Mazda Automatic Transaxle JA5A-EL. Manual — part 8

AUTOMATIC TRANSAXLE

K–13

K

First gear

Planetary gear setting

The rotation speed is "0" for "fix

ed

" as it does not rotate.

Taking i1 as the gear ratio in first gear,

i1=Rear planetary gear ratio (i1’) x Reduction planetary gear ratio (iRD)

First, find i1’:

• Since the setting of the planetary gear in first gear is NRR = fixed = 0, substitute this condition in formula (1).

(ZRR+ZRS)NRC=ZRSxNRS

i1’=NRS/NRC=(ZRR+ZRS)/ZRS

Next, find iRD:

• Since the setting of the planetary gear in first gear is NDS = fixed = 0, substitute this condition in formula (1).

(ZDR+ZDS)NDC=ZDRxNDR

iRD=NDR/NDC=(ZDR+ZDS)/ZDR

(Since the iRD of first to fourth gears and reverse gear are common, the calculation formula is omitted except for

fifth gear.)

Therefore, i1 shall be as follows:

i1=i1’xiRD=(ZRR+ZRS)/ZRSx(ZDR+ZDS)/ZDR =(75+42)/42x(85+31)/85=3.802

Planetary gear unit

Front

Rear

Reduction

Internal gear

–

NRR (fixed)

NDR (input)

planetary carrier

–

NRC (output)

NDC (output)

Sun gear

–

NRS (input)

NDS (fixed)

AMU0517A512

K–14

AUTOMATIC TRANSAXLE

Second gear

AMU0517A513

AUTOMATIC TRANSAXLE

K–15

K

Planetary gear setting

The rotation speed is "0" for "fixed" as it does not rotate.

Taking i2 as the gear ratio in second gear,

i2=Front and rear planetary gear ratio (i2’)x reduction planetary gear ratio (iRD)

i2’=NRS/NRR

NRC=NFR, NRR=NFC: condition A

• From formula (1), the relation between the front and rear planetary gear unit is indicated in following formulas

(2) and (3).

(ZFR+ZFS)xNFC=ZFRxNFR+ZFSxNFS: (2)

(ZRR+ZRS)xNRC=ZRRxNRR+ZRSxNRS: (3)

• Since the setting of the planetary gear in second gear is NFS = fixed = 0, substitute this condition in formula (2).

NFC=ZFR/(ZFR+ZFS)xNFR: (4)

• According to condition A

NFC=NRR=ZFR/(ZFR+ZFS)xNRC

• Here we substitute condition A in formula (3)

(ZRR+ZRS)xNRC=ZRRxZFR/(ZFR+ZFS)xNRC+ZRSxNRS

i2’=NRS/NRC=((ZRR+ZRS)-ZRRxZFR/(ZFR+ZFS))/ZRS

Therefore, i2 shall be as follows:

i2=i2’xiRD=((ZRR+ZRS)-ZRRxZFS/(ZFR+ZFS))/ZRSx(ZDR+ZDS)/ZDR

=((75+42)-75x74/(74+34))/42x(85+31)/85

=2.132

Planetary gear unit

Front

Rear

Reduction

Internal gear

NFR (output)

NRR

NDR (input)

planetary carrier

NFC

NRC (output)

NDC (output)

Sun gear

NFS (fixed)

NRS (input)

NDS (fixed)

K–16

AUTOMATIC TRANSAXLE

Third gear

AMU0517A514