. Kinematics of the two planetary gear configurations.
RESULTS AND DISCUSSION Table 3. Kinematics of the two planetary gear configurations.
Figures 5 and 6 illustrate the present simulated results of the efficiency and torque ratio against the speed ratio. Comparison is made with the experimental results [2, 4]. These plots display good matching between the simulated results of the present model and the experimental results. This denotes the capability of the present model to predict acceptably the performance of the torque converter at different conditions.
Figures 5 and 6 illustrate the present simulated results of the efficiency and torque ratio against the speed ratio. Comparison is made with the experimental results [2, 4]. These plots display good matching between the simulated results of the present model and the experimental results. This denotes the capability of the present model to predict acceptably the performance of the torque converter at different conditions.
Figure 7 illustrates the performance map for the power transmission system showing the torque ratio and the efficiency lines. The figure depicts the efficiency lines at different values of m (Ratio of power portion transferred mechanically to the input power). This enables the operation in a band of torque ration and efficiencies. Moreover, this will sacrifice the torque converter torque fluctuations damping effect. Nevertheless, the variable capacity inherent in the present system will give full control to the equipment user and the flexibility selecti 1on according to loads and demands. At a defined speed ratio, a switching can be done from torque converter operation to the power split modes with variable power ratio path. It is notable that the choice of m value is varying according to the load requirements and the best efficiency. This figure illustrates the three operational zones. In the first zone, torque is represented by the operation of the torque converter is directly connected with a reducti gear for starting demand. In the second zone, it is represented by the operation of the configuration and finally the third zone is the second configuration operating range. 10n first ee eS he. a a ee : Cee Oe Pe) ae eS
Figure 7 illustrates the performance map for the power transmission system showing the torque ratio and the efficiency lines. The figure depicts the efficiency lines at different values of m (Ratio of power portion transferred mechanically to the input power). This enables the operation in a band of torque ration and efficiencies. Moreover, this will sacrifice the torque converter torque fluctuations damping effect. Nevertheless, the variable capacity inherent in the present system will give full control to the equipment user and the flexibility selecti 1on according to loads and demands. At a defined speed ratio, a switching can be done from torque converter operation to the power split modes with variable power ratio path. It is notable that the choice of m value is varying according to the load requirements and the best efficiency. This figure illustrates the three operational zones. In the first zone, torque is represented by the operation of the torque converter is directly connected with a reducti gear for starting demand. In the second zone, it is represented by the operation of the configuration and finally the third zone is the second configuration operating range. 10n first ee eS he. a a ee : Cee Oe Pe) ae eS
Figure 10 represents the performance map of the present system when installed in the passenger vehicle instead of the automatic transmission. Operation of the present system is achieved at full load, full throttle engine map. Unlike the automatic transmission, this system offers an operational band for each engine speed. This band is established through changing the m value. Moreover, changing the vehicle speed will cover the whole area of the demand traction. This feature of the present system has a superior performance than the automatic
Figure 10 represents the performance map of the present system when installed in the passenger vehicle instead of the automatic transmission. Operation of the present system is achieved at full load, full throttle engine map. Unlike the automatic transmission, this system offers an operational band for each engine speed. This band is established through changing the m value. Moreover, changing the vehicle speed will cover the whole area of the demand traction. This feature of the present system has a superior performance than the automatic
Figure 10. the present system road performance.
Figure 10. the present system road performance.