Prior art

Analysis of Prior Art for U.S. Patent No. 11,374,508

This analysis reviews the prior art references cited during the prosecution of U.S. Patent No. 11,374,508. The independent claims (1, 7, and 12) of this patent describe a dual-electric motor drive system for a vehicle. The core inventive concept appears to be the specific powertrain architecture and the corresponding control strategy. This architecture includes a first electric motor coupled to a transmission device, and a second electric motor, with both feeding into a power split device that contains one or more planetary gear sets. An Energy Management System (EMS) selectively engages only the first motor for low-demand situations (starting, cruising) and both motors for high-demand situations (accelerating, climbing hills).

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Cited U.S. Patent References

The following prior art patents were considered by the USPTO examiner during the patent's prosecution.

1. U.S. Patent No. 9,800,182 B2 (Zhou et al.)

• Full Citation: US 9,800,182 B2
• Title: Electric drive system and energy management method
• Publication Date: October 24, 2017
• Filing Date: December 2, 2013
• Assignee: General Electric Company
• Brief Description: This patent, which shares inventors with the '508 patent and arises from the same original priority application (filed in 2012), describes a similar electric drive system. It includes two energy storage units (e.g., a battery and an ultra-capacitor), a power conversion system, and two AC drive devices (motors). It also discloses an energy management system that controls power flow and motor operation based on vehicle operating modes, including starting, accelerating, cruising, and regenerative braking. Figure 2 explicitly shows a first AC drive device (20) and a second AC drive device (22) coupled to a power split device (19).
• Potential Anticipation of Claims:
  • Claims 1, 7, and 12: This reference is highly relevant as it is part of the same patent family. It discloses the core components: a dual electric motor setup, a power split device, and an energy management system that selects operational modes. The description details enabling one or both motors based on the vehicle's state (e.g., "when the propulsion system is driving a heavy load, the first mechanical terminal 32 receives a first mechanical torque from the first AC drive device 20, the second mechanical terminal 34 receives a second mechanical torque from the second AC drive device 22" (Col. 5, ll. 40-45)). It further describes using only one motor for light loads. This disclosure strongly aligns with the limitations of the independent claims of the '508 patent. The '508 patent is a continuation of the application that led to this patent, suggesting it claims a variant of the same core invention. It is likely that the specific combination of a "transmission device" coupled to the first motor before the power split device and the explicit inclusion of "one or more planetary sets" were the distinguishing features argued for patentability.

2. U.S. Patent No. 9,878,632 B2 (Tabata et al.)

• Full Citation: US 9,878,632 B2
• Title: Vehicle propulsion system having an energy storage system and optimized method of controlling operation thereof
• Publication Date: January 30, 2018
• Filing Date: August 19, 2014
• Assignee: General Electric Company
• Brief Description: Tabata discloses a propulsion system, particularly for large vehicles like mining trucks, with an engine, generator, and an energy storage system powering multiple electric traction motors. The control method is optimized for a "haul cycle," managing power from the engine and battery to improve fuel efficiency based on whether the vehicle is, for example, accelerating on a graded surface.
• Potential Anticipation of Claims:
  • Claims 1, 7, and 12: Tabata teaches a multi-motor system with a controller that manages power based on operational states, including acceleration and grade. This is conceptually similar to the EMS in the '508 patent. However, Tabata's system is a hybrid that includes a combustion engine and generator, not a purely electric dual-motor system as claimed. Furthermore, it does not appear to disclose the specific mechanical layout of a transmission on one motor connected to a planetary-based power split device which is also connected to a second motor. Therefore, it would not anticipate the claims under 35 U.S.C. § 102.

3. U.S. Patent No. 10,291,158 B2 and U.S. Patent No. 10,374,529 B2 (Zhou et al.)

• Full Citation: US 10,291,158 B2 and US 10,374,529 B2
• Title: Electric drive system and energy management method
• Publication Dates: May 14, 2019, and August 6, 2019
• Assignee: General Electric Company
• Brief Description: These patents are also continuations from the same parent application as the '182 and '508 patents. They describe the same fundamental system of a dual-source ESS, dual AC motors, and an EMS for controlling power flow and selecting between single- or dual-motor operation depending on vehicle mode.
• Potential Anticipation of Claims:
  • Claims 1, 7, and 12: Like the '182 patent, these family members disclose the foundational elements of the '508 patent's claims. Their text and figures describe the same architecture and control logic. The patentability of the '508 claims over these references would hinge entirely on the specific claim language added in the '508 patent's application, such as the explicit combination of the transmission device and the planetary-based power split device, if not already claimed in the same manner in these prior patents. Given they are from the same family, they serve as powerful prior art but would not be used for a novelty rejection against a continuation patent claiming a distinct combination.

4. U.S. Patent Application Publication No. 2011/0237385 A1 (Sato et al.)

• Full Citation: US 2011/0237385 A1
• Title: Vehicle Drive Device
• Publication Date: September 29, 2011
• Filing Date: March 24, 2011
• Assignee: Aisin AW Co., Ltd.
• Brief Description: Sato discloses a drive device for a hybrid vehicle that includes two electric motors (MG1, MG2) and a power splitting mechanism, which is explicitly described as a planetary gear set. The system is designed to control the vehicle based on different running states, such as low-speed and high-speed driving, by managing the operation of the two motors.
• Potential Anticipation of Claims:
  • Claims 1, 7, and 12: Sato is highly relevant as it teaches a dual-electric motor system coupled via a planetary gear-based power split device. It also discloses a control unit that operates the motors differently based on the vehicle's running state to improve efficiency. This combination reads closely on the core elements of the '508 patent's claims. An argument for anticipation could be strong if Sato's disclosure of a "speed reducer" or similar transmission-like element, combined with its control logic for different running states, is found to be equivalent to the system claimed in the '508 patent. The distinction may lie in the specific modes described (e.g., "starting" using only one motor) and the precise mechanical linkage of the transmission, power split, and motors.