# US 8,540,041 B2 · Driving system for electric vehicle

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 8,540,041 B2
- Document ID: US8540041B2
- Status: Granted
- Kind: B2
- Application number: 13/052,356
- Filed: 2011-03-21
- Published: 2012-09-27
- Granted: 2013-09-24
- Earliest claimed: 2011-03-21
- Applicants: Kuo-Hsin Su; Ta-Yu Su
- Inventors: Kuo-Hsin Su; Ta-Yu Su
- Web page: https://patentgrep.com/patent/US8540041B2

## CPC

- B60K 17/046: {with planetary gearing having orbital motion}
- B60K 7/0007: {the motor being electric}
- F16H 3/54: one of the central gears being internally toothed and the other externally toothed
- B60K 2007/0092: {the motor axle being coaxial to the wheel axle}
- B60L 2220/44: Wheel Hub motors, i.e. integrated in the wheel hub
- B60Y 2200/12: Motorcycles, Trikes; Quads; Scooters
- Y02T 10/72: Electric energy management in electromobility
- B60K: ARRANGEMENT OR MOUNTING OF PROPULSION UNITS OR OF TRANSMISSIONS IN VEHICLES; ARRANGEMENT OR MOUNTING OF PLURAL DIVERSE PRIME-MOVERS IN VEHICLES; AUXILIARY DRIVES FOR VEHICLES; INSTRUMENTATION OR DASHBOARDS FOR VEHICLES; ARRANGEMENTS IN CONNECTION WITH COOLING, AIR INTAKE, GAS EXHAUST OR FUEL SUPPLY OF PROPULSION UNITS IN VEHICLES
- F16H: GEARING
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- B60Y: INDEXING SCHEME RELATING TO ASPECTS CROSS-CUTTING VEHICLE TECHNOLOGY
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A driving system for electric vehicle is disclosed to use a clutch switching unit for controlling a motor rotor-driven bushing to rotate a wheel hub via a direct-drive active clutch or via a set of planet gears and a reducing clutch. At the initial state after startup of the motor, the direct-drive active clutch runs idle, enabling the wheel hub to provide a low-speed high-torque output, saving power consumption. When the vehicle speed reaches a predetermined level, a control circuit drives a clutch motor to move the clutch switching unit in releasing the reducing clutch to idle the planet gears, enabling the direct-drive active clutch to be switched on so that the rotor of the motor can rotate the wheel hub directly to accelerate the vehicle speed.

## Claims

### Claim 1

A driving system used in an electric vehicle, comprising:
a wheel hub defining therein an accommodation space;
a vehicle motor mounted in one side of said wheel hub, said vehicle motor comprising a rotor, and a stator having an axle inserted through the center of said wheel hub;
a bushing sleeved onto said axle of said stator and rotatably supported on said axle by axle bearings;
a pinion rotatably supported on said axle of said stator and connected to one end of said bushing;
a driving wheel fixedly mounted on said bushing for synchronous rotation, said driving wheel having a plurality of transverse grooves spaced around the periphery thereof;
a hubcap fastened to an opposite side of said wheel hub, said hubcap having an annular flange protruded from an outside wall thereof opposite to said wheel hub;
a direct-drive active clutch mounted in the accommodation space inside said wheel hub;
a switching push-pull plate mounted on the annular flange of said hubcap;
a reducing clutch mounted on the annular flange of said hubcap at one side relative to said switching push-pull plate;
a planet gear holder disposed at one side relative to said switching push-pull plate for enabling said reducing clutch to be set in between said planet gear holder and said switching push-pull plate;
a plurality of planet gears equiangularly and pivotally mounted on said planet gear holder and meshed with said pinion;
an outer cover covered on said wheel hub over said hubcap;
a clutch switching unit mounted in said outer cover and adapted for selectively switching said switching push-pull plate and said direct-drive active clutch; and
a tooth ring mounted inside said outer cover, said tooth ring comprising an internal gear meshed with said planet gears for enabling said planet gears to reduce the output speed of said vehicle motor and increase the output torque thereof.

### Claim 2 (depends on 1)

The driving system as claimed in claim 1, wherein said wheel hub and said hubcap are rotatably supported on said bushing by axle bearings.

### Claim 3 (depends on 1)

The driving system as claimed in claim 1, wherein said wheel hub comprises an internal toothed engagement portion; said direct-drive active clutch comprises a clutch drive plate, a clutch driven plate, a first clutch presser plate and associating spring members, said clutch drive plate having a plurality of radially extending peripheral teeth meshed with said internal toothed engagement portion of said wheel hub, said clutch driven plate being set between said clutch drive plate and said first clutch presser plate and having a plurality of inner teeth respectively engaged into the transverse grooves of said driving wheel, said first clutch presser plate having a plurality of radially extending peripheral teeth meshed with said internal toothed engagement portion of said wheel hub, the spring members of said direct-drive active clutch being equiangularly mounted in said wheel hub to impart a pressure to said first clutch presser plate toward said clutch driven plate.

### Claim 4 (depends on 1)

The driving system as claimed in claim 1, wherein said annular flange of said hubcap comprises a plurality of transverse groove equiangularly spaced around the periphery thereof; said planet gear holder comprises a toothed engagement portion; said reducing clutch comprises a clutch drive plate, a clutch driven plate and a second clutch presser plate, said clutch driven plate comprising a plurality of inner teeth respectively engaged into the transverse grooves of said annular flange of said hubcap, said clutch drive plate and said second clutch presser plate each comprising a plurality of radially extending peripheral teeth respectively meshed with said toothed engagement portion of said planet gear holder for synchronous rotation.

### Claim 5 (depends on 1)

The driving system as claimed in claim 1, wherein said outer cover comprises an external mounting portion affixed to a vehicle frame of said electric vehicle.

### Claim 6 (depends on 1)

The driving system as claimed in claim 1, wherein said planet gear holder comprises a plurality of equiangularly spaced through holes; said clutch switching unit comprises a clutch motor, a worm gear set, a constraint member, a sliding guide sleeve, a cylindrical sliding member, an axial drive gear, a push-pull plate and a plurality of spring members, said sliding guide sleeve being fixedly mounted on the axle of said stator of said vehicle motor, said sliding guide sleeve being connected to said outer cover and having a plurality of longitudinal grooves equiangularly spaced around the periphery thereof, said axial drive gearing being mounted in said constraint member inside said outer cover and having an inner thread, said cylindrical sliding member being axially slidably mounted on said sliding guide sleeve and having a plurality of longitudinal ribs respectively slidably coupled to the longitudinal grooves of said sliding guide sleeve and an outer thread spirally extending around the periphery thereof and meshed with the inner thread of said axial drive gear, said push-pull plate being mounted on said cylindrical sliding member by an axle bearing and a retainer, the spring members of said clutch switching unit being inserted through equiangularly spaced through holes of said planet gear holder and stopped between the push-pull plate of said clutch switching unit and said second clutch presser plate such that when said electric vehicle is started, said cylindrical sliding member is moved toward said hubcap to the extent subject to a predetermined setting, causing said push-pull plate to move said planet gears, said planet gear holder and the spring members of said clutch switching unit in forcing said reducing clutch into engagement with said hubcap to turn said wheel hub to a deceleration driving status; when said rotor of said vehicle motor rotates said bushing as said wheel hub is in a deceleration driving status, said pinion is meshed with said planet gears that are also meshed with the internal gear of said tooth ring, thus, said planet gears are rotated in one same direction between said tooth ring and said pinion for enabling said wheel hub to provide the desired low-speed high-torque output, and therefore said electric vehicle is started with low power consumption; when said axial drive gear is rotated, said cylindrical sliding member is forced to move said push-pull plate toward said outer cover, and therefore said reducing clutch is released from the pressure of the associating spring members, and at this time, said first clutch presser plate of said direct-drive active clutch is compressed by the associating spring members, allowing said wheel hub to be rotated by said vehicle motor directly, thereby accelerating the speed of said electric vehicle.

### Claim 7 (depends on 6)

The driving system as claimed in claim 6, wherein said outer cover comprises grooved positioning portion; said sliding guide sleeve has a toothed end engaged into the grooved positioning portion of said outer cover.

### Claim 8 (depends on 6)

The driving system as claimed in claim 6, further comprising a control circuit, and a speed sensor adapted to sense the revolving speed of said electric vehicle and to output a signal to said control circuit for driving said control circuit to turn on said clutch motor in driving said clutch switching unit to pull apart said reducing clutch for enabling said direct-drive active clutch be forced by the associating spring members to let said wheel hub be directly rotated by said rotor of said vehicle motor at a high speed.