We are strengthening the brakes
During a lunch break, Sergeyich shared a brain teaser with colleagues: “At first there was no brake booster at all, then hydrovacuum boosters appeared, then vacuum… But that’s not all the designers came up with. There were also diverse systems that relied on drive belts, yet today some machines operate without an amplifier entirely….”
Tells about the other brake booster systems Sergeyich mentioned in passing.
Brief answers are not acceptable.
Submit the answer labeled “Contest” before July 1, 2022 to the address: 107045, Moscow, Seliverstov per., 10, Building 1; e-mail: [email protected] Please include a phone number or another fast means of communication.
Below are the results from the expert contest published in the March issue of “Behind the Wheel” magazine.
The next challenge asked how the hero could heat the windshield wipers of the second-generation Nissan X-Trail crossover (T31) that park low and freeze in winter. There is no heated windshield or at least the wiper parking area is not heated. No such glass exists among non-original parts. The modification was intended to make returning to normal easier.
Some readers proposed using plastic tubing to channel warm air from the deflectors. Others suggested installing a plastic plate to direct airflow beneath. But the glass area where the wipers stop lies under the instrument panel, and the shape of the engine screen separating the passenger compartment from the engine compartment prevents air from reaching it. Not everyone would like the salon view with pipes or plates.
The task noted that many people faced the problem and solved it in a fairly intricate way. They cut and welded with slight alterations.
To understand how the wiper drive can be recreated, one must first learn how it works, and the contest winner will assist in this.
Wiper mechanism diagram: A – standard position; B – after modification. 1 – passenger wiper line; 2 – passenger wiper lever; 3 – passenger windshield wiper with thrust drive; 4 – driver’s wiper lever; 5 – driver’s wiper belt; 6 – thrust of the geared motor; 7 – geared motor; 8 – pendulum.
The wiper is a structure consisting of several swing arms and a crank mechanism. The crank sits on the gearmotor’s output shaft and rotates. It sets in motion the thrust that acts on the lever linking the driver’s wiper line. Nearby sits the thrust hinge that guides the passenger brush handle.
The lengths of the levers on the driver’s and passenger’s sides were chosen so that both cleaning sectors are optimal from the designers’ point of view (apparently from a country with a relatively warm climate). The driver’s sector reaches the body style near the top position, while the passenger’s top position blocks the driver’s wiper sector.
What can be done to make the wipers park higher? For instance, reduce their working sector slightly. One could shorten the crank on the gearbox or increase the lengths of the driver’s and passenger’s wiper arms. Yet such changes would require cutting and modification.
There is a much easier route to parking the wipers higher. It involves lowering them to the lower position and freezing them higher where warm air reaches the glass. How is that achieved? A look at the windshield wiper gearbox design helps explain it.
One regular reader suggested a practical solution involving an adapter that can be bought. However, adjusting the parking height alone does not guarantee proper heating.
On the driven gear there is a cam that, during wiper operation, opens and closes contacts in the wiper stop zone. Keyways are made on the gearbox output shaft to prevent the crank from slipping during operation. The crank is attached to the output shaft with a nut. Then there is room for adjustment.
By loosening the nut, the crank can be rotated a bit along the keyways in the direction of movement relative to the shaft. This keeps the wipers’ extreme upper position unchanged, and as they move downward, they pass the factory’s lowest position and stop higher, allowing the warm heater air to reach the glass. In summer, everything can be returned to its original state.
Congratulations to Ilya Kryuchkov on his victory!
- Old windshield wipers: sharpen or discard? The answer is here.
- A trip outside the city? Carry anti-theft devices in the trunk at the right time.
- “Behind the Wheel” can also be read on VKontakte.