Modulatable power transmission clutch and a marine transmission

• US 6,443,286 B1
• Filed: 01/18/2001
• Issued: 09/03/2002
• Est. Priority Date: 01/18/2001
• Status: Expired due to Term

• Current Assignee: Twin Disc Incorporated
• Original Assignee: Twin Disc Incorporated
• Inventors: Pelligrino, Paul A., Bratel, Dean J.
• Primary Examiner(s): Rodriguez, Saul
• Application Number:
  US09/765,117
• Publication Number:
  US 20020094903A1
• Time in Patent Office: 593 Days
• Field of Search: 192/51, 192/52.4, 192/109.F, 192/21, 192/85.AA, 440/75
• US Class Current: 192/85.32
• CPC Class Codes: B63H 23/30 characterised by use of clutches
• CPC Class Codes: F16D 2048/0209 characterised by fluid valves having control pistons, e.g. spools
• CPC Class Codes: F16D 25/0638 with more than two discs, e.g. multiple lamellae
• CPC Class Codes: F16D 25/14 Fluid pressure control
• CPC Class Codes: F16D 48/02 Control by fluid pressure

Abstract

A modulatable power transmission clutch including interleaved clutch plates and having a central power transmitting shaft extending axially through the clutch. The clutch includes a fluid operated movable piston for effecting clutch operation by compression of the plates. The piston has a smaller piston area and a larger piston area, the smaller piston area has fluid flow directed to it a variable fluid pressure whereby the clutch is modulatable. The larger piston area is adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of the clutch. A spring loaded normally closed trigger valve controls fluid flow to the larger piston area in response to fluid pressure above a predetermined amount at the smaller piston area. The trigger valve is mounted in the shaft and is normally closed so that pressure fluid is directed to the smaller piston area at a variable fluid pressure whereby the clutch is modulatable. When the valve is open by said fluid pressure over a predetermined amount, the valve permits fluid flow to the larger piston area to effect maximum and unmodulatable engagement of the clutch for full clutch capacity.

Claims

1. A modulatable power transmission clutch including interleaved clutch plates, said clutch having a central power transmitting shaft extending axially through said clutch mounted thereon, said clutch including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having smaller and larger piston areas thereon, the smaller piston area being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable, the larger piston area being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch;

and a spring loaded normally closed valve for controlling fluid flow to said larger piston area in response to fluid pressure above a predetermined amount at said smaller piston area, said valve being mounted in said shaft and being normally closed whereby pressure fluid is directed to said smaller piston area at a variable fluid pressure whereby said clutch is modulatable, and when said valve is open by said fluid pressure over a predetermined amount permits fluid flow to said larger piston area to effect maximum and unmodulatable engagement of said clutch for full clutch capacity.

2. A modulatable power transmission clutch including interleaved clutch plates, said clutch comprising a power transmitting shaft extending axially and centrally through said clutch mounted thereon, said clutch including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having two separate fluid application piston areas of different areas thereon, one smaller of said piston areas being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable, the other larger of said piston areas being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch;

and valve means for controlling fluid flow to said other larger of said piston areas in response to fluid pressure at said one smaller of said piston areas, said valve means being axially slidably mounted in an axially extending hole in said shaft and spring loaded to a normally closed position in which pressure fluid is directed to said one smaller piston area at a variable fluid pressure whereby said clutch is modulatable, and when said valve means is open it permits fluid flow to said other larger of said piston area to effect maximum and unmodulatable engagement of said clutch for full clutch capacity.

3. A modulatable power transmission clutch including interleaved clutch plates, said clutch comprising a power transmitting shaft extending axially and centrally through said clutch mounted thereon, said clutch including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having two separate fluid application piston areas of different areas thereon, one smaller of said piston areas being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable, the other larger of said piston areas being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch;

and a trigger valve for controlling fluid flow to said other larger of said piston areas in response to fluid pressure above a certain valve at said one smaller of said piston areas, a pressure fluid passage in said shaft for conducting pressure fluid to said smaller area and to said larger piston area, said trigger valve being located in said shaft passage and being spring loaded to a normally closed position in which pressure fluid is directed to said one smaller piston area at a variable fluid pressure whereby said clutch is modulatable, said trigger valve when closed acting to block flow of fluid to said larger area below a predetermined pressure and when open acting to permit fluid flow above a predetermined pressure to said larger area of said piston to effect maximum and unmodulatable engagement of said clutch for full clutch capacity.

4. A marine transmission for variable speed control of a boat having a propeller for providing modulatable lower speed in both forward and reverse direction for maneuvering during docking of said boat to provide enhanced docking control and boat positioning;

said transmission providing seamless transition from modulation during which speed can be increased slightly to full clutch engagement and capacity for driving said propeller;

said transmission including a modulatable power transmission clutch including interleaved clutch plates, said clutch comprising a power transmitting shaft extending axially and centrally through said clutch mounted thereon, said clutch including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having two separate fluid application piston areas of different areas thereon, one smaller of said piston areas being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable for said docking, the other larger of said piston areas being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch for driving said propeller;

and valve means for controlling fluid flow to said other larger of said piston areas in response to fluid pressure at said one smaller of said piston areas, said valve means being axially slidably mounted in an axially extending hole in said shaft and spring loaded to a normally closed position in which pressure fluid is directed to said one smaller piston area at a variable fluid pressure whereby said clutch is modulatable, and when said valve means is open it permits fluid flow to said other larger of said piston area to effect maximum and unmodulatable engagement of said clutch for full clutch capacity available to said propeller.

5. A power transmission including a forward modulatable power transmission clutch and a rear modulatable power transmission clutch, said forward clutch connected in power receiving connection with a prime mover and in power delivering connection with load to be driven,

said rear clutch being connected in driven engagement with said forward clutch and engageable with said load to be driven for driving the latter in a reverse direction,

said forward and rear clutches each including clutch plates, a power transmitting shaft extending axially and centrally therethrough, said clutch including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having two separate fluid application piston areas of different areas thereon, one smaller of said piston areas being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable, the other larger of said piston areas being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch;

and valve means for controlling fluid flow to said other larger of said piston areas in response to fluid pressure above a predetermined amount at said one smaller of said piston areas, said valve means being axially slidably mounted in an axially extending hole in said shaft and spring loaded to a normally closed position in which pressure fluid is directed to said one smaller piston area at a variable fluid pressure whereby said clutch is modulatable, and when said valve means is open it permits fluid flow to said other larger of said piston area to effect maximum and unmodulatable engagement of said clutch for full clutch capacity.

6. A power transmission including a forward modulatable power transmission clutch and a rear modulatable power transmission clutch, said forward clutch connected in power receiving connection with a prime mover and in power delivering connection with load to be driven,

said rear clutch being connected in driven engagement with said forward clutch and engageable with said load to be driven for driving the latter in a reverse direction,

said forward and rear clutches each including clutch plates, a power transmitting shaft extending axially and centrally therethrough, each of said clutches including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having two separate fluid application piston areas of different areas thereon, one smaller of said piston areas being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable, the other larger of said piston areas being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch;

and for each of said forward and rear clutches,

a trigger valve for controlling fluid flow to said other larger of said piston areas in response to fluid pressure above a certain valve at said one smaller of said piston areas, a pressure fluid passage in said shaft for conducting pressure fluid to said smaller area and to said larger piston area, said trigger valve being located in said shaft passage and being spring loaded to a normally closed position in which pressure fluid is directed to said one smaller piston area at a variable fluid pressure whereby said clutch is modulatable, said trigger valve when closed acting to block flow of fluid to said larger area below a predetermined pressure, and when said trigger valve is open acting to permit fluid flow above a predetermined pressure to said larger area of said piston to effect maximum and unmodulatable engagement of said clutch for full clutch capacity.

7. A marine transmission for variable speed control of a boat having a propeller for providing modulatable lower speed in both forward and reverse direction for maneuvering during docking of said boat to provide enhanced docking control and boat positioning;

said transmission providing seamless transition from modulation during which speed can be increased slightly to full clutch engagement and capacity for driving said propeller;

said transmission including a forward modulatable power transmission clutch and a rear modulatable power transmission clutch, said forward clutch connected in power receiving connection with a prime mover and in power delivering connection with load to be driven,

said rear clutch being connected in driven engagement with said forward clutch and engageable with said load to be driven for driving the latter in a reverse direction,

said forward and rear clutches each including clutch plates, a power transmitting shaft extending axially and centrally therethrough, said clutches including a fluid operated movable piston for effecting clutch operation by compression of said plates, said piston having two separate fluid application piston areas of different areas thereon, one smaller of said piston areas being adapted to have fluid flow directed thereto at a variable fluid pressure whereby said clutch is modulatable for said docking, the other larger of said piston areas being adapted to have fluid flow directed thereto to effect maximum and unmodulatable engagement of said clutch for driving said propeller;

and for each of said forward and rear clutches,

a trigger valve for controlling fluid flow to said other larger of said piston areas in response to fluid pressure above a certain valve at said one smaller of said piston areas, a pressure fluid passage in said shaft for conducting pressure fluid to said smaller area and to said larger piston area, said trigger valve being located in said shaft passage and being spring loaded to a normally closed position in which pressure fluid is directed to said one smaller piston area at a variable fluid pressure whereby said clutch is modulatable, said trigger valve when closed acting to block flow of fluid to said larger area below a predetermined pressure, and when said trigger valve is open acting to permit fluid flow above a predetermined pressure to said larger area of said piston to effect maximum and unmodulatable engagement of said clutch for full clutch capacity,

and an electronic control circuit for said transmission including a source of pressure fluid, a proportional valve connected to said source for delivering pressure fluid to said rear clutch, said source connected to another proportional valve for delivering pressure fluid to said forward clutch,

said circuit also including a control lever operatively connected with said proportional valves for selective operation thereof to effect forward or reverse operation of said boat.