Agricultural vehicle combination

Manuel Billich, Dischingen (DE); Michael Meid, Waghaeusel (DE)

USPTO: us-12622337 · published 2026-05-12 · patents · A01B 59/043· B60D 1/141

Agricultural vehicle combination

Michael Meid, Waghaeusel (DE) , Manuel Billich, Dischingen (DE) This is my paper

Pith reviewed 2026-05-15 15:05 UTC · model grok-4.3

classification patents A01B 59/043B60D 1/141

keywords agricultural tractorancillary drive unitelectric motorpower-split gearboxenergy recuperationpower boostthree-point hitchPTO

0 comments

The pith

An attachable electric axle recovers braking energy from an auxiliary trailer and returns it to the tractor's power take-off.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The patent describes a tractor plus removable ancillary unit that forms a hybrid drive. The ancillary axle carries an electric motor and a power-split gearbox linked to the tractor's PTO. When the vehicle brakes on the auxiliary wheels, the motor acts as a generator and stores energy in a battery mounted on the tractor's front hitch. In boost mode the same motor drives the gearbox to deliver stored power back into the tractor PTO. The ancillary unit mounts and dismounts using standard three-point hitches while preserving hydraulic, steering, and power connections.

Core claim

The ancillary drive unit is removably attached to the agricultural tractor by the rear three-point hitch and contains an electric motor and power-split gearbox connected to the tractor PTO; in generator mode the motor recuperates braking energy from the auxiliary axle into the front-mounted storage battery, and in power-boost mode the motor returns that energy through the gearbox into the tractor PTO.

What carries the argument

Power-split gearbox that couples the electric motor to the tractor PTO in both generator and boost directions while the ancillary unit remains mechanically attached only through the three-point hitch.

If this is right

The tractor can operate in pure diesel mode when the ancillary unit is detached.
Braking energy from trailed implements is captured instead of dissipated as heat.
Peak power demand on the main engine is reduced during acceleration or hill climbing.
The same battery can supply hydraulic or steering assist when the motor is not boosting the PTO.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

Existing tractors could gain hybrid capability without redesign of the main drivetrain.
The system could be extended to front-mounted ancillary units for four-wheel drive hybrids.
Fuel savings would be largest on stop-and-go transport runs between fields.

Load-bearing premise

The ancillary unit can be attached and detached repeatedly via the rear three-point hitch without losing reliable power, hydraulic, and steering connections under field loads and vibration.

What would settle it

A field test in which the ancillary unit is hitched and unhitched twenty times on rough terrain and then driven at full load for one hour without loss of steering authority, hydraulic pressure, or electrical connection.

read the original abstract

1 . An agricultural vehicle combination, comprising: an agricultural tractor including a main drive unit, a power take-off, a rear three-point hitch, a front three-point hitch, a hydraulic steering and braking system, and a hydraulic control valve block; an ancillary drive unit including an auxiliary axle, an electric motor, a power-split gearbox connected to the power take-off of the agricultural tractor, a further three-point hitch, a further power take-off, a further hydraulic control valve block connected to the hydraulic control valve block of the agricultural tractor, and an auxiliary steering system of active design actuated in accordance with a steering input of the tractor, the ancillary drive unit removably attached to the agricultural tractor by the rear three-point hitch; a storage battery attached to the front three-point hitch of the agricultural tractor; in a generator operating mode, the electric motor recuperates and temporarily stores energy released during braking of the auxiliary axle in the storage battery; and in a power boost mode, the electric motor retrieves the energy temporarily stored in the storage battery to feed via the power-split gearbox into the power take-off of the agricultural tractor.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

A patent for a detachable electric axle unit on tractors that recovers braking energy and routes it back through the PTO, but supplies no measurements or mechanical details on the reverse torque path.

read the letter

The core idea is a modular ancillary axle that mounts on the tractor's rear three-point hitch. It carries its own electric motor and power-split gearbox tied to the tractor PTO, plus active steering. A battery sits on the front hitch. Braking energy from the auxiliary wheels charges the battery; later the motor feeds that energy into the PTO for a power boost. The arrangement is new in its specific combination of removable hitch, power-split connection, and front-battery placement, and it does keep the base tractor largely unmodified. That is the useful engineering sketch here. The text gives only a functional layout. It states that the gearbox is connected to the PTO and that energy flows in both directions, yet it never describes the clutch, shaft, or auxiliary input path that would let torque travel backward into a standard unidirectional PTO under load. The same gap appears on repeated attachment: hydraulic, electrical, and steering interfaces are claimed to work under field vibration, but no load cases or retention details are supplied. Without those elements the central energy-recovery claim stays untestable. This document is a patent specification, not a research paper. An engineer designing hybrid tractors might note the configuration as one possible layout. No one would treat the claims as validated results or build from them without further analysis. I would not bring it to a reading group, would not cite it, and would recommend desk rejection if submitted as a technical manuscript.

Referee Report

1 major / 1 minor

Summary. The patent claims an agricultural vehicle combination in which a tractor equipped with front and rear three-point hitches, PTO, and hydraulic systems is removably coupled to an ancillary drive unit containing an auxiliary axle, electric motor, power-split gearbox, and active steering. A storage battery is mounted on the front hitch. In generator mode the motor recuperates braking energy from the auxiliary axle into the battery; in power-boost mode the stored energy is returned through the gearbox into the tractor PTO.

Significance. If the bidirectional power path and repeated hitch attachment prove mechanically reliable under field loads, the architecture offers a practical route to hybrid energy recovery and temporary power boost for existing tractors without permanent driveline modifications.

major comments (1)

[Claim 1] Claim 1 and the accompanying description: the power-split gearbox is stated to be “connected to the power take-off,” yet no mechanical arrangement, clutch, or auxiliary input path is given that would permit reverse torque flow from the electric motor into the tractor PTO shaft while preserving driveline integrity. Standard agricultural PTOs are unidirectional; this omission directly undermines the power-boost mode.

minor comments (1)

[Abstract] The abstract and claim language use “further three-point hitch” and “further hydraulic control valve block” without clarifying whether these are additional interfaces or simply renamings of the ancillary unit’s components.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the detailed reading and the single substantive comment on bidirectional torque flow. We address it directly below and will incorporate clarifying language into the next version of the application.

read point-by-point responses

Referee: [Claim 1] Claim 1 and the accompanying description: the power-split gearbox is stated to be “connected to the power take-off,” yet no mechanical arrangement, clutch, or auxiliary input path is given that would permit reverse torque flow from the electric motor into the tractor PTO shaft while preserving driveline integrity. Standard agricultural PTOs are unidirectional; this omission directly undermines the power-boost mode.

Authors: We agree that Claim 1, as written, states only the functional connection and does not recite the internal elements of the power-split gearbox that enable torque to be fed into the PTO shaft. In the revised description we will add that the gearbox contains a planetary power-split stage with an auxiliary motor input path protected by a one-way clutch (or equivalent selectable coupling) that permits the electric motor to drive the PTO shaft in boost mode while leaving the standard unidirectional PTO operation unaffected when the motor is inactive. This addition directly answers the concern without altering the scope of Claim 1 itself. revision: yes

Circularity Check

0 steps flagged

No derivation chain or fitted parameters; patent is pure engineering specification

full rationale

The document contains no equations, first-principles derivations, predictions, or fitted parameters. All content consists of direct mechanical and operational claims describing component interconnections and two operating modes. Because nothing is derived from prior steps within the document, no reduction to self-definition or self-citation is possible.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The patent rests on standard mechanical assumptions (three-point hitch load ratings, PTO torque transmission, hydraulic compatibility) plus the unstated premise that the added axle mass and steering response remain safe and controllable.

axioms (1)

domain assumption The rear three-point hitch can transmit the required torque, hydraulic power, and steering signals without structural or control failure.
Invoked by the attachment description; no supporting load or fatigue analysis is supplied.

pith-pipeline@v0.9.0 · 5511 in / 1166 out tokens · 27209 ms · 2026-05-15T15:05:18.155440+00:00 · methodology

Agricultural vehicle combination

Core claim

What carries the argument

If this is right

Where Pith is reading between the lines

Load-bearing premise

What would settle it

discussion (0)