CA1103554A - Transmission control system - Google Patents
Transmission control systemInfo
- Publication number
- CA1103554A CA1103554A CA336,576A CA336576A CA1103554A CA 1103554 A CA1103554 A CA 1103554A CA 336576 A CA336576 A CA 336576A CA 1103554 A CA1103554 A CA 1103554A
- Authority
- CA
- Canada
- Prior art keywords
- torque converter
- fluid
- pressure
- inlet
- transmission control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- General Details Of Gearings (AREA)
- Control Of Fluid Gearings (AREA)
- Control Of Transmission Device (AREA)
Abstract
Transmission Control System Abstract of the Disclosure A transmission control system (10) for a transmission including a torque converter (66) has fluid inlet and fluid outlet passages (64,80) connected to the torque converter (66), a pressure regulating valve (20) for relieving fluid from a pressure source (12,16) to the inlet passage (64) of the torque conver-ter (66), and a flow limiting passage (96) directly connecting the inlet and outlet passages (64,80) for continually bypassing fluid past the torque converter (66) and controlling the pressure drop thereacross.
Description
35~
Description Transmission Control_S stem Technical ~leld The present invention relates to a trans-mission control systemr and more particularly to a control system for improved fluid flow control with respect to a torque conVerter and an associated heat exchanger.
Background Art The Waxner Gear Division of Borg-Warner Corporation~located at Muncie, Indiana, manufactures a single-speed transmission known as a Model PRl Power Ranger Shuttle Transmission. This transmission is used with a ~odel No Wll torque converter manufactured by the Borg & Beck Division of Borg-Warner Corporation and located at Sterling Heights, Michigan~ That trans-mission and associated hydraulic torque converter find particular utility in the power train of a fork lift truck, for example.
The referenced transmission and torque con-verter has heretofore utilized a transmission control system that has~experienced fluid flow control problems including undeslrable pressure fluctuations at the luid inlet pas~sage to the torque converter. Moreover, a pressure relief valve or regulator incorporated in that transmission control sVstem has undesirably relieved an excessiVe p~oportion of ~luid from the inlet passage of the torque convertex directly to the outlet of a cooler which receiVes and cools fluid from the outlet passage o the torque converter. Thus, under certain conditions an undesirable portion of the circulating fluid b~passes the cooler via that relief valve, so . . ~
35~
that the torque conVerter cooler ~low rate dld not uniformly incxease over the operatin~ range as desired A large nu~ber of valves are known which can modulate and contxol the fluid ~low rate to and rom a torque converter or alternately the pressure at the - inlet ~nd~or outlet thereof. Some valves can even control multiple combinations of these parameters.
However, these valves are not only usually complex and c05tly in construction, but also the~ take up valuable room where space is at a premium~ Still further, what is needed is a solution to the aforementioned problems that can be incorporated in commercially available transmission control systems with but minimal delay to the ultimate consu~er.
The present invention is directed to over-coming one or more of the problems as set forth above.
Disclosure of Invention Xn accordance with one aspect of the present invention a flow limitin~ passage directly connects a fluîd inlet passage to a torque converter and a fluid outlet from the torque converter. Thus, although a preselected amount of fluid is caused to continually bypass the torque converter, such amount is still desirably directed to the torque converter cooler~
Advantageously, because o~ the incorporation of the controlled fluid flow bypass passa~e around the torque conVerter, a pressure relief valve associated with the trans~ission contxol system is no longer adversely affected by back pressure fluctuations at the inlet passa~e to ~he~convexter~ and also the fluid flow rate throu~h both the cooler and the torque converter increase uniformly in pxoportion to an increase in the torque conVextex input speed.
,:, 35.~5~
Brief Description of Drawin~s Figure 1 is a dia~rammatic view of one embodiment of the t~ansmission control system of the present invention wlth a portion o~ the valving shown therein broken open to better illustrate details thereof.
Flgure 2 is a diagrammatic view of the torque converter shown in Figu~e 1, with a fragmentary portion thereof shown in cross section to illustrate certain fluid passages therein~
Best Mode -~or Carr~ing Out the Invention Refexring initiall~ to Figure 1, a trans-mission control system 10 is shown as having a pump 12 whlch draws fluid from a sump 14 and directs it through a main line conduit 16 as a fluid pressure source to a transmission control assembly 18 and to a pressure regulator valve or pressure relief valve 20. The transmission control assembly 18 includes a control or inchin~ valve 22 connected to the pressure source and a directional selector valve 24 connected to the control 2Q valve 22 and the pressure source. Manual control of the directional selector valve enables a forward clutch 32 or a reverse clutch 34 to be controllably supplied with pressure fluid for operation of the associated vehicle. Such transmission control assembly 18 can be of conventional construction, such as has been hereto-fore incorporated on the previously mentioned Model PRl Power Ran~er Shuttle Transmission, produced by Borg~
Waxner Corpora~ion.
~ known p~essuxe relief valve 36 is connected to the main line condui~ 16 to provide a preselected maximum pxe5suxe le~el thereat. For example, at a settin~ of about 138U RP~ ~200 psi) the relief valve 36 : . :, .~::-;-; . : . :
- ,: - , ; :
~355~
relieves ~luid fro~ the main line conduit back to the sump 14.
The pressure regulator valve 20 has a housing 38 defining an elon~ate cylindrical bore 40, a pressure port 42, an inlet port 44, an outlet port 46, and a drain port 48, all communicating with the bore. A
valve spool 50 having a pair of spaced apart cylindrical lands 52, 54 and a neck 56 is reciprocably disposed in the bore, and the valve spool is continually biased to the left when viewing the drawing by a compression spring 58. A preselected pressure at the pressure port 42r for example of about 830 KPa (120 psi), serves to overcome the spring and move the spool to ~e right when viewing the drawing. A throttling slot 60 formed in the land 54 is then placed in open communication with the inlet port 44, whereupon fluid in the main line conduit 16 is relieved to an outlet conduit 62 via the inlet port, the throttling slot and the outlet port 46.
A major purpose of the pressure regulating valve 20 is to cut off fluid flow to the torque converter 66 when the pressure in the main line conduit drops below its preselected pressure level setting, and thus to assure that the transmission con-trol assembly 18 will get full - benefit of this available flow from the pump 12 for fast response during a transmission shift.
Fluid in the outlet conduit 62 from the regulatin~ valve 20 is directed to an inlet pa~sage 64 leading to a h~drodynamic torque conVerter 66~ As shown in Figure 2, this tor~ue converter has a pump ox impeller element 68 coupled to an engine, not shown, a reactor element 7Q suitably coupled to a stationary kubular member 72, and a turbine element 74 connected to a rotary sha~t 76 leading to a transmission, not . shown.
, .
. ,: :.-. , : :.:: : . ~, . : : : ~ , :
, .. . .
3~
Basically, the tor~ue converter is similar in construction to the ~odel Wll tor~ue conVerter produced by Borg & Beck and the txansmission is similar in cons-truction to the Model PRl Power Ranger Shuttla Transmission produced by Warner Gear.as previously mentioned~ With the construction of the torque con-verter 66 shown in Figure 2 it is apparent that fluid charging pressure is directed to the torque converter via the inlet`passage 64 located in part between the tubular member 72 and a surrounding rotary member 78.
Fluid is communicated from the torque converter via an outlet passage 80 defined in part between the shaft 76 and the tubular member 72. secause of such relationship the inlet and outlet passages 64 and 80 present some restriction to fluid flow.
Referring again to Figure 1, from the outlet passage 80 of the torque converter 66 heated fluid flows to a cooler or heat exchanger 82 where its temp-erature is desirably reduced prior to being passed on : 20 to a conduit 84 and to a plurality of lubrication points 86.
A pressure relief valve 88 of known con-struction is in f-luid communication with the conduit 6~
~ leading to the inlet passage 64 of the torque converter 66 such *hat at a preselected pressure thereat, for example about 900 KPa (130 psi~, fluid is allowed to flow from the conduit 62 to a conduit 90 and the conduit 84 in b~passing relation to the cooler 82. This relief valve protects the torque converter 66 by limiting the maximum pressure level at the inlet passage thereto.
A branch conduit 92 havin~ a flow control orifice 94 therein i.s connected between the main line conduit 16 and the inlet.passage 64 of the torque : ~ - : . : . ~, ................... . . ..
: - ,,, ., : . : ..
. , ,: . . : : , : : .; , : : .
: : :. : ,: :: : .
~3~S~
converter 66. The flow control orifice is preferably about 1.52 mm (0~060") in diameter so that a fluid flow rate of about 1.9 to 3.8 litres/min. (1/2 to 1 gpm) will be directly communicated to the inlet passage of the torque converter to insure that it is supplied with at least a preselected minimwn amount of fluid at all times, such as during a transmission shift when the pressure regulator valve 20 is closed.
In accordance with the present embodiment, a flow limiting passage 96 having an~effective orifice diameter of about 3.8 mm (0.150") is directly connected between the inlet passage 64 and the outlet passage 80 in fluid bypassing relation to the torque converter 66. In this way, a preselected proportion of the fluid flow to the inlet passage 64 can be continually passed directly to the cooler 82.
Industrial Applicability In actual operation of the transmission control system 10, the input speed of the impeller 68 of the torque converter 66 varies with engine speed, for example from about~1000 to 2400 rpm. With the transmission in neutral the fluid flow rate through the torque converter ~ desirably increases relatively uniformly from about 7.6 to ; ~ 18.9 litres/min. t2 to 5 gpm). Simultaneously, the cooler
Description Transmission Control_S stem Technical ~leld The present invention relates to a trans-mission control systemr and more particularly to a control system for improved fluid flow control with respect to a torque conVerter and an associated heat exchanger.
Background Art The Waxner Gear Division of Borg-Warner Corporation~located at Muncie, Indiana, manufactures a single-speed transmission known as a Model PRl Power Ranger Shuttle Transmission. This transmission is used with a ~odel No Wll torque converter manufactured by the Borg & Beck Division of Borg-Warner Corporation and located at Sterling Heights, Michigan~ That trans-mission and associated hydraulic torque converter find particular utility in the power train of a fork lift truck, for example.
The referenced transmission and torque con-verter has heretofore utilized a transmission control system that has~experienced fluid flow control problems including undeslrable pressure fluctuations at the luid inlet pas~sage to the torque converter. Moreover, a pressure relief valve or regulator incorporated in that transmission control sVstem has undesirably relieved an excessiVe p~oportion of ~luid from the inlet passage of the torque convertex directly to the outlet of a cooler which receiVes and cools fluid from the outlet passage o the torque converter. Thus, under certain conditions an undesirable portion of the circulating fluid b~passes the cooler via that relief valve, so . . ~
35~
that the torque conVerter cooler ~low rate dld not uniformly incxease over the operatin~ range as desired A large nu~ber of valves are known which can modulate and contxol the fluid ~low rate to and rom a torque converter or alternately the pressure at the - inlet ~nd~or outlet thereof. Some valves can even control multiple combinations of these parameters.
However, these valves are not only usually complex and c05tly in construction, but also the~ take up valuable room where space is at a premium~ Still further, what is needed is a solution to the aforementioned problems that can be incorporated in commercially available transmission control systems with but minimal delay to the ultimate consu~er.
The present invention is directed to over-coming one or more of the problems as set forth above.
Disclosure of Invention Xn accordance with one aspect of the present invention a flow limitin~ passage directly connects a fluîd inlet passage to a torque converter and a fluid outlet from the torque converter. Thus, although a preselected amount of fluid is caused to continually bypass the torque converter, such amount is still desirably directed to the torque converter cooler~
Advantageously, because o~ the incorporation of the controlled fluid flow bypass passa~e around the torque conVerter, a pressure relief valve associated with the trans~ission contxol system is no longer adversely affected by back pressure fluctuations at the inlet passa~e to ~he~convexter~ and also the fluid flow rate throu~h both the cooler and the torque converter increase uniformly in pxoportion to an increase in the torque conVextex input speed.
,:, 35.~5~
Brief Description of Drawin~s Figure 1 is a dia~rammatic view of one embodiment of the t~ansmission control system of the present invention wlth a portion o~ the valving shown therein broken open to better illustrate details thereof.
Flgure 2 is a diagrammatic view of the torque converter shown in Figu~e 1, with a fragmentary portion thereof shown in cross section to illustrate certain fluid passages therein~
Best Mode -~or Carr~ing Out the Invention Refexring initiall~ to Figure 1, a trans-mission control system 10 is shown as having a pump 12 whlch draws fluid from a sump 14 and directs it through a main line conduit 16 as a fluid pressure source to a transmission control assembly 18 and to a pressure regulator valve or pressure relief valve 20. The transmission control assembly 18 includes a control or inchin~ valve 22 connected to the pressure source and a directional selector valve 24 connected to the control 2Q valve 22 and the pressure source. Manual control of the directional selector valve enables a forward clutch 32 or a reverse clutch 34 to be controllably supplied with pressure fluid for operation of the associated vehicle. Such transmission control assembly 18 can be of conventional construction, such as has been hereto-fore incorporated on the previously mentioned Model PRl Power Ran~er Shuttle Transmission, produced by Borg~
Waxner Corpora~ion.
~ known p~essuxe relief valve 36 is connected to the main line condui~ 16 to provide a preselected maximum pxe5suxe le~el thereat. For example, at a settin~ of about 138U RP~ ~200 psi) the relief valve 36 : . :, .~::-;-; . : . :
- ,: - , ; :
~355~
relieves ~luid fro~ the main line conduit back to the sump 14.
The pressure regulator valve 20 has a housing 38 defining an elon~ate cylindrical bore 40, a pressure port 42, an inlet port 44, an outlet port 46, and a drain port 48, all communicating with the bore. A
valve spool 50 having a pair of spaced apart cylindrical lands 52, 54 and a neck 56 is reciprocably disposed in the bore, and the valve spool is continually biased to the left when viewing the drawing by a compression spring 58. A preselected pressure at the pressure port 42r for example of about 830 KPa (120 psi), serves to overcome the spring and move the spool to ~e right when viewing the drawing. A throttling slot 60 formed in the land 54 is then placed in open communication with the inlet port 44, whereupon fluid in the main line conduit 16 is relieved to an outlet conduit 62 via the inlet port, the throttling slot and the outlet port 46.
A major purpose of the pressure regulating valve 20 is to cut off fluid flow to the torque converter 66 when the pressure in the main line conduit drops below its preselected pressure level setting, and thus to assure that the transmission con-trol assembly 18 will get full - benefit of this available flow from the pump 12 for fast response during a transmission shift.
Fluid in the outlet conduit 62 from the regulatin~ valve 20 is directed to an inlet pa~sage 64 leading to a h~drodynamic torque conVerter 66~ As shown in Figure 2, this tor~ue converter has a pump ox impeller element 68 coupled to an engine, not shown, a reactor element 7Q suitably coupled to a stationary kubular member 72, and a turbine element 74 connected to a rotary sha~t 76 leading to a transmission, not . shown.
, .
. ,: :.-. , : :.:: : . ~, . : : : ~ , :
, .. . .
3~
Basically, the tor~ue converter is similar in construction to the ~odel Wll tor~ue conVerter produced by Borg & Beck and the txansmission is similar in cons-truction to the Model PRl Power Ranger Shuttla Transmission produced by Warner Gear.as previously mentioned~ With the construction of the torque con-verter 66 shown in Figure 2 it is apparent that fluid charging pressure is directed to the torque converter via the inlet`passage 64 located in part between the tubular member 72 and a surrounding rotary member 78.
Fluid is communicated from the torque converter via an outlet passage 80 defined in part between the shaft 76 and the tubular member 72. secause of such relationship the inlet and outlet passages 64 and 80 present some restriction to fluid flow.
Referring again to Figure 1, from the outlet passage 80 of the torque converter 66 heated fluid flows to a cooler or heat exchanger 82 where its temp-erature is desirably reduced prior to being passed on : 20 to a conduit 84 and to a plurality of lubrication points 86.
A pressure relief valve 88 of known con-struction is in f-luid communication with the conduit 6~
~ leading to the inlet passage 64 of the torque converter 66 such *hat at a preselected pressure thereat, for example about 900 KPa (130 psi~, fluid is allowed to flow from the conduit 62 to a conduit 90 and the conduit 84 in b~passing relation to the cooler 82. This relief valve protects the torque converter 66 by limiting the maximum pressure level at the inlet passage thereto.
A branch conduit 92 havin~ a flow control orifice 94 therein i.s connected between the main line conduit 16 and the inlet.passage 64 of the torque : ~ - : . : . ~, ................... . . ..
: - ,,, ., : . : ..
. , ,: . . : : , : : .; , : : .
: : :. : ,: :: : .
~3~S~
converter 66. The flow control orifice is preferably about 1.52 mm (0~060") in diameter so that a fluid flow rate of about 1.9 to 3.8 litres/min. (1/2 to 1 gpm) will be directly communicated to the inlet passage of the torque converter to insure that it is supplied with at least a preselected minimwn amount of fluid at all times, such as during a transmission shift when the pressure regulator valve 20 is closed.
In accordance with the present embodiment, a flow limiting passage 96 having an~effective orifice diameter of about 3.8 mm (0.150") is directly connected between the inlet passage 64 and the outlet passage 80 in fluid bypassing relation to the torque converter 66. In this way, a preselected proportion of the fluid flow to the inlet passage 64 can be continually passed directly to the cooler 82.
Industrial Applicability In actual operation of the transmission control system 10, the input speed of the impeller 68 of the torque converter 66 varies with engine speed, for example from about~1000 to 2400 rpm. With the transmission in neutral the fluid flow rate through the torque converter ~ desirably increases relatively uniformly from about 7.6 to ; ~ 18.9 litres/min. t2 to 5 gpm). Simultaneously, the cooler
2~ flow rate desirably increases relatively uniformly from about 15.1 to 30.3 litres/min~ (4 to 8 gpm). Thus a flow rate of about 7.6 to 11.4 litres/min. ~2 to 3 gpm) continually occurs through the torque converter bypass passage 960 This contrasts sharply with the operation of the known transmission control system without the flow limiting a bypass passage 96, wherein the flow rate 'r ' ' ''; I' : .. ' .' ~':. '''. . ' ': ' ::'' : I
_7~ 3~5~
increased across the cooler with increasing engine .,, speed only up to the point where the back pressure at the inlet passage 64 to the torque converter became.
so high and erratic that the relief valve 88 located thereat opened. This undesirably influenced the pres-sure level in the main line conduit as well as in the torque converter, and also adversely affected opera-tion of the transmission control assembly 18. More over, the increased quanti.ty of fluid passing through the relief valve 88 did not pass through the cooler' 82 contributing to an undesirable build up in the fluid temperature of the transmission control system 1 0 .
As best shown in Figure 2, the flow limiting passage 96 is preferably located in the region of the torque converter 66. For example, the flow limiting passage 96 can be defined in the tubular member 72 operatively connected to the converte.r reactor el,e-ment 70. In the embodiment illustrated the flow limiting passage 96,extends radially through the tubular member to be in direct fluid communication with the inlet and outlet passages 64, 80 located : thereat. In such location the flow limiting passage results in immediately improved operating performance of the transmission control assembly, without the need to provide another valve to solve the previously set forth problems or without any slgnificant change to the system.
Other aspects, objects and advantages of this invention,can be obtained from a study of the drawings, the disclosure and the appended claims.
.
: : . . . . ... ,; .. / .. _ .
.. ; :: : . ; , . ..
.. .: ,. :: : : :
. .... .. .
_7~ 3~5~
increased across the cooler with increasing engine .,, speed only up to the point where the back pressure at the inlet passage 64 to the torque converter became.
so high and erratic that the relief valve 88 located thereat opened. This undesirably influenced the pres-sure level in the main line conduit as well as in the torque converter, and also adversely affected opera-tion of the transmission control assembly 18. More over, the increased quanti.ty of fluid passing through the relief valve 88 did not pass through the cooler' 82 contributing to an undesirable build up in the fluid temperature of the transmission control system 1 0 .
As best shown in Figure 2, the flow limiting passage 96 is preferably located in the region of the torque converter 66. For example, the flow limiting passage 96 can be defined in the tubular member 72 operatively connected to the converte.r reactor el,e-ment 70. In the embodiment illustrated the flow limiting passage 96,extends radially through the tubular member to be in direct fluid communication with the inlet and outlet passages 64, 80 located : thereat. In such location the flow limiting passage results in immediately improved operating performance of the transmission control assembly, without the need to provide another valve to solve the previously set forth problems or without any slgnificant change to the system.
Other aspects, objects and advantages of this invention,can be obtained from a study of the drawings, the disclosure and the appended claims.
.
: : . . . . ... ,; .. / .. _ .
.. ; :: : . ; , . ..
.. .: ,. :: : : :
. .... .. .
Claims (5)
1. In a transmission control system for a trans-mission including a torque converter, and of the type having fluid inlet and outlet passages leading respectively to and from the torque converter, a source of fluid pressure, and a pressure regulating valve for re-lieving fluid from the source at a preselected pressure to the fluid inlet passage, the improvement comprising:
a flow limiting passage directly connecting said fluid inlet and outlet passages to said torque converter.
a flow limiting passage directly connecting said fluid inlet and outlet passages to said torque converter.
2. The transmission control system of claim 1 wherein said torque converter includes a turbine element, a rotary shaft connected to the turbine element, and a tubular member surrounding the rotary shaft, the flow limiting passage being defined in said tubular member.
3. The transmission control system of claim 1 or claim 2 wherein said torque converter has a reactor element and said tubular member is connected to said reactor element.
4. A transmission control system comprising:
a hydrodynamic torque converter;
fluid inlet and outlet passages connected to said torque converter;
a fluid pressure source;
pressure regulating valve means for relieving fluid from said source at a first preselected pressure to said inlet passage;
pressure relief valve means for relieving fluid from said inlet passage at a second preselected pressure above said first preselected pressure; and a flow limiting passage directly connecting said fluid inlet and outlet passages and being of a construction sufficient for continually and controllably bypassing fluid around said torque converter.
a hydrodynamic torque converter;
fluid inlet and outlet passages connected to said torque converter;
a fluid pressure source;
pressure regulating valve means for relieving fluid from said source at a first preselected pressure to said inlet passage;
pressure relief valve means for relieving fluid from said inlet passage at a second preselected pressure above said first preselected pressure; and a flow limiting passage directly connecting said fluid inlet and outlet passages and being of a construction sufficient for continually and controllably bypassing fluid around said torque converter.
5. The transmission control system of claim 4 wherein said torque converter includes a tubular member, said inlet and outlet passages are located radially interiorly and exteriorly of said tubular member, and said flow limiting passage is defined through said tubular member.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/973,047 US4209985A (en) | 1978-12-11 | 1978-12-11 | Transmission control system |
| US973,047 | 1978-12-11 | ||
| PCT/US1978/000200 WO1980001194A1 (en) | 1978-12-11 | 1978-12-11 | Transmission control system |
| USPCT78/00200 | 1978-12-11 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1103554A true CA1103554A (en) | 1981-06-23 |
Family
ID=26759990
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA336,576A Expired CA1103554A (en) | 1978-12-11 | 1979-09-28 | Transmission control system |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1103554A (en) |
| ES (1) | ES486770A1 (en) |
-
1979
- 1979-09-28 CA CA336,576A patent/CA1103554A/en not_active Expired
- 1979-12-11 ES ES486770A patent/ES486770A1/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| ES486770A1 (en) | 1980-06-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |