Ventilated brake shoe with cooling water channel

Abstract

The ventilation type brake shoe with the cooling water channel comprises a brake shoe piece, a brake shoe body and a brake bottom plate, the brake shoe body is arranged on the brake bottom plate through a cam, the brake shoe piece is arranged on the brake shoe body, and the brake shoe piece is of a double-layer split type brake shoe base plate structure; according to the ventilated brake shoe, an active liquid cooling and passive air cooling synergistic heat dissipation method is adopted, a shoe base plate is decoupled into an inner-layer component and an outer-layer component, and grooves are machined in corresponding thermal load gradient distribution areas of the two components respectively, so that a closed embedded cooling liquid flow channel is formed in a high-heat-flux area of a friction interface after an assembly is assembled; directional ventilation ducts are independently formed in the low-heat-load area. The brake efficiency stability and the component structure integrity are improved, the service cycle of key components is greatly prolonged, the essential reduction of the maintenance frequency is finally achieved, and the heat management bottleneck of a traditional closed drum brake is thoroughly broken through.

Description

Technical Field

[0001] This invention relates to a brake shoe, and more particularly to a ventilated brake shoe with cooling water channels. Background Technology

[0002] Drum brakes, as one of the most crucial braking actuators in modern transportation and industrial equipment, directly impact driving safety and equipment reliability. Their core working principle utilizes friction to convert and dissipate the kinetic energy of a moving object into heat. During frequent or high-intensity braking, the friction between the brake shoes and the brake drum generates a significant amount of heat. Due to the enclosed structure of drum brakes, this heat is difficult to dissipate effectively, leading to a decline in the performance of the brake shoe material and a phenomenon known as "heat fade" (a sharp drop in braking performance). Furthermore, drum brakes have a complex structure, requiring specialized tools for disassembly and maintenance, and brake shoe adjustment necessitates manual operation, which can easily result in reduced braking effectiveness due to improper handling. Therefore, addressing the core shortcomings of traditional brake drum / shoe systems—such as extremely low heat dissipation efficiency due to their enclosed structure, leading to heat fade, high-temperature damage to the brake shoes and drum, and frequent maintenance—is currently a hot research topic.

[0003] Through patent searching, a comparison was made between the water-cooled brakes in Document 1 (Publication No. CN112555307A) and Document 2 (Publication No. CN109356952A). The former innovatively integrates water-cooling and air-cooling technologies into the automotive drum brake system, proposing a brake design scheme that combines efficient heat dissipation and thermal stability. Its core technology lies in the connection structure between the inner cavity and the water outlet pipe of the water-cooled brake drum. Combined with the synergistic effect of the air-cooling components and the internal and external air ducts of the drum, it achieves active regulation of the heat generated during braking through dual heat dissipation paths, thereby significantly improving the thermal stability and continuous braking capability of the brake. However, this design has certain limitations in terms of structural complexity. The introduction of the water-cooling system may increase manufacturing costs and maintenance difficulties. At the same time, the water-cooling components have high sealing requirements, posing a potential risk of leakage. In addition, the air-cooling efficiency is easily affected by environmental airflow conditions, and system integration requires adaptation adjustments to the original vehicle structure, which may limit its application in some vehicle models. In summary, the thermal management of existing drum brakes represents a technological breakthrough, but their practical application requires comprehensive consideration of multiple factors such as system reliability, cost control, and environmental adaptability.

[0004] A drum brake cooling device based on the synergistic effect of water cooling and air cooling is innovatively designed to achieve simultaneous cooling of the brake shoe and brake drum through a circulating loop of a first and second cooling water channel. This is combined with a structural design of a circumferential annular groove and bearing in the brake drum to adapt to heat dissipation requirements in space-constrained scenarios. This technical solution directly contacts the brake component surface through water cooling, significantly improving heat transfer efficiency. Simultaneously, the nested structure of the annular groove and bearing effectively solves the engineering challenge of installing heat transfer mechanisms in narrow-gap environments such as trucks using traditional cooling systems, demonstrating targeted optimization for heat dissipation requirements under complex operating conditions. However, while improving cooling performance, this design increases the overall weight and structural complexity of the brake due to the introduction of the water cooling system. Furthermore, the precise fit between the annular groove and bearing places higher demands on manufacturing processes and sealing performance. During long-term operation, attention must be paid to the circulation stability of the cooling medium and potential thermal stress accumulation. Therefore, there is an urgent need for a brake shoe design that can effectively suppress material thermal decay, structural deformation, and ablation cracking, and significantly extend maintenance cycles.

[0005] Traditional drum braking systems, constrained by their enclosed structure, suffer from significantly limited internal airflow, leading to inefficient heat dissipation at the friction interface and resulting in poor systemic heat dissipation. This heat accumulation further induces thermal degradation of the friction material, causing nonlinear decline in braking performance and loss of stability. Simultaneously, sustained high temperatures cause thermal stress distortion, ablation, carbonization, and delamination in the brake pad substrate and friction material, accompanied by thermal cracking and out-of-roundness deformation of the brake drum, resulting in irreversible structural damage. These thermo-mechanical coupling failure modes not only accelerate the performance degradation of critical components but also significantly increase maintenance costs and downtime due to frequent replacement of brake pads, drums, and related components, highlighting the fundamental deficiencies of existing technologies in terms of thermal management mechanisms and durability design. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a ventilated brake shoe with cooling water channels, which can solve the problems of severe heat fade and difficult maintenance of ordinary brake shoes.

[0007] The technical solution to the above-mentioned technical problems is: a ventilated brake shoe with cooling water channels, including brake pads, brake shoes, and a brake backing plate. The brake shoes are mounted on the brake backing plate, and cams are provided on the brake backing plate. The cams contact the two halves of the brake shoes respectively, and the rotation of the cams drives the two halves of the brake shoes to move. The two halves of the brake shoes are reset by springs. The brake pads are respectively mounted on the brake shoes. The brake pads are a double-layer split brake shoe pad structure. The ventilated brake shoe adopts a synergistic heat dissipation method of active liquid cooling and passive air cooling. The specific heat dissipation method is as follows: the brake pads are decoupled into inner and outer double-layer components, and grooves are machined in the corresponding heat load gradient distribution areas of the two inner and outer double-layer components. The grooves are water channels. After the components are assembled, the grooves of the inner and outer double-layer components form coolant channels. The coolant channels are closed embedded coolant channels in the high heat flux area of ​​the friction interface, forming active liquid cooling heat dissipation through the coolant channels. At the same time, ventilation channels are independently opened in the low heat load area, forming passive air cooling heat dissipation through the ventilation channels.

[0008] A further technical solution of the present invention is as follows: the brake pad includes an outer brake pad and an inner brake pad, which together form a double-layer split brake pad structure; the outer brake pad and the inner brake pad are respectively provided with corresponding water channels, which form coolant channels for active liquid cooling. Corresponding ventilation holes are respectively provided on the outer brake pad, the inner brake pad, and the brake shoe; the outer brake pad, the inner brake pad, and the brake shoe are fixed together, and the ventilation holes are aligned to form a ventilation channel penetrating the brake pad and the brake shoe for passive air cooling.

[0009] Water channels are arranged in the middle of the outer and inner brake pads, which is the high heat flux zone of the friction interface. Ventilation holes are distributed on both sides of the outer, inner, and brake pads, with the ventilation holes located on both sides of the water channels.

[0010] The outer brake pad, inner brake pad, and brake shoe each have rivet holes, and the outer brake pad and inner brake pad are fixedly installed on the brake shoe by rivets.

[0011] The outer brake pad is provided with an outer water channel, which is located on the end face of the outer brake pad that contacts the inner brake pad. The outer water channel includes a long water channel and multiple short water channels. The long water channel runs through both ends of the outer brake pad, and the multiple short water channels intersect and connect with the long water channel.

[0012] The inner brake pad is provided with an inner water channel. The inner water channel is located on the two end faces of the inner brake pad and the outer brake pad and brake shoe. The inner water channel includes a long water channel and multiple short water channels. The long water channel on the two end faces of the inner brake pad is interconnected to form an annular groove. The multiple short water channels are respectively intersected and connected with the long water channel.

[0013] The water channels on the outer and inner brake pads form a coolant passage, with the water inlet and outlet at each end of the coolant passage.

[0014] Due to the adoption of the above technical solution, the ventilated brake shoe with cooling water channels of the present invention has the following beneficial effects: This invention systematically overcomes the inherent defects of traditional braking systems through an innovative dual-layer decoupled brake shoe architecture and a zoned thermal management strategy. The integral brake shoe is decoupled into inner and outer double-layer pads. By pre-setting pre-assembled cooling water channels in the peak heat flux density region, directional forced convection dissipation of high heat at the friction interface is achieved. Simultaneously, ventilation channels are arranged in low heat load regions, synergistically utilizing the rotating airflow of the brake drum to enhance passive heat dissipation. This structural design ensures precise matching between the heat dissipation path and the spatial distribution of the heat load. The cooling water channels directly suppress material thermal decay and matrix distortion caused by the main heat sources, while the ventilation holes eliminate localized temperature rises and optimize airflow organization. This synergistic mechanism significantly reduces the risks of brake shoe ablation and carbonization, delamination, and brake drum thermal cracking and out-of-roundness, fundamentally improving braking performance stability and component structural integrity, significantly extending the service life of key components, and ultimately achieving a substantial reduction in maintenance frequency, completely breaking through the thermal management bottleneck of traditional enclosed drum brakes.

[0015] The technical features of a ventilated brake shoe with cooling water channels according to the present invention will be further described below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0016] Figure 1 : An overall assembly drawing of a ventilated brake shoe with cooling water channels.

[0017] Figure 2 : A schematic diagram of a ventilated brake shoe with cooling water channels.

[0018] Figure 3 : Schematic diagram of the inner brake pad structure.

[0019] Figure 4 : Schematic diagram of the inner brake pad structure.

[0020] Figure 5 : Schematic diagram of the outer brake pad structure.

[0021] Figure 6 : Schematic diagram of the outer brake pad structure.

[0022] Figure 7 : Schematic diagram of the brake shoe structure.

[0023] Figure 8 : Schematic diagram of the brake base plate.

[0024] In the above figures, the reference numerals are explained as follows: 1-Outer brake pad, 2-Inner brake pad, 3-Coolant flow channel, 4-Brake shoe, 5-Rotating shaft I, 6-Cam, 7-Rotating shaft II, 8-Brake base plate, 9-Inner water channel inlet, 10-Inner ventilation hole, 11-Rivet hole, 12-Inner water channel outlet, 13-Outer ventilation hole, 14-Outer water channel inlet, 15-Outer water channel outlet. Detailed Implementation

[0025] A ventilated brake shoe with cooling channels includes brake pads, a brake shoe, and a brake backing plate. The brake shoe is mounted on the brake backing plate, which has cams that contact the two halves of the brake shoe. The cams are connected to a motor, and their rotation drives the two halves of the brake shoe to move. The two halves of the brake shoe are then reset by springs. The brake pads are mounted on the brake shoes. The brake pads have a double-layer, split brake shoe pad structure. The ventilated brake shoe employs a combined heat dissipation method of active liquid cooling and passive air cooling.

[0026] Specific heat dissipation method: The brake pads are decoupled into inner and outer double-layer components, and grooves are machined in the corresponding heat load gradient distribution areas of the two double-layer components. These grooves serve as water channels. After assembly, the grooves of the inner and outer double-layer components form coolant flow channels 3. These coolant flow channels 3 are closed-loop embedded coolant flow channels in the high heat flux area of ​​the friction interface, forming active liquid cooling. Simultaneously, ventilation channels are independently opened in the low heat load area, forming passive air cooling. This synergistic thermal management mechanism, consisting of the embedded cooling water channel system (active liquid cooling) and the low-heat zone ventilation channel system (passive air cooling), utilizes the synergistic heat dissipation of active liquid cooling and passive air cooling through the coolant flow channels and directional ventilation channels.

[0027] The brake pads consist of an outer brake pad 1 and an inner brake pad 2, forming a double-layer decoupled structure. The outer brake pad 1 and inner brake pad 2 each have corresponding water channels, which together form a coolant passage 3 for active liquid cooling. Corresponding ventilation holes are provided on the outer brake pad 1, inner brake pad 2, and brake shoe 4. The outer brake pad 1, inner brake pad 2, and brake shoe 4 are fixed together, and the ventilation holes are aligned to form a through-hole for passive air cooling.

[0028] Ventilation holes are distributed on both sides of the outer brake shoe 1, the inner brake shoe 2, and the brake shoe itself, located on both sides of the water channel. Rivet holes are present on the outer brake shoe 1, the inner brake shoe 2, and the brake shoe, and the outer brake shoe 1 and inner brake shoe 2 are fixed to the brake shoe by rivets. Two mounting holes are provided at each end of the brake base plate. One end of each of the two brake shoe halves 4 is secured to one mounting hole on the brake base plate via a caliper. The other ends of the two brake shoe halves 4 are connected by springs and contact cams 6 respectively. Rotating shafts (rotating shaft I 5 and rotating shaft II 7) are fixed to each of the two brake shoe halves 4. Support holes on one end of each brake shoe halves 4 are fitted onto rotating shafts I 5 and II 7 respectively, and the rotating shafts contact cams 6. The two ends of the springs are connected to the two brake shoe halves 4 by welding and hooking. Cams are mounted on a rotating shaft passing through another mounting hole in the brake base plate. The rotating shaft is connected to a motor, and the motor drives the rotating shaft to rotate, which in turn drives the cams to rotate and push the brake shoes to brake.

[0029] The outer brake shoe 1 has an outer water channel and an outer ventilation hole 13, while the inner brake shoe 2 has an inner water channel and an inner ventilation hole 10. A brake shoe ventilation hole is also provided on the brake shoe. The outer ventilation hole 13, the inner ventilation hole 10, and the brake shoe ventilation hole correspond to each other, forming a ventilation hole that penetrates the brake shoe and brake shoe, serving as a passive air-cooled heat dissipation ventilation hole. The outer water channel has an inlet 14 and an outlet 15 at both ends, while the inner water channel has an inlet 9 and an outlet 12 at both ends. The water channels on the outer brake shoe 1 and the inner brake shoe 2 form a coolant passage 3, meaning the outer and inner water channels correspond to each other to form a coolant flow channel, with an inlet and an outlet at both ends. The outer brake shoe 1, inner brake shoe 2, and brake shoe 4 are fixed together with rivets, with the inner and outer water channels forming a coolant passage, aligning with the inner ventilation hole 10 and the outer ventilation hole 13.

[0030] The water channels on the outer brake pad 1 and the inner brake pad 2 are respectively arranged in the middle, which is the high heat flux zone of the friction interface. Ventilation holes on the outer brake pad 1, the inner brake pad 2, and the brake shoe are distributed on both sides, with the ventilation holes located on both sides of the water channels. The outer water channel is located on the end face where the outer brake pad 1 contacts the inner brake pad 2; the outer water channel includes one long water channel and multiple short water channels, with the long water channel extending to both ends of the outer brake pad, and the multiple short water channels intersecting and connecting with the long water channel. The inner water channel is located on the two end faces where the inner brake pad 2 contacts the outer brake pad 1 and the brake shoe; the inner water channel includes one long water channel and multiple short water channels, with the long water channel on both end faces of the inner brake pad 2 interconnecting to form an annular groove, and the multiple short water channels intersecting and connecting with the long water channel.

[0031] The inner and outer brake pads are the two core components constituting the "friction liner" or "brake pad assembly." This invention, through a split design, highly integrates friction and cooling functions. The outer brake pad directly serves as the friction surface, and together with the inner brake pad, they form a cooling channel. The outer brake pad 1 is the component that directly rubs against the brake drum. Therefore, its outer surface is the actual friction surface. Simultaneously, its inner surface is machined with grooves (outer water channels) to cooperate with the inner brake pad, forming half of the coolant flow channel. The inner brake pad 2 does not directly participate in friction but is sandwiched between the outer brake pad 1 and the brake pad 4.

[0032] The basic braking process is completely consistent with that of a traditional S-cam drum brake, representing a mature mechanical actuation process. Braking command issued: The driver presses the brake pedal.

[0033] Power transmission: The brake valve opens, and compressed air enters the brake chamber.

[0034] Cam actuation: The push rod of the brake chamber extends and pushes the adjusting arm. The adjusting arm or the motor drives the camshaft (i.e., cam 6) to rotate.

[0035] Brake shoes open: The rotating cam 6 pushes the middle of the two brake shoes 4 outward.

[0036] Friction braking: The brake shoe 4 moves outward, forcing the brake pad assembly mounted on it to rub against the inner surface of the internally rotating brake drum, generating braking force and converting the vehicle's kinetic energy into heat energy.

[0037] Brake release: The driver releases the pedal, compressed air is expelled (or the motor reverses), and cam 6 returns to its original position. Under the tension of the return spring, brake shoe 4 separates from the brake drum, and friction stops.

[0038] The central region of the friction surface is a high heat flux zone (high temperature, high heat load), while the two sides are low heat load zones. For the central "high heat flux zone," this invention employs active liquid cooling, using coolant for forced convection heat transfer to remove the enormous heat generated by the core heat source, fundamentally suppressing thermal decay and thermal damage. For the two sides "low heat load zones," passive air cooling is used, utilizing the airflow generated by the rotation of the brake drum. This airflow is channeled through these channels to enhance air circulation, assisting in heat dissipation, preventing excessively high local temperatures, and optimizing the overall thermal environment within the brake chamber, thus supplementing heat dissipation at extremely low cost.

[0039] Addressing the inherent drawbacks of traditional brake drum / shoe systems, such as low heat dissipation efficiency, significant thermal fade, and high-temperature damage to key components (brake pads and brake drum) due to their enclosed structure, this invention integrates integrated cooling channels and optimized ventilation structures, achieving a breakthrough improvement in thermal management efficiency. A synergistic heat dissipation mechanism combining active liquid cooling and passive air cooling is constructed. The enclosed cooling channels embedded in the brake shoe substrate efficiently dissipate accumulated heat flux at the friction interface through forced convection heat transfer, significantly reducing the transient and steady-state operating temperatures of the shoe body and friction materials. Simultaneously, the ventilation channels utilize the airflow dynamics generated by the brake drum's rotation to enhance air convection within the brake cavity, promoting surface heat dissipation and effectively suppressing the formation of localized hot spots. By systematically optimizing the energy dissipation process along the heat conduction and convection paths, this not only significantly alleviates the thermal fade of friction materials to maintain braking performance stability but also significantly reduces the risk of shoe ablation and cracking, as well as brake drum thermal deformation and cracking, by suppressing thermal stress accumulation. This extends the service life of core components and reduces the safety hazards associated with brake fluid vapor lock. It fundamentally overcomes the heat dissipation bottleneck of traditional drum braking systems, providing an innovative solution for their reliability and durability under high-load conditions.

[0040] To address the core drawback of traditional brake shoes—insufficient heat dissipation in areas of concentrated thermal stress due to their monolithic structure, leading to accelerated material degradation and frequent maintenance—this invention employs a dual-layer, split brake shoe pad architecture. This architecture decouples the brake shoe substrate into inner and outer dual-layer components, with precision-machined grooves in the corresponding thermal load gradient distribution areas of each component. This creates a closed, embedded coolant channel in the high heat flux zone of the friction interface after assembly. Simultaneously, directional ventilation channels are independently created in low heat load zones. This structure achieves spatially differentiated heat dissipation strategies: the coolant channels are closely aligned with the peak heat flux zone for efficient forced convection heat transfer, directly dissipating the main heat sources leading to material thermal decay and structural failure; the ventilation holes enhance airflow in low-heat zones, synergistically suppressing overall temperature rise and optimizing airflow organization. This zoned thermal management mechanism significantly reduces the risks of brake shoe ablation, substrate warping, and friction material delamination, extending the service life of critical components from a thermodynamic perspective. It systematically reduces maintenance frequency and resource consumption caused by high-temperature damage, providing a fundamental structural innovation improvement to the reliability of the braking system.

[0041] In summary, addressing the core shortcomings of traditional brake shoe systems—such as low heat dissipation efficiency, significant thermal fade, high-temperature damage to critical components, and frequent maintenance due to their enclosed structure—this invention proposes a dual-layer, split brake shoe architecture and a collaborative thermal management strategy. By using a decoupled pad design to pre-install cooling channels in the peak heat flux density region, efficient forced convection heat transfer is achieved to precisely dissipate the main heat source. Simultaneously, ventilation channels are arranged in the low heat load region to enhance airflow organization, supplemented by passive air cooling. This zoned heat dissipation mechanism fundamentally suppresses material thermal fade, structural deformation, and ablation cracking, significantly improving braking performance stability and component durability, thereby systematically extending maintenance cycles and providing a fundamental solution to overcoming the inherent heat dissipation bottleneck of drum brakes.

Claims

1. A ventilated brake shoe with cooling water channel, comprising brake shoe sheet, brake shoe and brake bottom plate, the brake shoe is arranged on the brake bottom plate, the brake bottom plate is provided with cam, the cam is in contact with two half brake shoes respectively, the two half brake shoes are driven to move through the rotation of the cam, the two half brake shoes are reset through the spring, the brake shoe sheet is arranged on the brake shoe respectively, characterized in that: The brake shoe is a double-layer split brake shoe plate structure; the ventilated brake shoe adopts a cooperative heat dissipation method of active liquid cooling and passive air cooling, and the specific heat dissipation method is as follows: the brake shoe is decoupled into inner and outer double-layer components, grooves are respectively machined in the corresponding thermal load gradient distribution areas of the inner and outer double-layer components, the grooves are water channels, the grooves of the inner and outer double-layer components form cooling liquid flow channels after assembly, the cooling liquid flow channels are closed embedded cooling liquid flow channels formed in the high heat flux area of the friction interface, and active liquid cooling is formed through the cooling liquid flow channels; meanwhile, ventilation holes are independently provided in low heat load areas, and passive air cooling is formed through the ventilation holes. ​ 2. A ventilated brake shoe with cooling water channels as defined in claim 1, characterized in that: The brake shoe includes an outer brake shoe and an inner brake shoe, and the outer brake shoe and the inner brake shoe form a double-layer split brake shoe plate structure; corresponding water channels are respectively provided on the outer brake shoe and the inner brake shoe, and the water channels on the outer brake shoe and the inner brake shoe form a cooling liquid channel for active liquid cooling.

3. A ventilated brake shoe with cooling channels as defined in claim 2, characterized in that: Corresponding ventilation holes are respectively provided on the outer brake shoe, the inner brake shoe and the brake shoe; the outer brake shoe, the inner brake shoe and the brake shoe are fixed together, the ventilation holes are aligned to form a ventilation hole channel penetrating through the brake shoe and the brake shoe, and passive air cooling is formed through the ventilation hole channel.

4. A ventilated brake shoe with cooling channels as defined in claim 3, characterized in that: The water channels are respectively arranged in the middle parts of the outer brake shoe and the inner brake shoe, the middle parts are high heat flux areas of the friction interface, and the ventilation holes are respectively distributed on the two sides of the outer brake shoe, the inner brake shoe and the brake shoe, and the ventilation holes are located on the two sides of the water channels.

5. The vented brake shoe with cooling water channels of claim 2 wherein: Riveting holes are respectively provided on the outer brake shoe, the inner brake shoe and the brake shoe, and the outer brake shoe and the inner brake shoe are fixed and installed on the brake shoe through rivets.

6. The vented brake shoe with cooling water channels of claim 2 wherein: An outer water channel is provided on the outer brake shoe, and the outer water channel is located on the end face of the outer brake shoe in contact with the inner brake shoe; the outer water channel includes one long water channel and a plurality of short water channels, the long water channel penetrates to both ends of the outer brake shoe, and the plurality of short water channels cross and penetrate with the long water channel.

7. The vented brake shoe with cooling water channels of claim 2 wherein: An inner water channel is provided on the inner brake shoe, and the inner water channel is located on the two end faces of the inner brake shoe in contact with the outer brake shoe and the brake shoe; the inner water channel includes one long water channel and a plurality of short water channels, the long water channels on the two end faces of the inner brake shoe penetrate each other to form an annular groove, and the plurality of short water channels cross and penetrate with the long water channel.

8. A ventilated brake shoe with cooling channels as defined in claim 7, characterized in that: The water channels on the outer brake shoe and the inner brake shoe form a cooling liquid channel, and the cooling liquid channel has a water channel inlet and a water channel outlet at both ends.

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