Steel straight bevel gears with a straight tooth system and a 2.5:1 ratio are conical gears designed to transmit power between intersecting shafts, typically at a 90-degree angle. The 2.5:1 ratio indicates that for every 2.5 rotations of the smaller gear pinion, the larger gear wheel completes one rotation, providing a speed reduction or torque increase. These gears, often made from materials like C45 steel, feature straight teeth parallel to the cone's generators, resembling conical spur gears. They are milled, not hardened or lapped, with a tooth quality of around DIN 3967 (grade 8 for modules ≥2.5). Sold individually, they must be paired with a matching gear of the same module and ratio. Suitable for applications like machinery and vehicles.
Steel Straight Bevel Gear Ratio 2.5:1
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| Module | Number of teeth |
da | d | ND | NL | L1 | L | S | b | BH7 | E | Torque* | Weight |
| mm | mm | mm | mm | mm | mm | mm | mm | mm | mm | Ncm | g | ||
| 0,5 | 20 | 11,3 | 10 | 8 | 4,0 | 7 | 7,6 | 4,9 | 3 | 4 | 17,1 | 0,018 | 3 |
| 0,5 | 50 | 25,2 | 25 | 14 | 5,0 | 7 | 7,8 | 6,8 | 3 | 4 | 11,5 | 0,045 | 10 |
| 1 | 16 | 18,6 | 16 | 13 | 7,4 | 13 | 14,4 | 8,5 | 6,5 | 5 | 28 | 0,090 | 13 |
| 1 | 40 | 40,5 | 40 | 25 | 9,0 | 13 | 14,8 | 12,6 | 6,5 | 8 | 20 | 0,225 | 65 |
| 1,5 | 16 | 27,9 | 24 | 18 | 8,8 | 18 | 19,5 | 10,8 | 9,7 | 8 | 40 | 0,32 | 36 |
| 1,5 | 40 | 60,7 | 60 | 40 | 10,0 | 17 | 20,1 | 16,9 | 9,7 | 15 | 28 | 0,80 | 220 |
| 1,5 | 18 | 30,9 | 27 | 20 | 10,8 | 21 | 22,9 | 13,0 | 10,9 | 8 | 46 | 0,47 | 54 |
| 1,5 | 45 | 68,2 | 67,5 | 50 | 12,0 | 20 | 24,1 | 20,4 | 10,9 | 15 | 33 | 1,18 | 370 |
| 2 | 16 | 35,9 | 32 | 20 | 9,0 | 25 | 26,4 | 12,7 | 15 | 10 | 52 | 0,84 | 76 |
| 2 | 40 | 81,5 | 80 | 50 | 15,0 | 29 | 32,7 | 27,9 | 15 | 20 | 42 | 2,10 | 650 |
| 2 | 18 | 39,8 | 36 | 30 | 11,8 | 26 | 27,4 | 13,8 | 15 | 10 | 58 | 1,18 | 133 |
| 2 | 45 | 91,5 | 90 | 60 | 18,0 | 30 | 33,8 | 28,9 | 15 | 25 | 45 | 2,95 | 830 |
| 2,5 | 16 | 44,8 | 40 | 30 | 13,0 | 32 | 34,1 | 15,9 | 20 | 10 | 65 | 5,0 | 180 |
| 2,5 | 40 | 101,9 | 100 | 60 | 15,0 | 29 | 33,8 | 27,4 | 20 | 25 | 45 | 12,5 | 1000 |
| 2,5 | 18 | 49,8 | 45 | 30 | 15,75 | 36 | 37,9 | 19,7 | 20 | 10 | 75 | 7,1 | 240 |
| 2,5 | 45 | 114,4 | 112,5 | 70 | 15,0 | 28 | 33,4 | 26,9 | 20 | 25 | 47 | 17,8 | 1200 |
| 3 | 16 | 53,8 | 48 | 40 | 13,6 | 37 | 38,8 | 16,1 | 25 | 15 | 75 | 9,0 | 310 |
| 3 | 40 | 122,3 | 120 | 60 | 16,0 | 32 | 36,8 | 28,9 | 25 | 25 | 50 | 22,5 | 1400 |
| 3 | 18 | 59,8 | 54 | 40 | 11,7 | 36 | 38,4 | 15,7 | 25 | 15 | 82 | 12,8 | 380 |
| 3 | 45 | 137,3 | 135 | 70 | 18,0 | 34 | 39,0 | 30,9 | 25 | 30 | 55 | 32,0 | 1900 |
| 4 | 16 | 71,8 | 64 | 50 | 12,0 | 41 | 43,8 | 16,5 | 30 | 20 | 95 | 20,9 | 600 |
| 4 | 40 | 163,1 | 160 | 80 | 20,0 | 40 | 46,4 | 36,9 | 30 | 30 | 65 | 52,3 | 3400 |
| 4 | 18 | 79,7 | 72 | 50 | 13,8 | 44 | 46,8 | 19,5 | 30 | 20 | 108 | 29,3 | 800 |
| 4 | 45 | 183,0 | 180 | 90 | 20,0 | 43 | 49,6 | 39,9 | 30 | 30 | 72 | 73,3 | 4900 |
| 5 | 18 | 99,6 | 90 | 60 | 16,5 | 57 | 60,8 | 24,4 | 40 | 25 | 135 | 61,0 | 1560 |
| 5 | 45 | 228,8 | 225 | 100 | 20,0 | 50 | 57,8 | 44,8 | 40 | 40 | 85 | 152,5 | 9080 |
Key Features of Steel Straight Bevel Gears
- Material Composition: Steel straight bevel gears are typically crafted from high-quality C45 steel, offering excellent strength and durability. This material ensures resistance to wear and deformation under heavy loads, making them ideal for demanding industrial applications where reliability is critical.
- Straight Tooth Design: The bevel gear sets feature straight teeth cut parallel to the cone's generators, resembling a conical spur gear. This design simplifies manufacturing and maintenance, providing efficient power transmission with minimal backlash, though it may generate more noise compared to spiral bevel gears.
- 2.5:1 Gear Ratio: With a 2.5:1 ratio, the pinion rotates 2.5 times for each full rotation of the gear wheel. This configuration allows for effective speed reduction and torque amplification, which is suitable for applications requiring precise control of rotational speed.
- 90-Degree Shaft Angle: These steel bevel gears are designed to transmit power between shafts intersecting at a 90-degree angle. This makes them essential in machinery where perpendicular shaft alignment is needed, such as in automotive differentials or industrial gearboxes.
- Milled Tooth Quality: The gears are milled to a tooth quality of approximately DIN 3967 (grade 8 for modules ≥2.5). While not hardened or lapped, this milling ensures sufficient precision for many applications, balancing cost and performance for non-extreme conditions.
- Application Limitations: Best suited for linear speeds below 1000 feet/min, these straight bevel gears avoid excessive noise and impact stress. They are ideal for machinery like pumps, conveyors, or vehicles, but are less suitable for high-speed applications due to vibration concerns.
Steel Straight Bevel Gear Uses
- Automotive Differentials: Steel straight bevel gears are integral in vehicle differentials, enabling smooth power transfer from the engine to the wheels. They allow wheels to rotate at different speeds during turns, ensuring stability and traction, particularly in heavy-duty vehicles like trucks.
- Industrial Machinery: These gears are employed in industrial equipment such as conveyors, mixers, and presses. Their robust steel construction handles high torque and heavy loads, ensuring reliable operation in manufacturing and processing plants under demanding conditions.
- Power Tools: In power tools like drills and saws, straight bevel gears transmit rotational motion between non-parallel shafts. Their durability and precision ensure efficient performance, allowing tools to handle tough materials while maintaining consistent power delivery.
- Marine Propulsion Systems: Used in marine applications, these gears transfer power in boat propeller systems. Their ability to withstand harsh environments and high loads makes them suitable for ensuring reliable propulsion in small to medium-sized vessels.
- Agricultural Equipment: Steel bevel gears are found in tractors and harvesters, driving components like cutters and conveyors. Their strength and ability to handle angular motion make them essential for efficient operation in rugged agricultural environments.
- Mining Equipment: In mining machinery, such as crushers and conveyors, these steel bevel gears manage heavy-duty power transmission. Their high load capacity and durability ensure consistent performance in harsh, dusty conditions, supporting critical operations in mining processes.
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| Agricultural Machinery | Automotive Industry |
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| Robotics and Automation | Marine Industry |
Straight Bevel Gear vs Spiral Bevel Gear
Straight Bevel Gears feature teeth that are cut straight and radially on a conical surface, resembling a cone with flat, evenly spaced teeth. This design is simpler and less expensive to manufacture, making it suitable for applications where cost is a priority. They transmit power efficiently in low- to moderate-speed applications, such as hand tools, simple machinery, or low-RPM industrial equipment. However, their straight teeth engage abruptly, leading to higher noise, vibration, and impact stress during operation. This can cause wear and reduced lifespan in high-speed or heavy-load scenarios. Additionally, straight bevel gears are less tolerant of misalignment, requiring precise installation to avoid inefficiencies or damage. Their load-carrying capacity is limited compared to other bevel gear types due to the smaller contact area during tooth engagement.
Spiral Bevel Gears, in contrast, have curved, helical teeth that engage gradually, resulting in smoother and quieter operation. The spiral angle allows multiple teeth to mesh simultaneously, distributing the load over a larger surface area, which enhances strength, durability, and load-carrying capacity. This makes them ideal for high-speed, high-torque applications, such as automotive differentials, aerospace systems, and heavy machinery. The gradual tooth engagement reduces noise and vibration, improving performance in precision-driven environments. However, spiral bevel gears are more complex and costly to produce due to their intricate tooth geometry, requiring advanced manufacturing techniques like precision grinding. They also generate axial thrust forces, necessitating robust bearing systems to manage these loads.
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| Straight Bevel Gear | Spiral Bevel Gear |