Dana Dana Torque Converter: What are the selection requirements for a hydraulic torque converter?
Release date:
2022-08-08 17:27
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Dana Torque Converter: What are the selection requirements for a hydraulic torque converter?
Construction machinery typically operates under heavy loads, in harsh environments, with frequent use and low operating speeds, coupled with poor cooling conditions, resulting in a high thermal load on the engine. Under normal circumstances, the engine’s power output must be reduced by 10% to 20%. Based on the performance requirements of construction equipment and the corresponding demands on engine power, what are the selection criteria for a Dana torque converter—the hydraulic torque converter?
Dana Torque Converter: What are the selection requirements for a hydraulic torque converter?
1. In accordance with the requirements for hill-climbing performance, the stall‑to‑torque ratio of the hydraulic torque converter should be as high as possible, typically ranging from 3 to 3.6, in order to reduce the number of gear ratios in the transmission.
2. To fully exploit the engine’s power, the hydraulic torque converter should possess a certain level of penetration, enabling it to deliver substantial traction during start-up and low-speed operation while maximizing engine output at high speeds, thereby increasing average velocity and enhancing both acceleration and pulling power. Typically, penetration is lower at low speeds and higher at high speeds; however, in certain applications, non‑penetrating torque converters are also employed.
3. When the torque converter and the engine operate in tandem, the engine delivers greater power output at full load to meet the demands of higher traction characteristics.
4. The hydraulic torque converter is required to maintain high efficiency over a wide operating range. When used in construction machinery, the converter must perform effectively at both low and high speeds, thereby enhancing engine fuel economy. In general, the minimum allowable efficiency of a hydraulic torque converter is 75%.
Dana torque converter: What is the matching relationship between a hydraulic torque converter and the engine?
1. To achieve optimal matching between the hydraulic torque converter and the engine, the engine’s maximum effective power must be fully utilized across the entire operating range of the torque converter. This requires a full‑load characteristic curve that passes through the torque point corresponding to the engine’s maximum net power; however, considering only this single operating point is insufficient, as it fails to account for power consumption under variable load conditions. To meet this requirement, the torque converter’s load‑range should be centered around the maximum‑power point Ne—specifically, the two load curves i0 and iMmax should lie on either side of Ne. The appropriate configuration should be selected based on industry standards and the actual operating conditions of the particular type of construction equipment.
2. To achieve good fuel economy, the engine should operate across its entire load range near its lowest‑fuel‑consumption point, thereby minimizing fuel consumption.
3. To achieve high output torque during vehicle start-up and under heavy load, the hydraulic torque converter must have a load curve that passes through the engine’s peak torque point at low gear ratios—particularly when i = 0 (i.e., during start-up)—in order to deliver substantial output torque. However, meeting this requirement is often challenging. Since the load‑carrying capability of a hydraulic torque converter spans a relatively wide range, it is possible to satisfy both conditions simultaneously. Consequently, many torque converters are designed with such permeability.
To achieve an optimal match between the torque converter and the engine, the pump impeller’s load curve should lie within the specified typical operating range.
Dana torque converter