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This paper describes the initial research and development of a novel parallel hybrid transmission that incorporates design features found in most production 3- and 4-speed automatic transmissions, except that the mechanism can transmit torque from two power sources to the drive wheels. The transmission functions with a heat engine and a single electric motor/ generator, and uses a Simpson gear set and four automatically controlled clutches. Thirteen modes of operation are possible, including one motor-only mode, three power modes, one CVT/charging mode, four engine-only modes, and four regenerative braking modes. Because the design is based on conventional automatic transmission components, the design is simple, compact, relatively efficient, and reliable.

This paper presents a systematic methodology for the enumeration of clutching sequences associated with epicyclic-gear-type automatic transmission mechanisms. The methodology is based on the concept that an epicyclic gear mechanism can be decomposed into several fundamental geared entities and that the overall speed ratio of an epicyclic gear mechanism can be symbolically expressed in terms of its fundamental geared entities. First, a procedure for estimating the overall speed ratio of an epicyclic gear mechanism, without specifying the exact gear dimensions, is outlined. Then, an algorithm for comparing various possible speed ratios of an epicyclic gear mechanism is described. Finally, a methodology for systematically enumerating all possible clutching sequences of an epicyclic gear mechanism is established.

An automotive transmission maintains a proper equilibrium between the power and torque produced by an engine and those demanded by the drive wheels. Most automatic, transmissions employ some kind of epicyclic gear mechanisms to achieve the above purpose. The first step in the design process of such a mechanism involves finding a configuration that provides a set of desired speed ratios, and meets other dynamic, and kinematic requirements. In this work, the kinematic structural characteristics of epicyclic gear mechanisms have been identified, and a methodology is formulated to systematically enumerate all possible configurations of such mechanisms. This is achieved by defining a canonical graph to represent the mechanisms. Graphs of mechanisms with up to ten links have been generated using this methodology.

An interactive design system has been developed for the design of automatic automotive transmission gear trains that can provide at least three forward and one reverse speed ratios. This user-friendly windowing system can access help files, display the functional representation of a mechanism, optimize the gear ratios and present the numerical results. The optimization procedure to find the optimum gear ratios and the corresponding number of gear teeth uses the Augmented Lagrangian Multiplier Method and can be applied to all epicyclic gear trains having two sets of three gears in which a ring gear is connected to a sun gear through a planetary gear. The Simpson and General Motors THM 440 gear trains are used to demonstrate the methodology. The gear teeth combinations are found such that they achieve the optimized gear ratios to within ±1% and satisfy the geometric constraints.

This paper describes a methodology for simple mathematical models to capture the handling behaviors of automobiles. The frequency response data obtained from random steer tests are assumed to fully represent the handling quality of a vehicle. The methodology calls for estimation of the values of some parameters in simple mathematical models. These models are developed from comprehensive understanding of vehicle handling dynamics. The parameter estimation process involves fit ting of the frequency response data numerically with a nonlinear optimization algorithm. Data of one sedan and three minivans are available to demonstrate the application of methodology. From the perspective of data fit, it can be concluded that roll motion does not play significant role in the handling dynamics of the sedan while it contributes more significantly to the handling dynamics of the three minivans.

In recent times, the emphasis on increased vehicle fuel economy has spurred considerable interest in the development of variable-valve-timing (VVT) mechanisms for internal-combustion engines. This investigation focuses on the determination of the kinematic structure and the creative design of VVT mechanisms. Following a review of some representative existing VVT mechanisms, several potentially useful, proposed VVT configurations are described; one of these is proportioned and analyzed in some detail.

This paper describes the effectiveness of an Oldham-coupling-type balancer in reducing the first- and second-harmonic rotating unbalance couples of a 90° V6 even-firing engine. It is shown that the prototype balancer can be configured to eliminate the residual, first-harmonic rocking couple usually remaining in a conventionally balanced 90° V6 engine. Further, the Oldham-coupling-type balancer can be used to reduce the elliptical second-harmonic rotating couple to a horizontal rocking couple. The power consumption of the balancer was measured to be approximately 0.35 kW at 2000 r/min and 1.5 kW at 4500 r/min.

This paper describes the effectiveness of an Oldham-coupling type balancer in reducing the second-harmonic inertia shaking force in a 2.5 liter in-line four-cylinder engine. It is shown that the prototype Oldham-coupling type balancer reduced the vertical shaking by 75-85% over the speed range from 1 200 to 4 200 r/min. The power consumption by the balancer was measured to be approximately 0.4 kW at 2 400 r/min and 1.25 kW at 4 200 r/min.