Sanyo VHR 3100 Mechanism

SERVICE MANUAL

VHR-3100 Series

Colour Video Cassette Recorder

MECHANISM DESCRIPTION AND MECHANISM ADJUSTMENT

("PN" Mechanism)

TABLE OF CONTENTS

Table Caption: This table outlines the structure and content of a manual, detailing sections on mechanism description (identification, outline, and operation) and mechanism adjustments (tools, maintenance, cleaning, repair, preparation, and specific tape-transport adjustments).

1 . MECHANISM DESCRIPTION

1-1 IDENTIFICATION AND LOCATION OF MECHANISM MAIN COMPONENTS

main parts changed from model VHR-2100, VHR-2300 and VHR-2500 series.

1-2 OUTLINE OF THE MECHANISM

The main differences between the machines of this unit and that of the previous model (VHR-2100, VHR-2300 and VHR-2500) are the four described below .

Although the individual components are changed in form to some extent, their basic functions remain unchanged from those of the previous model.

• Main slip gear mechanism
• Cam gear mechanism
• Capstan soft-braking mechanism
• Front-loading mechanism

Both-reel-base drive system

For the PN mechanism, in the same as for the mechanism of the previous model, the rotation of the capstan motor is transferred via the capstan belt to each gear , and rotational force is transferred from the roller assembly to both reel bases. way

The base or the take-up reel base, depending upon the direction of rotation of the capstan motor

During the fast-forward and rewind modes, the pulley gear and drive gear are locked, and, moreover the engagement of the drive gear and the play gear assembly upper part is disengaged, and the pulley gear and drive gear rotate as one During the reverse search mode, the reverse gear assembly meshes with the play gear assembly .

Figure 1-2-1 shows the route of transfer of rotational force The slip mechanism functions during playback , recording, forward search and slow motion playback. In other words, during these modes the drive gear is caused to rotate at the fixed torque by force via the play gear assembly's slip mechanism, from the pulley gear _

Main slip gear

The main slip gear is composed of the pulley gear, the play gear assembly (which is always meshed with the pulley gear and which generates the playback torque) , and the drive gear (which is on the same shaft as the pulley gear).

Figure 1-2-2 shows the normal (playback, record, forward & reverse search, slow , etc.) modes

When the capstan motor rotates in one of these modes , the pulley gear rotates , and, via the playback gear assembly , the drive gear rotates at fixed torque-

1-2-1 MAIN SLIP GEAR

In the mechanism for the previous model , for the main slip gear (which transfers the rotation of the capstan) , the drive gear and pulley gear were on the same shaft.

For the mechanism (hereafter referred to as the "PN" mechanism) of this model, however , the drive gear and the pulley gear are on separate shafts.

Figure 1-2-3 shows the gear conditions during the fastforward and rewind modes .

As a result of the movement of cam gear II, the sub slide, interlocked with the main slide, moves in the direction of the arrow (A).

Consequently , the spring coil (located between the sub slide

1-2-2 CAM GEAR COMPOSITION

The single cam gear that was used previously has now become two in the "PN" mechanism.

and the gear-switching lever) causes the gear-switching lever to turn in the clockwise direction (B) in the illustration.

When this happens, the end of the gear-switching lever presses the drive gear downward (in the direction of the (C) arrow) , thus disengaging the engagement with the playback gear assembly.

In addition, as result of the engagement of the "tab" at the lower part of the drive gear and the "tab" at the top part of the pulley gear , the pulley gear and drive gear become locked and rotate unified as one The result, in other words, is that there is no slippage .

• as viewed from the rear of the mechanism.

At the cam gear I surface (the mechanism viewed from the bottom) , the loading and unloading of both leading guides is performed, and, at the cam gear II surface the limiting of the position of the mode-detection switch is performed.

(The loading motor and both leading guides are at the top of the mechanism )

Transfer routes:

(2) Figure 1-2-5 shows the movement of the cam as viewed from the rear of the mechanism

The pinch roller pressure slide is controlled by the shape of the cam (at the rear of cam gear I); during the eject mode , therefore the pinch roller pressure slide pushes the EJECT lever with the result that the eject gear and the capstan motor gear are pressed tightly.

During the playback mode, the pinch roller lever is caused to move by shaft 3.

The main slide is controlled by the cam gear II gear surface

cam shape; as a result of both main brakes and the brake select lever being pushed by shafts and 2, the capstan "soft brake is caused to move, and braking force is applied to the capstan motor_

(The pinch roller lever , capstan shaft, pinch roller and both main brakes are located on the side of the mechanism ) Transfer routes: top

1-2-3 FRONT MECHANISM DRIVE BY THE CAPSTAN MOTOR

When there is transfer from any other mode to the eject mode, the movement of cam gear I causes the pinch roller pressure slide to move toward the left @.

As a result of this movement, the edge part (A) of the pinch roller pressure slide presses against the spring coil located on the eject lever which in turn causes the eject gear to engage with the gear provided on the outer circumference of the capstan rotor

From