It is known in the field of vehicle brakes to provide liquid cooling of the brake lining in order to minimize the brake wear and to maintain maximum braking power. Numerous attempts have been made to provide liquid coolant flow to the vehicle brake shoe. It is believed that further improvements can be made to liquid cooled brakes.
A vehicle brake includes a brake shoe having an annular rim carrying a layer of a brake friction material on a radially outer surface. A fluid flow passage is carried on a radially inner surface of the rim for circulating fluid past the rim to remove heat from the rim and the layer of brake friction material when the layer of brake friction material engages a rotating brake member.
The fluid passage is formed by a water jacket sealing joined to a pair of webs extending radially inward from the inner surface of the rim.
An inlet port and an outlet port are formed in either one of the pair of webs and receive fluid connections for coupling fluid carrying members, hoses or conduits to the inlet and outlet ports to provide a fluid flow path for coolant fluid through the inlet port, along the fluid flow passage, and out through the outlet port.
The water jacket can be a one piece member disposed between the pair of support webs and joined along exterior edges to the pair of support webs and the radial inner surface of the rim to form the closed fluid flow passage.
An inner central wall of the water jacket may have an arcuate shape complimentary to the arcuate shape of the inner edges of the pair of support webs.
The fluid flow passage may be integrally formed with the rim.
In one aspect, substantially all of the annular rim and at least a portion of the water jacket can be formed of the friction material.
In another aspect, a heat conductive member is disposed within the layer of brake friction material and coupled in heat transfer relationship with the rim.
A plurality of heat conductive members may be disposed within the layer of brake friction material and coupled in heat transfer relationship with the rim. The heat conductive member is at least one body formed of a high thermal conductive material.
A heat radiator member can be coupled in heat transfer relationship with the rim, and disposed in the fluid flow passageway. A heat conductive member can be disposed with the layer of brake friction material, and axially aligned with the heat radiator.
The various features, advantages and other uses of the present liquid cool brake will become more apparent by referring to the following detailed description and drawing in which:
Referring now to the
Generally, as shown in
A coolant fluid flow passageway 31 includes an arcuate web 30 extending intermediately between opposed side edges of the radially inward facing surface 24 of the rim 22. The web 30 has a thin, flange-like shape and can be integrally formed as part of the rim 22 or fixedly joined to the rim 22 by welding, mechanical fasteners, etc. The web 30 adds stiffness to the arcuate rim 22 to resist the forces encountered during movement of the brake shoe 20 into frictional engagement with the rotating vehicle brake drum 29.
According to a first aspect, a coolant passage 40 is formed in fluid flow contact or communication with the inner surface 24 of the rim 22 at a location on the inner surface 24 where the maximum temperature during braking is encountered. The coolant passage 40 extends completely through the web 30 between one side of the web 30 and the opposite side of the web 30. The coolant passage 40 may have any arcuate length and can be centered at the arcuate center of the rim 22 where maximum braking temperatures are typically encountered. For example, the passage 40 is in the form of a lateral bore 41 formed intermediately between the arcuate ends of the web 30.
Connections to a fluid flow system are provided to the coolant passage 40 as described hereafter.
Another aspect of the liquid cooled brake is shown in
At least one of the gussets 42 or 44, with gusset 42 being shown by way of example, has a first, inlet aperture 46 and a second, outlet aperture 48 typically located at opposite ends of the gusset 42. Fluid connectors are fixedly mounted in each aperture 46 and 48 to provide fluid flow through the inlet 46 into and through the fluid passage 40 to the outlet 46 for maximum heat transfer from the brake shoe 20. The fluid connectors can be any connection suitable for fluidically coupling flexible hoses or rigid pipes to the inlet and outlet ends of the passageway 40, such as pipe unions, quick connectors, etc.
Referring now to
The brake shoe 50 includes two spaced webs 60 and 62. Radial inward edges 64 and 66 of the first and second web 60 and 62, respectively, are closed off by an inner wall or gusset 68 which can be joined to the webs 60 and 62 by welding, mechanical fasteners, or any other joining technique suitable for use in a vehicle brake application.
The webs 60 and 62 and the inner wall 68 form a coolant passage 70 adjacent to the rim 52 which extends from an inlet 67 at one end of the webs 60 and 62 to an outlet 69 at the opposite end of the webs 60 and 62. Fluid connectors are mounted in the inlet 67 and the outlet 69. The coolant passage 70 places the liquid coolant flow at the longitudinal center of the rim 52 and the brake friction lining material 58 which is exposed to the highest braking temperature. The distance between the outer surface of the layer of braking material 58 and the liquid coolant in the passage 70 is minimized so as to maximize heat transfer efficiency.
As shown in
It will be understood that the inner wall 68 and the end wall 66 and 69 may be integrally formed as a one piece member. Further, the end of wall 67 and 69 may have a smaller width than the width of the inner wall 68 so as to fit in between the opposed ends of the webs 60 and 62.
A water jacket is sealingly coupled to a pair of wet port webs carried on the rim to create the fluid flow passage in conjunction with the pair of support webs.
The dual webs 60 and 62 and the inner endwall 68 may also be implemented as an integral part of a cast or molded brake shoe 76 are shown in
In the aspect shown in
A brake shoe 110 shown in
In this aspect, heat conductive means in the form of one or more heat conductive members, with three circumferentially spaced heat conductive members 124, 126, and 128 being shown by way of example only, are mounted within the layer 114 of brake friction material. The heat conductive members 124, 126, and 128 may be sintered or integrally cast as part of the friction material layer 114 or fixedly mounted in the layer 114 after the layer 114 has been bonded or otherwise mounted to the outer surface 116 of the rim 112 by forming bores in the layer 114 and then inserting and fixedly securing each of the heat conductive members 124, 126 and 128 in the layer 114.
The heat conductive members 124, 126, and 128 are preferably formed of a highly thermal or heat conductive material, such as copper, copper alloy, etc.
The radially outer end or surface of each of the heat conductive members 124, 126, and 128 may be covered by an outer portion of the layer 114 of brake friction material or exposed through the outer surface of the layer 114 as shown in
The heat conductive members 124, 126, and 128 function to rapidly transfer heat generated during vehicle braking in the surrounding wheel drum, not shown, and in the brake friction lining or layer 114 to the rim 112 where the heat is transferred to the liquid coolant flowing through the flow passage 121 formed between the one or more webs, with two webs 118 and an inner wall 119 being shown in
The heat radiator or fin 134 is shown in
The heat conductive members 124, 126, and 128 may have other shapes, lengths, and widths as shown, by way of example only, in
It will be understood that the heat conductive members 124, 126 and 128 or the heat conductive member 138 may be used independently and separately from the heat radiator or fin 134. As shown in
Referring now to
A pair of curved webs 152 and 154 are fixed, such as by welding, to the inner surface 144 of the rim 142. The webs 152 and 154 include connections to the brake cylinder for effecting radial movement of the entire brake shoe 140 into and out of engagement with the surrounding wheel brake drum. As shown in
A pair of bores are formed in one of the webs, such as web 154, to create an inlet port 158 and an outlet port 160. Alternately, the bores forming the inlet and outlet ports 158 and 160 may be located within one web 152 and the other in the other web 154.
A water jacket 164 is securely and sealingly attached to the webs 152 and 154 to form a coolant flow passage in conjunction with the inlet port 158 and the outlet port 160.
By way of example only, the water jacket 164 has an elongated, arcuate central wall 166 with two depending end walls 168 and 170, one extending outward from opposed ends of the central wall 166. Although the central wall 166 may be planar in form, it is also feasible, as shown in
As shown in
As shown in
Suitable coolant connections, such as threaded connections 180 and 182 in the form of threaded plugs, by example, are fixedly secured, such as by threading, welding, etc., to the bores forming the inlet port 158 and the outlet port 160. The threaded connectors 180 and 182 receiving mating connectors 184 and 186, respectively mounted on fluid coolant conduits or hoses 188 and 190 respectively. The fluid conduits or hoses 188 and 190 are coupled to a fluid flow source, such as that shown in
It should be noted that the coolant chamber or passage 176 is formed, in part, by using the existing pair of spaced webs 152 and 154 found on certain brake shoes 140. Only a simple water jacket 164 and the inlet and outlet fluid connections, shown in
Any of the alternate flow passage modifications including the interior flange 134 shown in
A brake coolant flow control system is depicted in
The engine 210 is also fluidically coupled by a second fluid flow loop to a passenger compartment heater 220. The second fluid flow loop includes a first conduit 222 coupled between the engine 210 and an inlet of the heater 220, and a second conduit 224 coupled between an outlet of the heater 220 and a second conduit 216 of the engine/radiator fluid flow loop.
A brake coolant flow loop is formed of a first conduit 230 branching off of the first heater conduit 222. The first conduit 230 is coupled to a diverter valve 232, such as a normally closed solenoid operated valve. A solenoid coil receives an input signal, as described hereafter, to cause the diverter valve, 232 to open thereby allowing a coolant flow through the brake coolant flow passages 40, 70, 92, 212 or 221 as shown in various aspects of the liquid cooled brake described above.
The input signal to the coil of the diverter valve 232 maybe a 12 volt D.C. signal from the vehicle brake stoplight or the brake pedal actuation switch as shown by a signal line 234.
The outlet of the diverter valve 232 is coupled to an inlet conduit 236 which is coupled to the inlet of the brake coolant passages 40, 70, 92, 112, or 221 shown in the various aspects described above.
The outlet of the liquid brake cooling passage is coupled to a conduit 238 which is connected to the first conduit 214 of the engine/radiator coolant flow loop so as to return the heated coolant fluid from the brakes to the top portion of the radiator 212.
A safety feature is also provided in the brake coolant flow circuit shown in
Referring now to
The outlets of the diverter valve 232 and heater core 220 are coupled to sub-conduit 236A and 236B, respectively which tee together then flow into the brake line fluid flow conduit 236.
This application is a continuation-in-part of co-pending U.S. application Ser. No. 12/834,347, filed Jul. 12, 2010, which claims priority benefit to the Jul. 10, 2009 filing date of U.S. Provisional Patent Application Ser. No. 61/224,711 for “Liquid Cooled Brake”, all filed in the name of Darrel Sand, the entire contents of all of which are incorporated herein in its entirety.
Number | Date | Country | |
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61224711 | Jul 2009 | US |
Number | Date | Country | |
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Parent | 12834347 | Jul 2010 | US |
Child | 14224604 | US |