JPS60204924A - Power-turbine power transmission mechanism and turbo- compound system - Google Patents

Abstract

PURPOSE:To allow a secondary pump to run idly and prevent the consumption of the shaft output of a base engine by combining said secondary pump which transmits the power of an exhaust turbine to a driven shaft, with a final gear of a reduction gear train in a power turbine transmission mechanism, through a one-way clutch. CONSTITUTION:A primary pump 1 is combined with a driving shaft 5 which is connected to the crank shaft of a base engine and a turbine runner 2 is combined with a driven shaft 6. A starter 3 is fixed to a transmission case through a one-way clutch 7. A secondary pump 4 is connected to a final gear 9 from an exhaust turbine 10 through a one-way clutch 8. At the same time the exhaust gas of the engine operates a turbocharger, the exhaust turbine 10 also rotates the crank shaft by means of the exhaust gas. When the rotation of the crank shaft is higher than that of the turbine 10, the transmission of the rotation is prevented by the one-way clutch 8.

Description

[Detailed description of the invention]

``Object of the Invention'' The present invention relates to a technology for improving the transmission efficiency of a power turbine power transmission mechanism, and a system for a turbocharged engine using the technology.
It is more established. The purpose of the invention is to expand the high efficiency range of exhaust turbine power recovery in a power turbine power transmission mechanism,
At the same time, the purpose is to simplify the mechanism, and in the case of turbo pump pound systems, to improve the deterioration of acceleration response. ``Summary of Improvements in the Power Turbine Power Transmission Mechanism of the Present Invention'' The core of this concept, which is the basis for the two inventions, is that the power of the exhaust turbine is installed in the torque converter of the automatic transmission for transmitting the power of the pace engine to the output shaft. It lies in the simple idea of putting it in. Therefore, I will first explain the power turbine power transmission mechanism. The known power turbine transmission mechanism recovers exhaust turbine power to the engine shaft via a high speed gear, a fluid coupling, and a low speed gear, but this is improved by the power turbine transmission mechanism of the present invention that utilizes a torque converter. The points are as follows. 1) By introducing the exhaust turbine power into the torque converter, it is possible to eliminate the fluid coupling dedicated to the power turbine drive system and simplify the mechanism. If) A fluid coupling is a fluid transmission that performs l:l torque transmission, and its efficiency η is the speed ratio itself,
It decreases in proportion to the slip. Therefore, the high efficiency range is extremely narrow. On the other hand, in a torque converter, since the stator takes charge of the torque, the speed change is performed accompanied by torque conversion, and the efficiency curve thereof generally takes a parabolic shape closer to the high speed ratio side, and the high efficiency range is widened. Moreover, efficiency in the coupling range is also improved in torque converter bets. Therefore, it becomes possible to increase the recovery efficiency of exhaust turbine power over a wide range. 111) It has been pointed out that known power turbines have the disadvantage that at low speeds and low loads, the friction loss of the recovery system such as the gear train is greater than the amount of exhaust heat recovered, which consumes the shaft output of the base engine. In the power turbine transmission mechanism of the present invention, the dorkko/bar 2
By connecting the secondary pump that transmits exhaust turbine power to the driven shaft in the circuit and the final gear of the reduction gear train in the power turbine transmission* through a one-way clutch,
In the region where the power turbine output is not generated, the secondary pump can be idled to prevent consumption of the base engine shaft output. ``Mechanism explanation'' Next, based on Figure 1,

[The mechanism of the power turbine power transmission mechanism of the present invention will be explained.] First, let me explain from the torque converter side. 1 is a primary pump, and 2 is a turbine runner. 3
is a stator, and 4 is a secondary pump. As shown in the figure, in the present invention, the pump impeller is divided into a primary pump 1 and a secondary pump 4. 5 is a driving shaft of a torque converter connected to the crankshaft of a base engine (not shown), and the driving shaft 5 is connected to the primary pump. Therefore, the engine power becomes the driving force of the primary pump 1. ,
6 is a driven shaft, which is connected to the turbine runner 2.

[There is. 7 is a one-way clutch that rotates in the same direction as the turbine runner 2, and the stator 3 is fixed to a transmission case (not shown) via the one-way clutch 7. 8 is a one-way clutch that rotates in the same direction as the primary pump 1, and 9 is the final gear of the reduction gear train. The secondary pump 4 and the final gear 9 are connected via a one-way launch 8. Further, the final gear 9 is rotatable with respect to the shaft of the stator 3 and the driven shaft 6. Next, the explanation will proceed from the exhaust turbine (power turbine) side. 10 is an exhaust turbine; 11 is an exhaust turbine l
This is the axis of O. 12 surrounded by a broken line is a planetary gear device, and the shaft 11 is an input shaft of the planetary gear device v112. 12
, S is a sun gear fixed to the input shaft 11, and P is a sun gear fixed to the input shaft 11.
is the pinion, C is the pinion P, the planet carrier R is the ring gear, and the ring gear R is fixed.
and does not rotate. 13 is an output shaft of the planetary gear device 12, which is fixed to the planet carrier CK. The other end of the output shaft 13 is fixed to a gear 14. ] 5 is an intermediate gear, and 15 meshes with gears 14 and 9. Therefore, the driving force of the exhaust turbine 10 is the secondary pump 4.
It will be transmitted to "Transmission ratio of gear reduction mechanism" Rotational speed of the current base engine 5. OOOrpm f)
When the rotational speed of the exhaust turbine 10 is 120.00Orp
Assuming that m, the required speed ratio of the reduction gear train is 24, so the reduction ratio is approximately 0.0417. For now, among the gear trains in this transmission mechanism, gear 14,
If the ratio of the number of teeth of gears 15 and 9 is 1.2.4, then gear 14.
The gear ratio between 9 and 9 is 4, and the gear ratio required for the planetary gear device 12 is 6. The speed ratio i of the planetary gear device when the sun gear S is driven, the planet carrier C is driven, and the ring gear R is fixed is expressed as l=1+1/γ. Here k r = ZS/ZR, ZEI: f 7 key?
17) Number of teeth, ZR: ! I is the number of teeth of 7 Gugya. Therefore, if ZS:ZR=1:5, the speed ratio of the planetary gear device 12 will be 6, and the speed ratio of the entire gear reduction mechanism will be U. However, in reality, the base engine output and the exhaust turbine output have different values differentiated with respect to the engine rotation speed. Therefore, the gear ratio must be variable. A torque cosverter plays the role of this variable speed ratio device and a buffer mechanism. [Power transmission in the torque converter circuit and transmission efficiency] 1) The fluid in the torque converter circulates through the circuit and returns to its initial state, so the torque T applied to the body from each impeller in the circuit is The total sum is O. That is, since ΣT-=O, the primary pump 1, turbine runner 2, stator 3.2
Next, the torque at pump 4 is T, ,T! ,
If T, , T, then T, = T, + T, + T
, tl), and in the present invention, compared to the conventional three-element single-stage torque converter, the secondary pump torque is only 40 T4,
The torque T of the driven shaft 6 becomes large. i) For a torque converter with a load per unit time of Q ) Δ('t'u)l (
2)? IC is the blade number, ω: impeller rotation angular velocity, U two-impeller rotation circumferential speed = rωIr: radius from the rotation axis, υ1: rotational component of the overall fluid velocity, γ: specific weight of the fluid, 2: M force. acceleration, Q: circulation flow value. Taking the primary pump 1 as a reference, setting it to 1=1, and assigning a number to the direction of flow, it becomes K, which is the same as the symbol in the figure. In the present invention, the work per unit time given to the fluid by the two pump impellers is calculated from equation (2) as follows: γ T+ ``I + 7'4''<=(,Q)tl(sa
, 4), +Δ($11.)d (31) From equation (3), the rotational circumferential speed of the secondary pump 4 u, == r, ω4
The more the exhaust turbine 10 is added to the engine output, the more
It can be seen that the power of 111) Regarding the transmission efficiency of the torque converter according to the present invention, the rate of change of the exhaust turbine output with respect to the engine rotational speed is greater than the rate of change of the pace engine shaft output with respect to the engine rotational speed. How should the 40 rotations of the secondary pump be matched to the rotation of the secondary pump l, that is, at what position in the torque converter speed ratio should the reduction ratio of the power turbine gear reduction mechanism be set? It is necessary to clarify this, even if only qualitatively. Therefore, the transmission efficiency of the torque converter according to the present invention will be expressed mathematically. For this purpose, we introduce the following dimensionless quantity. Speed ratio el=ωI/ω. Dimensionless circulation flow rate β=C/r, 1 liter. m dimension) Luk fi =7'l/7ar1.2'cl
. Radius ratio ρl, l = ri, 1/ r+, t, ρi
+1 = “I-*/”1. t. Dimensionless flow path area a=A/r,, 2". 1.1-tanα1.+ for the number of blade angles, , 2=t
anα1.2 where C - meridional component of circulation flow velocity, A: cross-sectional area of flow path, α: angle rJ of the blade to the plane containing the rotation axis, front subscript I: blade number, rear subscript]; blade inlet,
Rear subscript 2: Blade outlet. Next, Professor Tomoo Ishihara of the University of Tokyo's fluid transmission flilli
Emulating the free-flow formula, it is assumed that the free flow path between adjacent impellers is extremely small in the inner surface of the torque converter circuit of the present invention shown in Fig. 2, and the exit radius of one impeller and the inlet of the next impeller are Assuming that the radii are equal to ℃, the general symbols are simplified as shown in Table 1. In the inner cylinder 2M, the chain line at the bottom is the center of the rotation axis. Table 1 Here, the secondary pump 4 is driven by the power of the exhaust turbine 10 and generates power, but since it is not directly coupled to the driving shaft 5, its speed ratio e4 is based on the primary pump l. Let e4=ω4/ω. Change in the angular momentum that the first impeller imparts to the fluid, that is, the torque T1 of rotation around the axis that the impeller imparts to the fluid
When we make it dimensionless, we get dingl−β((ρto*eI−β1.,)ρtoyo−(ρl
-+, *ei-+-β'to+, *MJ-1. ,)+4
It is expressed as 1. (4) In 2, in l-1, 1
-1-0, but the 1-1st impeller in this nine is n
This is the second impeller, that is, the secondary pump 4. The dimensionless torque of each vane is calculated from equation (4) as follows: 4.
, )A1) Turbine τ,=β((ρ, e−β to riρ
,-(1-βIC1,ri1stator τ,=β(-bird,
! ＾-(Ae-β~,t)A12nd pump 4-ha(
To A1-to β5. )ρ1+β~,,A) Note that the secondary pump 4 is not connected to the driving shaft 5, and the driving shaft torque τ=τ1-β(l-ρl'sound-β(to +
-t A'4-1)l (sl driven shaft torque T'=-
f,=β(1-7),"8-βCIc1-t-1's
'x, is month (6) If e-0 to 1 is the practical operating range, then in the present invention, the smaller e and the larger e4, the larger the torque ratio t becomes from equation (7). It can be seen that the rotational speed ω2 of the turbine runner 20 is small, and the rotational angular speed ω1 of the primary pump 1 and the secondary pump 4 is small. When ω4 is large, the torque ratio t becomes large. Efficiency η= t X e (8) (7) I From formula (8), qualitatively % e and e4
It can be seen that the larger both of them are, the higher the transmission efficiency of the torque converter according to the present invention becomes. Next, in the torque converter joint, in the range where the torque ratio t is smaller than 1 (range where e is large), the stator 3 can automatically idle, so T's becomes 0. Therefore, from equation (1), Therefore, in the vicinity of e-1, equation (8) shows that η〉
It becomes l. 1v) Transfer efficiency of secondary pump 4 +71. The torque ratio t and the efficiency η studied using the +81 equation are expressed mathematically with a view to the main shaft (primary pump 1) in the torque converter of the present invention, which is composed of two pump impellers. In order to clarify the difference in efficiency between the known power turbine transmission mechanism using a fluid coupling as an intermediary, and the present invention in which exhaust turbine power is transferred into a torque converter,
Of the two pump impellers, it is necessary to take out the secondary pump 4 that transmits power to the driven shaft 6 of the exhaust turbine 10 and consider its transmission efficiency by focusing on this. For that purpose, consider the secondary pump 4 as a driving impeller and I = 1
Then, renumber each impeller in the direction of flow as shown in Figure 3. [The general symbols are simplified as shown in Table 2.] The dimensionless] Luk of the second machine secondary pump and turbine runner is (4
), the secondary pump τ1-β((1-β is 3.,)+β is 4.
, ρ, ) Turbine τ, = β ((ρ, e − β to 8. ρ
4-(ρ1e2-β2.riρ,) Therefore. Driving shaft torque τ=τ, -β(1-β(ni1.,-ρ,
4. , )l t91 covered '1m axis torque y r' = i,
=β(J'52at-ρ=2e-βkuρs't-t (
'< 3.2) + (10) If the torque ratio when the secondary pump is a driving impeller is t', then (91, (10・)
From the formula, 12.2 ratio, ・=7・/□=this−8′−β(
pm'!・・・-'・5...) (11) 1-β('I
, t-ρ1'a・t) From equation 1, it can be seen that t' becomes large when el is large and e is small. That is, the ratio ω of the rotational angular velocity of the primary pump (1=2) to the secondary pump (1=1) K. /ω is large, and the turbine runner (
1-3) When the rotational angular velocity ratio ω, /ω1 is small. t' becomes larger. If the efficiency of the secondary pump is η', then from equation (8), when It is considered that the shape becomes a parabola closer to the speed ratio side. Here too, the performance in the coupling range is improved with the Dorkuco/Meter joint. ■) Summary of efficiency analysis Consideration on the efficiency of the torque converter according to the present invention so far. Putting everything together, a) Rotational angular velocity of turbine runner 2/rotational angular velocity of primary pump 1 → When large. (Example) Rotation angular velocity of secondary pump 4/rotation angular velocity of primary pump l → When the rotation angular velocity is too large. c) Rotation angular velocity of turbine runner 2/secondary pump 40 rotation angular velocity → when large. 2) When the rotational angular velocity of the primary pump 1 is 7 and the rotational angular velocity of the secondary pump 40 is too large. Efficiency is highest when all of the above conditions are met. Therefore, if we summarize the above matters using the primary pump 1 as a reference (assuming 1 = 1), in (a) the larger e and e4 are, the better the efficiency is, but in (c) 2), e4 = ω4/ω1 is 1. If you exceed it, it will become smaller. Therefore, it is absolutely certain that the point e4=1, which is the standard for setting the reduction ratio of the gear reduction mechanism, should be the same point as 8=1. Furthermore, from the above research, it will be understood that the present invention can improve the recovery efficiency of exhaust turbine power over a wide range compared to the conventional power turbine transmission mechanism using a fluid coupling whose efficiency is expressed as η-e. . ``Problem J in the power turbine output non-generation area'': In conventional power turbines, at low speeds and low loads, the friction loss of the recovery system is greater than the amount of exhaust heat recovered (and the shaft output is reduced). We will now discuss how the present invention solves the problem of consumption.The final gear 9 of the gear reduction mechanism in the present invention is connected to the secondary pump 4 via the one-way clutch 8. If the secondary pump 4 is fixed to the final gear 9, the secondary pump 4
The torque becomes 7', (o.Therefore, a one-way clutch 8 is provided between the secondary pump 4 and the final gear 90, which allows free rotation in only one direction, and the torque is set so that the secondary pump 4 idles. Then, T4-〇 becomes T4-〇, and the shaft output of the base engine is not consumed.In fact, by idling the secondary pump 4, a free flow is created between the outlet of the stator 3 and the inlet of the primary pump 10. As a result, the collision loss caused by the sudden direction change at the inlet of the primary pump is reduced, and the transmission efficiency of the torque converter is improved. [Turbo Compound System] Next, we will explain another invention, a turbo compound system using the present power turbine transmission mechanism. In the power turbine, the turbine output is maximized. At this point, exhaust energy of about 7.3 inches of engine shaft output is recovered.If this is advanced to turbo compound system K, exhaust energy of about 12 inches of rated output is recovered as shaft output at the rated point. The ratio of shaft output energy to the fuel calorific value increases.The well-known turbo-combined engine system operates the turbocharger using engine exhaust gas to perform supercharging, and at the same time, the exhaust gas after passing through the turbocharger generates further It drives the downstream output turbine and transmits the driving force to the output shaft via a high-speed gear, a fluid coupling, and a low-speed gear.The feature is that the driving force of the output turbine (power turbine) is transmitted to the output shaft. output is improved,
Fuel efficiency is improved. However, since the speed type expander is double-combined, the delay during acceleration increases. One of the features of the power turbine power transmission mechanism of the present invention is that
The point is that the shaft output of the engine is not consumed even in the region where the power turbine output is not generated. If this feature is utilized in a more advanced manner, it will be possible to revolutionize the way turbo compound systems are combined and improve acceleration response deterioration. Now, based on FIG. 4, the system of the turbo compound engine of the present invention will be explained. E is the base engine, TC is the turbocharger, and IO is the exhaust turbine (power turbine). G surrounded by a broken line indicates the planetary gear device 12, the gear 14,
15, 9, and HTC is a torque converter. As described above, in the power turbine transmission mechanism of the present invention, the final gear 9 of the gear reduction mechanism is coupled to the secondary pump provided in the circuit of the torque converter HTC via a one-way clutch. In the turbo compound system of the present invention, the exhaust turbine 10 is not disposed below the turbocharger TCO, but in parallel K11f. Figure 5 is a suction and exhaust system diagram. In the figure, Wv is the wastegate valve, and Wv is the actuator (not shown) K.
It works better. Only exhaust gas that has been bypassed is guided to the exhaust turbine 10. By configuring the turbocharger TC in this manner, it becomes possible to perform matching so that the effect of the turbocharger TC is exhibited in the low speed range where automobile engines are frequently used. In other words, since the exhaust turbine 10 is installed downstream of the turbocharger TC,
It is no longer necessary to put all the exhaust gas into the turbocharger. Therefore, by reducing the inertia of the TC rotating body and reducing the A/R value of the turbine fleur, the turbocharger output is driven with less exhaust gas and reaches the intercept point at low rotation speeds. Matching can be achieved. Therefore, it is possible to increase low-rpm torque and improve acceleration response. The reason why such an arrangement is possible in the present invention is as follows.
In the wastegate closed region, even when exhaust gas is not supplied to the exhaust turbine 10 and the exhaust turbine 10 is not operating, the secondary pump idles due to the intervention of the one-way clutch 8, so the shaft output of the engine is reduced. This is because it is not consumed. Therefore, in conventional turbocharged engines, the exhaust energy that was wasted by exhaust bypass can be effectively used to drive the power turbine. As mentioned above, supercharging also increases the exhaust heat recovery effect. As described above, the present invention facilitates the practical application of waste heat recovery technology,
It provides the world with an energy-saving engine.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of the power turbine power transmission mechanism of the present invention. 2 and 3 are model diagrams showing the upper half of a cross section of the torque converter according to the present invention taken along a plane including the center of its rotation axis, and FIG.
1), Figure 3 is based on the secondary pump (1-1)
That is. FIG. 4 is a system diagram of the turbo compound system of the present invention. FIG. 5 is a diagram of the suction/exhaust system. In Figures 1, 4, and 5, 1: primary pump, 2:
Turbine runner, 3: Stator, 4: Secondary pump, 5:
Driving shaft, 6: Driven shaft, 7 and 8 one-way clutch, 9:
4M gear of reduction gear train, 10: Exhaust turbine, 11:
10 shaft, 12: planetary gear system, 13: 12 output shaft, +4: gear fixed at @13, 15: intermediate gear, C nibraneno carrier, P: binion, R: ring gear, S: sun gear, E: base engine, TC: turbocharger, G: gear reduction mechanism, HTC: ) Lukhumverter, Wv: wastegate valve. Procedural amendment (voluntary) May 1, 1989 Director-General of the Japan Patent Office Kazuo Wakasugi1, Indication of the case Patent Application No. 59654 of 19822, Name of invention Power turbine 65pgg, 6, J, , 7 and turbo compound・System 3, Relationship with the case of the person making the amendment Patent applicant 5, Number of inventions increased by amendment None 6, Target of amendment Number of inventions described in the title section of the application and the scope of claims

Claims (1)

[Claims] 1.) A secondary pump is provided in the torque converter circuit in addition to the primary pump for transmitting engine power, and the final gear of the exhaust turbine reduction gear train is rotated on the torque converter driven shaft. A power turbine power transmission mechanism in which the secondary pump and the final gear are freely coupled via a one-way clutch. 2. In a turbo pump engine, a wastegate valve is provided in front of the turbine inlet of the turbocharger, and the inlet of the exhaust turbine having the power turbine power transmission mechanism according to claim IK is connected to the outlet of the wastegate valve. Turbo compound system made by tying.